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A system and method for performing a takeover procedure is disclosed. A plurality of storage system nodes is coupled in a cluster. One or more of the plurality of storage system nodes in the cluster is notified to takeover at least a portion of a writable storage device serviced by another storage system node in the cluster. In response to the notification, the portion of the writable storage device is assimilated into at least one of the notified storage system nodes.
1. A method for performing a takeover procedure, comprising:
coupling a plurality of storage system nodes in a cluster;
triggering a takeover process for a first storage system node of the plurality of storage system nodes in the cluster to takeover a portion of a writable storage device serviced by a second storage system node of the plurality of storage system nodes in the cluster;
in response to triggering the takeover process, assimilating the portion of the writable storage device into one or more data containers serviced by the first storage system node;
checking whether the assimilated portion comprises a first volume identification (ID) that matches a second volume ID of the first storage system node; and
in response to a match, assigning a new volume ID to the first volume ID or assigning the new volume ID to the second volume ID.
2. The method of
3. The method of
4. The method of
5. The method of
assigning a status in an ownership locations associated with the portion of the writable storage device; and
identifying the first storage system node as a current owners of the portion of the writable storage device by the assigned status.
6. The method of
7. The method of
8. The method of
storing memory data from the second storage system node to a memory of the first storage system node; and
replaying the stored memory data from the memory of the first storage system node.
9. The method of
10. The method of
11. The method of
12. The method of
13. The method of
14. The method of
pre-empting a second storage system node reservation on the portion of the writable storage device; and
asserting a first storage system node reservation on the portion of the writable storage device.
15. The method of
16. The method of
17. A computer system for use in a clustered environment, comprising:
a first storage system node configured to operatively connect with a second storage system node;
the first storage system node further configured to provide a communication path between the first storage system node and the second storage system node; and
a processor operatively interconnected with the first storage system node and configured to execute a takeover procedure, the takeover procedure configured to assimilate a portion of a writable storage device serviced by the second storage system node into one or more data containers serviced by the first storage system node, the takeover procedure further configured to check whether the assimilated portion comprises a first volume identification (ID) that matches a second volume ID of the first storage system node, and in response to a match, assign a new volume ID to the first volume ID or assign the new volume ID to the second volume ID.
18. The computer system of
19. The computer system of
20. The computer system of
21. The computer system of
22. The computer system of
23. A computer-readable storage medium containing executable program instructions executed by a processor, comprising:
program instructions that trigger a takeover process for a first storage system node of a plurality of storage system nodes in a cluster to takeover a portion of a writable storage device serviced by a second storage system node in the cluster;
program instructions that, in response to triggering the takeover process, assimilate the portion of the writable storage device into one or more data containers serviced by the first storage system node;
program instructions that check whether the assimilated portion comprises a first volume identification (ID) that matches a second volume ID of the first storage system node; and
program instructions that, in response to a match, assign a new volume ID to the first volume ID or that assign the new volume ID to the second volume ID.
24. The computer-readable medium of
25. The computer system of
26. The computer-readable medium of
27. The computer system of
28. The computer system of
29. The computer-readable medium of
30. The computer-readable medium of
This application is a continuation of U.S. patent application Ser. No. 11/606,727 entitled SYSTEM AND METHOD FOR STORAGE TAKEOVER, by Susan M. Coatney et al., filed Nov. 30, 2006, now issued as U.S. Pat. No. 7,613,947 on Nov. 3, 2009.
This application is related to the following United States Patent Applications:
U.S. patent application Ser. No. 11/606,452 entitled SYSTEM AND METHOD FOR IMPROVED RESOURCE GIVE BACK, by Susan M. Coatney et al., now issued as U.S. Pat. No. 7,546,302 on Jun. 9, 2009, which is presently incorporated by reference in its entirety; and
U.S. patent application Ser. No. 11/606,538 entitled SYSTEM AND METHOD FOR MAINTAINING DISK LOCATION VIA HOMENESS, by Steven S. Watanabe et al., now issued as U.S. Pat. No. 7,711,683 on May 4, 2010, which is presently incorporated by reference herein in its entirety.
1. Field of the Invention
The present invention relates to networked storage systems and, more particularly, to takeover procedures in clustered storage systems.
2. Background Information
A storage system is a computer that provides storage service relating to the organization of information on writeable persistent storage devices, such as memories, tapes or disks. The storage system is commonly deployed within a storage area network (SAN) or a network attached storage (NAS) environment. When used within a NAS environment, the storage system may be embodied as a file server including an operating system that implements a file system to logically organize the information as a hierarchical structure of directories and files on, e.g. the disks. Each "on-disk" file may be implemented as a set of data structures, e.g., disk blocks, configured to store information, such as the actual data for the file. A directory, on the other hand, may be implemented as a specially formatted file in which information about other files and directories are stored.
The file server, or filer, may be further configured to operate according to a client/server model of information delivery to thereby allow many client systems (clients) to access shared resources, such as files, stored on the filer. Sharing of files is a hallmark of a NAS system, which is enabled because of semantic level of access to files and file systems. Storage of information on a NAS system is typically deployed over a computer network comprising a geographically distributed collection of interconnected communication links, such as Ethernet, that allow clients to remotely access the information (files) is on the file server. The clients typically communicate with the filer by exchanging discrete frames or packets of data according to pre-defined protocols, such as the Transmission Control Protocol/Internet Protocol (TCP/IP).
In the client/server model, the client may comprise an application executing on a computer that "connects" to the filer over a computer network, such as a point-to-point link, shared local area network, wide area network or virtual private network implemented over a public network, such as the Internet. NAS systems generally utilize file-based access protocols; therefore, each client may request the services of the filer by issuing file system protocol messages (in the form of packets) to the file system over the network. By supporting a plurality of file system protocols, such as the conventional Common Internet File System (CIFS), the Network File System (NFS) and the Direct Access File System (DAFS) protocols, the utility of the filer may be enhanced for networking clients.
A SAN is a high-speed network that enables establishment of direct connections between a storage system and its storage devices. The SAN may thus be viewed as an extension to a storage bus and, as such, an operating system of the storage system enables access to stored information using block-based access protocols over the "extended bus". In this context, the extended bus is typically embodied as Fibre Channel (FC) or Ethernet media adapted to operate with block access protocols, such as Small Computer Systems Interface (SCSI) protocol encapsulation over FC (FCP) or TCP/IP/Ethernet (iSCSI). A SAN arrangement or deployment allows decoupling of storage from the storage system, such as an application server, and some level of storage sharing at the application server level. There are, however, environments wherein a SAN is dedicated to a single server. When used within a SAN environment, the storage system may be embodied as a storage appliance that manages access to information in terms of block addressing on disks using, e.g., a logical unit number (LUN) in accordance with one or more block-based protocols, such as FCP.
One example of a SAN arrangement, including a multi-protocol storage appliance suitable for use in the SAN, is described in United States Patent Application Publication No. US2004/0030668 A1, filed on Feb. 14, 2004, entitled MULTI-PROTOCOL STORAGE APPLIANCE THAT PROVIDES INTEGRATED SUPPORT FOR FILE AND BLOCK ACCESS PROTOCOLS by Brian Pawlowski et al., which is incorporated herein by reference in its entirety.
It is advantageous for the services and data provided by a storage system, such as a storage node, to be available for access to the greatest degree possible. Accordingly, some storage systems provide a plurality of storage system nodes organized as a cluster, with a first storage system node being clustered with a second storage system node. Each storage system node is configured to take over serving data access requests for the other storage system node if the other storage system node fails. The storage nodes in the cluster notify one another of continued operation using a heartbeat signal which is passed back and forth over a cluster interconnect, and over a cluster switching fabric. If one of the storage system nodes detects the absence of a heartbeat from the other storage node over both the cluster interconnect and the cluster switching fabric, a failure is detected and a takeover procedure is initiated. It is noted that the failure is also usually confirmed by the surviving storage node by checking a master mailbox disk of the other storage node to confirm that it is in fact a failure of the other storage node itself and not simply a failure of the cluster interconnect coupling.
More specifically, a mailbox mechanism includes a set of procedures for determining the most up-to-date coordinating information through the use of one or more mailbox disks. Such disks receive messages from the node with which they are associated in order to confirm that the node continues to be in communication with the mailbox disk, which indicates that the node continues to be capable of writing to the disks assigned to that node. Further details on the configuration and operation of the master mailbox disk are provided in commonly-owned U.S. Pat. No. 7,231,489, of Larson et al., for a SYSTEM AND METHOD FOR COORDINATING CLUSTER STATE INFORMATION, issued on Jun. 12, 2007, which is presently incorporated by reference herein in its entirety.
Many cluster configurations include the concept of partnering. Specifically, each is storage system node in the cluster is partnered with a second storage system node in such a manner that the partner storage system node is available to take over and provide the services and the data otherwise provided by the second storage system node. The partner assumes the tasks of processing and handling any data access requests normally processed by the second storage system node. One such example of a partnered storage system cluster configuration is described in U.S. Pat. No. 7,260,737, entitled SYSTEM AND METHOD FOR TRANSPORT-LEVEL FAILOVER OF FCP DEVICES IN A CLUSTER, by Arthur F. Lent, et al., the contents of which are hereby incorporated by reference. It is further noted that in such storage system node clusters, an administrator may desire to take one of the storage system nodes offline for a variety of reasons including, for example, to upgrade hardware, etc. In such situations, it may be advantageous to perform a "voluntary" user-initiated takeover operation, as opposed to a failover operation. After the takeover operation is complete, the storage system node's data is serviced by its partner until a giveback operation is performed.
Another example of a storage system node cluster configuration takeover technique is described in U.S. patent application Ser. No. 11/411,502, entitled SINGLE NODE NAME CLUSTER SYSTEM FOR FIBER CHANNEL, by Britt Bolen et al., the contents of which are hereby incorporated by reference. In this configuration, the cluster has a single world wide node name so that the cluster as a whole appears to the client as a single device. In such clusters, two storage system nodes are partnered such that a first storage system node serves its own "locally owned" data from the disks to which it is directly connected, and proxies requests for its partner disks to a partner storage system node. During takeover operations, the locally owned data of the failed storage system node is serviced by its partner until a give back operation is performed.
In such cases employing a partner mode, additional infrastructure is often required. For example, requests are tracked to determine whether they are partner requests. Data structures are also duplicated. Separate tables describing the data, such as for example, a volume location database (VLDB) must be maintained for the local disks and is for the partner disks. In addition, registry files which store options and configuration parameters are also maintained separately in a local registry file and a partner registry file. As will be apparent to those skilled in the art, this results in additional code complexity in many systems.
It is also noted that, in some storage system architectures, the nodes in each cluster are generally organized as a network element (N-module) and a disk element (D-module). The N-module includes functionality that enables the node to connect to clients over a computer network, while each D-module connects to one or more storage devices such as the disks of a disk array. A file system architecture of the type is generally described in U.S. Pat. No. 6,671,773, issued on Dec. 30, 2003 entitled METHOD AND SYSTEM FOR RESPONDING TO FILE SYSTEM REQUESTS, by M. Kazar et al. (the contents of which are incorporated herein by reference in entirety).
In some recent architectures however, additional functionality has been moved to the N-module which may have previously been performed by the D-module. For example, the N-module handles aspects such as network connectivity. In such configurations, it may be desirable to deliver to upper layers of the N-module a single view of all aggregates that a particular D-module is serving, rather than exposing two sets of aggregates to the N-module (i.e., a local image of the disks being served by the surviving D-module, and a set of partner disks). In previous designs, in a failover, the surviving N-module and D-module took over network addresses and performed other administrative tasks which consumed operational bandwidth in the storage architecture system.
There remains a need, therefore, for a system which eliminates partner mode failover, but allows for a takeover that results in one or more newly assimilated aggregates to be available for access by the N-modules in a multiple node cluster.
The disadvantages of prior techniques are overcome by the present invention which provides a technique for takeover of a failed node's disks and that produces one or more newly assimilated aggregates to be available for access by the N-modules in a multiple node cluster. When a takeover procedure is triggered, either through a lack of heartbeat, or a command for a takeover is received, the system of the present invention is configured such that one or more surviving nodes of the cluster asserts ownership of disks previously served by a failed node, so that all of the disks are locally owned by one of the surviving nodes in the cluster. So, as a result, one or more new aggregates are established that include all of the failed node's disks. According to the invention, one or more newly assimilated aggregates, now served by one or more surviving D-modules, is then exposed to any N-module that interfaces with the surviving nodes. For clarity of illustration, the invention is described with reference to a single newly assimilated aggregate. It should be understood, however, that one or more newly assimilated aggregates can be served by one or more surviving D-modules, while remaining within the scope of the present invention.
In the illustrative embodiment, when the takeover procedure is invoked, a surviving node changes two elements of ownership with respect to each disk or portion thereof. Specifically, the surviving node first changes one or more ownership attributes (such as SCSI-3 reservations or export rules, as described further herein) to reflect its access rights to the failed node's disks, and secondly, it changes a "current owner" status in an ownership location on the disk to reflect itself (the surviving node) as the current owner of the disk assigned to that surviving node. The newly acquired disks are then properly assimilated into one or more aggregates by a suitable process such as a RAID system of the surviving node. A section of the non-volatile memory (NVRAM), which contains the most recent data about the RAID system, referred to herein as the RAID section of the NVRAM is replayed to flush any final parity computations with respect to the disks forming the new aggregate(s).
Duplications in fsid numbers are corrected so that each volume in the newly assimilated aggregate has its own unique fsid identifier. A file system section of the NVRAM of the node is replayed to bring all data up to date, and the volumes are then brought online to thereby enable the surviving node to serve data access requests as if it locally owns all of the volumes that it claimed from the failed node, which volumes are is now contained in the newly assimilated aggregate. Notably, the system and method described herein are performed without requiring a partner mode in the takeover procedure.
The above and further advantages of the invention may be better understood by reference to the following description in conjunction with the accompanying drawings in which like reference numerals indicate identical or functionally similar elements:
The nodes 200 a,b are also coupled across a cluster interconnect 190 which provides an additional communication path between the nodes. The cluster interconnect 190 may be Fibre Channel (FC), InfiniBand or another suitable medium. The cluster interconnect 190 may be used to provide heartbeat signals ("heartbeats") between the two nodes, which signals are used monitor the active state of each node. The cluster heartbeats are also sent across the cluster switching fabric 150 over which communications between an N-module and D-module are illustratively effected through remote message passing over the cluster switching fabric 150, which is sometimes also referred to as the "storage layer." The "death" of a node is indicated by the loss of heartbeat from both the cluster interconnect and the storage layer. The cluster interconnect is sometimes also referred to as the storage takeover interconnect. That is, as described further hereinafter, if the heartbeat terminates (i.e., "times out"), then a takeover procedure is enabled.
The clients 180 may be general-purpose computers configured to interact with the nodes 200 a,b in accordance with a client/server model of information delivery. That is, each client may request the services of the node, and the node may return the results of the services requested by the client, by exchanging packets over the network 140. The client may issue packets including file-based access protocols, such as the Common Internet File System (CIFS) protocol or Network File System (NFS) protocol, over the Transmission Control Protocol/Internet Protocol (TCP/IP) when accessing information in the form of files and directories. Alternatively, the client may issue packets including block-based access protocols, such as the Small Computer Systems Interface (SCSI) protocol encapsulated over TCP (iSCSI) and SCSI encapsulated over Fibre Channel (FCP), when accessing information in the form of blocks.
During normal cluster operation, the storage system node (e.g., node 200 a) that is connected to a set of disks 130 a is identified as the "home" of the disks 130 a. That storage system node is also identified as the "current owner" at initialization and is primarily responsible for servicing data requests directed to blocks on volumes contained on its set of disks. For example, the storage system node 200 a is primarily responsible for the volumes of the disk array which are represented as disk 130 a. Similarly, the storage system node 200 b is primarily responsible for the disks in the volumes represented as disk 130 b in
Each node 200 is illustratively embodied as a dual processor storage system executing a storage operating system 300 that preferably implements a high-level module, such as a file system, to logically organize the information as a hierarchical structure of named data containers, such as directories, files and special types of files called virtual disks (hereinafter generally "blocks") on the disks. However, it will be apparent to those of ordinary skill in the art that the node 200 may alternatively comprise a single or more than two processor system. Illustratively, one processor 222 a executes the functions of the N-module 310 on the node, while the other processor 222 b executes the functions of the D-module 350.
The memory 224 illustratively comprises storage locations that are addressable by the processors and adapters for storing software program code and data structures associated with the present invention. The processor and adapters may, in turn, comprise processing elements and/or logic circuitry configured to execute the software code and manipulate the data structures. The storage operating system 300, portions of which are typically resident in memory and executed by the processing elements, functionally organizes the node 200 by, inter alia, invoking storage operations in support of the storage service implemented by the node. It will be apparent to those skilled in the art that other processing and memory means, including various computer readable media, may be used for storing and executing program instructions pertaining to the invention described herein.
The network adapter 225 comprises a plurality of ports adapted to couple the node 200 to one or more clients 180 over point-to-point links, wide area networks, virtual private networks implemented over a public network (Internet) or a shared local area network. The network adapter 225 thus may comprise the mechanical, electrical and signaling circuitry needed to connect the node to the network. Illustratively, the computer network 140 (
The storage adapter 228 cooperates with the storage operating system 300 executing on the node 200 to access information requested by the clients. The information may be stored on any type of attached array of writable storage device media such as video tape, optical, DVD, magnetic tape, bubble memory, electronic random access memory, micro-electro mechanical and any other similar media adapted to store information, including data and parity information. However, as illustratively described herein, the information is preferably stored on the disks 130 of the disk array 120. The storage adapter comprises a plurality of ports having input/output (I/O) interface circuitry that couples to the disks over an I/O interconnect arrangement, such as a conventional high-performance, FC link topology.
Storage of information on each disk array 120 is preferably implemented as one or more storage "volumes" that comprise a collection of physical storage disks 130 cooperating to define an overall logical arrangement of volume block number (vbn) space on the volume(s). Each logical volume is generally, although not necessarily, associated with its own file system. The disks within a logical volume/file system are typically organized as one or more groups, wherein each group may be operated as a Redundant Array of Independent (or Inexpensive) Disks (RAID). Most RAID implementations, such as a RAID-4 level implementation, enhance the reliability/integrity of data storage through the redundant writing of data "stripes" across a given number of physical disks in the RAID group, and the appropriate storing of parity information with respect to the striped data, once all of the disks in a given RAID group are assimilated. An illustrative example of a RAID implementation is a RAID-4 level implementation, although it should be understood that other types and levels of RAID implementations may be used in accordance with the inventive principles described herein.
