Fixes are available
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for AIX
7.0.0.15: Java SDK 1.6 SR9 Cumulative Fix for WebSphere Application Server
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for HP-UX
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for IBM i
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Linux
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Solaris
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Windows
7.0.0.17: WebSphere Application Server V7.0 Fix Pack 17
7.0.0.17: Java SDK 1.6 SR9 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.19: WebSphere Application Server V7.0 Fix Pack 19
7.0.0.21: WebSphere Application Server V7.0 Fix Pack 21
7.0.0.23: WebSphere Application Server V7.0 Fix Pack 23
7.0.0.25: WebSphere Application Server V7.0 Fix Pack 25
7.0.0.27: WebSphere Application Server V7.0 Fix Pack 27
7.0.0.29: WebSphere Application Server V7.0 Fix Pack 29
7.0.0.31: WebSphere Application Server V7.0 Fix Pack 31
7.0.0.27: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.33: WebSphere Application Server V7.0 Fix Pack 33
7.0.0.35: WebSphere Application Server V7.0 Fix Pack 35
7.0.0.37: WebSphere Application Server V7.0 Fix Pack 37
7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
7.0.0.19: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.21: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere
7.0.0.23: Java SDK 1.6 SR10 FP1 Cumulative Fix for WebSphere
7.0.0.25: Java SDK 1.6 SR11 Cumulative Fix for WebSphere Application Server
7.0.0.27: Java SDK 1.6 SR12 Cumulative Fix for WebSphere Application Server
7.0.0.29: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.31: Java SDK 1.6 SR15 Cumulative Fix for WebSphere Application Server
7.0.0.35: Java SDK 1.6 SR16 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.37: Java SDK 1.6 SR16 FP3 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server
APAR status
Closed as program error.
Error description
A javacore showed a large number (about 45) "SIBFAPInboundThreadPool" threads blocked waiting for a lock on the following object: com/ibm/ws/sib/jfapchannel/impl/rldispatcher/DispatchToAllNonEmp tyDispatchableImpl$DispatchToAllDispatchQueue The thread that owned that lock was executing the following method: com/ibm/ws/sib/jfapchannel/impl/rldispatcher/ DispatchToAllNonEmptyDispatchableImpl$ The system appeared hung, as no messages appeared to be consumed from queues once the system entered this state.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: Users of the default messaging provider for * * IBM WebSphere Application Server Version 7.0* **************************************************************** * PROBLEM DESCRIPTION: Close operations being processed * * serially by a messaging engine might * * cause transaction timeouts under load * **************************************************************** * RECOMMENDATION: * **************************************************************** The problem occurs when applications are connecting over a network to the queue manager, and a large number of close operations are happening concurrently. A javacore taken from a messaging engine experiencing this problem will show a large number of "SIBFAPInboundThreadPool" threads blocked waiting on a DispatchToAllNonEmptyDispatchableImpl$DispatchToAllDispatchQueue object. Only a single thread is likely to be performing any actual work. Internally two inter-related issues contribute to the serial mode of processing performed by the messaging engine, when a large number of close operations come into the messaging engine concurrently: * Incorrect serialization caused threads to wait for the completion of each active work item being processed by the messaging engine, before processing the close operation. * The close operation then might be process in-line, on the thread pool used to accept data arriving over the network, and only one close operation is able to process concurrently in this scenario. Whereas other operations being performed by the messaging engine are dispatched to the separate pool of worker threads, allowing concurrent processing. When enough close operations arrive at the messaging engine, the messaging engine becomes basically serial in its operation, as the network receiving threads all become blocked and new work of any type cannot be processed until the close operations have been handled, which occurs serially.
Problem conclusion
The fix for this APAR corrects the serialization, preventing the thread handling the close operation from needing to wait for work being actively handled to complete. The fix also introduces a new sib.properties tuning parameter with the following name: com.ibm.ws.sib.jfapchannel.ALWAYS_DISPATCH_CLOSE When set to a value of 'true', this tuning property ensures that all close operations are dispatched to the messaging engine's worker threads, rather than sometimes being processed serially on the network receive threads. See the "Setting tuning properties by editing the sib.properties file" topic in the WebSphere Application Server for details of setting properties in the sib.properties file. The fix for this APAR is currently targeted for inclusion in fix pack 7.0.0.15. Please refer to the Recommended Updates page for delivery information: http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix
Comments
APAR Information
APAR number
PM19834
Reported component name
PLAT MSG COM
Reported component ID
620800101
Reported release
300
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-08-04
Closed date
2010-09-21
Last modified date
2010-09-21
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
PLAT MSG COM
Fixed component ID
620800101
Applicable component levels
R300 PSY
UP
Document Information
Modified date:
24 October 2021