Direct links to fixes
APAR status
Closed as program error.
Error description
Communications Server for Windows --------------------------------- After a network outage, CP-CP sessions may retry too quickly and timeout before the mainframe is ready, then give up and not retry again once the mainframe is ready.
Local fix
Stop/restart the link station.
Problem summary
The cause of the problem is as follows: - CS has established CP-CP sessions with VTAM. For some reason these two sessions are carried over a pair of RTP pipes. This is not expected for EN-NN CP-CP sessions but will work in the protocol. - A problem in the network or at the mainframe causes CS to fail to send a packet on its ConWinner CP-CP session. The RTP pipe is marked as failed, and CS sends an UNBIND for the other CP-CP session in order to recycle these sessions on the other RTP pipe (which is still working okay). - VTAM sends a fresh BIND (our ConLoser session) on that pipe, which CS accepts. - CS sends a fresh ConWinner BIND on the same pipe (instead of creating a fresh pipe) since it has already timed out its ConWinner session. - VTAM believes the ConWinner session is still up (it has not yet timed out the first RTP pipe) and rejects the BIND with sense code 0805 indicating that session limits have been exceeded. - A bug in CS caused it to retry to establish the CP-CP sessions immediately five times before giving up.
Problem conclusion
CS has been corrected to introduce a timer that is backed off in this error case. Retries will occur after 5, then 10, then 15, then 20, then 25 seconds, for a total of 75 seconds. If VTAM still has not recovered after 75 seconds, then the retry code introduced with APAR JR49602 will take effect to ensure that CS will try to establish CP-CP sessions as soon as the mainframe has recovered.
Temporary fix
Comments
APAR Information
APAR number
JR52832
Reported component name
COMM SERV NT 6.
Reported component ID
5639F2503
Reported release
613
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2015-03-17
Closed date
2015-07-08
Last modified date
2015-07-08
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
COMM SERV NT 6.
Fixed component ID
5639F2503
Applicable component levels
[{"Business Unit":{"code":"BU029","label":"Software"},"Product":{"code":"SSHQNF","label":"Communications Server for Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"613"}]
Document Information
Modified date:
21 September 2023