This type is a class for model objects.
An optional extension to a resource ref which allows specifying IBM isolation level support at a resource ref level. @since WAS5.0
Package: commonextAttributes Summary | |
isolationLevel : IsolationLevelKind | * No description is available * |
connectionManagementPolicy : ConnectionManagementPolicyKind |
This resource ref extension can be used for specifying the connection management policy on WebSphere platforms which support this option (such as zOS).
Connection Starvation
Connection starvation occurs when the number of connections being held by applications reaches the maxium number of
connections set during configuration. If connections aren't being returned to the pool fast enough, or not at all, then new
requests for connections will not be able to be serviced.
Connection starvation due to users not closing connections is one of the main issues this design wants to address. Poorly
written applications often have one or two places where they forget to close connections (sometimes in error paths). If nothing
is done, it does not take long before the connection pool is completely and indefinitely out of connections. This type of starvation,
which is permanent, is different from that where connections are closed when the user is done with them, but because of high
usage the pool is temporarily exhausted.
Reducing Connection Starvation
Shareable Connections
For shareable connections, the ManagedConnection will always be returned to the pool when the UOW ends. Since all connections will always run in a UOW this means that it won't be possible for users to "leak" connections because they forgot to close them. It also means that the connection handles will be "parked" on a dummy connection and reassociated to a new connection on the next preinvoke.
Unshareable Connections
For unshareable connections we'll have two options for the user to choose from to police users who don't close their connection handles in a timely maner.
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resourceRef : ResourceRef @ | * No description is available * |
Attribute Details |