Use this task to control the sizes of the memory buffers used by a messaging engine.
Name | Value |
---|---|
sib.msgstore.discardableDataBufferSize | The size in bytes of the data buffer used by the messaging engine to
contain data for which the quality of service attribute is best effort nonpersistent.
The messaging engine holds this data
entirely within this memory buffer and never writes this data to the data store.
When the messaging engine adds data
to this buffer, for example when the messaging engine receives
a best effort nonpersistent message from a client,
the messaging engine might discard
data already in the buffer to make space. This behavior enables the messaging engine to
discard best effort nonpersistent messages. The discardable data buffer contains all data for which the quality of service attribute is best effort nonpersistent. That data comprises data both that is involved in active transactions, and any other best effort nonpersistent that the messaging engine has neither discarded nor consumed. The messaging engine can discard only data that is not involved in active transactions. Tip: If
the messaging engine attempts to
add data to the discardable data buffer when insufficient space remains after
discarding all the data that is not involved in active transaction, the messaging engine throws a com.ibm.ws.sib.msgstore.OutOfCacheSpace exception.
Client applications can catch this exception, wrapped inside API-specific
exceptions such as javax.jms.JMSException.
The sib.msgstore.discardableDataBufferSize property of the messaging engine controls the size of the discardable data buffer. You specify the value of this property in bytes. The default value is 320000, which is approximately 320 kilobytes. |
sib.msgstore.cachedDataBufferSize | The size in bytes of the data buffer used by the messaging engine to
contain data for which the quality of service attribute is better than best effort nonpersistent and which is held in the data store. The purpose of the
cached data buffer is to optimize the performance of the messaging engine by
caching in memory the data that the messaging engine might
otherwise need to read from the data store.
As it writes data to the data store and
reads from the data store,
the messaging engine attempts to
add that data to the cached data buffer. The messaging engine might
discard data already in the buffer to make space. The sib.msgstore.cachedDataBufferSize property of the messaging engine controls the size of the cached data buffer. You specify the value of this property in bytes. The default value is 320000, which is approximately 320 kilobytes. |
sib.msgstore.transactionSendLimit | The maximum number of operations that the messaging engine includes in each transaction. For example, each JMS send or receive is an operation that counts towards the transaction send limit. The default value is 100. |
To set the properties of a messaging engine to improve its interaction with its data store, use the administrative console to complete the following steps: