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CICS CM CCVI abends AEXZ on startup in CCVIINIT

Question & Answer


Question

Why am I receiving an message DFHAC2236 with an abend AEXZ each time that I attempt to startup a newly installed CICS Configuration Manager (CICS CM) server using the CCVI transaction? It looks like it is starting up, but after about 10 seconds it fails with the AEXZ. The last messages I see in the CICS MSGUSR indicate it successfully opened the TCPIPSERVICE:

DFHSO0107 mm/dd/yyyy hh:mm:ss applid TCPIPSERVICE CCVBASIC has been opened on port nnnnn at IP address nnn.nn.nn.nnn.

DFHDU0203I mm/dd/yyyy hh:mm:ss applid A transaction dump was taken for dumpcode: AEXZ, Dumpid: 1/0001.

DFHAC2236 mm/dd/yyyy hh:mm:ss applid Transaction CCVI abend AEXZ in program CCVIINIT term ????. Updates to local recoverable resources will be backed out.

CEEMSG shows:

CEE3250C The system or user abend AEXZ was issued. From compile unit CCVIINIT at entry point CCVIINIT at compile unit offset +0000832E at entry offset 18E8854E.

If CCVI is run a few more times, it eventually seems to initialize the server successfully.

Answer

The AEXZ abend indicates a command has failed due to a serious failure in a CICS component (resource manager). The transaction dump will not contain any trace entries for the CICS CM CCVI task as it is distributed with TRACE(NO) in the supplied TRANSACTION definition. Without any other previous error messages, you need to start with the Transaction Abend Control Block (TACB) PSW and registers. In this instance, R14 pointed x'1296' into CICS TS module DFHEIQSO. This module provides CICS Transaction Server (CICS TS) system programming interface (SPI services for TCPIP. A CICS trace is needed to see what SPI call the CCVI task performed. Based on the previous DFHSO0107 message, it is most like a SET TCPIPSERVICE(CCVBASIC) OPEN command that did not complete.

In order to get a trace for the CCVI transaction along with CICS socket domain tracing and some other domains, use the CICS TS CETR transaction to request special tracing for transaction CCVI (use PF5 and specify 'CCVI' as the transaction ID and for Transaction Status, specify 'SPECIAL'). Then use PF4 for components and ensure all CICS components show at least a '1' for tracing and specify 1-2 for the AP, EI, LM, PG, and SO domains.

Ensure that CETR show the master system trace flag as 'ON' and that the internal trace table size is at least 8M as CICS CM generates a lot of trace which is why it is shipped with TRACE(NO).

Enter CEMT SET TRDUMPCODE(AEXY) ADD MAX(1) SYSDUMP to obtain a full dump with trace.

In this instance, the new AEXZ system dump showed trace entries for the CICS CSOL sockets listener task :

SO 0433 SOIS EVENT GETNAMEINFO_ENTRY at TIME-17:14:43.6077257568

SO 0434 SOIS EVENT - GETNAMEINFO_EXIT at TIME-17:14:54.0243463835

This is almost 11 seconds later for the GETNAMEINFO to complete.

The CCVI transaction definition is shipped with DTIMOUT(10) for a 10 second timeout which is why it was purged and got a disaster response from the call.

As part of CICS TS is registering the CCVBASIC TCPIPSERVICE it uses Unix System Services to make a BpxGetNameInfo call. This will use the TCPIP RESOLVER services to search. In this instance, the problem was due to having the wrong DNS defined on the configuration resolver file. After getting rid of the wrong DNS, CCVI initialized successfully each time.

Technote 1115689, Understanding how the z/OS Communications Server IP resolver queries DNS for a host name to IP address resolution, describes how TCPIP searches for the host-name and how to obtain a resolver trace.

The IBM Knowledge Center also describes the search order for Base resolver configuration files.

A temporary workaround could have been to redefine the CCVI transaction with DTIMOUT(15) for 15 seconds as this specific system took 11 seconds to search, however the correct fix is to properly configure the DNS resolver.

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Product Synonym

CICSCM CICS CM

Document Information

Modified date:
19 May 2015

UID

dwa1186054