A fix is available
APAR status
Closed as program error.
Error description
DB2DDF DB2TCPIP defect pi25682 dpi25682 DSNL511I message with indicated return code and reason code on a DB2 11 for z/os server system may occur. It is possible for the messages to occur at a high rate on some systems. Example: (the location, ipaddr and port will contain valid values, the message below is a sample only) DSNL511I DSNLIENO TCP/IP CONVERSATION FAILED TO LOCATION .... IPADDR=.... PORT=.... SOCKET=CLOSE RETURN CODE=113 REASON CODE=0523011C The return code=113 and reason code=0523011C indicate a possible second close may be occuring after the socket is already closed. Additionally, DSNL511I with SOCKET=CLOSE RETURN CODE=112 REASON CODE=05230138 may also be seen. *************************************************************** Additional Symptoms and Keywords: DSNL511I MSGDSNL511I DSNLIENO SOCKET=CLOSE CLOSE RETURN CODE=112 REASON CODE=05230138 RC112 112 05230138 RETURN CODE=113 REASON CODE=0523011C RC113 113 0523011C SOCKET=SENDMSG SENDMSG RETURN CODE=113 REASON CODE=111D011C RC113 113 111D011C SOCKET=READ READ RETURN CODE=1121 REASON CODE=74520442 RC1121 1121 74520442 RETURN CODE=113 REASON CODE=1123011C RC113 113 1123011C RETURN CODE=0 REASON CODE=00000000 RC000 000 00000000 SOCKET=RECV RECV RETURN CODE=113 REASON CODE=1179011C RC113 113 1179011C DSNL405I MSGDSNL405I DSNL415I MSGDSNL415I DSNL412I MSGDSNL412I DSNL425I MSGDSNL425I DSNL031I MSGDSNL031I DSNLZDJN 00D35102 RC00D35102 DSNLZRPA0102 DSNL031I MSGDSNL031I DSNLZDJN 00D35116 RC00D35516 DSNLZRPA0116 DSNV417I MSGDSNV417I ABEND04E AB04E S004E 04E 04E-00D3440B 00D3440B RC00D3440B DSNLXSRX DSNLXSRX:0019 0019 ABNDID0019 ABID0019 VRADC0019 04E-00D34412 00D34412 RC00D34412 DSNLXRBT DSNLXRBT:000A 000A ABNDID000A ABID000A VRADC000A 04E-00D34424 00D34424 RC00D34424 DSNLXRAX DSNLXRAX:000A 000A ABNDID000A ABID000A VRADC000A 04E-00D30014 00D30014 RC00D30014 DSNLTRSI DSNLTRSI+1C60 1C60 OFFSET1C60 DSNLTRSI+1C64 1C64 OFFSET1C64 DSNLTRSI+1C8E 1C8E OFFSET1C8E ABEND0C4 AB0C4 S00C4 0C4 0C4-00000004 00000004 RC00000004 DSNLZRPY DSNLZRPY+27E2 27E2 OFFSET27E2 0C4-00000010 00000010 RC00000010 DSNLZTRC DSNLZTRC+16BA 16BA OFFSET16BA DSNXROHB DSNXROHB+02CA 02CA OFFSET02CA 0C4-00000038 00000038 RC00000038 DSNLZTRC DSNLZTRC+1030 1030 OFFSET1030 SQLCODE -30081 SQLCODE30081 SQL30081N
Local fix
no local fix or workaround
Problem summary
**************************************************************** * USERS AFFECTED: All Distributed Data Facility (DDF) users. * * DB2 11 for z/OS only. * **************************************************************** * PROBLEM DESCRIPTION: Various DSNL511I message conditions * * and other unpredictable symptoms * * related to unexpected socket close * * conditions. * **************************************************************** * RECOMMENDATION: * **************************************************************** Relative to DB2 server processing, DB2 11 for z/OS includes the following two enhancements: 1. A performance improvement that is achieved by utilizing TCP/IP Synchronous, as opposed to Asynchronous, Receive operations while the server thread (DBAT) is processing an active transaction. This utilization of Synchronous Receive operations (while in an active transaction) requires that DB2 also utilize TCP/IP "MsgConnTerm" exit support so DB2 can be made aware of connection termination events in which case it may be necessary to interrupt the DBAT. 2. A completion of connection termination processing in situations where connection termination processing happens to be interrupted. The combination of these two enhancements leads to a condition where a DBAT may be incorrectly interrupted when it is not necessary and, as a result of this (unnecessary) interruption, then repeat a close of a socket that was already successfully closed prior to the DBAT being interrupted. This leads to a situation where a DBAT may close a socket that has already been closed or, worse, has since been assigned to another (requester or server related) thread. This leads to various unexpected DSNL511I messages and other unpredictable symptoms that can occur as a result of unexpected socket close conditions that appear to be randomly generated. The condition appears to be prevalent relative to connections with remote DB2 for z/OS partners, and this is due to the use of DRDA two phase commit support which tends to lead to an abundance of unnecessary DBAT interruption conditions. The conditions may also appear to occur after z/OS 1.13 maintenance (see APARs PM80004 and OA39810), or migration to z/OS 2.1, due to the MsgConnTerm support that now becomes available to DB2 11 for z/OS. Symptoms may be unpredictable but the following symptoms have been observed at, either or both, the DB2 11 for z/OS server and remote (usually also DB2 for z/OS) requester partners: . Message DSNL511I Socket Return Code Reason Code CLOSE 113 0523011C CLOSE 112 05230138 SENDMSG 113 011D011C READ 0 00000000 READ 1121 74520442 or 76650446 . SQLCODE -30081. . Hung inactive connection or DBAT, as observed in the Display Thread Inactive command report. . Message DSNL425I. . Message DSNL405I and an unexpected entry in the Display Thread Indoubt command report. The indoubt thread should be automatically resolved as indicated by a DSNL415I message. . Message DSNL406I and an unexpected entry in the Display Thread Indoubt command report. The indoubt thread should be automatically resolved as indicated by a DSNL423I message. . An increase in LOGREC entries describing 04E-00E50013 abend (interruption) conditions. Most symptoms occur relative to the failing DB2 11 for z/OS server system in which case the APAR solution can be applied at the DB2 11 for z/OS system where the symptom occurs. But due to the nature of the error, it's difficult to be certain of the origin (server or requester system) of the error. As a result, the best approach is to apply the APAR solution to the system reporting the symptom, if DB2 11 for z/OS, and any DB2 11 for z/OS partner(s).
Problem conclusion
DB2 11 for z/OS is changed to: 1. eliminate the unnecessary interruption of a DBAT as a result of "MsgConnTerm" exit processing, and 2. eliminate the potential of a duplicate socket close condition.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI25682
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
B10
Status
CLOSED PER
PE
NoPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2014-09-12
Closed date
2014-10-01
Last modified date
2014-11-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI21918
Modules/Macros
DSNLCTRC DSNLIDDC DSNLIXIT
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RB10 PSY UI21918
UP14/10/17 P F410
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
06 May 2020