To facilitate access to the disks 130, the storage operating system 300 implements a write-anywhere file system that cooperates with one or more virtualization modules to "virtualize" the storage space provided by disks 130. The file system logically organizes the information as a hierarchical structure of named data containers such as directories and files on the disks. Each "on-disk" file may be implemented as set of disk blocks configured to store information, such as data, whereas the directory may be implemented as a specially formatted file in which names and links to other files and directories are stored. The virtualization module(s) allow the file system to further logically organize information as a hierarchical structure of data containers such as blocks on the disks that are exported as named logical unit numbers (LUNs).
In the illustrative embodiment, the storage operating system is preferably the NetApp� Data ONTAP� operating system available from Network Appliance, Inc., Sunnyvale, Calif. that implements a Write Anywhere File Layout (WAFL�) file system. However, it is expressly contemplated that any appropriate storage operating system may be enhanced for use in accordance with the inventive principles described herein. As such, where the term "WAFL" is employed, it should be taken broadly to refer to any storage operating system that is otherwise adaptable to the teachings of this invention.
In addition, the storage operating system includes a series of software layers organized to form a storage server 365 that provides data paths for accessing information stored on the disks 130 of the node 200. As described further herein, the software layers of the storage server are illustratively embodied as a D-module 350. The storage server 365 illustratively comprises a takeover monitor module 376 that maintains a data structure such as the takeover monitor resource table 362. It should be understood that the takeover monitor resource table 362 is not the only possible embodiment of the data structure, but it is described herein for illustrative purposes. The takeover monitor resource table 362 is configured to maintain information regarding takeover procedures, as described further herein. The file system module 360 interacts in cooperating relation with a volume striping module (VSM) 370, a RAID system module 380 and a disk driver system module 390. The RAID system 380 manages the storage and retrieval of information to and from the volumes/disks in accordance with I/O operations, while the disk driver system 390 implements a disk access protocol such as, e.g., the Small Computer System Interface (SCSI) protocol. However, it should be understood that processes other than the RAID system 380 may in other embodiments perform such tasks while remaining within the scope of the present invention.
The VSM 370 illustratively implements a striped volume set (SVS) and, as such cooperates with the file system 360 to enable storage server 365 to service a volume of the SVS. In particular, the VSM 370 implements a Locate( ) function 375 to compute the location of data container content in the SVS volume to thereby ensure consistency of such content served by the cluster.
A disk ownership module 382 manages ownership of the disks with respect to their related aggregates and volumes using, for example, one or more data structures such as tables, including, for example, the disk ownership table 400. In particular, the ownership module 382 cooperates with the disk driver system 390 to identify the appropriate D-module for processing data access requests for particular volumes on the disk array 120. To that end, the ownership module consults disk ownership table 400, which contains disk ownership information that is illustratively generated at boot-up time, and that is updated by various components of the storage operating system to reflect changes in ownership of disks. Further details regarding the data structure implemented as ownership table 400 are provided in the above-incorporated U.S. patent application Ser. No. 11/606,538.
Notably, the disk ownership module 382 includes program instructions for writing proper ownership information at a proper location on each disk, which is referred to herein as the ownership location. The disk ownership module 382 also includes program instructions for asserting and eliminating SCSI reservation tags.
Initially, the disk ownership table 400 is generated upon boot up of the system. More specifically, I/O services of the disk driver system 390 query all devices (e.g., disks 130) attached to the system. This query requests information as to the nature of the attached disks. Upon completion of the query, the ownership module 382 instructs the disk driver system 390 to read the ownership information from each disk. In response, the disk driver system reads the ownership information for each disk 132 a from each on-disk ownership location 134 a (
Subsequently, the ownership module 382 accesses the disk ownership table 400 to extract the identification of all disks that are owned by the appropriate D-module. The ownership module then verifies the SCSI reservations on each disk owned by that D-module by reading the ownership information stored in the ownership location on each disk. If the SCSI reservations and on-disk information do not match, the ownership module changes the SCSI reservation to match the on-disk ownership information. Once the SCSI reservations and on-disk ownership information match for all disks identified as owned by the D-module, the ownership module 382 then passes the information to the file system and the RAID module, which configure the individual disks into the appropriate RAID groups and volumes for the D-module 350.
Referring again to
The file system 360 implements a virtualization system of the storage operating system 300 through the interaction with one or more virtualization modules illustratively embodied as, e.g., a virtual disk (vdisk) module (not shown) and a SCSI target module 335. The vdisk module enables access by administrative interfaces, such as a user interface of a management framework 900 (see
The file system 360 is illustratively a message-based system that provides logical volume management capabilities for use in access to the information stored on the storage devices, such as disks. That is, in addition to providing file system semantics, the file system 360 provides functions normally associated with a volume manager. These functions include (i) aggregation of the disks, (ii) aggregation of storage bandwidth of the disks, and (iii) reliability guarantees, such as mirroring and/or parity (RAID). The file system 360 illustratively implements the WAFL� file system (hereinafter generally the "write-anywhere file system") having an on-disk format representation that is block-based using, e.g., 4 kilobyte (kB) blocks and using index nodes ("modes") to identify files and file attributes (such as creation time, access permissions, size and block location). The file system uses files to store metadata describing the layout of its file system; these metadata files include, among others, an mode file. A file handle, i.e., an identifier that includes an mode number, is used to retrieve an mode from disk.
Broadly stated, all modes of the write-anywhere file system are organized into the mode file. A file system (fs) info block specifies the layout of information in the file system and includes an mode of a file that includes all other modes of the file system. Each logical volume (file system) has an fsinfo block that is preferably stored at a fixed location within, e.g., a RAID group. The mode of the mode file may directly reference (point to) data blocks of the mode file or may reference indirect blocks of the mode file that, in turn, reference data blocks of the mode file. Within each data block of the mode file are embedded modes, each of which may reference indirect blocks that, in turn, reference data blocks of a file.
Operationally, a request from the client 180 is forwarded as a packet over the computer network 140 and onto the node 200 where it is received at the network adapter 225. A network driver (of layer 312 or layer 330) processes the packet and, if appropriate, passes it on to a network protocol and file access layer for additional processing prior to forwarding to the write-anywhere file system 360. Here, the file system generates operations to load (retrieve) the requested data from disk 130 if it is not resident "in core", i.e., in memory 224. If the information is not in memory, the file system 360 indexes into the mode file using the mode number to access an appropriate entry and retrieve a logical vbn. The file system then passes a message structure including the logical vbn to the RAID system 380; the logical vbn is mapped to a disk identifier and disk block number (disk,dbn) and sent to an appropriate driver (e.g., SCSI) of the disk driver system 390. The disk driver accesses the dbn from the specified disk 130 and loads the requested data block(s) in memory for processing by the node. Upon completion of the request, the node (and operating system) returns a reply to the client 180 over the network 140.
It should be noted that the software "path" through the storage operating system layers described above needed to perform data storage access for the client request received at the node may alternatively be implemented in hardware. That is, in an alternate embodiment of the invention, a storage access request data path may be implemented as logic circuitry embodied within a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). This type of hardware implementation increases the performance of the storage service provided by node 200 in response to a request issued by client 180. Moreover, in another alternate embodiment of the invention, the processing elements of adapters 225, 228 may be configured to offload some or all of the packet processing and storage access operations, respectively, from processor 222, to thereby increase the performance of the storage service provided by the node. It is expressly contemplated that the various processes, architectures and procedures described herein can be implemented in hardware, firmware or software.
As used herein, the term "storage operating system" generally refers to the computer-executable code operable on a computer to perform a storage function that manages data access and may, in the case of a node 200, implement data access semantics of a general purpose operating system. The storage operating system can also be implemented as a microkernel, an application program operating over a general-purpose operating system, such as UNIX� or Windows XP�, or as a general-purpose operating system with configurable functionality, which is configured for storage applications as described herein.
In addition, it will be understood to those skilled in the art that the invention described herein may apply to any type of special-purpose (e.g., file server, filer or storage serving appliance) or general-purpose computer, including a standalone computer or portion thereof, embodied as or including a storage system. Moreover, the teachings of this invention can be adapted to a variety of storage system architectures including, but not limited to, a network-attached storage environment, and a storage area network and disk assembly directly attached to a client or host computer. The term "storage system" should therefore be taken broadly to include such arrangements in addition to any subsystems configured to perform a storage function and associated with other equipment or systems. It should be noted that while this description is written in terms of a write-anywhere file system, the teachings of the present invention may be utilized with any suitable file system, including a write-in-place file system.
In the illustrative embodiment, the storage server 365 is embodied as D-module 350 of the storage operating system 300 to service one or more volumes of array 120. In addition, the multi-protocol engine 325 is embodied as N-module 310 to (i) perform protocol termination with respect to a client issuing incoming data access request packets over the network 140, as well as (ii) redirect those data access requests to any storage server 365 of the cluster 100. Moreover, the N-module 310 and D-module 350 cooperate to provide a highly-scalable, distributed storage system architecture of the cluster 100. To that end, each blade includes a CF interface module 340 a,b adapted to implement intra-cluster communication among the N- and D-modules, including D-module-to-D-module communication for data container striping operations.
