A fix is available
APAR status
Closed as program error.
Error description
After upgrade the CICS Liberty from 17.0.0.4 to 18.0.0.1 CICS WLP is using more threads than before. CICS was started with the new Liberty release, and the CICS region went out of threads (the service was degraded, the liberty server was not responding). The problem that it can see from the dumps is that an OSGi application is attempting to run within the same JVMSERVER Liberty. This has been allowed for a while now and looks to have been ok until this point. With the change in the Liberty thread model it appears to be more aggressive at getting threads than before and so its preloaded all the threads up to the threadlimit. This means that when DFHSJTH attempts to allocate another thread its unable to do this and so its suspended waiting on threads that may never be freed by Liberty.
Local fix
Increase THREADLIMIT value on the JVMSERVER resource.
Problem summary
**************************************************************** * USERS AFFECTED: All CICS Users. * **************************************************************** * PROBLEM DESCRIPTION: OSGi Applications within a Liberty * * JVM server hang because Liberty has * * all the threads. * **************************************************************** An OSGi Application is installed within a Liberty JVM server. When the OSGi Application attempts to execute it hangs due to no JVM threads being available to process it. Liberty is currently using all the available threads which blocks the application.
Problem conclusion
Liberty JVM servers have been updated so that if an OSGi application is installed then 10% of threads will be reserved for its use. The JVMProfile option: -Dcom.ibm.cics.jvmserver.wlp.reserve.thread.percentage can be used to configure the percentage reserved. This can be set from 1 to 50. The CICS Transaction Server for z/OS v5.3 Knowledge Center, CICS Transaction Server for z/OS v5.4 Knowledge Center and CICS Transaction Server for z/OS v5.5 Knowledge Center have been updated as follows: JVM system properties Table 1 has been updated to add the new property: com.ibm.cics.jvmserver.wlp.reserve.thread.percentage which is supported in Liberty JVM servers only Plus the following description is added: Reserves a percentage of the threadlimit of the JVMSERVER for use by OSGi Applications. The value can be between 1% and 50%.
Temporary fix
Comments
APAR Information
APAR number
PH03693
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
00L
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2018-10-08
Closed date
2019-03-05
Last modified date
2019-04-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI61673 UI61674 UI61676 UI61677 UI61678
Modules/Macros
DFHSJJS DFJ@H351 DFJ@H352 DFJ@H427 DFJ@H561 DFJ@H563
Fix information
Fixed component name
CICS TS Z/OS V5
Fixed component ID
5655Y0400
Applicable component levels
R000 PSY UI61673
UP19/03/08 P F903
R00D PSY UI61674
UP19/03/08 P F903
R100 PSY UI61676
UP19/03/06 P F903
R10D PSY UI61677
UP19/03/06 P F903
R200 PSY UI61678
UP19/03/06 P F903
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.
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.3","Edition":"","Line of Business":{"code":"LOB35","label":"Mainframe SW"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"5.3","Edition":"","Line of Business":{"code":"","label":""}}]
Document Information
Modified date:
02 April 2019