text:
|Numéro de publication
|Type de publication
|Numéro de demande
|Date de publication
|26 juil. 1994
|Date de dépôt
|28 mars 1991
|Date de priorité
|28 mars 1991
|État de paiement des frais
|Autre référence de publication
|Numéro de publication
|Chandrasekaran Mohan
|Cessionnaire d'origine
|International Business Machines Corporation
|Exporter la citation
|BiBTeX, EndNote, RefMan
|Citations de brevets (2), Citations hors brevets (55), Référencé par (79), Classifications (8), Événements juridiques (6)
|Liens externes: USPTO, Cession USPTO, Espacenet
This patent application concerns material which is related to pending U.S. patent application Ser. No. 07/406,186, which was filed Sep. 7, 1989, for "METHOD FOR MANAGING SUBPAGE CONCURRENCY CONTROL AND PARTIAL TRANSACTION ROLLBACK IN A TRANSACTION-ORIENTED SYSTEM OF THE WRITE-AHEAD LOGGING TYPE", and pending U.S. patent application Ser. No. 07/480,700, which was filed on Feb. 15, 1990, for "TRANSACTION PROCESSING SYSTEM AND METHOD WITH REDUCED LOCKING", both assigned to the assignee of this application, and both incorporated herein by reference.
This invention concerns a method for providing access to data in a database management system (DBMS) when the system is being restarted after a failure. A transaction-oriented database system of the write-ahead logging type which includes a restart mechanism for returning the system to a transaction consistent state following a failure is particularly relevant to this invention.
Exemplary references which frame the background of this invention are:
1. C. J. Date, "AN INTRODUCTION TO DATABASE SYSTEMS", Vol. 1, Fourth Edition, Addison Wesley Publishing Company, Copyright 1986, Chapter 18.
2. H. F. Korth, et al, "DATABASE SYSTEM CONCEPTS" McGraw-Hill Book Company, Copyright 1986, Chapter 10.
3. C. Mohan, et al, "ARIES: A TRANSACTION RECOVERY METHOD SUPPORTING FINE-GRANULARITY LOCKING AND PARTIAL ROLLBACKS USING WRITE-AHEAD LOGGING" IBM Research Report RJ 6649 (63960) , Jan. 23, 1989, Revised Nov. 2, 1990.
4. C. Mohan, "COMMIT-- LSN: A NOVEL AND SIMPLE METHOD FOR REDUCING LOCKING AND LATCHING IN TRANSACTION PROCESSING SYSTEM", Proceedings of the Sixteenth VLDB Conference, August, 1990.
5. C. Mohan, et al, "TRANSACTION MANAGEMENT IN THE R* DISTRIBUTED DATABASE MANAGEMENT SYSTEM", ACM Transactions on Database Systems, Vol. 11, No. 4, December, 1986, pgs. 378-396.
These references cover two-phase, commit-type, transaction-oriented database systems which utilize write-ahead logging to register commitment of updates to database data structures. The Date and Korth references document the inherent features of a recovery mechanism which utilizes a log to reset data resources to a state at which a transaction-based system can resume operation following a failure. The first-cited Mohan reference concerns the use of a log to record the operation of a transaction which updates data objects. The log contains in chronological sequence records of committed updating actions taken by a transaction. In this reference, Mohan critically observed that the assignment of a unique log sequence number (LSN) to every log record such that the LSNs are assigned in ascending sequence provides a powerful and efficient basis for recovery, concurrency control, and buffer management in a database system. In the second-cited Mohan reference, a COMMIT13 LSN is posited to determine if a data object (such as a page) contains committed updates. Relatedly, each page has recorded on it the LSN of the last update made to it. Equating the COMMIT13 LSN to the LSN of the first log record of the oldest update transaction still in progress permits a system to infer that all updates in pages with page13 LSN less than COMMIT13 LSN have been committed. The last-cited Mohan et al reference is relevant to the state of the art.
In transaction processing, the property of atomicity guarantees that if a transaction executes some updates against a recoverable data resource, and a failure occurs before the transaction reaches its normal termination or an interim point of consistency ("commits"), then those updates will be undone. As Date teaches, atomicity is provided by COMMIT and ABORT operations. The COMMIT operation signifies that a transaction has completed and that all of its updates must be permanently entered into the database. The ABORT operation signifies the unnatural termination of a transaction caused by the occurrence of a fault; it signifies inconsistency of the database and implies that all updates made by the unsuccessfully-completed transaction must be undone ("rolled back").
In the incorporated patent application and in the first-cited Mohan reference, a system failure which interrupts transaction processing initiates operation of a restart recovery mechanism (a "Mohan-type" restart recovery mechanism) including REDO and UNDO components. The REDO component tracks back in the system log from the point of failure to obtain log records whose updates had not been entered into the database, by the time of the failure. Those log records that were written by committed transactions are used to permanently enter those updates into the record. The UNDO component utilizes the log records to track back from the point of failure all transactions which were unnaturally terminated by the failure and rolls those transactions back.
Relatedly, transactions with uncommitted updates which are terminated by a system failure are referred to as "in flight" transactions.
The Mohan-type restart recovery mechanism also processes transactions which have had updates committed but which have not naturally ended at the point of failure. These transactions are referred to as "in doubt" transactions and are either redone or undone according to conditions which exist at the time of recovery.
Various solutions have been proposed to provide improved data availability during restart recovery. One of the solutions is system redundancy in which the failure of one system initiates the operation of a redundant standby system. This solution is exemplified, for example, in the XRF (extended recovery facility) of the IMS product available from the assignee. Another solution uses parallel non-volatile memory. See, for example, R. Agrawal et al, "RECOVERY ARCHITECTURES FOR MULTIPROCESSOR DATABASE MACHINES", ACM Reprint 0-89791-160-1/85/005/0131, Copyright 1985. All of these solutions are relatively expensive.
There is, therefore, an evident need for a cost-effective technique which makes data available during restart recovery processing in a database management system. This need is particularly critical in view of the possibility that recovery may entail undoing very long transactions by a single process in which all read I/Os are performed synchronously, one page at a time. The desired solution should be one which supports beneficial features of a DBMS such as fine-granularity locking with semantically-rich lock modes and operation logging, partial rollbacks, write-ahead logging, as well as steal and no-force buffer management policies. A force buffer management policy states that before a transaction is allowed to commit, all data structures modified by the transition must be forced to non-volatile storage. The steal policy states that a page with uncommitted updates may be written to non-volatile storage.
Accordingly, it is an object of this invention to devise a method for assuring data availability during restart recovery and transaction rollback in a database management environment which utilizes write-ahead operation logging and the steal and no-force buffer management policy. It is a related object to devise a method which reduces the standby time of restart recovery during which initiation of transactions is delayed pending an assurance that data used by the transactions will be consistent.
The foregoing objects are satisfied by a method in which transaction processing is permitted to start as soon as a DBMS is brought up after failure, instead of waiting for all of the DBMS recovery to be completed. The peril in permitting new transaction activity to occur even before restart recovery is completed stems from the fact that some of the data structures that the new transactions want to access might be in undesirable states which will leave data inconsistencies if access is permitted. Two of the undesirable states are:
1. Under the no-force policy, transaction updates are recorded in a log, but updated pages are not necessarily written to non-volatile storage when a transaction's commit point is reached. Thus, a failure may occur after updates are recorded on the log but before they are made in non-volatile storage. Thus, a page on disk at restart may not contain some updates for which log records exist. These updates might be ones that were performed by uncommitted and/or committed transactions. Permitting access to such a page might lead to a new transaction reading an older version of a piece of data for which one or more log records written by one or more committed transactions remain to be applied during the REDO phase of restart recovery. Assuming record locking is used with flexible storage management, even if the new transaction were to access the page for updating or inserting some record for which no unapplied log records exists, permitting that operation to complete might result in some space on the page being consumed which results in a state in which it is impossible to redo some of the unapplied changes relating to other records on the same page for which log records exist. Since the REDO phase is page-oriented and not performed logically across pages, the REDO phase must be completed for these pages before new transactions are permitted access to them.
2. A page on disk may contain all the updates logged for that page. However, permitting access to such a page could cause inconsistencies if the page contains updates of in-flight transactions which are to be rolled back during the UNDO phase of restart. The page may also contain updates of in-doubt transactions whose commit or abort outcome will remain doubtful at the end of restart and for which locks will be reacquired during the course of the REDO phase to protect their uncommitted updates. Allowing access during these conditions might result in a new transaction reading some uncommitted data even though the new transaction will be acquiring locks.
The invention is a method which permits new transactions to gain access to data resources during restart recovery, while avoiding the two situations just described. The invention permits access during both the REDO and UNDO phases of restart recovery. The method of the invention employs two mechanisms. First, every page written to non-volatile storage has a first field for entry of the log sequence number for the most recent update to the page. This number is referred to as the "page13 LSN". Whenever a new transaction requests access to a page in non-volatile storage during restart recovery, the page-- LSN of the requested page is compared with an LSN representing the oldest update of the earliest-commencing in-flight transaction. Any page with a page13 LSN having a value less than this "low-water" LSN can safely be accessed because its last update was made by a transaction which had completed prior to the beginning of the oldest in-flight transaction.
The second mechanism is provided as a data bit in a second information field in every page in non-volatile storage. This bit is called the "unlocked13 uncommitted13 data13 bit" (UUD13 Bit). If the bit is set to a first state (preferrably `0`) then the page does not contain any updates not protected by locks. In particular, if a new transaction is given access to the page under the first mechanism, updates the page and returns it than the value of the "senior" LSN. However, the conditioning of the UUD13 Bit to `0` indicates that all uncommitted updates are protected by locks. The page can be accessed by a new transaction under the guarantee that the locks will protect any uncommitted updates which may be removed during restart recovery.
During restart recovery after a failure, the method of the invention:
uses restart recovery to add to pages the results of logged transaction updates which are missing in the database pages and to rollback uncommitted transactions which were executing at the time of the failure for which no log commit or in-doubt records exist; and
concurrently with operation of the restart recovery, provides for transaction processing data structures whose contents were not changed after the beginning of the earliest-starting uncommitted transaction.
A method which provides data structures for transaction processing in a database system including a restart recovery mechanism:
assigns a log sequence number (LSN) to each log record which denotes the log record's position in a log sequence;
enters into each data structure staged into a non-volatile storage an LSN denoting the last update made to the data structure;
operates the recovery restart mechanism in response to a failure in the system; and
during operation of the restart recovery mechanism:
commences a transaction and issues a request from the transaction for a data structure in the non-volatile storage;
compares the LSN in the data structure with a COMMIT13 LSN, the COMMIT13 LSN being the minimum of LSNs denoting begin transaction log records of all in-flight transactions at the time of failure; and
if the LSN in the data structure is less than the COMMIT LSN, provides the data structure to the transaction, otherwise:
suspends the transaction until restart recovery is completed.
Preferably, the method of providing data structures for transaction processing operates the recovery restart mechanism by performing REDO processing before UNDO processing, the method providing the data structure to a new transaction during the REDO phase only if the LSN in the data structure is less than the COMMIT13 LSN and the data structure is not one which will be redone during the REDO pass.
FIG. 1 depicts a database management system with a main memory, a non-volatile storage for staging data structures to and from the main memory for transaction processing, and a transaction log. The DBMS includes a Mohan-like restart recovery mechanism.
FIG. 2 is a flow diagram illustrating how the method of the invention employs the page13 LSN and COMMIT13 LSN to provide new transactions with access to data resources during restart recovery operations.
FIG. 2A is a partial flow diagram illustrating the addition of the step of checking an uncommitted objects list in the method of FIG. 2.
FIG. 2B is a partial flow diagram illustrating the addition of the step of checking a UUD13 Bit in the method illustrated in FIG. 2.
FIG. 3 is a flow diagram illustrating UUD13 Bit processing during the REDO and UNDO phases of restart recovery.
Refer to FIG. 1 where a representative database management system (DBMS) 10 is coupled to a main memory 12 and to a non-volatile storage subsystem 14. Preferably, the non-volatile storage 14 is a direct access storage device (DASD) such as a disk. Such storage is also called stable storage because it remains intact and its contents are available in the face of failures characterized by Korth as logical errors, system errors, or system crashes. The DBMS 10 is conventional and can include almost any transaction-based system such as the SQL/DS, or DB2 systems available from the assignee. (DB2 is a trademark of the assignee.) The DBMS 10 includes, among other components, a transaction manager TM 16 and a buffer manager BM 17. The DBMS 10 further includes a Mohan-type restart recovery mechanism 18 with REDO and UNDO components as described in the cross-referenced U.S. patent application Ser. No. 07/406,186 and in the referenced IBM Research Report.
The non-volatile storage 14 stores data structures which are accessed through the DBMS by transactions, two of which are indicated by T1 and T2. Preferably, the data structures are contained in a database 20 in the DASD 14 and comprise pages such as page 22. A transaction requests, through the TM 16, access to a page for transaction processing. The request is passed to the BM 17 which operates a buffer pool in the memory 12 into which pages are staged from the database 20 for access by executing transactions. A copy 22' of the page 22 is shown in FIG. 1 residing in the memory 12.