The protocol layers, e.g., the NFS/CIFS layers and the iSCSI/FC layers, of the N-module 310 function as protocol servers that translate file-based and block-based data access requests from clients into CF protocol messages used for communication with the D-module 350. That is, the N-module servers convert the incoming data access requests into file system primitive operations (commands) that are embedded within CF messages by the CF interface module 340 for transmission to the D-modules 350 of the cluster 100. Notably, the CF interface modules 340 cooperate to provide a single file system image across all D-modules 350 in the cluster 100. Thus, any network port of an N-module that receives a client request can access any data container within the single file system image located on any D-module 350 of the cluster.
Further to the illustrative embodiment, the N-module 310 and D-module 350 are implemented as separately-scheduled processes of storage operating system 300; however, in an alternate embodiment, the modules may be implemented as pieces of code within a single operating system process. Communication between an N-module and D-module is thus illustratively effected through the use of message passing between the modules although, in the case of remote communication between an N-module and D-module of different nodes, such message passing occurs over the cluster switching fabric 150. As noted, the cluster switching fabric 150 is also used as a second medium over which heartbeats between the nodes are transmitted and received. A known message-passing mechanism provided by the storage operating system to transfer information between modules (processes) is the Inter Process Communication (IPC) mechanism. The protocol used with the IPC mechanism is illustratively a generic file and/or block-based "agnostic" CF protocol that comprises a collection of methods/functions constituting a CF application programming interface (API). Examples of such an agnostic protocol are the SpinFS and SpinNP protocols available from Network Appliance, Inc. The SpinFS protocol is described in the above-referenced U.S. Pat. No. 6,671,773.
The CF interface module 340 implements the CF protocol for communicating file system commands among the modules of cluster 100. Communication is illustratively effected by the D-module exposing the CF API to which an N-module (or another D-module) issues calls. To that end, the CF interface module 340 is organized as a CF encoder and CF decoder. The CF encoder of, e.g., CF interface 340 a on N-module 310 encapsulates a CF message as (i) a local procedure call (LPC) when communicating a file system command to a D-module 350 residing on the same node 200 or (ii) a remote procedure call (RPC) when communicating the command to a D-module residing on a remote node of the cluster 100. In either case, the CF decoder of CF interface 340 b on D-module 350 de-encapsulates the CF message and processes the file system command.
A data container, e.g., a file, is accessed in the file system using a data container handle.
Whereas the aggregate 700 is analogous to a physical volume of a conventional storage system, a flexible volume is analogous to a file within that physical volume. That is, the aggregate 700 may include one or more files, wherein each file contains a flexible volume 710 and wherein the sum of the storage space consumed by the flexible volumes is physically smaller than (or equal to) the size of the overall physical volume. The aggregate utilizes a physical pvbn space that defines a storage space of blocks provided by the disks of the physical volume, while each embedded flexible volume (within a file) utilizes a logical vvbn space to organize those blocks, e.g., as files. Each vvbn space is an independent set of numbers, each of which corresponds to an offset within the file. These offset values are then translated to dbns on disks. Since the flexible volume 710 is also a logical volume, it has its own block allocation structures (e.g., active, space and summary maps) in its vvbn space.
A container file is a file in the aggregate that contains all blocks used by a flexible volume. The container file is an internal (to the aggregate) feature that supports a flexible volume; illustratively, there is one container file per flexible volume. Similar to a pure logical volume in a file approach, the container file is a hidden file (not accessible to a user) in the aggregate that holds every block in use by the flexible volume. The aggregate includes an illustrative hidden metadata root directory that contains subdirectories of flexible volumes:
Specifically, a physical file system (WAFL) directory includes a subdirectory for each flexible volume in the aggregate, with the name of the subdirectory being a file system identifier (fsid) of the flexible volume. Each fsid subdirectory (flexible volume) contains at least two files, a file system file and a storage label file. The storage label file is illustratively a 4 kB file that contains metadata similar to that stored in a conventional RAID label. In other words, the storage label file is the analog of a RAID label and, as such, contains information about the state of the flexible volume such as, e.g., the name of the flexible volume, a universal unique identifier (uuid) and fsid of the flexible volume, whether it is online, being created or being destroyed, etc.
Each fsinfo block 804 includes a block pointer to an mode file 806 that contains modes of a plurality of files, including an owner map 810, an active map 812, a summary map 814 and a space map 816, as well as other special meta-data files. The mode file 806 further includes a root directory 820 and a "hidden" meta-data root directory 830, the latter of which includes a namespace having files related to a flexible volume in which users cannot "see" the files. The hidden meta-data root directory includes the WAFL/fsid/directory structure that contains filesystem file 840 and storage label file 890. Note that root directory 820 in the aggregate is empty; all files related to the aggregate are organized within the hidden meta-data root directory 830.
In addition to being embodied as a container file having level 1 blocks organized as a container map, the filesystem file 840 includes block pointers that reference various file systems embodied as flexible volumes 850. The aggregate 800 maintains these flexible volumes 850 at special reserved mode numbers. Each flexible volume 850 also has special reserved mode numbers within its flexible volume space that are used for, among other things, the block allocation bitmap structures. As noted, the block allocation bitmap structures, e.g., active map 862, summary map 864 and space map 866, are located in each flexible volume.
Specifically, each flexible volume 850 has the same mode file structure/content as the aggregate, with the exception that there is no owner map and no WAFL/fsid/filesystem file, storage label file directory structure in a hidden meta-data root directory 880. To that end, each flexible volume 850 has a volinfo block 852 that points to one or more fsinfo blocks 854, each of which may represent a snapshot, along with the active file system of the flexible volume. Each fsinfo block, in turn, points to an mode file 860 that, as noted, has the same mode structure/content as the aggregate with the exceptions noted above. Each flexible volume 850 has its own mode file 860 and distinct mode space with corresponding mode numbers, as well as its own root (fsid) directory 870 and subdirectories of files that can be exported separately from other flexible volumes.
The storage label file 890 contained within the hidden meta-data root directory 830 of the aggregate is a small file that functions as an analog to a conventional RAID label. A RAID label includes physical information about the storage system, such as the volume name; that information is loaded into the storage label file 890. Illustratively, the storage label file 890 includes the name 892 of the associated flexible volume 850, the online/offline status 894 of the flexible volume, and other identity and state information 896 of the associated flexible volume (whether it is in the process of being created or destroyed).
The VLDB 930 is a database process that tracks the locations of various storage components (e.g., SVSs, flexible volumes, aggregates, etc.) within the cluster 100 to thereby facilitate routing of requests throughout the cluster. In the illustrative embodiment, the N-module 310 of each node accesses a configuration table 235 that maps the SVS ID 602 of a data container handle 600 to a D-module 350 that "owns" (services) the data container within the cluster. The VLDB includes a plurality of entries which, in turn, provide the contents of entries in the configuration table 235; among other things, these VLDB entries keep track of the locations of the flexible volumes (hereinafter generally "volumes 710") and aggregates 700 within the cluster. Examples of such VLDB entries include a VLDB volume entry 1000 (
The VLDB illustratively implements a RPC interface, e.g., a Sun RPC interface, which allows the N-module 310 to query the VLDB 930. When encountering contents of a data container handle 600 that are not stored in its configuration table, the N-module sends an RPC to the VLDB process. In response, the VLDB 930 returns to the N-module the appropriate mapping information, including an ID of the D-module that owns the data container. The N-module caches the information in its configuration table 235 and uses the D-module ID to forward the incoming request to the appropriate data container. All functions and interactions between the N-module 310 and D-module 350 are coordinated on a cluster-wide basis through the collection of management processes and RDB library user mode applications.
To that end, the management processes have interfaces to (are closely coupled to) RDB 950. The RDB comprises a library that provides a persistent object store (storing of objects) for the management data processed by the management processes. Notably, the RDB 950 replicates and synchronizes the management data object store access across all nodes 200 of the cluster 100 to thereby ensure that the RDB database image is identical on all of the nodes 200. At system startup, each node 200 records the status/state of its interfaces and IP addresses (those IP addresses it "owns") into the RDB database.
As discussed, a takeover process is performed upon absence of a heartbeat, or when the storage takeover command is issued. In either case, the takeover monitor 376 receives notice of the triggered failover and consults the takeover monitor resource table 362 to obtain the procedures which are to be followed by one or more processes in the storage server 365 in order to perform a takeover of the failed node's disks by the surviving storage system node. For example, the takeover monitor process 376 notifies other processes, such as the file system 360, the RAID system 380, the ownership module 382 and the disk driver system 390, instructing each to perform respective routines/threads that are necessary steps to implement the takeover procedures, in the manner described herein.
One of the procedures, illustratively, is to confirm that there is, in fact, a failure of the node (and not simply a failure of the cluster interconnect coupling or the cluster switching fabric). To that end, the surviving node accesses a master mailbox disk of the failed node (i.e., D-module). The mailbox is created upon boot up of the takeover process software. If the failed D-module has not written to the mailbox in a timely fashion, the failure is confirmed and the takeover monitor instructs the surviving node to begin takeover of the disks.
Next, the takeover monitor process 376 instructs the disk driver system 390 of the surviving storage system node's D-module to assert new SCSI-3 reservations on each is disk formerly owned by the failed D-module. Notably, the illustrative embodiment is described with reference to a SCSI environment, as will be understood by those skilled in the art, in which SCSI level 3 persistent reservations (as described in SCSI primary commands-3 by Community 10 of the National Committee for Information Technology Standards, which is incorporated fully herein by reference) would have been previously placed on the disks by the now failed D-module. Using SCSI-3 reservations, a D-module can write to a disk if it holds the SCSI-3 reservations for that disk, i.e., non-owning D-modules are prevented from writing to disks because they do not have the SCSI-3 reservation. However, the non-owning file service can read ownership information from a predetermined location on the disk. In accordance with the invention, the disk driver process in the D-module has been programmed with instructions allowing it to pre-empt SCSI reservations on disks in the cluster. Thus, upon a failure, the takeover monitor instructs the surviving D-module to first pre-empt the existing SCSI reservations on the disks previously serviced by the failed node. Once these SCSI reservations have been pre-empted, the surviving node asserts its own SCSI reservations on the disks of the failed node, in the manner defined in the above-cited SCSI-3 ANSI standard specification.
