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:
- Enter ZMQSC DISPLAY CHS-channelname DEBUG, where channelname is the name of the channel definition.
- 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
MQSC0085I 14.23.33 CHANNEL STATUS DISPLAY:
CHANNEL - FROMPERFTOXA1 CHLTYPE - SDR
NPMSPEED - NORMAL STATUS - RUNNING
RQMNAME - TPFQM
CONNAME - 126.96.36.199 _
LOCLADDR - 188.8.131.52(1034) 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
- 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
- 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 ....
END OF DISPLAY - ZEROED LINES NOT DISPLAYED+
If the ZDCOR command display shows 00000004, this indicates that the channel is still version 4 (MQCD_VERSION_4).
- 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.