Chapter 12. Scalability, reliability, and availability architectures 287
Application design
Modern computer systems contain multiple cores. They can perform multithreaded 
processing. Modern computer system operating systems allow parallelism in operations. To 
take advantage of these hardware and software features, an application must be designed so 
that it can run in parallel at multiple levels. Content Manager OnDemand can take advantage 
of both. 
At the process level, the Content Manager OnDemand server runs multiple processes:
/SM590000A library server 
/SM590000One or more object servers 
/SM590000One or more load jobs 
/SM590000The expiration process
At the thread level:
/SM590000The library server is designed so that it is multithreaded and it can service multiple 
incoming data requests on different threads and perform multiple database queries in 
parallel.
/SM590000The object server is also multithreaded so that multiple users can concurrently retrieve 
data from the Content Manager OnDemand archive.
Parallel archive access
When you access the Tivoli Storage Manager or object access method (OAM) archives, a 
store or retrieve request is sent to Archive Storage Manager (ASM). ASM then either stores or 
retrieves the data and returns the result to the Content Manager OnDemand server. If this 
process is conducted in a serial fashion, the archive storage access mechanism becomes a 
bottleneck at high transaction rates. To overcome this potential bottleneck, Content Manager 
OnDemand implements connection pooling to the storage archives. 
Content Manager OnDemand maintains a pool of connections to the archive. When an 
archive store or retrieve request is received, an available connection from the pool is selected 
to perform the request. This connection allows both faster access to the archive (by 
eliminating the start process each time a connection is requested) and for the parallel 
execution of the store or retrieve operations.
On IBM i, when you access the ASM archives, connection pooling is not required for store 
requests. When a store request is made, ASM opens a connection and keeps it open until the 
data store request is complete. In addition, ASM allows the aggregation of objects, sending 
fewer objects to storage media than otherwise are sent without aggregation.
On Multiplatforms and z/OS, you can aggregate documents that are loaded from Content 
Manager OnDemand Web Enablement Kit (ODWEK) before you store them in the archive. 
The document is stored to cache where it is appended to the storage object until the object 
reaches 10 MB (defined storage object size), at which point it is migrated to a storage 
manager, such as Tivoli Storage Manager. For more information about this topic, see the 
following website:
http://www.ibm.com/support/docview.wss?uid=swg21587507