In an alternative aspect of the invention, two or more nodes can simultaneously access and serve data from a common set of disks, but from separate regions (i.e., blocks) on those disks. More specifically, as will be understood by those skilled in the art, individual disks may be logically divided up into regions of contiguous blocks, and ownership information for each region is maintained in a separate ownership location on the disk for each region. This allows two or more nodes to simultaneously access and to serve data access requests from a common set of disks, but from separate regions of those disks. However, in such a configuration, SCSI reservations would not be applicable because such SCSI reservations apply to an entire disk. Consequently, alternative software and/or hardware mechanisms are applied in accordance with the invention to permit or to restrict access to portions of disks.
For example, access can be controlled by appropriately changing the ownership information for each region of the disk and/or by using a fencing technique whereby access permission rights are granted or denied for specific regions of the disks. Such fencing techniques may be for example: A) a distributed protocol running across the D-modules that guarantees that only one node has access to a file system region of the disk at any one time (a region being defined as one or more disk blocks, up to the entire disk, not necessarily contiguous) in a system in which each D-module is programmed to honor its access constraints; and B) hardware and/or firmware logic in the shared storage stack underneath the D-modules, e.g., the disk shelf, provides the fencing. A distributed protocol is typically still required; however, enforcement is stricter in that a D-module in this embodiment cannot write outside its ownership areas. These and other suitable techniques may also be employed when the invention is implemented in a non-SCSI environment for the assertion of ownership on the disks by the takeover node.
As noted herein, in an illustrative embodiment of the invention, ownership information is also stored in a particular location of the disk, which acts as the definitive ownership location on the disk. In an illustrative embodiment of the invention, if the SCSI-3 reservations do not match the on-disk ownership location data, the on-disk ownership information is used. In the case of takeover, the takeover monitor 376 cooperates with the disk driver system 390 to assert new SCSI-3 reservations on each disk formerly owned by the failed D-module and which now are under the control of the surviving D-module.
After asserting its SCSI-3 reservations, the surviving node calls the surviving D-module's RAID system 380 to assimilate all newly owned disks into one or more aggregates 700. The proper RAID calculations and configurations are then performed. Thereafter, to finalize the RAID assimilation, the RAID system initiates replay of the RAID section of the NVRAM to flush any final parity computations therefrom.
Specifically, the RAID system 380 adjusts the "current owner" status in the ownership location of each newly assimilated disk to indicate that the surviving node is now the "current owner" of that disk. Thereafter, each newly assimilated aggregate appears to be locally owned by the surviving D-module. On the surviving node, the NVRAM log containing NVRAM entries of the failed node is replayed so that any data in the newly assimilated aggregates are fully up to date.
As will be understood by those skilled in the art, a data write request issued by a client is not acknowledged as having been received successfully until the data has been written and stored in a non-volatile memory. Illustratively, in the present cluster environment, a client-issued data write request is first stored in the NVRAM 227 of the node 200 having the D-module that currently owns the relevant disk. The write request data is then written to a backup NVRAM of another (partner) D-module in the cluster prior to the write operation being acknowledged to the client. Later, at a consistency point, the newly obtained data is written from the NVRAM of the current owner D-module to the actual disk. This protects the data in such a cluster environment, so that if a failure occurs prior to the data being written to disk, that data has been stored in the backup NVRAM of the partner D-module in the cluster.
Accordingly, when a takeover occurs, the NVRAM data of the failed node is stored within the NVRAM of the surviving node and can be played back (written to the disks) at the appropriate time to bring the data into the most current state possible. Illustratively, the NVRAM has a RAID section which stores RAID calculation updates, and a file system section which stores file system data. Each section of the NVRAM is replayed at the appropriate time as discussed in further detail with respect to the flow chart of
In accordance with the present invention, the data of the failed node is to be assimilated into a new aggregate image. However, as noted herein, the data had been originally owned by two different D-modules, and thus some of the file system IDs ("fsids") may be duplicated. In accordance with the invention, in order to avoid any inconsistencies and errors, these duplicate fsids are corrected so that each fsid for each volume in the newly assimilated aggregate is unique. This, in turn, ensures that the newly assimilated aggregate does not contain any identical (duplicate) fsids.
The volumes of the newly assimilated aggregate are then brought online and the VLDB is updated. As noted, the VLDB keeps track of the location of the volumes 710 and aggregates 700 within the cluster as well as their host D-module. Thus, the VLDB 930 changes the D-module ID 1110 to reflect the new D-module hosting the aggregate. Thereafter, the N-module is allowed to send requests to the updated surviving D-module. The D-module processes data access requests for its locally-owned disks and the newly acquired disks until further notice. The surviving D-module then continues to process data access requests while the failed D-module remains in a "waiting for send home" state.
The method of takeover in accordance with the present invention is described in further detail in the flowcharts of
In the illustrative implementation of the invention, the surviving storage system node then calls the RAID system of the surviving D-module in step 1210. In step 1212, each disk previously associated with the failed storage system node is assimilated into a new data container. Illustratively, the RAID system 380 performs block-based assimilation of the newly acquired disks into aggregates, and the proper RAID calculations and configurations are performed. Notably, other embodiments of the invention may not include a RAID system, in which case other suitable processes will assimilate the disks into aggregates. In step 1213, the VLDB is updated. The procedure continues to step 1214 where the RAID system initiates replay of the RAID section of the NVRAM to flush any final parity computations from the RAID section of the NVRAM. It should be appreciated, however, that if the storage network does not use RAID, the blocks of data on the disks can be assimilated by another suitable process while remaining within the scope of the present invention.
Once the RAID assimilation has been performed, then, as illustrated in step 1215, in order to avoid any inconsistencies and errors, any fsid duplications are corrected if the new aggregate refers to an identical fsid as the node's original aggregate. It is noted that aggregate IDs are unique within a cluster, so the aggregate ID numbers will not need to be checked because there should not be such duplications. Then, the procedure continues to step 1216 where the RAID system adjusts the "current owner" status in the ownership location on the disks to indicate that the surviving node is now the current owner of the newly assimilated disks. In step 1218, the newly assimilated aggregates now appear to be locally owned by the surviving D-module. The file system 360 on the surviving node then receives notice that the aggregates have been successfully assimilated, as illustrated in step 1218. On the surviving node, the file system NVRAM log containing the file system NVRAM entries of the failed node is replayed so that data in the newly assimilated aggregates is brought fully up to date (step 1220). As noted, for purposes of clarity of illustration, the invention is described with reference to a single newly assimilated aggregate. It should be under stood, however, that one or more newly assimilated aggregates can be served by one or more surviving D-modules, while remaining within the scope of the present invention.
The volumes are brought online as shown in step 1224. The procedure then continues to step 1228, in which the N-module is allowed to send requests to the updated surviving D-module. As shown in step 1230, the D-module processes data access requests for its locally owned disks and for the newly acquired disks until further notice. The surviving D-module then continues to process data access requests while the failed D-module remains in the waiting for send home state. The procedure ends at step 1232.
The procedure of
It should be understood that once the takeover is performed, all aggregate/volumes operate as if they are local to the surviving D-module. From this point onward, there is no partner to local association as in prior systems. In addition, management processes ensure that there is a unique aggregate name throughout the cluster. It should be understood that the present invention provides a simple process for takeover of disks in a storage takeover cluster. The technique has the feature of eliminating partner mode such that it presents a newly assimilated aggregate to its upper software layers and to the N-module. In other words, the images of the disks exposed by the D-module are collapsed into a newly assimilated aggregate during takeover as opposed to requiring a separate partner and local image to be maintained.
Advantageously, the present invention reduces code complexity and operational resources. Thus, the present invention provides a system in which in any set of disks that represents an aggregate can be taken over by any D-module so that the disks are properly recognized as being served by the surviving D-module. It is further noted that the procedure described herein is accomplished without involvement of the processes of the N-module.
The foregoing description has been directed to particular embodiments of the invention. It will be apparent, however, that other variations and modifications may be made to the described embodiments, with the attainment of some or all of their advantages. Specifically, it should be noted that the principles of the invention may be implemented in a non-distributed file system. Furthermore, while this description has been written in terms of D and N-modules, the teachings of the present invention are equally suitable to systems where the functionality of the N- and D-modules is implemented in a single system. Alternatively, the functions of the N- and D-modules may be distributed among a number of separate systems, wherein each system performs one or more functions. Additionally, the features of the present invention have been described with respect to a cluster which contains two nodes, however, it is equally applicable to clusters including a plurality of nodes, which allow for n-way fail over. Additionally, the procedures, processes and/or modules described herein may be implemented in hardware, software, embodied as a computer readable medium having program instructions, firmware, or a combination thereof. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.