The transaction manager 16 maintains a write-ahead log 30 in the storage subsystem 14. The log 30 is conventional in all respects. In this regard, the transaction manager of the DBMS 10 ensures that, for any transaction which alters a page, the sequence of actions causing the alteration is recorded. As an example, log records for two transactions, T1 and T2, are recorded in the log. The log records for each transaction are entered into the log in a sequence, with each record being assigned a log sequence number corresponding to its place in the sequence. The log sequence numbers (LSNs) are assigned in a monotonicly increasing sequence. As Mohan points out in the IBM Research Report, LSNs are usually logical addresses of corresponding log records but can also comprise version numbers or timestamps.
The sequence of log records for transaction T1 shows when the transaction began with a BEGIN T1 log record at LSN 100, an update to page P1 at LSN 110, another update to P1 at LSN 130, and a commit record at LSN 150. Transaction T2 is described in a record sequence beginning at LSN 140 and showing updates at LSNs 160, 170, and 250.
As is typical in a transaction-based system, a checkpoint is periodically taken of the status of transactions. The checkpoint information is entered in the log and assigned the LSN for its place in the sequence. In the usual case, the checkpoint log record will include information about the contents of all the updated database buffers in the main memory 12. Two components of a checkpoint log record of particular interest in this invention are an uncommitted object list (UOL 44 and a dirty page list 42, both obtained from status information maintained by the transaction manager 16 and buffer manager 17 during transaction processing. The TM 16 maintains, for active transactions, a list of objects that have the transaction's uncommitted updates. For example, list 40 is maintained for transaction T1. At checkpoint time, the TM 16 obtains the union of all uncommitted lists, and the combined list is referred to in the checkpoint log record as the uncommitted objects list. The BM 17 also maintains a dirty page list 42. In this regard, a "dirty page" is a page staged into the memory 12 from the non-volatile storage 14 and modified, but not as yet written back to the storage 14. During normal processing, when a page is staged from the storage 14 into the memory 12 and is subsequently modified, the identification of the page is entered into the list 42 together with the current end-of-log address (dirty LSN-DLSN) which will be the address of some log record to be written in the future. The value of DLSN indicates from what point in the log there may be updates which are, possibly, not yet in the non-volatile storage version of the page. Whenever pages are staged back to the non-volatile storage 14, the corresponding entries in the dirty page list are removed. If later the page is dirtied again, then the page will be re-entered into the dirty pages list.
Thus, assume that the transaction T1 requests access to a record on page 22 and that the page is not in storage. The request is forwarded by the TM 16 to the BM 17, which stages the page in the non-volatile storage 14 into the main memory 12. The structure of the page includes at least four identification and status fields and the contents of the page. The first field contains the identification of the object (OBJID) to which the page belongs. Such an object can be, for example, a file or a folder. A second field contains the identification of the page (PAGE ID). A third field contains the LSN of the log record recording the last update made to the page prior to the page being staged into the non-volatile storage 14. The UUD (unlocked13 uncommitted13 data13 bit) field is used to indicate whether, after restart recovery commences, the page contains uncommitted updates which are not protected by locks.
When the page 22 is staged from the non-volatile storage 14 into the memory 12 and is about to be modified, a corresponding entry is made into the dirty page list. Assume that the page 22 corresponds to the page P1 identified in the log records for transaction T1 and that its contents have been updated from "page contents" to "page contents". The updated page is identified by reference numeral 22' in the memory 12. Assume that the updates corresponding to LSNs 110 and 130 are made to the page. When the first of these updates is made, the corresponding entry is made by the transaction manager into T1's uncommitted list. The entry consists of the OBJID field value of the page and the begin transaction LSN (BTLSN) for T1. Assume that page P1 is a component of file F1; the entry for the page in the list 40 includes F1 in the OBJID field. The LSN for the BEGIN T1 log record is entered into the BTLSN field of the list 40. Later, the updates made to P1 by T1 are committed, as indicated by LSN 150. At this time, the corresponding entry in T1's uncommitted list 40 is removed; however, page P1 remains in the dirty page list until it is returned to the non-volatile storage 14.
Assume now that a failure occurs when the LSN sequence has advanced to 260 and that the last checkpoint is at LSN 120. Assume further that, while the updates made by T1 to P1 have been recorded on the log, the updated version of the P1 has not yet replaced the previous version in the non-volatile storage 14. Further, at the point of failure, T2 is in-flight, having had none of its updates committed.
When failure occurs, the restart recovery mechanism 18 is invoked. This mechanism, using the log records and backward-chained LSNs restarts the DBMS 10 in response to the failure. The mechanism corresponds essentially with that described by Mohan et al in the cited IBM Research Report. As Mohan et al describe it, in an ANALYSIS pass through the log, the mechanism finds the last checkpoint prior to failure and scans from that point to the end of the log to acquire information about dirty pages, and about in-flight, in-doubt, and completed transactions. The dirty pages information provides a starting point from which the REDO PASS of the mechanism 18 re-establishes the state of the database as of the time of the system failure by processing log records for all transaction 81 updates from the REDO starting point up to the point of failure. The REDO pass acquires the necessary locks for protecting uncommitted updates of transactions which were in the in doubt state at the time of the failure. During the UNDO pass, the mechanism 18 rolls back all updates of all in-flight transactions. For transactions which were rolling back when the failure occurred, the UNDO phase of the mechanism 18 rolls back only updates which have not already been undone.
Controlling status information respecting the restart recovery mechanism 18 is found in a restart control block (RESTART CB) 60. In addition to other information, the restart control block 60 includes a RESTART flag which can be tested to see if the restart recovery mechanism is in operation. The RESTART flag is set to `Y` if restart is still in progress; otherwise, the flag is set `N`. The control block 60 also includes a RESTART LATCH which the mechanism 18 holds in the X (exclusive) mode whenever the RESTART flag is equal to `Y`. A third control block field PASS is checked when restart is in progress to see in which phase the mechanism is currently operating. Another latch, the REDO LATCH, is held in the X mode by the mechanism whenever PASS field is set to `REDO`. This latch is released once the REDO pass is completed. The RESTART LATCH is released only after restart recovery is completed (REDO and UNDO passes). Prior to the beginning of the REDO and UNDO passes, the current end-of-log LSN is determined (the "fail13 LSN"), and an FLSN field in the control block is set to that value. In the example, the FLSN would be set to `260` by the restart recovery mechanism 18 by the time the REDO phase is initiated.
Following a system failure, the invention permits new transactions to begin execution concurrently with the operation of the restart recovery mechanism 18 by guaranteeing that any data structure requested by a new transaction is not in either of the two undesirable states. Although for discussion the data structures are assumed to be pages, the inventor contemplates that other data structures may be protected by this guarantee.
The invention depends upon the provision by the restart recovery mechanism 18 of a point of reference for determining if a page requested by a new transaction may be provided from the non-volatile storage without the risk that either REDO or UNDO processing will make the required version inconsistent with a redone or undone version of the page in non-volatile storage. This reference is called the COMMIT13 LSN. The "global" COMMIT13 LSN is the minimum of LSNs of the begin13 transaction log records of all transactions which were in-flight at the point of failure. The COMMIT13 LSN is computed at the end of the analysis pass by the restart recovery mechanism. Its use in the method of the invention is illustrated in FIG. 2.
In FIG. 2, a new transaction begins in step 70 and the method of the invention tests, in 70A whether access to a page is required. If not, the transaction continues in step 76. If access is required, the method tests the RESTART flag step 71. If restart recovery is in progress, the positive exit is taken from the decision 71 in the PASS field of the restart control block is tested in step 72. Assume, first, that the REDO phase has completed and that restart recovery is in the UNDO phase. In decision 75, a test of the page-LSN is made.
To this point, the test 75 establishes an UNDO13 PASS condition, which is given by:
page.sub.13 LSN<COMMIT.sub.13 LSN
The UNDO pass condition is predicated upon retrieval of the requested page from the non-volatile storage 14 so that its page13 LSN can be obtained. In conducting the UNDO13 PASS test, the first undesirable state is avoided since the REDO pass has been completed. The second undesirable state is avoided because no page will be delivered to a new transaction if that page has an update made after the beginning of the earliest-commenced in-flight transaction subject to the UNDO phase processing. In this case, the PASS exit is taken from decision 75 and the new transaction is permitted to acquire the page for transaction processing in step 76.
If, on the other hand, the UNDO13 PASS condition is not met, the requesting transaction next seeks the RESTART latch in the S (shared) mode (step 78) , thereby waiting for restart recovery processing to complete. The inventor contemplates that avoidance of deadlocks involving the RESTART latch will require the requesting transaction to surrender any other latches that it holds before waiting on the RESTART latch. For example, the new transaction may have acquired a latch on the page that has been accessed and, in the case of an index access, possibly the latch on the parent of that page. After surrendering its held latches and submitting the S mode request for the RESTART latch, the new transaction will enter the wait state in step 79, awaiting its own restart following the end of restart recovery processing.
Permitting a new transaction to obtain only pages which meet the UNDO13 PASS condition may be unnecessarily conservative. FIG. 2A illustrates a more liberal UNDO-PASS condition which will permit even greater availability of data during restart recovery. In FIG. 2A, it is assumed that the DBMS logs at checkpoint time an uncommitted objects list (UOL) such as that indicated by reference numeral 44 in the log 30. UOL 44 is the union of all uncommitted lists existing at the time the checkpoint was taken. The list tabulates all objects (for example, at the gross granularity of file, folder, or table) that have uncommitted updates for transactions which were ongoing at the time of checkpoint. During the analysis pass, UOL 44 is brought up to date as of the FLSN. In fact, although during the REDO pass the UOL 44 must contain even objects for which there are uncommitted updates by only in-doubt transactions, at the end of the REDO pass such objects would be safely removed from the UOL since by then the in-doubt transactions would have reacquired their locks on such objects. Furthermore, as the UNDO pass progresses, the UOL is updated. That is, once all of the in-flight transactions which had, as of the failure of the system, uncommitted updates in a particular object are completely undone, that object is removed from the list.
With reference now to FIG. 2A, assuming that the UOL 44 is available, if the restart flag is set to `Y` then a new transaction is allowed to access a page for reading or writing only under the modified UNDO13 PASS condition illustrated in FIG. 2A. In this regard, once it is determined that the UNDO pass is in progress, the positive exit is taken from decision 73 and the UOL 44 is consulted in step 80 to determine whether the page belongs to an object in the list. If the page does not belong to an object on the list, the negative exit can be taken from the decision 80 and the transaction can safely acquire access to the page. If the page is in the list, the positive exit is taken from the decision 80 and the UNDO test is performed in step 75. From this point, the procedure executes as illustrated in FIG. 2.
FIG. 2A establishes a modified UNDO13 PASS condition which is expressed as:
(page belongs to object not in UOL) OR ((page belongs to object in UOL) AND (page.sub.13 LSN<COMMIT.sub.13 LSN))
Instead of using the begin transaction LSN for the earliest-commencing in-flight transaction for the COMMIT13 LSN in testing the UNDO13 PASS condition, a more liberal method would be to compute, for each object in the UOL 44, the object-specific COMMIT13 LSN. This LSN is described in the fourth-cited article, describing the COMMIT13 LSN. In this invention, the restart recovery mechanism 18 considers, for each object, only those transactions that have uncommitted updates on it and computes the minimum of the begin13 transaction LSNs of only those transactions (the "object-specific COMMIT13 LSN"). Then, during the UNDO pass, the object-specific COMMIT13 LSN is used for that object, instead of the global COMMIT13 LSN. The advantage of an object-specific COMMIT13 LSN over the global COMMIT13 LSN is that in general the former will be greater than the latter (in the worst case, they will be equal) thereby allowing more page accesses to new transactions. The object-specific value reduces the negative impact of long-running transactions accessing private or semi-private data. The object-specific COMMIT13 LSNs can also be computed at the end of the ANALYSIS pass prior to the REDO pass. In this case, apart from the in-flight transactions, the calculation must take into account even those transactions that were in the in-doubt state at the time of failure. However, during the UNDO pass, only the in-flight transactions that are being undone as part of the pass need be considered in calculating object-specific COMMIT13 LSNs.
The inventor has observed that, once a page of an object in the UOL 44 meets the UNDO13 PASS condition and receives its first update by a new transaction, its page13 LSN will cause it to fail all subsequent occasions of the test. Thereafter, no update or read will be possible on that page until restart recovery is finished or the object is removed from the uncommitted objects list 44, whichever happens first. Without further provision, after the first update, the procedure of FIG. 2 would lose track of the fact that the page does not contain any committed update of the transactions being rolled back in the UNDO pass. This information, however, can be preserved and utilized to permit further access to the page after the first update by the UUD13 Bit which is provided on every page of the database. If the bit is `1`, the page may contain some uncommitted updates which are not protected by locks. If the bit is `0`, the page definitely does not contain any updates which are not protected by locks. Note that in the latter instance, the page may still contain some uncommitted updates; however, these updates will be lock-protected.
Use of the UUD13 Bit in the invention is illustrated in FIG. 2B. FIG. 2B illustrates an addition to the UNDO-PASS condition illustrated in FIGS. 2 and 2A. In FIG. 2B, the UNDO13 PASS condition to be checked first tests, in decision 80, whether the requested page is in the UOL 44. If not, the UUD13 Bit of the page is checked in test have been protected by locks and the page can be provided to the new transaction with the assurance that those updates will be preserved by the locks. The new transaction then is permitted to continue processing in step 76. However, if the bit equals `1`, the negative exit from the test is taken and the page13 LSN is checked against the COMMIT13 LSN (either global or object-specific as provided above). Following this test, the procedure executes according to FIG. 2.
