Use this information to troubleshoot issues with your database loaders.
Explanation: The loader plug-in can fail when it is unable to communicate to the database back end. This failure can happen if the database server or the network connection is down. The write-behind loader queues the updates and tries to push the data changes to the loader periodically. The loader must notify the ObjectGrid run time that there is a database connectivity problem by throwing a LoaderNotAvailableException exception.
[jcc][t4][10120][10898][3.57.82] Invalid operation: result set is closed.
Solution: By
default, the application server configures the resultSetHoldability
custom property with a value of 2 (CLOSE_CURSORS_AT_COMMIT).
This property causes DB2 to
close its resultSet/cursor at transaction boundaries. To remove the
exception, change the value of the custom property to 1
(HOLD_CURSORS_OVER_COMMIT). Set the resultSetHoldability custom property
on the following path in the WebSphere Application Server cell: Resources > JDBC provider > DB2 Universal JDBC Driver Provider > DataSources > data_source_name > Custom
properties > New.This exception occurs because of a lock contention problem when you are running with OpenJPA with DB2 in WebSphere Application Server. The default isolation level for WebSphere Application Server is Repeatable Read (RR), which obtains long-lived locks with DB2.
Solution:Set the isolation level to Read Committed to reduce the lock contention. Set the webSphereDefaultIsolationLevel data source custom property to set the isolation level to 2(TRANSACTION_READ_COMMITTED) on the following path in the WebSphere Application Server cell: Resources > JDBC provider > JDBC_provider > Data sources > data_source_name > Custom properties > New. For more information about the webSphereDefaultIsolationLevel custom property and transaction isolation levels, see Requirements for setting data access isolation levels.
Instead, a TargetNotAvailableException exception occurs in the container server, which activates the partition that is specified by the preloadPartition property.
BackingMap bm = og.defineMap( "map1" );
bm.setPreloadMode( true );
You can also set the preloadMode
attribute by using an XML file as illustrated in the following example: <backingMap name="map1" preloadMode="true" pluginCollectionRef="map1"
lockStrategy="OPTIMISTIC" />