A fix is available
APAR status
Closed as program error.
Error description
During a period of high CPU a connection (IPCONN) is dropped by TCPIP or a TCPIP Client. This high CPU situation takes away CPU resources from other CICS regions. Since the CICS region associated with the dropped connection is not getting enough CPU there is a window in IPCONN acquire processing where the CISS task can get delayed due to the CPU shortage. . When the inbound connection is closed by the client, because the IPIC connection wasn't established in time, CSOL is notified but cannot locate the correct IPCONN or CISS task to notify of this. The fact the connection is closed then gets lost. The send of the IPCONN capex (Capability Exchange) response is successful even though the client will never receive it. . Inbound only IPCONNs are able to acquire with just a single socket so that is why the IPCONN ends up acquired at this point even though the connection is closed. Since the IPCONN appears as ACQuired in CICS the INITIALIZE_CONNECTION from the client fails because you cannot ACQuire an IPCONN that is already ACQuired. This results in the DFHIS1015 code (x'0515) message being issued. . Additional Symptom(s) Search Keyword(s): DFHIS1015 0515 INITIALIZE_CONNECTION , KIXREVRJL
Local fix
The IPCONN can be made to work again by manually releasing it. A simple SET IPCONN REL command is enough because the client will reconnect successfully on its next retry interval
Problem summary
**************************************************************** * USERS AFFECTED: All CICS Users. * **************************************************************** * PROBLEM DESCRIPTION: CICS suffers a DFHIS1015 error code * * (X'0515'). * **************************************************************** It is possible for CICS to suffer a DFHIS1015 error code (X'0515') during times when the CICS region is being CPU constrained. The error happens when a client system connected to a CICS region using an IPCONN does not get a response to its capability exchange quickly enough and closes the socket. This can result in CICS believing the IPCONN is acquired and the client believing it is released, and the client will keep sending in CAPEX (Capability Exchange requests) into CICS. Each of these CAPEX requests will result in a DFHIS1015 message.
Problem conclusion
CICS has been changed to issue a new message DFHIS1047 and an exception trace entry to indicate the client has closed the socket. The CICS TS IBM Documentation has been changed to add a new message DFHIS1047: DFHIS1047 date time applid The capability exchange was abandoned for IPCONN ipconn from applid applid because the client has closed the connection. Explanation During processing of a connection request for an IPIC web session IPCONN ipconn, CICS received a capability exchange request at the same time the connection was being closed. System Action An exception trace is written by IS domain, indicating the connection has been unexpectedly closed. The capability exchange will fail and the IPCONN is not acquired. User Response Investigate why the client has closed the connection. The new exception trace is IS 0550: IS 0550 DFHSICO Exc CLIENT SOCKET CLOSED 1 ISCO parameter list
Temporary fix
Comments
APAR Information
APAR number
PH34965
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2021-03-02
Closed date
2021-05-24
Last modified date
2022-01-13
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI75535 UI75536 UI75537
Modules/Macros
DFHCIS4 DFHISAL DFHISCO DFHISCOP DFHISCOT DFHISCU DFHISDM DFHISDUF DFHISEM DFHISEMP DFHISFS DFHISIC DFHISIF DFHISIS DFHISJU DFHISLQ DFHISLQP DFHISPH DFHISPHP DFHISPRP DFHISRE DFHISREU DFHISREX DFHISRR DFHISRRP DFHISRS DFHISRSP DFHISSR DFHISST DFHISTRI DFHISUE DFHISXF DFHISXM DFHISXS DFHISZA DFHMEISC DFHMEISE DFHMEISK DFHMIRS DFHMNXM DFHWBAP DFHWBAPF DFHWBCL DFHWBDM DFHWBDUF DFHWBSO DFHWBSV DFHWBSVT DFHWBXM
Fix information
Fixed component name
CICS TS Z/OS V5
Fixed component ID
5655Y0400
Applicable component levels
R100 PSY UI75537
UP21/05/25 P F105
R200 PSY UI75536
UP21/05/25 P F105
R300 PSY UI75535
UP21/05/26 P F105
Fix is available
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Document Information
Modified date:
14 January 2022