Therefore, the UNDO13 PASS condition to be checked according to FIG. 2B becomes:
(page belongs to object not in UOL) 0R ((page belongs to object in UOL) AND (UUD.sub.13 Bit=`0`)) OR ((page belongs to object in UOL) AND (page.sub.13 LSN<COMMIT.sub.13 LSN))
FIG. 3 illustrates how the UUD13 Bit is conditioned during restart recovery processing according to the invention. Initially, a page must be staged from the non-volatile storage 14 to the memory 12. This step (100) is always performed by the buffer manager, which also performs steps 101 and 102. If, when the page is staged to the memory 12, the RESTART flag is set to `N`, the negative exit is taken from decision 101 and normal transaction processing proceeds in steps 101a and 101b. In this event, normal transaction updates including forward processing and normal UNDO procedures result in setting the UUD13 Bit to `0`. Thus, the page is returned to the non-volatile storage with the bit in this state.
If, however, the RESTART flag indicates that restart recovery is in process, the positive exit is taken from decision 101 and the page13 LSN is tested in step 102 to see whether it is in the range bracketed between the COMMIT13 LSN and FLSN.
If the page13 LSN is in the range tested at 102, the positive exit is taken and the buffer manager sets the UUD13 Bit to `1`. This is conservative action; the fact that the page is in the range defined in step 102 does not necessarily mean that there is some uncommitted data on the page that is not protected by locks. Since a system failure could happen anytime, the burden is placed on the buffer manager to ensure that the correct setting for the bit is present on the page when the page is staged from the non-volatile storage 14 and restart is still in progress. This is important since, during restart after a failure, it is the non-volatile storage version of the database with which recovery processing and new transactions will be dealing. The buffer manager can apply the test of step 102 using either the global COMMIT13 LSN or the object-specific version, but preferably the latter.
It is observed that setting the UUD13 Bit by the buffer manager does not cause the page to become dirty. Further, the buffer manager does not disturb the existing setting of the bit on the page if the page13 LSN is outside of the range of step 102. If the page13 LSN is greater than FLSN, it is incorrect to assume that there is no uncommitted data on the page that is not protected by a lock. This is because this may be the second time that the page is being read from the non-volatile storage during this restart recovery and, when it was read from storage, but before it was subsequently rewritten to the storage (the first time), some in-flight transaction's undo processing might have been performed on the page, causing the page13 LSN to become greater than FLSN. Under these conditions, it is essential that the UUD13 Bit remain at the value of `1`, since the page may still contain some uncommitted updates which are not protected by locks. If, on the other hand, the page13 LSN is greater than FLSN because during the first time it was staged into the memory a new transaction had modified it, then it is desirable to retain the UUD13 Bit value of `0` that would exist as a result.
If page13 LSN is not in the range of step 102, the negative exit is taken, and the current setting of the UUD13 Bit is retained in step 103. Subsequently, when the page is accessed for recovery purposes, the following actions are taken. The PASS flag is checked in step 107. Following the REDO exit from this test, if the page is accessed for redoing the update of an in-flight transaction, the positive exit is taken from the decision 109 and the UUD13 Bit is set to `1`. This is necessary since the transaction is redoing an update which is not protected by a lock. As of this time, the bit on the page may have a value of `0`, and in that case, this update will be the first unprotected one for the page.
If the test in decision 109 indicates that the transaction is not an in-flight one, the test in decision 114 determines whether the update action is for redoing log records for leaf pages in transactions which modify the structures of objects (such as transactions which split or delete pages in a B-tree index) or for redoing record locations in a hash-based storage method for all transactions. In this case, the LSNs of the log records are compared against the COMMIT13 LSN in step 115. If the log record's LSN is greater than the value of the COMMIT13 LSN, the UUD13 Bit for the page is set to `1`. Otherwise, the bit setting currently on the page is unaltered and processing continues in step 115a.
The test of decisions 114 and 115 is necessary because, with the high concurrency supported by index protocols and recovery for hash-based storages, one transaction's uncommitted updates on a certain page may be moved to a totally different page by another transaction. The second transaction may terminate or get into the in-doubt state even though the first transaction may remain in the in-flight state. Under these conditions, after a failure, the only way to ensure that the first transaction's uncommitted updates remain protected is to insist that the mover of the uncommitted data to a different page causes the UUD13 Bit to get set to `1` on the second page.
Assuming that a transaction requesting a page is not an in-flight transaction and that a log record does not relate to structure modification, the test in decision 116 is made before a log record's update is redone. In this test, if the LSN for the page is less than the COMMIT13 LSN, the page's UUD13 Bit is set to `0` in step 117. Here, the method takes advantage of the fact that the page is known to contain only committed updates before this update is redone and the fact that this update itself is either a committed update or an ucommitted update by an in-doubt transaction, which will be protected by locks by the time the UNDO pass starts. Note that after the current log record's update is redone, the page's LSN may become greater than the COMMIT--LSN.
Returning now to FIG. 2, assume that a new transaction begins, that restart recovery is in progress, and that the PASS flag indicates that the REDO phase is being executed. At this point, allowing new transaction activity concurrently with REDO processing also requires that the first undesirable state described above be dealt with. This is done in the invention by taking advantage of information typically logged at the time of the checkpoint in the dirty pages list (DPL), which is indicatead by reference numeral 42 in FIG. 1. The DPL 42 includes only those pages that might potentially be involved in redoing operations. In particular, the DPL 42 may not include any pages on which UNDO may have to be performed, which would be tabulated in the UOL 44. As long as the DPL 42 is available, if the REDO exit is taken from the test 72, a new transaction is allowed to access a page for reading or writing only if the following REDO13 PASS condition holds:
(UNDO.sub.13 PASS Condition) AND (page not in DPL)
This condition is tested in steps 200 and 202. Thus, if the UNDO13 PASS condition is met and the page is not in the DPL, the process sequence is 200, 202, and 204, permitting the transaction to acquire the page and continue processing. Otherwise, the transaction requests the REDO latch in the S (shared) mode in step 205 and awaits the latch in step 206. When the REDO pass finishes and the transaction acquires the latch, the new transaction must once again check the UNDO13 PASS condition and then await the RESTART latch if the condition is not met. Otherwise, transaction processing proceeds.
If, as in some DBMSs, the buffer manager logs at checkpoint time the dirty objects information at a level of granularity above page, the DPL would become a dirty objects list (DOL) which would be substituted for the DPL in the REDO13 PASS condition.
Even in those systems which do not log a DPL or equivalent at checkpoint, DPL table could be generated by the restart recovery mechanism by scanning the log from the REDO13 LSN to the end of the log. This extra pass can be performed by a process separate from the analysis, REDO and UNDO components. It is initiated when the REDO13 PASS is initiated and it uses a dirty objects list to determine what pages of the objects in the dirty objects list might have updates on them which must be redone. This is done by noting the page numbers in the log records relating to objects in the dirty objects list. Since no data page accesses were made, this extra pass would be completed long before the REDO pass completes. As soon as this extra pass is finished, new transactions could be let into the system during REDO. The dirty pages list generated in this fashion will be equal to or will be a superset of the DPL that would have been obtained were the system to log it at checkpoint time and bring it up to date during the ANALYSIS pass as in the Mohan-type restart recovery mechanism.
Since processing new transactions will result in continuous growth of the log beyond the FLSN, the REDO pass must be terminated when the FLSN is encountered.
In addition to single -system DBMS such as are illustrated in FIG. 1, the invention is also applicable in the data sharing environment in which a plurality of non-volatile storage subsystems are concurrently accessed by one or more transactions. In such a system, all of the storage subsystems containing the database are shared amongst the different DBMSs. Every DBMS may access and modify any portion of the database on the shared disks. Since each DBMS instance has its own buffer pool and because conflicting accesses to the same data may be made from different systems, the interactions amongst the systems must be controlled via various synchronization protocols. This necessitates global locking and protocols for the maintenance of buffer coherency. Such an approach is exemplified in the IMS/VS Data Sharing product available from the assignee of this application.
In the data sharing context, when one system fails, the locks needed to protect the failed system's uncommitted updates may be retained in one or more other systems. In such an event, the still operational systems will continue to be able to access the rest of the data. By using the invention, even as the failed system is recovering, the invention would permit new transaction processing to begin on the same system. Depending on the level of sharing that was in effect at the time of the system failure, the granularity at which the other systems retained the failed system's locks may vary all the way from table level to record level, even if the locking being done by the transactions at the failed system was at the record level. The coarser the granularity at which the locks are retained, the more beneficial the invention becomes.
It should be noted that the locks would be retained by the other systems with the failed system being identified as the owner of those locks rather than by using the identifiers of the individual transactions which caused those locks to be acquired. As a result, the retained logical locks cannot be released until the failed system finishes its UNDO pass and the retained physical locks cannot be released until the failed system finishes its REDO pass. The physical locks are acquired to ensure that at any given time only one system is modifying a given page. That is, the physical locks are used to assure coherency of the data in the different systems buffer pools. Logical locks are used to perform the more traditional concurrency control amongst the different transactions. See the IBM Research Report entitled "RECOVERY AND COHERENCY-CONTROL PROTOCOLS FORMAT INTERSYSTEM PAGE TRANSFER AND FINE-GRANULARITY LOCKING IN A SHARED DISK TRANSITION ENVIRONMENT" March 1991, RJ 8017 by C. Mohan and I. Narang.
If the physical locks are obtained at the page level, the list of such locks can be used to generate the DPL and the invention can be applied to allow new transaction processing during the REDO pass of the failed system. The DPL will consist of exactly those pages for which physical locks have been retained. Under these conditions, if the logical locks have been retained at the same granularity at which the transactions were acquiring those locks, then the invention can be used by assuming that all the retained logical locks were acquired by a system transaction at the failed system and by treating the UNDO13 PASS condition to be true. What this means is that a new transaction will be able to access a page and make progress during the REDO pass if the page is not in the DPL and if the lock needed by the new transaction is not one of the retained locks. If either condition is not true, then the new transaction would wait for the retained locks to be released by the system transaction.
On the other hand, if the logical locks had been retained at a coarser granularity than the granularity at which the transactions were acquiring those locks, the invention can employ the techniques (COMMIT13 LSN, UOL, DOL, generating EPL via log analysis, and so on) described earlier for the single system case.
The overhead involved with the invention during normal processing includes the extra check during every page access to see if restart recovery is in progress and the manipulation of the UUD13 Bit. These overheads are insignificant.
The extent of the benefit of the invention for executing new transactions during the UNDO pass would depend on the particular mix of transactions normally run by the users of a given DBMS installation. The higher the number and the longer the duration of update transactions, the greater the benefit enjoyed by practice of the invention. Under these circumstances, new transaction processing will start much earlier than in a system without the invention. In fact, the motivation for this invention stemmed from the inventor's realization that some users very regularly produce many tapes worth of log records as a result of the execution of a single transaction. For such users, the invention would be of immense value.
The extent of the benefit conferred by the practice of the invention for executing new transactions during the REDO pass would depend upon the speed at which the buffer manager writes dirty pages to disk. There is a trade-off. The more quickly the buffer manager writes the pages, the less the amount of REDO work to be performed. But then, if there is any locality of reference amongst a set of pages across different transactions, the quick writing of dirty pages would not permit the amoritization of the cost of writing a page to disk across multiple updates to the same page by different transactions or by a single long transaction. Frequent writing of "hot spot" pages would also cause concurrency problems if a page cannot be modified when it is being written to disk. Some DBMS systems delay writing to disk also in order to accumulate multiple dirty pages for a single file so that the capability of the operating system to write multiple pages using a single start I/O command could be exploited to reduce CPU and I/O overheads.
|Brevet cité
|Date de dépôt
|Date de publication
|3 févr. 1986
|29 déc. 1987
|International Business Machines Corporation
|Method for managing lock escalation in a multiprocessing, multiprogramming environment
|8 avr. 1988
|31 juil. 1990
|Internatinal Business Machines Corporation
|Method for restoring a database after I/O error employing write-ahead logging protocols
|Abstract of Japanese Patent Application 84 JP 276025, 59 276025, Dec. 25, 1985.
|Abstract of Japanese Patent Application 84 JP-276025, 59-276025, Dec. 25, 1985.
|Abstract of Japanese Patent Application 87 JP 026307, 62 26307, Feb. 9, 1987.
|Abstract of Japanese Patent Application 87 JP 227105, 62 227105, Sep. 10, 1987.
|Abstract of Japanese Patent Application 87 JP-026307, 62-26307, Feb. 9, 1987.
|Abstract of Japanese Patent Application 87 JP-227105, 62-227105, Sep. 10, 1987.
|Agrawal, et al., "Recovery Architectures for Multiprocessor Database Machines", ACMO-89791-160-1/85/005/0131, pp. 131-145.
|Agrawal, et al., Recovery Architectures for Multiprocessor Database Machines , ACMO 89791 160 1/85/005/0131, pp. 131 145.
|Borr, "Robustness to Crash in a Distributed Database: A Non-Shared Memory Multi-Process or Approach", Proceedings 10th International Conference on Very Large Databases, Aug. 1984, pp. 445-452.
|Borr, Robustness to Crash in a Distributed Database: A Non Shared Memory Multi Process or Approach , Proceedings 10th International Conference on Very Large Databases, Aug. 1984, pp. 445 452.
|CICS/MVS Extended Recovery Facility Performance, IBM Publication GG66 0281 00, Jul., 1988.