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NYA boys' lax gets elusive state title
(Ed. Note: This story originally appeared June 21, 2007)
PORTLAND—The North Yarmouth Academy boys' lacrosse team was almost unbeatable this spring and it capped a year of dominance with a brilliant performance in the Class B state championship game Saturday afternoon at Fitzpatrick Stadium.
The Panthers, riding high after finally ridding themselves of their long-lasting Yarmouth Clippers albatross, had an answer for everything the Western B champion Kennebunk Rams tried and pulled away in the second half for a 10-3 victory, ending their year at 14-1 with the program's second state championship and first since 2001.
NYA got scoring from eight different players, allowed just one goal after the first period and gave its long-suffering senior class a reason to exult.
"It feels amazing," said senior standout All-American Than Wellin. "Four years in the making. We've been thinking about this since I was in the sixth grade."
"I'm at a loss for words," added senior Nick Lolar, who scored twice. "It's great."
Back on top
In 2001, the Panthers became the first team to beat Cape Elizabeth in a state final, as they won their initial championship with a 13-10 victory. Every year since, however, NYA was eliminated by crosstown rival Yarmouth in the postseason.
This spring was different. The Panthers opened the year with a decisive home romp over Cape Elizabeth and rolled to an 11-1 mark, with the only blemish coming May 4 at Yarmouth (a thrilling 12-11 loss). NYA avenged that setback with a 9-6 home win May 30 in the regular season finale to earn all-important homefield advantage for the Eastern B playoffs.
After a 17-4 semifinal round drubbing of No. 4 Oak Hill, the Panthers were finally able to defeat the Clippers, rallying for a 10-9 win on Wellin's late goal.
That sent NYA back to the championship game. This time, however, Cape Elizabeth wasn't waiting. The Rams of Kennebunk were.
NYA didn't face the Rams during the regular year and hadn't met them in the playoffs since a 15-7 victory in the 1999 quarterfinals. The teams also squared off in the quarterfinals the year before (a 14-6 win for the Panthers).
Kennebunk was playing in its second state final and second in succession (the Rams lost 8-5 to Yarmouth last spring) and was hoping to slow the NYA offense enough to earn the win.
The Panthers went a whole quarter (the second) without scoring, but they turned it on in the second half and got a stellar game-long dominant effort from their defense.
Kennebunk actually scored first. With 9:58 to go in the first quarter, junior Conor Finn fed senior Chris Gassman, who beat NYA senior goalie Stephen Hansel for a 1-0 lead.
Less than two minutes later, the Panthers drew even when senior faceoff man extraordinaire Peter Bates passed to Wellin, who sent a patented rocket past Rams sophomore goalkeeper Cullen Finn.
"Than gets a lot of press and he's great," Lolar said. "He'll still score even with the other team's best player on him."
The squads then traded opportunities.
For NYA, Bates shot wide and senior Henry Gerrity was denied. Conor Finn then had a pair of shots denied by Hansel.
With 5:02 to go in the first, the Panthers took the lead for good. Wellin passed to junior Taylor Gorman, whose shot hit the inside of the right post and trickled in.
NYA kept the pressure on. After senior Kevin Catir shot high, he took a nice pass from Wellin and beat Finn to make it 3-1.
"Than was instrumental in finding the openings and finding the open man," Panthers coach Jeff Thoreck said.
With 3:04 to play in the first quarter, Conor Finn scored unassisted to make it a 3-2 game, but 23 seconds later, Gorman set up Catir for a goal to give the Panthers a 4-2 lead. With time winding down in the quarter, Hansel made a spectacular save on a bid by Kennebunk senior Ben Kelly, maintaining the two-goal advantage.
Neither team would score in the second quarter, but both had chances.
Early on, Catir, Gorman and junior Graham Bartlett were denied by Finn. With 10:04 to play in the first half, a disturbing trend began when a Bates shot hit the post. It wouldn't be the last NYA bid to have that result.
With 8:05 left in the half, Finn's shot was saved by Hansel.
NYA then took a couple of penalties, but Kennebunk couldn't take advantage as junior Noel Graydon and senior Chris Kain had shots go wide.
With 2:56 left before halftime, Wellin hit the post. After Finn shot wide for Kennebunk, the Panthers moved back down the field and were frustrated again when Gerrity's bid ricocheted off the crossbar.
Despite forcing 14 Rams turnovers and having myriad good scoring chances, NYA still clung to a 4-2 lead at the break.
"We took a few penalties, but we settled it down," Thoreck said. "We killed the penalties. It was hard to get in a flow playing man-down like that."
At the half, NYA's seniors took command of the situation.
"It was 4-2 at halftime and the seniors stood up and said, 'Hey guys, just play the game and relax,'" Thoreck said. "It wasn't just one or two of them. It was all nine."
Just 53 seconds into the third period, Lolar scored unassisted for a 5-2 lead. He faked a pass to Wellin, eluded a defender and beat Finn to snap a 15 minute, 34 second drought.
"We all stepped up today," Lolar said. "This year's seniors wanted to bring it home. It?s a great way to go out."
Over the next four-plus minutes, the Panthers hit the post again (Bates), shot wide once and high twice. Hansel also made an amazing save on Rams senior Aaron Bassett in the stretch.
With 6:45 to play in the third, Lolar took a pass from Gerrity and scored man-up for a 6-2 lead. At the 5:05 mark, senior defensive standout George Reiche got in on the offensive fun.
Reiche collected a turnover, raced through the defense and fired a shot past Finn to make it 7-2.
Those who remember the 2001 victory had to see Reiche's goal as fitting. In that year's title game, Chris Chalke, also wielding a longstick, stole the ball and scored a pivotal late goal to seal the title. Reiche's goal was huge as well.
Kennebunk finally got back on the scoreboard with 4:19 left in the third when Finn (from Kain) snapped a 22 minute, 45 second drought. Moments later, senior Jeff Dube had a good look at the goal, but Hansel stood tall, allowing the Panthers to take a 7-3 lead into the final period.
Early in the fourth, the Rams tried desperately to climb back in the contest. Graydon, Finn and Kelly all had good looks, but Hansel saved each shot.
After Bartlett was robbed at the other end and Bates hit yet another post, NYA iced its victory with two goals in 33 seconds. Bates (from Gerrity) finally found net and not iron with 3:50 to play and Gerrity (from Lolar) scored at the 3:17 mark for a 9-3 lead.
Two seconds after hitting the post, junior Henry Gleason capped the scoring at the 2:06 mark with a goal which accounted for the 10-3 final score.
After so many close calls and heartbreaks, the Panthers danced on the field and celebrated their win and long-awaited crown.
"Everyone stepped up big," Wellin said. "We were ready for this game. We scouted them and saw how they played and what we needed to do. We came up huge. We got so close before. I sat in the stands for the other finals and thought that had to be me. What a way to finish."
"We were struggling, but everybody came through at the end," Catir said. "The defense was amazing. We've worked for this all year. Hard work in practice and games."
"It feels great," Reiche added. "We waited seven years. We've been together since middle school. We never got past Yarmouth before. That really drove us. Beating them felt like a state title. We were a little slow at the beginning, but we picked it up. We only let one in in the second half and got the groundballs. Overall, we picked it up as a team. We weren't going to be denied."
Thoreck paid tribute to his players, especially his seniors.
"The seniors have been able to teach the younger guys what it takes to be successful," he said. "That's a great message to send the underclassmen. I'm so proud of these guys. They worked so hard all year. The nine seniors played so hard. They have excellent leadership qualities. It came down to them stepping up in practices and on game day."
For NYA (14-1), Catir and Lolar both scored twice. Six others (Bates, Gerrity, Gleason, Gorman, Reiche and Wellin) had one goal apiece. Wellin and Gerrity both had two assists. Bates, Gorman and Lolar had one each. Hansel made 11 saves.
Kennebunk won 11 of the 17 faceoffs, but NYA forced the Rams into 30 turnovers and corralled numerous groundballs (led by Bates, Gorman, Lolar, Pilitsis, senior Alex Preston, and Reiche). The Panthers were even able to prevail despite hitting the post five times and the crossbar once.
"The important thing for us was coming out and winning faceoffs and groundballs," Thoreck said. "We focused on what we needed to do to win.
"The defense played well. It's been a good group all year. A lot of these guys have played together for six years. They communicate well. They slide well. We worked all year on putting pressure on the ball. We're athletic enough to extend out and force turnovers. This veteran group was able to recognize double-team situations and avoid mistakes. We were able to transition it down the field. With a veteran group of six guys who can score, we were tough to stop."
Kennebunk (12-3) got two goals from Conor Finn and one from Gassman. Cullen Finn stopped six shots.
Back for more?
The Panthers will be hit hard by graduation as nine depart. Bates, Catir, Gerrity, Zach Garcia, Hansel, Lolar, Preston, Reiche and Wellin returned the program to the pinnacle and will long be hailed.
Those writing off NYA for next spring, however, could be in for a surprise. The program returns such stalwarts as Bartlett, Gleason, Gorman and Pilitsis and should be hungry to attempt to become the first squad in program history to repeat.
"Hopefully, the younger guys can take this experience and make it back," Wellin said. "I'll come back to see it."

subset: commoncrawl


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Taco Veloz
Posted by jass on 03/26/2014
this place doesn't even need a review, my boyfriend and i could go at 3am with cravings from long island, just to get a taco. no place like it! me encanta!


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Autumn and Winter Tales of Tiptoes Lightly ~ Tiptoes and her friends - including Farmer Johns children, Tom Nutcracker and June Berry - celebrate the festivals of Michaelmas, Halloween, Martinmas, Advent and Christmas. Wonderfully captures the inner mood of nature during autumn and winter. You'll find these lavishly illustrated tales are reverent, humorous and sacred. Soft cover; 100 pages.
Author: Reg Down
Ages 4 to 9. Older children and adults enjoy these tales. too.


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Merry Pielsmas
Disclaimer: While Merry Pielsmas is a Grey Lodge event, it is not technically a beer event. It is fun though.
Every December 24th at the stroke of Midnight, everyone is invited to join the Cliver Brothers in Merry Pielsmas. As the clock strikes midnight and Christmas Eve becomes Christmas Day, we raise a (entire) can of Piels (no dumping) to celebrate. Sure it makes little sense, but is it that much weirder than putting a dead tree in your living room? And Piels is a little bit less of a fire hazard. Poem below by Andy Cliver.
''Twas the night before Pielsmas, and all through the bar,
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Cranial transillumination device includes a shielded light source mounted in a cup-like housing and connected by an intermediate band to a similarly shielded light meter for indicating any abnormal spiral fluid accumulation on the brain.
1. A cranial transillumination device comprising a first housing, said first housing being open at one end and otherwise light impervious, a light source mounted in said first housing, a second housing, said second housing being open at one end and otherwise light impervious, a light sensor mounted in said second housing, mounting means in the form of a headband connecting said first and second housings with said open ends disposed toward each other, said headband being shaped to attach on the patient's head with said light source and said light sensor juxtaposed the patient's head in line with each other so that light may pass through the patient's head from said light source to reach and be detected by said sensor, and said first and second housings being made of a material capable of fitting snugly against the head of the patient to close said open ends whereby light emitted from said light source would be detected by said light sensor for indicating any abnormal spinal fluid accumulation.
2. The device of claim 1 wherein said first and second housings are cup shaped.
3. The device of claim 1 including a light meter responsive to said light detector for providing a visual indication of the amount of light transmitted through the head, and said light meter being externally visible from said second housing.
4. The device of claim 3 wherein said first and second housings are cup shaped.
5. The device of claim 4 wherein said headband is generally U-shaped and adjustable.
6. The device of claim 5 including common power means for said light source and said light sensor and said light meter.
7. The device of claim 6 wherein said open ends of said housings are disposed for being aligned with each other.
This invention relates to a transillumination device and more particularly to a cranial transillumination device for determining whether or not there is any abnormal spinal fluid accumulation on the brain. Such procedures are generally done on children. The most common practice is similar to egg candling where the child is placed in a relatively dark room and a source of light is disposed on one side of the child's head. The passage of light through the head would be evident in the dark room to indicate such an abnormal spinal fluid accumulation. This procedure has the obvious disadvantage of frightening the child because of the necessity for a dark room.
U.S. Pat. No. 3,527,932 discloses a transilluminating arrangement which utilizes a conventional flashlight provided with a cylindrical hood or shield for being pressed against the head of the child. Although the patent indicates that the arrangement obviates the need for the room being completely dark, such an arrangement should not effectively indicate the transmission of light through the head without some degree of darkening of the room.
An object of this invention is to provide a cranial transillumination device which may be used in a normally lit room without requiring any special darkening.
A further object of this invention is to provide such a cranial transillumination device which effectively indicates the presence of abnormal spinal accumulation with a quantitative meaningful indication.
In accordance with this invention the cranial transillumination device includes a shielded light source mounted in a conformable cup-like housing and connected by an intermediate band to a similarly shielded light meter for indicating any abnormal fluid accumulation on the brain.
The light indicating means may be a conventional photocell to which an externally visible light meter is electrically connected. The headband may be adjustable to permit its adaptability to various size children and may include pivotal attachments for the cups containing the light source and light meter to assure a firm fitting of the cups to the head.
FIG. 1 is a front elevation view partly in section showing the cranial transillumination device of this invention; and
FIG. 2 is a side elevation view of the device of FIG. 1.
FIG. 1 illustrates the cranial transillumination device 10 of this invention. As indicated therein the first cup 12 is connected to a second cup 14 by means of an intermediate band 16. Each cup is open at one end but otherwise light impervious. Cup 12 houses a suitable light source 18 suitably powered by any convenient conventional power source 20. Cup 14 in turn houses light sensitive means which in the schematically illustrated form is a photocell 22 having connected thereto a light meter 24 (FIG. 2) with the same power source 20 being utilized therefor. Headband 16 may be of any suitable construction which preferably provides adjustability for the device for rendering it adaptable for use with different patients. In the illustrated form headband 16 includes a padded central sleeve 26 into which is inserted a metal plate-like member 28. Each cup 12, 14 has attached thereto a metal plate-like member 29 which is arranged for sliding contact on top of central plate 28. Suitable temporary locking devices 30 are provided to maintain the proper relationship of member 28, 29 so that the headband 16 may be adjusted for conforming to a particular patient and then locked in place. Although FIG. 1 illustrates band 16 in general contact with the head, the band may be spaced therefrom. Similarly, the band may be disposed about the back instead of the top of the head. As also illustrated each cup 12, 14 is pivotally connected to its respective plate 29 by shaft 32. Cups 12, 14 are made of a suitable flexible resilient cushioning material which may closely conform to the patient's head without causing undue discomfort. In this manner each cup 12, 14 provides a closed housing wherein its open end is closed by the patient's head.
In use power source 20 is actuated to illuminate light source 18. Any light transmitted through the head is detected by light detector or photocell 22 which is disposed generally in line with light source 18. Light meter 24 is connected to detector 22 and visually indicates a quantity reflecting the amount of light transmitted during the actual use of the device. Thus by virtue of the completely shielded light source and light detector and by virtue of the visible light meter it is possible to use the device in a normally lit room. Further the device 10 obviates the need to be hand held since it is mounted directly on the head.
Patent Citations
Referenced by
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Getting Started
At Parrish Construction Co., we want you to have it your way.
- If you're interested in design-build, let us provide and lead your team. We have the experience and skill to deliver your project on time and on budget.
- If you have already completed your plans and specifications, we'd love to build for you. We'd be happy to tell you if your plans are feasible with your budget and provide you with an estimate. Contact us.
- If you've recently hired your architect, and the design has just begun, we'd love to be part of a virtual design-build team, and work with you and your architect to provide cost feedback and our experience with what materials and construction techniques yield the best value.
Getting Started with Design/Build
Communication is vital to successfully completing your project, and we make every effort to be available to you by e-mail, cell phones, and even a home phone number, if necessary. We don't want your remodeling project or building your new home to be a daunting and overwhelming undertaking, which is why we've developed the processes and procedures to make your project run smoothly.
Hopefully you've flipped through some magazines and started a file of inspiration images, and maybe you've even read some of Larry's Blog articles, like "How to Choose a Remodeling Contractor" and "Why You Should Remodel Now." We also invite you to browse our Portfolio for example images and information about the various types of projects we specialize in, including Kitchens, Baths, Custom Cabinets, Remodels & New Homes and Commercial Finishes. There you may also take a 360 Degree Virtual Tour of several of our projects.
Your journey begins now with a free consultation where we learn about your needs and desires, and find out whether our services are a good fit for you. Once you've decided to hire Parrish Construction, we will guide you every step of the way. Just as an airline pilot consults his checklist before landing, our detailed checklists ensure that your project finishes on time, on budget and to code. The following is only a general outline of the building process and the steps necessary to complete your project.
I. Feasibility—the intersection of dreams and reality
Imagine the possibilities. It's creative. It's fun…but is it practical?
Defining local rules & green requirements
Documenting existing conditions
Preliminary floor plans, elevations, and product selections
Establishing a budget & preliminary estimate
II. Design—working with the details
- Refining the final concept drawings into finished blueprints
- Assembling your construction team
- Approving the final Description of Work
- Determining the final budget
- The Construction Commitment
- Preliminary schedule of work is approved
III. Construction—making your dreams a reality
- Signing of Construction Contract
- Confirming Start Date
- Finalizing Construction Schedule
- Ordering of products and preparations for site
- Communicating regularly with all team members
- Completion of project on-time and on-budget
You are likely to remodel or build, at best, a few times in your life. On the other hand, we've been doing it for over 40 years, a lifetime in its own right. Our staff continue to be industry leaders by attending continuing education programs on new technology including green technology.
If you would like to schedule a free consultation or have further questions, Contact Us.


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Remy Ma Talks About Beef With Nicki Minaj & New MixTape Release [VIDEO]
Remy Ma has been working hard since being released from her 6 yr prison term. Today she stopped by the Wendy Williams show to talk about her new mixtape and beef with Nicki Minaj. Watch the full interview here


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Aikikai Hombu Dojo celebrates 70 years
by Stanley Pranin
Aikido Journal #121
A celebration in commemoration of the 60th anniversary of the Aikikai Foundation and the 70th anniversary of the Aikido Hombu Dojo was held at the Keio Plaza Hotel in Tokyo on October 21. Some 1,500 people including many foreign visitors were on hand for this festive occasion that centered on Aikido Doshu Moriteru Ueshiba. A number of dignitaries gave speeches among them Chairman of the Board of Directors Yoshimasa Miyazaki, former Japanese Prime Minister Toshio Kaifu, and the Doshu. In addition, several Japanese shihan residing abroad and heads of foreign aikido organizations traveled to Tokyo to join in the celebration. I think that if it were not for the tragic events in the USA in September many more participants would have come from abroad.
