A fix is available
APAR status
Closed as program error.
Error description
You are experiencing a region slowdown issue. The lock Manager shows most of the lock requests and suspends are from SOLOCK and SOTCPIPS. This is due to one of your programs issuing an EXEC CICS TCPIP CLIENTNAME which results in a GETHOSTBYADDR call, and your network has slow response on this GETHOSTBYADDR call. CICS needs to measure the elasped time of issuing the call. A warning message needs to be issued regarding what program is issuing this call and which IP address is being involved if the time goes above a certain threshold. Additional Symptom(s) Search Keyword(s): KIXREVSPW
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS Users * **************************************************************** * PROBLEM DESCRIPTION: EXEC CICS EXTRACT TCPIP CLIENTNAME * * results in a TCPIP GETHOSTBYADDR * * call which is slow to respond * * leading to a back up of CICS tasks. * **************************************************************** * RECOMMENDATION: * **************************************************************** A CICS slowdown occurred which showed lots of waits on the SOTCPIPS lock and the SOLOCK. A task had issued EXEC CICS EXTRACT TCPIP CLIENTNAME to obtain the client name as known by the domain name server. DFHSOIS obtains the SOLOCK (SHARED), switches to the SO TCB and then issues a GETHOSTBYADDR call. The GETHOSTBYADDR is a blocking call. This took several seconds to complete. During this time, other tasks back up waiting for the SOLOCK and waiting for the SO TCB to become available. CICS fails to report this occurrence and as such diagnosis of this problem is difficult.
Problem conclusion
DFHSOIS ?get_client_hostname has been updated to issue a new message (DFHSO0118) if the GETHOSTBYADDR call takes longer than three seconds to complete. The following message will be added to the CICS Transaction Server for z/OS Version 3 Release 1 and Version 3 Release 2 CICS Messages and Codes manuals (GC34-6442-04,GC34-6827-01) in Chapter 1 "DFH messages" under section "DFHSOxxxx" after message DFHSO0117 and before message DFHSO0119. The message will read: DFHSO0118 "APPLID" THE GETHOSTBYADDR CALL TO RESOLVE IP ADDRESS "IP_ADDRESS" TO A HOST NAME TOOK OVER 3 SECONDS TO COMPLETE. EXPLANATION: CICS has issued the TCP/IP function gethostbyaddr to resolve the IP address "ip_address" to a host name. This call took greater than three seconds during which time the sockets TCB was blocked. During this time no socket IO was possible. SYSTEM ACTION: CICS continues. USER RESPONSE: The gethostbyaddr function will usually perform a name server reverse lookup to resolve the IP address into a host name. This call took over three seconds to complete. The gethostbyaddr function is most commonly driven by EXEC CICS EXTRACT TCPIP CLIENTNAME. Check that the name server defined to TCP/IP in the /etc/resolv.conf file is valid and responding correctly. You can issue the TSO NSLOOKUP command to query the name server. If a SYSTCPD DD name has been defined in the CICS job, check that the file it references correctly defines the name server. If the name server is defined correctly to CICS then contact the administrator to determine why the IP address lookup failed to respond in a timely fashion. The TCP/IP RESOLVERTIMEOUT parameter can be used to control the duration of a gethostbyaddr call. DESTINATION: Console MODULE: DFHSOIS XMEOUT PARAMETERS: applid, ip_address
Temporary fix
FIX AVAILABLE BY PTF ONLY
Comments
APAR Information
APAR number
PK78543
Reported component name
CICSTS V3 Z/OS
Reported component ID
5655M1500
Reported release
400
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-01-14
Closed date
2009-03-18
Last modified date
2009-04-02
APAR is sysrouted FROM one or more of the following:
PK58814
APAR is sysrouted TO one or more of the following:
UK44943 UK44944
Modules/Macros
DESSOAN DESSOIS DFHMESOE DFHSOCCC DFHSODCC DFHSOIS DFHSOREC DFH78543 MFHMESOE
GC34644204 | GC34682701 |
Fix information
Fixed component name
CICSTS V3 Z/OS
Fixed component ID
5655M1500
Applicable component levels
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:
02 April 2009