|CICS/MVS Extended Recovery Facility Performance, IBM Publication GG66-0281-00, Jul., 1988.
|CICS/MVS Version 2.1.2 XRF Guide, IBM Publication No. SC33 0522 02, Mar., 1991.
|CICS/MVS Version 2.1.2 XRF Guide, IBM Publication No. SC33-0522-02, Mar., 1991.
|Copeland, et al., "The Case for Safe RAM", Proceedings 15th International Conference on Very Large Databases, Aug. 1989, pp. 327-334.
|Copeland, et al., The Case for Safe RAM , Proceedings 15th International Conference on Very Large Databases, Aug. 1989, pp. 327 334.
|Date, An Introduction to Database Systems, Addison Wesley, 1986, pp. 413 436.
|Date, An Introduction to Database Systems, Addison-Wesley, 1986, pp. 413-436.
|Daudenard, et al., "Implementation of a File System with a Fast and Selective Recovery", IBM TDB, Feb. 1987, pp. 3837-3838.
|Daudenard, et al., Implementation of a File System with a Fast and Selective Recovery , IBM TDB, Feb. 1987, pp. 3837 3838.
|IMS/VS Extended Recovery Facility: General Information IBM Publication GG24 3150 0, Mar., 1987.
|IMS/VS Extended Recovery Facility: General Information IBM Publication GG24-3150-0, Mar., 1987.
|IMS/VS Extended Recovery Facility: Technical Reference, IBM Publication GG24 3153 0, Apr., 1987.
|IMS/VS Extended Recovery Facility: Technical Reference, IBM Publication GG24-3153-0, Apr., 1987.
|Korth, Database System Concepts, McGraw Hill, 1986, pp. 325 353.
|Korth, Database System Concepts, McGraw-Hill, 1986, pp. 325-353.
|Lehman, A Recovery Algorithm for a High Performance Memory Resident Database System, IBM Research Report RJ5707, Jun. 18, 1987.
|Lehman, A Recovery Algorithm for a High-Performance Memory-Resident Database System, IBM Research Report RJ5707, Jun. 18, 1987.
|Levy, "Incremental Restart", IEEE Publication Reprint No. CH2968-6/0000/0640, 1991, pp. 640-648.
|Levy, Incremental Restart , IEEE Publication Reprint No. CH2968 6/0000/0640, 1991, pp. 640 648.
|Mohan et al., Efficient Commit Protocols for the Tree of Processes Model of Distributed Transactions, IBM Research Report RJ3881, Jun. 12, 1983.
|Mohan, "ARIES/KLV: A Key-Value Locking Method for Concurrency Control of Multiaction Transactions Operating of B-Tree Indexes", Proceedings of the 16th VLDB Conference, Aug., 1990, pp. 1-14.
|Mohan, "ARIES: A Transaction Recovery Method Supporting Fine-Granularity Locking and Partial Rollbacks Using Write-Ahead Logging", IBM Research Report RJ 6649, Jan. 23, 1990.
|Mohan, "Commit-LSN: A Novel and Simple Method for Reducing Locking and Latching in Transaction Processing Systems", Proceedings 16th VLDB Conference, Aug. 1990, pp. 1-13.
|Mohan, ARIES/KLV: A Key Value Locking Method for Concurrency Control of Multiaction Transactions Operating of B Tree Indexes , Proceedings of the 16th VLDB Conference, Aug., 1990, pp. 1 14.
|Mohan, ARIES/LHS: A Concurrency Control and Recovery Method Using Write Ahead Logging for Linear Hashing with Separations, IBM Research Report, Jun. 1990.
|Mohan, ARIES/LHS: A Concurrency Control and Recovery Method Using Write-Ahead Logging for Linear Hashing with Separations, IBM Research Report, Jun. 1990.
|Mohan, ARIES: A Transaction Recovery Method Supporting Fine Granularity Locking and Partial Rollbacks Using Write Ahead Logging , IBM Research Report RJ 6649, Jan. 23, 1990.
|Mohan, Commit LSN: A Novel and Simple Method for Reducing Locking and Latching in Transaction Processing Systems , Proceedings 16th VLDB Conference, Aug. 1990, pp. 1 13.
|Mohan, et al., "Transaction Management in the R* Distributed Database Management System", ACM Transactions on Database Systems, vol. 11, No. 4, Dec. 1986, pp. 378-396.
|Mohan, et al., A Case Study of Problems in Migrating to Distributed Computing: Data Base Recovery Using Multiple Logs in the Shared Disks Environment, IBM Research Report RJ7343, May 3, 1990.
|Mohan, et al., ARIES/IM: An Efficient and High Concurrency Index Management Method Using Write Ahead Logging, IBM Research Report RJ6846, Aug. 29, 1989.
|Mohan, et al., ARIES/IM: An Efficient and High Concurrency Index Management Method Using Write-Ahead Logging, IBM Research Report RJ6846, Aug. 29, 1989.
|Mohan, et al., Transaction Management in the R* Distributed Database Management System , ACM Transactions on Database Systems, vol. 11, No. 4, Dec. 1986, pp. 378 396.
|Ng, P., "A Commit Protocol for Checkpointing Transactions", IEEE CH2612-0, 1988, pp. 22-31.
|Ng, P., A Commit Protocol for Checkpointing Transactions , IEEE CH2612 0, 1988, pp. 22 31.
|Rahm, "Recovery Concepts for Data Sharing Systems", IEEE Reprint No. CH2985-0/91/0000/0368, 1991, pp. 368-375.
|Rahm, Recovery Concepts for Data Sharing Systems , IEEE Reprint No. CH2985 0/91/0000/0368, 1991, pp. 368 375.
|Rahm, Recovery Concepts for Data Sharing Systems, University Kaiserslautern Technical Report, Oct., 1989.
|Rothermal, et al., "ARIES/NT: A Recovery Method Based on Write-Ahead Logging for Nested Transactions", Proceedings of the 15th International Conference on Very Large Data Bases, Aug., 1989, pp. 337-346.
|Rothermal, et al., ARIES/NT: A Recovery Method Based on Write Ahead Logging for Nested Transactions , Proceedings of the 15th International Conference on Very Large Data Bases, Aug., 1989, pp. 337 346.
|Stonebraker, "The Design of Post Gres Storage System", Proceedings of the 13th VLDB Conference, Sep., 1987, pp. 289-300.
|Stonebraker, The Design of Post Gres Storage System , Proceedings of the 13th VLDB Conference, Sep., 1987, pp. 289 300.
|Teng, et al., "Managing IBM Database 2 Buffers to Maximize Performance", IBM Systems Journal, vol. 23, No. 2, 1984, pp. 211-218.
|Teng, et al., Managing IBM Database 2 Buffers to Maximize Performance , IBM Systems Journal, vol. 23, No. 2, 1984, pp. 211 218.
|Brevet citant
|Date de dépôt
|Date de publication
|21 mai 1993
|3 oct. 1995
|International Business Machines Corporation
|Method and means for archiving modifiable pages in a log based transaction management system
|14 janv. 1994
|7 nov. 1995
|International Business Machines Corporation
|Fault-tolerant transaction-oriented data processing
|5 févr. 1993
|16 janv. 1996
|Digital Equipment Corporation
|Concurrency-control method and apparatus in a database management system utilizing key-valued locking
|2 mai 1994
|13 aoűt 1996
|International Business Machines Corporation
|Page refreshing procedure using two locking granularities to ensure cache coherency in a multisystem database processing environment having a high-speed shared electronic store
|7 juin 1995
|1 oct. 1996
|International Business Machines Corporation
|Computer program product and program storage device for improving data recovery performance
|2 mai 1994
|12 nov. 1996
|International Business Machines Corporation
|Efficient destaging of updated local cache pages for a transaction in a multisystem and multiprocess database management system with a high-speed shared electronic store
|15 mars 1993
|3 déc. 1996
|International Business Machines Corporation
|System and method for improving data recovery performance
|12 févr. 1993
|17 déc. 1996
|L.I.D.P. Consulting Services, Inc.
|Method for updating a file
|12 avr. 1996
|29 avr. 1997
|Tandem Computers, Incorporated
|Relational database system and method with high data availability during table data restructuring
|22 mai 1995
|7 oct. 1997
|Nec Corporation
|Difference recording apparatus having a processing unit, recording unit, log update section, and log comparator using a classification key in a log of input data
|6 févr. 1996
|24 févr. 1998
|Telefonaktiebolaget Lm Ericsson
|Method and system for fast recovery of a primary store database using selective recovery by data type
|12 sept. 1995
|26 mai 1998
|Hitachi, Ltd.
|High concurrency and recoverable B-tree index management method and system
|13 janv. 1997
|2 juin 1998
|Fujitsu Limited
|Apparatus for copying disk
|15 sept. 1995
|7 juil. 1998
|Hitachi, Ltd.
|Method of processing a synchronization point in a database management system to assure a database version using update logs from accumulated transactions
|2 nov. 1995
|25 aoűt 1998
|Informix Software, Inc.
|Method of commitment in a distributed database transaction
|10 sept. 1996
|1 sept. 1998
|Kabushiki Kaisha Toshiba
|Method for checkpointing in computer system under distributed processing environment
|23 janv. 1995
|3 nov. 1998
|Tandem Computers Incorporated
|Method for providing recovery from a failure in a system utilizing distributed audit
|19 mars 1996
|15 déc. 1998
|Oracle Corporation
|Method and apparatus for improved transaction recovery
|20 nov. 1997
|15 déc. 1998
|Electronics And Telecommunications Research Institute
|Method of prevention of dangling transaction occurrence using a transaction table initialization technique at an analysis step
|19 nov. 1997
|9 nov. 1999
|Electronics And Telecommunications Research Institute
|Method of prevention of dangling transaction occurrence using a terminated transaction process technique at redo step
|22 janv. 1997
|30 nov. 1999
|Oracle Corporation
|High-speed database checkpointing through sequential I/O to disk
|30 janv. 1998
|15 févr. 2000
|Kabushiki Kaisha Toshiba
|Scheme for restarting processes at distributed checkpoints in client-server computer system
|16 juin 1995
|28 mars 2000
|Lucent Technologies, Inc.
|Checkpoint and restoration systems for execution control
|16 juin 1995
|15 aoűt 2000
|Lucent Technologies Inc.
|Persistent state checkpoint and restoration systems
|28 mars 1998
|5 sept. 2000
|Compaq Computer Corporation
|Failure recovery for process relationships in a single system image environment
|30 mars 1998
|12 sept. 2000
|International Business Machines Corporation
|Recovering different types of objects with one pass of the log
|4 mars 1998
|9 janv. 2001
|International Business Machines Corporation
|Data recovery in a transactional database using write-ahead logging and file caching
|27 aoűt 1998
|30 janv. 2001
|Oracle Corporation
|Method and apparatus for improved transaction recovery
|5 janv. 1998
|6 févr. 2001
|International Business Machines Corporation
|Method and apparatus providing system availability during DBMS restart recovery
|10 juin 1998
|22 mai 2001
|Oracle Corporation
|Managing access to data in a distributed database environment
|17 sept. 1998
|25 sept. 2001
|Oracle Corporation
|Recovering resources in parallel
|27 févr. 1997
|9 oct. 2001
|Carreker-Antinori, Inc.
|Electronic check presentment systems and methods employing volatile memory datastore access techniques
|18 févr. 2000
|21 oct. 2003
|Hewlett-Packard Development Company, L.P.
|Write posting with global ordering in multi-path systems
|22 déc. 2000
|11 nov. 2003
|Oracle International Corporation
|Method and apparatus for making available data that was locked by a dead transaction before rolling back the entire dead transaction
|23 mai 2000
|18 nov. 2003
|International Business Machines Corporation
|Method and apparatus for insuring database data integrity without data recovery logging
|1 juin 2001
|15 juin 2004
|Lsi Logic Corporation
|Method to protect and recover a write ahead log from interruptions
|18 sept. 2000
|5 oct. 2004
|Stratus Technologies Bermuda Ltd.
|Maintenance of consistent, redundant mass storage images
|14 avr. 2000
|11 janv. 2005
|Stratus Technologies Bermuda Ltd
|Methods and apparatus for persistent volatile computer memory
|23 oct. 2000
|4 oct. 2005
|International Business Machines Corporation
|Efficient sequence number generation in a multi-system data-sharing environment
|31 mai 2001
|7 mars 2006
|International Business Machines Corporation
|Optimizing command execution in database systems that provide support for updatable scrollable cursors
|3 nov. 2000
|5 déc. 2006
|International Business Machines Corporation
|Method and system for recovering data in a plurality of systems
|27 aoűt 2003
|26 juin 2007
|Oracle International Corporation
|Method and apparatus for making available data that was locked by a dead transaction before rolling back the entire dead transaction
|8 mai 2003
|23 oct. 2007
|Oracle International Corporation
|On-demand multi-version data dictionary to support distributed applications
|18 mars 2004
|19 aoűt 2008
|Oracle International Corporation
|Parallel transaction recovery
|7 déc. 2005
|20 juil. 2010
|International Business Machines Corporation
|Data protection in storage systems
|21 nov. 2005
|9 nov. 2010
|Ubs Ag
|Technique for the migration of a host environment to a new system platform
|10 déc. 2009
|25 oct. 2011
|International Business Machines Corporation
|Improving data availability during failure detection and recovery processing in a shared resource system
|23 nov. 2009
|6 mars 2012
|International Business Machines Corporation
|Method and system for a sharing buffer
|8 mai 2012
|30 avr. 2013
|Fujitsu Limited
|Solution method of in-doubt state in two-phase commit protocol of distributed transaction
|24 mai 2004
|27 mai 2014
|International Business Machines Corporation
|Method for performing a warm shutdown and restart of a buffer pool
|18 mars 2011
|26 aoűt 2014
|Microsoft Corporation
|Tracking redo completion at a page level
|24 sept. 2012
|10 mars 2015
|Emc Corporation
|Concurrent access to data during replay of a transaction log
|29 janv. 2013
|28 avr. 2015
|Emc Corporation
|Multi-threaded in-memory processing of a transaction log for concurrent access to data during log replay
|30 nov. 2012
|9 juin 2015
|Hewlett-Packard Development Company, L. P.
|Transactions and failure
|14 aoűt 2013
|2 févr. 2016
|Amazon Technologies, Inc.
|Database cache survivability across database failures
|26 aoűt 2014
|5 juil. 2016
|Microsoft Technology Licensing, Llc
|Tracking redo completion at a page level
|29 mars 2012
|19 juil. 2016
|Hewlett Packard Enterprise Development Lp
|Controlled lock violation for data transactions
|24 oct. 2008
|10 janv. 2017
|Microsoft Technology Licensing, Llc
|Cyclic commit transaction protocol
|31 mai 2001
|11 avr. 2002
|Goralwalla Iqbal A.
|Optimizing updatable scrollable cursors in database systems
|27 aoűt 2003
|26 févr. 2004
|Amit Ganesh
|Method and apparatus for making available data that was locked by a dead transaction before rolling back the entire dead transaction
|18 mars 2004
|9 sept. 2004
|Oracle International Corporation
|Parallel transaction recovery
|8 mai 2003
|11 nov. 2004
|Lik Wong
|On-demand multi-version data dictionary to support distributed applications
|24 mai 2004
|30 déc. 2004
|International Business Machines Corporation
|System and method for performing a warm shutdown and restart of a buffer pool
|15 juil. 2004
|24 mars 2005
|International Business Machines Corporation
|Automated fault finding in repository management program code
|21 nov. 2005
|11 janv. 2007
|Markus Wietlisbach
|Technique for the migration of a host environment to a new system platform
|7 déc. 2005
|19 juil. 2007
|Kern Robert F
|Data protection in storage systems
|11 mai 2007
|21 févr. 2008
|Alok Pareek
|Apparatus and method for read consistency in a log mining system
|20 oct. 2006
|24 avr. 2008
|Saleem Mohideen
|Remote file system with efficient handling of uncommitted pages
|24 oct. 2008
|29 avr. 2010
|Microsoft Corporation
|Cyclic commit transaction protocol
|23 nov. 2009
|3 juin 2010
|International Business Machines Corporation
|Method and system for a sharing buffer
|10 déc. 2009
|16 juin 2011
|International Business Machines Corporation
|Improving data availability during failure detection and recovery processing in a shared resource system
|11 févr. 2011
|16 févr. 2012
|Oracle International Corporation
|Techniques for increasing the usefulness of transaction logs
|18 mars 2011
|20 sept. 2012
|Microsoft Corporation
|Tracking redo completion at a page level
|30 nov. 2012
|5 juin 2014
|Hewlett-Packard Development Company, L.P.
|Transactions and failure
|16 mars 2012
|3 oct. 2012
|Tracking redo completion at a page level
|5 févr. 1997
|20 aoűt 1997
|Telefonaktiebolaget Lm Ericsson
|Method and system for fast recovery of a primary store database
|3 nov. 1994
|11 mai 1995
|Eo, Inc.
|Recovery boot process
|16 juin 1995
|3 janv. 1997
|Lucent Technologies
|Persistent state checkpoint and restoration systems
|16 juin 1995
|3 janv. 1997
|Lucent Technologies
|Checkpoint and restoration systems for execution control
|Classification aux États-Unis
|Classification internationale
|Classification coopérative
|Classification européenne
|11 oct. 1991
Owner name: INTERNATIONAL BUSINESS MACHINES CORPORATION A COR
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:MOHAN, CHANDRASEKARAN;REEL/FRAME:005869/0474
Effective date: 19911003
|27 déc. 1994
|Certificate of correction
|12 nov. 1997
|Fee payment
Year of fee payment: 4
|20 févr. 2002
|Maintenance fee reminder mailed
|26 juil. 2002
|Lapse for failure to pay maintenance fees
|24 sept. 2002
|Expired due to failure to pay maintenance fee
Effective date: 20020726


text:
TAMPA -- A loitering Anglophone horned in on a French-Canadian media scrum yesterday, pressing Chris Simon for words of wisdom.
The Flames winger, who can stickhandle with equal aplomb in both French and English, rambled en Francais about tonight's clash with the Bolts before pausing to check if the only unilingual bystander was keeping pace.
"Did you get that?" smiles the sturdy Simon, a 12-year NHL veteran who owns a Stanley Cup ring from his days in Colorado.
In either official language, tonight's Game 7 of the Stanley Cup final is a test of skill and nerves for both the Flames and host Tampa Bay Lightning. And despite watching Game 6 slip away in overtime Saturday in Calgary, Simon is convinced his club will recover to win the Cup tonight.
"I think both teams are at the same point where everybody's going to be excited and work hard," Simon notes.
"I've never been in a Game 7 in a final, so it's going to be great. We have a lot of confidence in ourselves and we're going to go out and win the game, that's all we've got to do."
The odds seem stacked against them -- the home team has won 10 of the 12 seventh games in the Stanley Cup final.
"Game 7, one team is going to win, one's going to lose," points out Simon.
"We have to do everything we can to win. We're confident in our game and our system.
"We seem to keep things a lot simpler when we're on the road. I think that might be one of the reasons we play better on the road."
Simon supports system
DAN TOTH -- Calgary Sun
, Last Updated: 3:12 PM ET

