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4.7.4 Messaging tuning
This section describes performance tuning for messaging.
Choosing data store or file store for messaging engines
Messaging engine persistence is backed by a database. However, a stand-alone Business
Process Manager configuration might have the persistence storage of BPE and SCA buses
backed by the file system (file store). You must choose a file store at profile-creation time. Use
the Profile Management Tool to create a new stand-alone enterprise service bus profile or
stand-alone process server profile:
1. Click Profile Creation Options Advanced profile creation Database
Configuration.
2. Select the Use a file store for Messaging Engine (MEs) check box. When this profile is
used, file stores are used for BPE and SCA service integration buses.
Setting data buffer sizes (discardable or cached)
The DiscardableDataBufferSize property is the size in bytes of the data buffer uses when
processing best-effort non-persistent messages. The purpose of the discardable data buffer
is to hold message data in memory because this data is never written to the data store for this
quality of service. Messages that are too large to fit into this buffer are discarded.
The CachedDataBufferSize property is the size in bytes of the data buffer used when
processing all messages other than best-effort non-persistent messages. The purpose of the
cached data buffer is to optimize performance by caching in memory data that might
otherwise need to be read from the data store.
You can set the DiscardableDataBufferSize and CachedDataBufferSize in the administrative
console:
1. Click Service Integration-Buses and select the bus name.
2. Click Messaging Engines and select the messaging engine name.
3. Click Additional properties Custom properties and enter the values for
DiscardableDataBufferSize and CachedDataBufferSize.
Using a high-performance database management system for messaging
engine data stores
For better performance, use production-quality databases, such as DB2, for the messaging
engine data stores. You can choose the database at profile creation time using the advanced
profile creation option.
Creating the DB2 database and loading the data store schema
Instead of having one DB2 database per messaging engine, we put all messaging engines
into the same database, and using different schema to separate them, as shown in Table 4-1.
Table 4-1 Messaging engine schemas
Schema
SCASYS
SCAAPP
CEIMSG
BPCMSG
Messaging engine
box01-server1.SCA.SYSTEM.box01Node01Cell.Bus
box01-server1.SCA.APPLICATION. box01Node01Cell.Bus
box01-server1.CommonEventInfrastructure_Bus
box01-server1.BPC.box01Node01Cell.Bus
Chapter 4. Performance tuning and configuration 67