IBM Support

IT31485: CONTENTION ON SQLO_LT_SRVLST_CB__SRVLSTLATCHL LATCH DURING SSL CONNECTIONS

Subscribe to this APAR

By subscribing, you receive periodic emails alerting you to the status of the APAR, along with a link to the fix after it becomes available. You can track this item individually or track all items by product.

Notify me when this APAR changes.

Notify me when an APAR for this component changes.

 

APAR status

  • Closed as program error.

Error description

  • During SSL connections, there may be some contentions observed
    which are resulted from SQLO_LT_SRVLST_CB__srvLstLatchl latch
    waits.
    
    This latch is held during the reading for SSL port number entry
    in /etc/services file upon db2 database connection. And for any
    reason, the read I/O is taking long, and there is high
    concurrency in number of connections to the database, then
    longer latch waits on SQLO_LT_SRVLST_CB__srvLstLatchl can be
    observed, causing longer connection times.
    
    This defect will add an enhancement to not read SSL port number
    from /etc/services file upon each connection, but rather load it
    into the memory upon the first connection and be used by
    subsequent connections.
    
    db2pd -latches output collected during the issue, may show the
    following output:
    
    0x0780000000470D68 1183602    84416      sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    165652     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    155143     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    91878      sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    185478     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    286680     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    425941     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    269915     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    125267     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    128346     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    78456      sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    261764     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    289963     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    85535      sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    111414     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    175238     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    194977     sqleu_serverd.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    219593     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    0x0780000000470D68 1183602    245242     sqleu_server.C
    6329       SQLO_LT_SRVLST_CB__srvLstLatch 1
    

Local fix

  • As a temp workaround, SSL port number can be bumped up inside
    /etc/services file to help reads be faster.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All users on DB2 v111m4FP5 and earlier                       *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Upgrade to DB2 v111m4FP6 or apply Local Fix is available     *
    ****************************************************************
    

Problem conclusion

  • First Fixed in DB2 v111m4FP6
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT31485

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-01-10

  • Closed date

    2021-03-15

  • Last modified date

    2021-03-15

  • 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

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1"}]

Document Information

Modified date:
16 March 2021