subset: commoncrawl


text:
THE Somerset Troubled Families Programme has been awarded £475,500 in 'success money' after helping nearly 600 families in crisis in two years.
The Government gave all local authorities a target to turn around the lives of 40 per cent of families viewed as 'troubled' within two years.
Somerset has beaten the target, turning around the lives of 580 families – 67% of 870 families it had identified.


text:
What's a disaffected blue-collar white guy supposed to do for a laugh in a world full of gay, handicapped and ethnocentric comedians? Come on down to Jeff Wayne's right-of-center one-man comedy show, Big Daddy's Barbeque.
"I never say conservative or liberal because that's very divisive with people," says Wayne, whose mother was a Republican and father was a Democrat. Big Daddy's views "certainly aren't PC, let's put it that way."
Big Daddy is unapologetic about his hamburgers, for one thing, and he lampoons California as the kind of place that will outlaw cigarettes but create marijuana smoking sections in restaurants. At the height of the PC movement the show was subtitled "It's O.K. to Be a White Male," but now that it's almost politically incorrect to be politically correct, the show has been subtitled "It's All My Fault" to keep with the times. Big Daddy now jokes that Osama bin Laden should have turned himself in because he "could have pulled the O.J. jury and gotten off." He says Bush didn't send Jesse Jackson to Afghanistan because "we don't hate them that much."
Big Daddy's Barbeque
Spellbinders Variety Theatre, Marq*E Entertainment Complex, 7620 Katy Freeway
November 6 through November 25. 8 p.m. Tuesday through Thursday and Sunday; 7:45 p.m. and 10:30 p.m. Friday; and 7 p.m. and 10 p.m. Saturday. $16.95 to $19.95. For more information, call 713-22-FUNNY.
The director of the show is Ted Lange, the actor made famous by his portrayal of bartender Isaac Washington on The Love Boat. Though that association has provided the show with some protection from offended critics, Wayne says Lange's skin color had nothing to do with his selection. "He was the best man for the job," Wayne says.
If you like this story, consider signing up for our email newsletters.
You have successfully signed up for your selected newsletter(s) - please keep an eye on your mailbox, we're movin' in!
Big Daddy is too likable to be hated. Time and again reviewers have noted that black people -- particularly women -- laugh the loudest at Wayne's routines. Big Daddy is not so much threatening as revealing of a new American reality. White people are slowly losing their majority status to become but the largest in a nation of minorities. Perhaps it's inevitable that they would turn into what conservatives hate most: yet another vocal ethnic group touting their cultural identity.


text:
I came across this idea a while ago, and was reminded from this disney props thread, and knew it'd be a simple thing to do that would make a great gift. I am going to be able to do it for under $35.
Here is the goal:
$32.10 = $17.55 plus $14.55 shipping for the jar. The proportions of the jar seem to change since it is an animation, but I've selected a jar that is 8" diameter and 11" tall, plus the handle.
$2.00 for a single rose
$0.10 worth of hot glue
$0.05 worth of fishing wire
I plan on hot glueing one end of the fishing line to the top inside of the jar, and tieing the other end in a loop. That way the rose will appear to float. When the real rose dies after a week or so, it will be easy to remove the rose, and add another into the loop without having to reglue and retie the rose.
Progress pics coming early next week, with the goal to have it done by next weekend for her birthday.


text:
Artist description:
Look what smoking will do.We have ti fight for what is right.rate and comment.
Flash Draw Created Apr 16, 2008 470 x 338px Unless noted Copyright 2008 n.z.islanders.
We encourage you to submit a comment and let the artist know what you think of this drawing. Please log in or join to post a comment.
Post a comment
Nobody has commented on this drawing yet. Be the first!


text:
Discover a selection of top forums pedro destruction on the internet. Come to share your passion on forums pedro destruction and meet other fans of pedro destruction. Then, why don't you create your own forum of pedro destruction ?
After the destruction of the multiverse, Portal Breach was created to be a safe haven for those that survived and managed to make their way here. Join us as any canon or original character!
roleplay, portal, breach, collision, worlds, cartoon, crossover, roleplaying, site, role-playing, role, playing, play, role-play


text:
CHICAGO, June 20 (UPI) -- Kate Upton turned 22 on June 11 and celebrated in the company of close friends and her on-again boyfriend Justin Verlander.
The Sports Illustrated cover girl was spotted celebrating her special day at Chicago tiki bar Three Dots and a Dash along with six of her friends. According to Page Six, the model wore a tight red dress for the celebration and sipped on champagne for a midnight toast courtesy of a friend who was unable to attend the gathering.
The The Other Woman actress was also seen with her Detroit Tigers boyfriend whose game was postponed June 12.
A week after her big day, Upton made headlines for her appearance in Lady Antebellum's "Bartender" music video alongside Tony Hale.


