A fix is available
APAR status
Closed as unreproducible.
Error description
Having intermittent issues with the socket interface, the following message appears: . +DFHSO0002 REGNNAME A severe error (code X'0206') has occurred in module DFHSOCK . Soon after, the ability to use the interface stops and the following message comes out repeatedly: . +DFHSO0126 W REGNNAME An attempt to create a socket has failed because the MAXSOCKETS limit has been reached. . To temporarily resolve the issue you can Stop and then Start the TCPIPSERVICE. . The TASK suffering the DFHSO0002 is CSOL, below is the Kernel Stack for CSOL: . OFFSET ERR NAME 0003BC DFHKETA 000218 DFHDSKE 0011CC DFHXMTA 000FBA DFHPGPG 000192 INITIAL_LINK 000000 DFHAPLI1 000AAC CICS_INTERFACE 003E70 DFHSOLS 0001BC LISTEN_SOLS 00202E ACCEPTED_CONNECTION . ACCEPTED_CONNECTION - calls get_exc_lock gets SOLOCK . 000A56 DFHSOM01 . DFHSOM01 - called to add lock, but at max.. so calls DFHSOCK to close . 004E72 DFHSOCK . DFHSOCK - tries to get the SOLOCK again causing the error below . 000282 CLOSE_SOCK 002076 GET_EXC_LOCK 004F22 SEVERE_ERROR 003C64 DFHMEME 000266 SEND 0032F8 CONTINUE_SEND 001578 TAKE_A_DUMP_FOR_CALLER 001504 DFHDUDU 000200 SYSTEM_DUMP 000F54 TAKE_SYSTEM_DUMP . Looking in the SO Domain you can see they are at MAXSOCKETs . Current MaxSockets: 255 HardLimit MaxSockets: 512 Owned Sockets: 254 . Then after this problem occurs they see continous DFHSO0126 messages. . In the Internal Trace you'll see the following entries: . SO 0E02 SOUS *EXC* - ASYNCIO_ERROR RETURN_VALUE(1) RETURN_CODE(0) REASON_CODE(00000000) . SO 0206 SOCK *EXC* - LOCK_ERROR . When maxsocket has been reached, the CSOL task will attempt to close sockets that are unused when a new request from a client is received. Part of DFHSOCK CLOSE is to obtain an exclusive LOCK for SOLOCK. However, the SOLOCK has already been obtain earlier by CSOL causing the resulting in the LOCK_ERROR see in the trace and the SO0002 SDUMP. . You may also see the following message as well in some instances: . DFHSO0001 An abend (code ---/ASOB) has occurred at offset X'0956' in module DFHSOM02. . Additional Symptom(s) Search Keyword(s): KIXREVDAM
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS users. * **************************************************************** * PROBLEM DESCRIPTION: Active IPIC connection is released * * when maxsocket condition is exceeded. * **************************************************************** * RECOMMENDATION: * **************************************************************** When MAX socket condition reached. CICS will free a dead unowned socket for use. If there is no dead socket, first socket in unowned socket chain will be chosen. If there is IPIC connection. It will be chosen and closed even if it is active. It will leads to IPIC connection released and succeeding async_io error by IPIC connection.
Problem conclusion
Temporary fix
FIX AVAILABLE BY PTF ONLY
Comments
DFHSOM01 has been changed to not choose first unowned socket if no dead socket found.
APAR Information
APAR number
PM37810
Reported component name
CICSTS V3 Z/OS
Reported component ID
5655M1500
Reported release
500
Status
CLOSED UR3
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2011-04-26
Closed date
2011-08-11
Last modified date
2011-09-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UK70721
Modules/Macros
DESSOMG DESSOSO DFHSOMGC DFHSOM01 DFHSOM02 DFHSOM03 DFHSOSOC DFHSOS00 DFHSOS01 DFHSOS02 DFHSOS03 DFHSOS04 DFHSOS05 DFHSOS06 DFHSOS07 DFHSOS08 DFHSOS09 DFHSOS10 DFHSOS11 DFHSOS12 DFHSOS13 DFHSOS14 DFHSOS15 DFHSOS16 DFHSOS17 DFHSOS18 DFHSOS19 DFHSOS20 DFHSOS21 DFHSOS22 DFHSOS23
Fix information
Fixed component name
CICSTS V3 Z/OS
Fixed component ID
5655M1500
Applicable component levels
R500 PSY UK70721
UP11/08/16 P F108
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
01 September 2011