Fixes are available
PM93217;8.0.0: In an edge case where udp send fails due to network issues, UDP ?
8.0.0.8: WebSphere Application Server V8.0 Fix Pack 8
8.5.5.2: WebSphere Application Server V8.5.5 Fix Pack 2
8.0.0.9: WebSphere Application Server V8.0 Fix Pack 9
8.5.5.3: WebSphere Application Server V8.5.5 Fix Pack 3
8.5.5.4: WebSphere Application Server V8.5.5 Fix Pack 4
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
8.5.5.5: WebSphere Application Server V8.5.5 Fix Pack 5
8.5.5.6: WebSphere Application Server V8.5.5 Fix Pack 6
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
8.5.5.7: WebSphere Application Server V8.5.5 Fix Pack 7
8.5.5.8: WebSphere Application Server V8.5.5 Fix Pack 8
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
8.5.5.9: WebSphere Application Server V8.5.5 Fix Pack 9
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21
APAR status
Closed as program error.
Error description
Customer is running into OutOfMemory condition. On review of the heapdump, following code is showing as the leak suspect. . com.ibm.ws.sip.stack.transaction.transport.connections.channelfr .channelframework.SipUdpConnLink$SendThread If a UDP send fails writing to the network card/interface in the UDP Channel, further UDP writes will hang, causing the caller (SIP Container in this case) to queue up its writes, leading to an OOM. This is a rare edge case.
Local fix
N/A
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM WebSphere Application * * Server V8.0 and V8.5 using SIP or the UDP * * Channel * **************************************************************** * PROBLEM DESCRIPTION: UDP Channel hangs if UDP Send fails * * when send buffer full. * **************************************************************** * RECOMMENDATION: * **************************************************************** In a rare edge case, the UDP Channel can hang if a UDP Send fails because the OS UDP Send Buffer is full. When the hang occurs, upstream components using the UDP Channel(like SIP Container or SIP Proxy) can experience an OOM because their responses backup. If this occurs in the SIP Container, the heapdump will show something similar to: "com.ibm.ws.sip.stack.transaction.transport.connections.channelf ramework.SipUdpConnLink$SendThread" occupies 1,334,818,488 (81.00%) bytes. The memory is accumulated in one instance of "java.util.LinkedList$Link". The problem occurs because after the send fails, it is reprocessed to be attempted again. When the second attempt succeeds, the code path handling the asynchronous send mis-interprets the result and gets into a state where it believes it needs to send something but has nothing to send (because it was successful).
Problem conclusion
This problem was corrected by altering the code that reprocesses the send, so that it correctly identifies a successful send the 2nd time around. This prevents the looping condition and allows for the correct upstream notification of the result. The fix for this APAR is currently targeted for inclusion in fix packs 8.0.0.8 & 8.5.5.2 . 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
PM93217
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
800
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2013-07-17
Closed date
2013-08-27
Last modified date
2013-08-27
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
WEBS APP SERV N
Fixed component ID
5724H8800
Applicable component levels
R800 PSY
UP
R850 PSY
UP
Document Information
Modified date:
28 April 2022