DB throttling is the mechanism to
control the number of database records processed by the SOA engine in a
particular interval through DB Adapter.
Throttling also can be used to
control the number of records send to the end systems. If the throttling is not
defined, the end systems may flood with number of messages that will affect the
functioning of the end systems. Throttling parameters should be configured
based on the end systems capacity to process the incoming messages.
Until Oracle SOA 11.1.1.6.0 the
message throttling will not work as we expect, all the messages matching the
where condition of the polling sql are processed in the same polling interval.
As of Oracle Adapters release 11.1.1.6.0
we can set the inbound DBAdapter property RowsPerPollingInterval to control the throttling. It acts as a limit on the number of records
which can be processed in one polling interval. The default value is unlimited.
The Patch 12881289 should be applied to enable this for SOA 11.1.1.5.0 and earlier versions.
The maximum rows processed per second
are:
Number of active nodes in SOA cluster
x NumberOfThreads x RowsPerPollingInterval / PollingInterval
MaxTransactionSize can be thought of as RowsPerDatabaseTransaction or DatabaseFetchSize that is how many records will be fetched to DB Adapter engine from the database for each transaction. It does not
affect how many rows can be processed in one polling interval period.
The one exception is the following
configuration:
-distributed
polling checked, usesSkipLocking="false"
In this one case RowsPerPollingInterval will default to MaxTransactionSize instead of unlimited in case of RowsPerPollingInterval
property is not specified in the jca file.
If RowsPerPollingInterval is set to
lower than MaxTransactionSize or MaxRaiseSize, they will be
effectively lowered to RowsPerPollingInterval that means the value RowsPerPollingInterval
will considered for MaxTransactionSize and MaxRaiseSize.
There is no UI support to add the RowsPerPollingInterval
property. We have to add the property
manually to the db.jca file for the inbound polling service. Add it to the same
section as the properties MaxRaiseSize, MaxTransactionSize, and PollingInterval, in any order.
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