The Hombu Dojo was originally opened in 1931 as the "Kobukan Dojo." It was the scene of the transition of the Founder Ueshiba's art into what would later become modern aikido. The dojo became incorporated as the Kobukai Foundation in 1940. The non-profit corporation was reestablished after the war in 1948 as the Aikikai Foundation.
A highlight of the event was the unveiling of a memorial plaque (see photo below) dedicated to Second Doshu Kisshomaru Ueshiba. A similar plaque of the Founder Morihei Ueshiba hangs in a prominent place at the Aikikai.
Those present were sent home with a gift package containing among other items a pamphlet with lots of interesting photos outlining the history of the Aikikai and the Hombu Dojo.
Cameras were flashing everywhere and here is a selection of shots I took to give an idea of the atmosphere inside the banquet room where the event was held.
Keio Plaza party highlights
(The full article is available for subscribers.)
View of crowd gathered in banquet room
Doshu addresses the audience
Another shot of Doshu Moriteru Ueshiba delivering speech
(The full article is available for subscribers.)


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Big Splash Indoor Waterpark at Rocking Horse Ranch Resort offers four exciting water slides and the Dynamite Alley Water Walk Challenge. There are also a variety of fun water features like geysers, dumping buckets, interactive fountains and more! The kids, and even the kid-at-heart, will love this waterpark adventure!... more
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|Hampton Inn Bridgewater properties are listed below. Search for cheap and discount Hampton Inn hotel prices in Bridgewater, MA for your business gathering or personal travels. We list the best Hampton Inn Bridgewater hotels & lodging so you can review the Bridgewater Hampton Inn hotel list below to find the perfect place.
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Cooking and Baking
I'm whipped - bought too much cream!
Help - I accidentally bought an extra container of 35 per cent whipping cream. So now I have like three cups of the stuff in my fridge. Recipe suggestions? This is not a product I work with terribly much beyond topping pumpkin pie with it!
Talk is closed, but that doesn't mean the conversations have to stop!
Check out this post for a more thorough explanation, and jump onto our Facebook page or our Twitter feed to keep the conversations going!


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Whoops! Something went baaaadly wrong!
We're sorry, but the page you requested can't be found!
Have you checked your address bar? Maybe there is just a small typo in the URL.
If there isn't, you could try searching my website for the content you were looking for:
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One last thing, if you're feeling so kind, please inform me about this so I can fix it.


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Flora Apartment Complex
from £19 /night help Price for guests, Nights
from £19 /night help Price for guests, Nights
Estimated nightly price based on a weekly stay. Excludes fees (if applicable). Enter your dates to see the total cost.
Apartment / 1 bedrooms / sleeps 5
Availability Your dates are available
Apartment / 1 bedrooms / sleeps 5
|Key Info
Flora is a landmark complex and architecturally very distinctive, having won the prestigious Best Project of 2005 award from the Bulgarian Industrial Association.
The complex offers a modern fitness centre & Jacuzzi, sauna, solarium, indoor swimming pool and games room. Ski and ski-boots storage area, laundry, underground garage and secured outdoor parking lot are of great convenience.
There are several shops, a restaurant serving traditional Bulgarian and international cuisine, lobby bar, Irish pub.
|Sleeps up to 5, 1 bedrooms
|Will consider
|Corporate bookings
|Car not necessary
|Nearest travel links
|Nearest airport: Sofia 70 km
|Family friendly
|Great for children of all ages
|No pets allowed, No smoking at this property
Features and Facilities
|Jacuzzi or hot tub, Sauna, DVD player
|Central heating, TV, CD player, Telephone
|Kettle, Iron, Hair dryer
|Cooker, Microwave, Fridge
|1 bedroom
|2 Sofa beds, Double beds (1)
|Linen provided, Towels provided
|Balcony or terrace
|Suitable for people with restricted mobility, Not suitable for wheelchair users
|Further details indoors
Our 75 sq. m. one bedroom apartment provides a generous living space for up to five people. Its spacious living room has a double sofa bed with two armchairs and a coffee table. It comes with satellite TV, DVD player and stereo system. There is a king-size bed in the bedroom with space for additional bed. The dining area has two bar chairs with table.
The kitchen, which is separate and well equipped, is fitted with a cooker, hob and extractor fan. There is also a fridge, coffee machine, microwave oven and grill.
The bathroom is completely tiled with a shower and bathtub. Each room sports a balcony. The apartment is non-smoking.
|Further details
Booking - The party leader must be authorised to make the booking by all persons named on the booking form and by parent/guardian of party members less than 18 years old.
The bookings can be made by telephone or email using contact form. You will receive a confirmation email within 48 hours with payment details.
The Sofia Region
Sofia is one of the oldest capital cities in Europe, blending its past and present in a remarkable architectural style. Historic landmarks include the 10th century Boyana Church (one of the UNESCO World Heritage protected sites), the Alexander Nevski Cathedral (one of the world's largest Orthodox churches), and the early Byzantine Church of St Sophia. Sofia has also a huge night-life scene with many different night clubs, live venues, pubs, mehani (Bulgarian traditional taverns), and restaurants.
Borovets is located in East Rila or the Musala Ridge. The highest and vastest part of Rila Mountain. The highest peak, as well as 12 of the 18 peaks over 2,700 m are located there — Musala, Yastrebets, Irechek, Deno Mancho, etc. The Musala Lakes lie in this part of Rila, as well as Ledeno ezero ("Icy Lake"), the highest lake of the Balkans at 2,709 m. Other lakes in East Rila include the Maritsa Lakes and the Ropalitsa Lakes.
Borovets is a modern ski resort of a high class spread over a large area of altitude between 1230m and 1390m in the beautiful Rila Mountains.
The winter is mild, long and snowy. It is a favourite East European winter fun destination with luxurious hotels, restaurants, discos and night clubs… at reasonable prices. Borovets provides very good conditions for snow sports during the winter: skiing, night- skiing, snowboarding, cross-country skiing, ski jumps and biathlon.
The ski lovers enjoy the 45 km ski slopes various in difficulty and length with highest runs at 2600m. The resort is a real hotspot for night-life with long happy hours and friendly atmosphere. Sofia the capital of Bulgaria is just 72 kilometres away.
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text: There isn't much doubt that Brazil will top the group, but can they stumble and let Croatia/Mexico draw a game ? I guess the best chance is against Croatia with the nerves of the first game in their World cup and the pressure from all the expectations of the people . It has to be nerve-wrecking no matter how professional these guys are.


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Mac OS X Leopard Ships October 26th
Yep, it's true. The new Mac OS that has been pushed back more than once finally has a date on it. There has been a lot of talk about the new features coming out on the new OS. I myself have been looking forward to the new and improved Boot Camp, creating stacks on my dock, an improved finder and also Quick Look. Apple has created an organized list with all 300+ new features being released on their site, take a look through them. You'll be suprised how many new ones you'll be interested, i was.


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Kantor column: Influencing for better or worse
Appropriate influence over the attitudes and behaviors of your employees is the heart of good, strong management. It is impossible to be an effective manager without influencing your employees. As a manager you do influence your employees "for better or worse." The type of influence you use can make or break yours and your company's success.
Five basic types of influence managers use are listed below. Which ones do you use to influence your employees?
Authoritarian. Employees generally accept the fact that bosses have a right to make requests and assign work. Having the authority to issue orders though doesn't give a boss the right to make arrogant demands. All too often bosses use their authority to be "little dictators." If you want to be effective in exercising your authority, do it by making polite requests. Legitimate requests should be as clear and simple as possible. Using your authority to influence employees is sometimes necessary, but it doesn't have to be abrasive. Mutual respect is your goal.
Rewarding. Often rewards are used to influence others. When you were a little kid, you probably got lots of messages such as, "act good and you will get a treat," Most of us have been programmed to expect rewards. This may be appropriate for some work tasks, but there are major drawbacks in using rewards to influence. Often employees will do no more than just what it takes to get the reward. It can also make employees expect a reward for every little thing they do.
When using rewards it is best to give the reward not as a bribe for doing something, but as a reinforcement, after the goal is completed. Remember rewards are not just tangible items, such as money or gifts, but praise and recognition too. Rewards can be used to positively influence employees, but a better way is to develop loyalty and team spirit among employees.
Persuade by credibility. To accumulate credibility a manager needs to create an image of experience and competence. A manager who is well informed, calm, confident, and fair has the credibility to persuade others. The respect this type of manager draws from employees allows them to influence positively.
Call upon loyalty. Often managers influence employees by calling upon their loyalty to their company. Managers develop loyalty in employees over time when they show concern, treat them fairly, and stand by them. When calling upon loyalty to influence an employee, keep in mind, that there are limits to what you should ask in the name of loyalty.
Remember, it is best not to call upon the issue of loyalty too often. If requests are unreasonable or made too often they decrease in effectiveness.
Role modeling. One of the very best ways to positively influence employees is to be their role model. You should set an example by behaving the way you want and expect your employees to. You can influence others positively or negatively without even making explicit requests.
Each way of influencing has it pluses and minuses. Each can be used to influence positively or negatively. Some ways can be more effective than others. But singling one out to use all the time would be a mistake. To be an effective manager you will want to employ all five ways. Being able to use the right one at the right time to influence positively shows effective management skill.
Jan Kantor is a Southwest Florida business consultant and executive coach. For more information, or to contact him regarding workplace solutions, his website is www.jankantor.com.
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