Symptoms

BIG-IP aborts when mirroring a large size (> 128K) session DB message which can be produced by table iRule command or APM session variable. For APM deployment, most scenario involves with AD/LDAP query with large size AD/LDAP attribute. Please restrict the AD/LDAP query with attributes which actually needed to avoid retrieving unncessary large size attribute which triggers this issue. For table iRule use case, please avoid having a single table entry to hold a large size of data. Please break them into pieces.

Impact

The Traffic Management Microkernel (TMM) may produce a core file when using an iRule table command with large datasets, and the BIG-IP system will temporarily fail to process traffic as it recovers from TMM restarting.

Conditions

This issue occurs when all of the following conditions are met: An iRule contains a table command, such as set, add or replace, which attempts to insert a large set of data (more than 128k): -- Session mirroring is enabled between BIG-IP high-availability devices. Note: Session mirroring is enabled by default through the StateMirror.MirrorSessions database variable.

Workaround

To work around this issue, revise the iRule to avoid insertion of large datasets. Note: Changing the design of an iRule may have additional effects on traffic processing. Ensure any modification is compatible with your environment.

Fix Information

This release provides improved handling of large objects in the session database.

Behavior Change