text:
Active Tags
Click tags to the right to narrow your search. Unclick tags to remove.
Judy & Her Parents— First Judy is seduced, then she seduces.
Wendy's Problem— Mom lets Daddy take care of daughter's needs.
Laura's Story Ch. 03— Laura gets a surprise visit.
She's A Slut: Moving On— He wakes to find step-daughter in bed with him.
Gwen Ch. 01— Girl with extra body part becomes papa's love.
Led Astray Ch. 01— Grandpa becomes sex tutor for granddaughter.
The Wedding— The first time with daddy.
Bedroom Scene— You get hot sex from a man you're not married to.
Daddy's Little Lesson— Mari learns an anal lesson from Daddy.
The Best & Worst Of Times— Hard times lead dad & daughter into hot, wrong night.
Sissy— Does cum really cure zits?
A Day Trip With Daddy's Little Girl— Everyone loves a trip.
The Visit— Daddy pays a surprise visit & gets his own surprise.
Lonely Craving— His voice, and her need for sex.
My Eighteenth Birthday Ch. 3— He takes his daughter's virginity.
Candy's Panties Ch. 1— Daddy gets a view of Candy's sexy panties.
Daddy Gets A Surprise— Daughter finds out that daddy wants more.
Jessica Comes Home Early— Sis walks in on Jen and her father.
Active Tags
Click tags to the right to narrow your search. Unclick tags to remove.
Please, separate your tags with comma: anal orgasm, oral sex.
Read the Literotica Story Tag FAQ for more information on these tags.


text:
'Machete': Ugly Beauty
Viewers know going in that as Machete escapes one ambush after another, there will be blood, lots of it, splattered on walls, people, animals, vegetables, hell, even minerals.
MacheteCast: Danny Trejo, Jessica Alba, Michelle Rodriguez, Steven Seagal, Cheech Marin, Jeff Fahey, Don Johnson, Robert De Niro
Directors: Robert Rodriguez, Ethan Maniquis
Rated: R
Studio: 20th Century Fox
Year: 2010
US date: 2010-09-03 (General release)
UK date: 2010-11-26 (General release)
Danny Trejo has acted in more than 200 films and television shows over his career. Still, Machete is his first leading role. Maybe it's because of the ugly beauty of that face, which in close-up seems as scratched and burned as the grindhouse-style film stock mimicked in Machete's opening credits. In contrast to the nipped, tucked, and artificially plumped surfaces that Hollywood usually proffers, Trejo's complexion is a tactile landscape of pockmarks, furrows, and scars. Just looking at it tickles your fingertips with anticipation. Co-directors Robert Rodriguez and Ethan Maniquis don't give you much time to pore over it, however. From the gangbuster opening to the final shootout, Machete's camera moves quickly and so do its edits.
Machete was spawned from one of the rip-roaring trailers that opened 2007's Grindhouse, the double feature directed by Rodriguez and Quentin Tarantino. While Machete doesn't boast the go-for-broke delirium of Rodriguez's contribution to that package, Planet Terror (or the gorgeous and inventive visuals his 2005 Sin City), it's just as gruesome and at times as exhilarating.
When the film opens, Machete is a federale in Mexico, on a mission to save a woman kidnapped by Torres (Steven Seagal), a notorious drug kingpin who punishes him horribly. Years later, Machete's a day laborer in Texas, where he's drafted by Booth (a greasy and growling Jeff Fahey) to assassinate Senator John McLaughlin (Robert De Niro), who is seeking re-election on a border-fence platform. Soon Machete is on the run from Booth, McLaughlin, Torres, and Von (Don Johnson), a vigilante in cahoots with the senator. Machete's hope for survival rests on two women: Luz, a.k.a. Shé (Michelle Rodriguez), who oversees an underground network of illegal immigrants, and Immigrations Officer Sartana (Jessica Alba), who should have an aura of toughness but doesn't. (Granted, it's hard to come across as a bad ass in skinny jeans and teetery heels.)
This isn't a movie made to surprise. Given the hero's favorite weapon, viewers know going in that as Machete escapes one ambush after another, there will be blood, lots of it, splattered on walls, people, animals, vegetables, hell, even minerals. Heads roll, hands are cut off, eyes say goodbye to their sockets. Some of the killings are so bravura, one can't help laughing, mainly in disbelief. (Preview audience members cheered and hooted from start to finish.) When Machete ends up in a hospital that treats rebel activists on the sly, you may wonder why his doctor points out that human entrails, when uncoiled, can measure as long as 60 feet. But not for long: the payoff comes in the form of a gag that's sidesplitting in more ways than one.
The sound design is as excessive and twisted as the images. Just listen to the flinty clink of that machete when it hits metal or bone, or the squish of a cell phone being retrieved from a spot I won't divulge. And whenever Machete gets it on, which is often (and once with a nude Lindsay Lohan in Lady Godiva blond locks, no less), the '70s porn soundtrack kicks in, but of course.
Despite the casting of hammy former heavyweights Johnson and Seagal, it's Cheech Marin as Padre, Machete's brother and a renegade priest, who gets the biggest guns -- and the best lines: "I absolve you of your sins. Now get the fuck out." Funny, yes. The height of wit? Not exactly. And though the filmmakers nearly neutralize their political satire by making Von and McLaughlin too cartoonish, they do land a few punches against virulent anti-immigration rhetoric with the senator's campaign spots (for instance, when animated Mexicans are zapped by electric fences). It's possible that viewers will leave Machete with more on their minds than the film's body count or the outrageousness of Johnson's mutton chops.
It remains to be seen if Machete will catapult Trejo to a new level of stardom, but bets should be placed on Michelle Rodriguez. When shows up for a gunfight wearing an eye patch, a bikini top, and black leather pants, as well as pistols strapped from her hips to her ankles, she is a slo-mo wet dream, instantly iconic (see also: the amputee Rose McGowan in Planet Terror). Rodriguez handles her firepower with aplomb. The end credits jokingly promise sequels to Machete, but man, this girl deserves a starring vehicle of her own.


text:
Public Hearing for Bedford Historic District Scheduled
The Landmarks Preservation Commission scheduled a public hearing for the Bedford Historic District, which extends south from Monroe Street to Verona Place (at Fulton) and east from Bedford to Tompkins Avenue. The Bed Stuy community has pushed for this district for years now and has garnered a lot of community support. This area is particularly rich in late 19th century buildings by some of the borough's most prominent architects, including Montrose Morris. If landmarked, more than 600 Renaissance, Greek Revival and Queen Anne townhouses would be protected. LPC will hold the public hearing on October 30th at 11 am, in the 9th Floor Conference Room at 1 Centre Street in Manhattan. They calendared the proposed district on May 15.
Tomorrow: Calendaring the Bedford Historic District [Brownstoner]


text:
For More Information
Contact Robert Nieske.
This ensemble performs throughout the semester. Check out the latest concert listings for all of the details.
Jazz Ensemble
The Brandeis Jazz Ensemble, open to the entire Brandeis community by audition, is comprised of 15-20 musicians led by one of Boston's best-known jazz men, Professor of the Practice Robert Nieske. In addition to the classic jazz repertory, the ensemble performs original compositions written specifically for the group. Students are encouraged to compose for the ensemble and receive guidance from the director.
Interested vocalists, saxophone, brass [including horn, euphonium or tuba], guitar, piano, bass or drum players will be asked to play scales and arpeggios, sight read and play a prepared piece at the audition. Improvising experience is not required, but reading skills are. Rehearsals are held on Mondays from 7 to 10 p.m. in the Slosberg Music Center.
Fall 2017 auditions will take place at the beginning of the semester. Please sign up on the bulletin board in the Slosberg lobby or email Robert Nieske to schedule a time.
Location: Slosberg 235
Audition Requirements for Jazz Ensemble:
Everyone except drums: [this includes all Brass, Saxes, Vocalists and any non traditional instruments who wish to audition]
1. Prepare one medium tempo jazz piece of your choice, no Ballads
[pieces by Ellington, Parker, Gershwin, Mingus, Monk, Porter ect.]
Prepare these SCALES IN EIGHT NOTES at quarter note = 60
2. Chromatic scale over the full range of your instrument
3. Major scales: B flat and F–two octaves if possible
4. Minor scales: C and A–two octaves if possible
5. Improvise over 12 bar blues in key of your choice [not necessary]
6. Sightread chart chosen by the director
Piano, Guitar and Bass must, in addition, comp/walk over 12 bar blues and Rhythm changes [chords from I Got Rhythm]
Drums will be asked to play various tempo swing and latin grooves and sightread a drum part.
Visit: www.bobnieske.com for sounds and ideas.


text:
Suffolk Bull Moose Rugby Football Club (RFC) is based out of Suffolk County but plays in and around the Tri-State area fielding both a Senior Men and Senior Women's team as part of the Metropolitan New York (MetNY) Rugby Football Union. The MetNY Union governs more than 80 men's and women's clubs, college, high school and youth rugby teams in the Metropolitan New York City region, covering parts of Connecticut, New Jersey and New York.
The Suffolk Bull Moose Women's Rugby Club started in 2004 with the aid of the internet and local college players. The women's team currently plays in Division II in the MetNY Union competing against teams from Monmouth, Morris, and Brooklyn.
The men's and women's teams together are a competitive and evolving rugby club that values hard work, dedication, as well as team camaraderie. Suffolk Bull Moose RFC plays year round and has both home games on Long Island and away games spreading throughout the North Eastern region.


text:
How should France act to protect its language from an invasion of Franglais? Is creating new words to rival English ones the best way to go about it? Following on from The Local's Tête-a-tête debate on Franglais, we asked the views of French people in the street.
Back to Language barriers: French resistance to Franglais»


text:
Aria Twin 60-40
The convenient side-by-side double stroller that easily maneuvers through doorways and walkways.This convenient side-by-side stroller is not only compact and superlight, but will also fit through the standard door with ease. Keeping two children happy is simple with the individual adjustable hoods with a loop to hang their favorite toy, individual reclining backrests and individual child trays.
Aria Twin 60-40 Product Video
Take a look at all of the features for the Aria Twin 60-40 stroller.


text:
Artist description:
I really needed a Giraffe moment... with my head near warmth and food.. A comfort moment.
Flash Draw Created Oct 05, 2011 460 x 640px Unless noted Copyright 2011 Catarsetrophy.
We encourage you to submit a comment and let the artist know what you think of this drawing. Please log in or join to post a comment.
Post a comment
Great picture! If it did not help you - I usually find chocolate does! This is probably better for the figure though (that is why I look like the "bathing beauty" in your picture - "Quack")
Great colors and such a cute design! 5H
gorgeous..your style is so unique :)
You have a wonderful and unique drawing style!!!! Lovely!!! 5/5!
love the way you think and draw 5h
Sooooooooooo CUTE!!! 5h!!!


