Diagnostic alerts
In WebSphere Application Server v9.0 the Performance and Diagnostic Advisors are extended to provide more diagnostic alerts to help common troubleshoot problems.
Several alerts are made available to monitor connection factory and data sources behavior. Some of these alerts are straightforward and easy to comprehend. Others are more involved and are intended for use by IBM support only.
ConnectionErrorOccured diagnostic alert
When a resource adapter or data source encounters a problem with connections such that the connection might no longer be usable, it informs the connection manager that a connection error occurred. This causes the destruction of the individual connection or a pool purge, which is the destruction of all connections in the pool, depending on the pool purge policy configuration setting. An alert is sent, indicating a potential problem with the back-end if an abnormally high number of unusable connections are detected.
Connection low-percent efficiency diagnostic alert
If the percentage of time that a connection is used versus held for any individual connections drops beneath a threshold, an alert is sent with a call stack.
Cross-Component Use JCA Programming Model Violation Diagnostic Alert
When we enable cross-component use detection, the application server raises an alert when a connection handle is used by a Java EE application component that is different from the component that originally acquired the handle through a connection factory. This condition might inadvertently occur if an application passes a connection handle in a parameter or an application obtains a handle from a cache shared by multiple application components. If components use a connection handle in this manner, this might result in problems with application or data integrity. Enable the alert to detect the cross-component connection use during development to identify and avoid potential application problems.
Local transaction containment (LTC) nesting threshold exceeded diagnostic alert
For LTC definition, see the Local transaction containment (LTC) and Transaction type and connection behavior information, and Default behavior of managed connections in WAS topic.
If a high number of LTCs are started on a thread before completing, an alert is raised. This alert is useful in debugging some situations where the connection pool is unexpectedly running out of connections due to multiple nested LTCs holding onto multiple shareable connections.
Multi-Thread Use JCA Programming Model Violation Diagnostic Alert
Multi-thread use detection raises an alert when an application component acquires a connection handle using a connection factory, and then the component uses the handle on a different thread from which the handle was acquired. If we use a connection in this manner, this behavior might cause data integrity problems, especially if an application uses a connection handle on a thread that is not managed. Enable the alert to detect multi-thread connection usage during application development.
Pool low-percent efficiency diagnostic alert
If the average time that a connection is held versus used for the all connections in the pool drops beneath a threshold, an alert is sent.
Serial reuse violation diagnostic alert
For information on what serial reuse is, see the transaction type and connection behavior information. Some legitimate scenarios exist, where a serial reuse violation is appropriate, but in most cases this violation is not intended and might lead to data integrity problems.
If this alert is enabled, any time a serial reuse violation occurs within an LTC, an alert is sent.
Surge mode entered or exited diagnostic alert
When surge mode is configured, an alert is sent whenever surge mode engages or disengages. See the surge mode documentation for more information.
Stuck connection block mode entered or exited diagnostic alert
When stuck connection detection is configured, an alert is sent whenever stuck connection blocking starts or stops. See the stuck connection information.
Thread maximum connections exceeded diagnostic alert
When one or more LTCs on a thread ties too many managed connections, or poolable connections for data sources an alert is issued.
Related:
Data sources Transaction type and connection behavior Unshareable and shareable connections Use the Performance and Diagnostic Advisor Local transaction containment Connection pool advanced settings