IBM Support

PM39613: OUT OF MEMORY WHEN SIP SERVLET CONTAINER STUCK ON MULTIPLE TCP CONNECTIONS DURING SIP LOAD

Fixes are available

7.0.0.19: WebSphere Application Server V7.0 Fix Pack 19
PM43988; 7.0.0.19: out of memory error in Session Initiation Protocol container
7.0.0.21: WebSphere Application Server V7.0 Fix Pack 21
8.0.0.2: WebSphere Application Server V8.0 Fix Pack 2
8.0.0.3: WebSphere Application Server V8.0 Fix Pack 3
7.0.0.23: WebSphere Application Server V7.0 Fix Pack 23
8.0.0.4: WebSphere Application Server V8.0 Fix Pack 4
7.0.0.25: WebSphere Application Server V7.0 Fix Pack 25
8.0.0.5: WebSphere Application Server V8.0 Fix Pack 5
7.0.0.27: WebSphere Application Server V7.0 Fix Pack 27
8.0.0.6: WebSphere Application Server V8.0 Fix Pack 6
7.0.0.29: WebSphere Application Server V7.0 Fix Pack 29
8.0.0.7: WebSphere Application Server V8.0 Fix Pack 7
8.0.0.8: WebSphere Application Server V8.0 Fix Pack 8
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
8.0.0.9: WebSphere Application Server V8.0 Fix Pack 9
7.0.0.35: WebSphere Application Server V7.0 Fix Pack 35
8.0.0.10: WebSphere Application Server V8.0 Fix Pack 10
7.0.0.37: WebSphere Application Server V7.0 Fix Pack 37
8.0.0.11: WebSphere Application Server V8.0 Fix Pack 11
7.0.0.39: WebSphere Application Server V7.0 Fix Pack 39
8.0.0.12: WebSphere Application Server V8.0 Fix Pack 12
7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
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

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Out of Memory when Session Initiation Protocol (SIP) Servlet
    Container is stuck on multiple TCP connections during SIP load
    
    Use of 100 TCP connections caused the WebSphere Application
    Server to hang afterr a long term Load running ~ 30 hours on
    OOM ( Out Of Memory ).
    

Local fix

  • n/a
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Session Initiation Protocol (SIP) users     *
    *                  of IBM WebSphere Application Server V7.0    *
    *                  and V8.0                                    *
    ****************************************************************
    * PROBLEM DESCRIPTION: There is a deadlock in the SIP          *
    *                      container under heavy TCP load.         *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The problem occurs when the server attempts to send a
    multitude of messages over TCP (or TLS) concurrently.
    
    When the container requests to send out a SIP message, it
    places the outbound message in a queue, and calls
    one of the worker threads to transmit the packet to the
    network. If there is no available thread in the pool, the
    container thread gets blocked, until some worker thread
    becomes available.
    
    In some cases, the thread that initiates the transaction, is
    a thread that is allocated from the same pool as the worker
    threads. Under extremely high load, it is possible to come to
    a point where all worker threads are busy, and they all
    request to send out a message, concurrently.
    
    In this situation, each thread in the pool is waiting for one
    of the others to become available, introducing a deadlock. The
    server remains unresponsive even after traffic slows down.
    

Problem conclusion

  • The problem is fixed in the SIP container by changing the
    code that initiates message sending. With this fix, the
    container first attempts to send the message from the
    initiating thread, instead of forcing the allocation of a
    worker thread. Only if the message cannot be delivered
    immediately, a worker thread is allocated for completing the
    work later. This reduces the chance of draining the thread
    pool. Moreover, this eliminates the deadlock, and allows the
    container to recover as soon as traffic slows back down to
    normal.
    
    The fix for this APAR is currently targeted for inclusion in
    fix packs 7.0.0.19 and 8.0.0.1. 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

    PM39613

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-05-19

  • Closed date

    2011-06-09

  • Last modified date

    2011-06-18

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    PM40650

Fix information

  • Fixed component name

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

  • R700 PSY

       UP

  • R800 PSY

       UP



Document information

More support for: WebSphere Application Server
General

Software version: 7.0

Reference #: PM39613

Modified date: 18 June 2011