text:
I am having some problems with an XML document. I am displaying elements using JavaScript. Everything works fine until I put some Spanish test into my XML doc.
Am I missing something?
Results 1 to 2 of 2
Thread Information
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)


text:
Roslyn Phillips has made a small change to her Wednesday routine.
A little after 11 a.m., she heads down from her office at the Jacksonville Bank building over to the parking lot at Forsyth and Main streets where the pink truck is parked.
It's not long before a line starts to form. Phillips has tried just about everything Baby's Badass Burgers has to offer. At one point, The Good Wife — a cheeseburger with a fried egg served over easy with special sauce — was the reigning favorite.
But now that she's trying to be healthier, she's getting a turkey burger topped with avocado, along with sweet potato fries.
Phillips had never had avocado before on a burger, but once she saw it on the menu she figured ... why not.
"It tastes like gourmet ... like a homemade burger. The sauce I believe sets it apart," she said.
Theresa Augustine, manager of Baby's Badass Burgers, a food truck franchise that originated in California, the burgers are gourmet. Baby's takes them up a notch, adding more upscale options such as avocados and eggs, premium beef, tasty buns and sauces.
"I think that everyone is trying to advance and create something that is bigger and better than the next guy," Augustine said. "Everybody is trying to do something different with them."
At MShack, owned by the Medure brothers Matthew and David, they're incorporating principles that have worked well in their fine dining restaurants.
For example, they still pride themselves on using the best possible ingredients. Jim Gruebel, the general manager of the Atlantic Beach location, said there is no reason a customer can't have an out-of-this-world dining experience with a burger.
"The main emphasis that we got from our fine dining is the quality of food, Gruebel said. "We make everything from scratch. The only thing we have in our freezer is French fries."
MShack guests can get a standard cheeseburger, or bacon cheeseburger, of course, but they can also go gourmet. MShack, also located at the St. Johns Town Center, offers the Portbello Truffle Burger: a beef patty, smoked Gouda cheese, bacon, truffle-flavored portobello mushrooms and a sherry glaze.
And if that's not fancy enough, there's the Medurable — a patty enhanced with foie gras (duck or goose liver) and carmelized onions.
The idea is taking those high-end ingredients and incorporating them to something everyone knows, Gruebel said.
Not to be outdone, Epik Burger on Atlantic Boulevard, also offers foie gras as a topping.
Korey Konopasek, owner of Epik Burger said better burgers have been the trend lately. For him, he said, his burger options are in part due to health. He wanted to create a restaurant where the whole family could come and find something they'd love and not feel guilty about eating.
"Just by doing different toppings and cheeses, you could fit other types of cuisine into hamburgers," said Konopasek, who said his menu features 34 different burgers as well as chicken and tuna.
Konopasek said if someone is open-minded, he can point them in the direction of something slightly unconventional yet delicious, such as the Hawaiian Local's Burger. It has an egg and Spam.
At Smashburger in Neptune Beach, they've found that customers are responding well to their goat cheese burger.
"It's actually been really, really popular lately. It's a healthy choice for a burger," said Joe Pellegrino, general manager.
The burger also has spinach and cucumbers.
"I think the people want the old with the new," Pellegrino said. "They want the old taste of a simple burger but new with fresh ingredients."
Yet if simple is what you want, all the burger masters say don't worry. Pickles, cheese and bacon are here to stay.
"It's a burger at the end of the day," Konopasek said. "And a burger is comfort food."


text:
Integrated power, cooling architecture with smart power module targets server rooms, data centers
Post a comment
American Power Conversion (APC), a global provider of end-to-end infrastructure availability solutions, announces a fully assembled InfraStruXure system integrated with a Smart-UPS VT power module, hot-swappable batteries and integrated power distribution. This new InfraStruXure system offers quick connect components and turnkey features to speed up deployment time. The system also decreases total-cost-of-ownership by minimizing space and reducing operating, installation and expansion costs. Since the InfraStruXure with Smart-UPS VT architecture uses a modular and scalable design approach, users can expand the system by adding APC's innovative in-row cooling, centralized management and security products for enhanced capabilities.
"Our legendary and award winning Smart-UPS line coupled with our innovative InfraStruXure architecture provide our customers with highly agile and available solutions for their IT environments," said Dwight Sperry, APC's vice president of Enterprise Systems and Business Networks. "The system's high power density, small form factor and modular architecture make it ideal for applications ranging from high density, disaster recovery and VoIP/IP telephony."
This new network critical physical infrastructure (NCPI) solution offers a fully-integrated system at a lower initial investment and incorporates several innovative features such as a single rack-based design for better utilization of floor space, higher power efficiency for lower operating costs and a new power distribution design for simplified installation and expansion. Finally, the system improves availability with additional internal battery capacity for runtime scalability.
The new InfraStruXure with Smart-UPS VT is ideal for server rooms and small data centers as well as for remote locations including regional offices. The systems are available in 20KVA and 30KVA, with 208V and 480V input and are now available in North America. InfraStruXure with Smart-UPS VT will be available in July for most countries worldwide.
For more information about InfraStruXure and APC's other products, please visit www.apc.com or call 800-877-4080.
APC's InfraStruXure is on-demand architecture for network-critical physical infrastructure (NCPI). The InfraStruXure design, which integrates power, cooling, rack, management and services, allows the selection of standardized components to create a solution through modular and mobile configurations. This standardization enables an easily scalable architecture designed to meet changing needs and future expansion. This award-winning, patent-pending approach provides increased availability, improved adaptability and speed of deployment as well as lower total cost of ownership for IT environments " from wiring closets to computer rooms to data centers.
With integrated management becoming a critical component in the NCPI, APC offers comprehensive management solutions including InfraStruXure Manager. A browser accessible, user-friendly tool, InfraStruXure Manager provides monitoring of power, cooling, and environmental management at the rack or room level. APC also provides professional services that optimize the NCPI over the complete data center life cycle, including planning, installation, operation and end-of-life services.


text:
SAN FRANCISCO (KCBS) – Thursday marks the end of an era, as the last processing machine to develop Kodachrome film is shut down at a plant in Kansas. However, photography enthusiasts say the demise shouldn't be blamed on the switch to digital technology.
San Diego photography consultant Ken Rockwell says he just processed his last five rolls of Kodachrome film, which expired in 1986, and it looks fine. But he's neither sad nor nostalgic about the end of what was the first successful color film.
"Ask everybody who is sitting there scratching their heads saying 'oh my God, this is horrible,' when was the last time they purchased a roll of Kodachrome, and when was the last time they actually paid to have it developed," said Rockwell.
KCBS' Holly Quan Reports:
That's why it's going away, according to Rockwell, because people weren't buying it anymore. They were buying other, better kinds of film. And while the switch to digital photography, especially from a camera phone, has been widespread, Rockwell says film will never disappear.
What he does blame digital technology for however, is making us lousy photographers.
"It makes serious people who could have been better photographers worse because they get sloppy, and if you don't care about something – you don't do good work," said Rockwell. "If you know you can throw it away, and it doesn't cost you anything you don't put a lot of effort into it, and therefore the reason digital pictures can look a lot worse than pictures taken on film is because nobody cares. If the best thing you can say about the digital process is that you can throw it away, then why take that picture in the first place."
(© 2010 CBS Broadcasting Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)


text:
The latest arrivals at dealerships. Compiled by Paul Hudson
Four-door saloon based on Mitsubishi's first global platform, including the latest Evo rally replica.We like Load space, looks, ride and handling, apparently good build quality.
Price: £12,499-£18,499 (Evo X £27,499-£37,999)
Engines: 1.5, 1.8, 2.0T petrol; 2.0 diesel
Dealer contact: 0845 330 2002/www.mitsubishi-cars.co.uk
We like: Solidity, reputation for reliability, traction and performance of Evo X.
We don't like: Dull to drive (Evo X excepted), interior plastics.


text:
We want to make sure that you look your best, and it's important to know how to properly wear makeup to achieve that goal. If you've ever stared wide-eyed at a palette of eye shadow wondering what colors would look best on you, the freak-outs stop here. Certain color combinations look best on specific eye colors. Let's take a look at what colors you should be using for your green, brown, or blue eyes.
Bright blue eyes typically stand out on their own, but it's always great to enhance them and make them pop even more. To do this, make sure that you have a bunch of brown and gold colors in your makeup collection. The blue and the brown contrast perfectly to make sure that your baby-blues will be the most prominent feature on your face. Beauties like Candice Swanepoel and Zooey Deschanel always rock a brown smokey-eye, and now you can bring out your blue eyes just like they do! Try using a light pink lipstick or gloss with your brown eye makeup to keep the browns on your lids vibrant. Also, make sure you bronze up your face to give you an overall glow that really makes your eyes stand out.
If you guessed that brown eyes stand out more when paired with a blue eye shadow, then you're correct. Many brown-eyed girls feel that their eye color is super plain, but it doesn't have to be that way! A navy or bright blue eye shadow combination can completely spice up your look and make your brown eyes sparkle like never before. Nicole Richie recently dazzled on the red carpet with her stunning blue eye makeup, and Vanessa Hudgens frequently adds a little blue to her eyes to get those brown eyes of hers to be the center of attention. A nude lip looks awesome with blue eye shadow because it doesn't take away from the brightness of the color on your eyelids. Avoid a hot pink lip color because it will make you look way too overdone! Keep your cheeks fairly bare by using just a small amount of a pretty pink blush.
Green-eyed girls shouldn't be afraid to wear purple eye shadow because it is the perfect color to emphasize that beautiful eye color. A deep purple haze across your lids and beneath your lash line looks so pretty against any skin type and especially for those girls who want to make sure that their emeralds are the thing on their face that stands out the most! Stars like Emma Stone always flaunt their green eyes by matching them with some purple liner or shadow, and the newly engaged Olivia Wilde loves to follow this makeup trend as well. To be daring, pair the purple eyes with a bright red lip! This look is gorgeous; just refer back to Selena Gomez in her "Love You Like a Love Song" music video to see what we mean. Top off your picture perfect look by sweeping a peach-toned blush across your cheekbones.
Get those eyes popping with these handy makeup tips! Let us know what your favorite color combinations are for your eye color.


text:
There is a special public town meeting tonight at 7 in the Meeting Room at Weston Town Hall to vote on a land conveyance on Oak Lane.
The town intends to convey three slivers of land, shown as parcels A, B, and C, on map number 2095, as recorded in the Weston Town Clerk's office.
The purpose of the conveyance is to correct a mistake made in the 1960s when the property was supposed to be conveyed by the town to three property owners.
"All we are doing is correcting something that should have been done years ago in the past," said First Selectman Gayle Weinstein.
She said an arrangement had been made by the town of Weston to transfer portions of a cul-de-sac that was no longer needed by the town to three homeowners. "For some reason, those conveyances were never made, so we are correcting that now," Ms. Weinstein said.
The transfer received 8-24 approval from the Planning and Zoning Commission. Because real property is involved, the conveyance requires approval at a town meeting.