APAR status
Closed as program error.
Error description
Error Message: N/A . Stack Trace: A javacore taken during the performance issue shows many threads with following stack trace. 3XMTHREADINFO3 Java callstack: 4XESTACKTRACE at java/util/TimeZone.getDefaultInAppContext(TimeZone.java:793(Comp iled Code)) 5XESTACKTRACE (entered lock: java/util/TimeZone@0x000000060006D3C0, entry count: 1) 4XESTACKTRACE at java/util/TimeZone.getDefaultRef(TimeZone.java:640(Compiled Code)) 4XESTACKTRACE at java/util/Calendar.getInstance(Calendar.java:979(Compiled Code)) The lock section of the javacore shows many threads are blocking for the lock on java/util/TimeZone 2LKMONINUSE sys_mon_t:0x0000010022A1C898 infl_mon_t: 0x0000010022A1C8E0: 3LKMONOBJECT java/util/TimeZone@0x000000060006D3C0: owner "SIBJMSRAThreadPool : 13" (0x0000000044BBAE00), entry count 1 3LKWAITERQ Waiting to enter: 3LKWAITER "SIBJMSRAThreadPool : 0" (0x00000000448DE700) 3LKWAITER "SIBJMSRAThreadPool : 2" (0x00000000428BD800) 3LKWAITER "SIBJMSRAThreadPool : 3" (0x000000004257A000) 3LKWAITER "SIBJMSRAThreadPool : 4" (0x0000000044852F00) 3LKWAITER "SIBJMSRAThreadPool : 6" (0x000000004493CF00) 3LKWAITER "SIBJMSRAThreadPool : 7" (0x0000000044945000) 3LKWAITER "SIBJMSRAThreadPool : 8" (0x000000004497D000) 3LKWAITER "SIBJMSRAThreadPool : 9" (0x0000000044BA0A00) 3LKWAITER "SIBJMSRAThreadPool : 10" (0x0000000044BA7300) 3LKWAITER "SIBJMSRAThreadPool : 11" (0x0000000044BADC00) 3LKWAITER "SIBJMSRAThreadPool : 12" (0x0000000044BB4500) 3LKWAITER "SIBJMSRAThreadPool : 14" (0x0000000044BC2F00) 3LKWAITER "SIBJMSRAThreadPool : 15" (0x0000000044BC9800) 3LKWAITER "SIBJMSRAThreadPool : 16" (0x0000000044BD0100) 3LKWAITER "SIBJMSRAThreadPool : 18" (0x0000000044BDD200) 3LKWAITER "SIBJMSRAThreadPool : 20" (0x0000000044BEA400) 3LKWAITER "SIBJMSRAThreadPool : 21" (0x0000000044BF0D00) 3LKWAITER "SIBJMSRAThreadPool : 22" (0x0000000044BF7600) . N/A
Local fix
Cache the default timezone in the application.
Problem summary
The Poor performance was due to the excess synchronization in TimeZone class as the entire method is synchronized.
Problem conclusion
This defect will be fixed in: 6.0.0 SR12 6.0.1 SR4 7.0.0 SR3 . The JDK is updated to limit the synchronization only when it is required and thereby minimize the contention.
Temporary fix
Comments
APAR Information
APAR number
IV28205
Reported component name
JAVA CLASS LIBS
Reported component ID
620700130
Reported release
600
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-09-20
Closed date
2012-10-05
Last modified date
2013-12-16
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
JAVA CLASS LIBS
Fixed component ID
620700130
Applicable component levels
R600 PSY
UP
R700 PSY
UP
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Document Information
Modified date:
16 December 2013