IBM Support

Service Bulletin 176: Sender channels stop after 10 seconds of inactivity

Technote (troubleshooting)


With APAR PJ40551, z/TPF sender channels with a channel version of MQCD_VERSION_4 or less might stop after 10 seconds of inactivity. When this timeout condition occurs, the z/TPF system issues the MQSC0345E message.

Resolving the problem

APAR PJ31241 added support for channel heartbeats. As part of this support, the channel version was updated to MQCD_VERSION_5. Channels that were defined after APAR PJ31241 was applied were created with the updated version number. Existing channels were only migrated to MQCD_VERSION_5 when the channel was changed by using the ZMQSC ALTER CHL command.

Any channel that was created before APAR PJ31241 was applied but was not changed since the APAR was applied will still be version MQCD_VERSION_4 and can be impacted by this timeout problem.

Complete the following steps to display the channel version, and if necessary, update the version:

  1. Enter ZMQSC DISPLAY CHS-channelname DEBUG, where channelname is the name of the channel definition.
  2. Find the channel address in the display. For example, in the following sample display message the channel address is 3058902C:
    CSMP0097I 14.23.33 CPU-B SS-BSS  SSU-HPN  IS-01
    CHANNEL  - FROMPERFTOXA1                 CHLTYPE   - SDR
    NPMSPEED - NORMAL                        STATUS    - RUNNING
    CONNAME  - _
    LOCLADDR -              SOCKET    - 0x00C0001E
    XMITQ    - XA1XMITQ                      INDOUBT   - NO
    CHSTATI  - 18.23.25                      CHSTADA   - 2013-08-19
    LSTMSGTI - UNKNOWN                       LSTMSGDA  - UNKNOWN
    SHORTRTS - 10                            LONGRTS   - 999999999 _
    CURSEQNO - 2                             LSTSEQNO  - 1
    CURLUWID - CBD6151F0AE09834              LSTLUWID  - CB327ABC3298924C
    MSGS     - 0                             BATCHES   - 0
    BYTSRCVD - 264                           BYTSSENT  - 328
    BUFSRCVD - 2                             BUFSSENT  - 4          _
    BATCHSZ  - 10                            HBINT     - 30
    SSL      - NO
    Chl Addr - 3058902C                      FAP       - 4
  3. Use the ZDCOR command to display 4 bytes of data starting at a displacement of 20 bytes past the channel address from the previous step. For example, if the channel address is 3058902C, enter ZDCOR 30589040.4
  4. If the ZDCOR command display shows 00000005, as shown in the following example, this indicates that the channel is version 5.
    CSMP0097I 14.24.59 CPU-B SS-BSS  SSU-HPN  IS-01
    DCOR0010I 14.24.59 BEGIN DISPLAY
    0000000030589040- 00000005                            ....

    If the ZDCOR command display shows 00000004, this indicates that the channel is still version 4 (MQCD_VERSION_4).
  5. If the channel is still version 4 (MQCD_VERSION_4), you can update the channel version without changing the channel behavior by entering ZMQSC ALTER CHL-channelname HBINT-0

If all channels are using heartbeat support (that is, HBINT > 0), the channels are already at version 5.

Related information

TPF Family Libraries

Document information

More support for: TPF
Service Bulletins

Software version: 1.1

Operating system(s): z/TPF

Reference #: 1647248

Modified date: 26 November 2013

Translate this page: