Fixes are available
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
9.0.0.11: WebSphere Application Server traditional V9.0 Fix Pack 11
9.0.5.0: WebSphere Application Server traditional Version 9.0.5 Refresh Pack
9.0.5.1: WebSphere Application Server traditional Version 9.0.5 Fix Pack 1
9.0.5.2: WebSphere Application Server traditional Version 9.0.5 Fix Pack 2
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
9.0.5.3: WebSphere Application Server traditional Version 9.0.5 Fix Pack 3
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21
APAR status
Closed as program error.
Error description
Starvation happens when threads waiting for lock on TypeRegistry as result of grammar's unresolved component cache size
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM WebSphere Application * * Server * **************************************************************** * PROBLEM DESCRIPTION: Thread starvation on TypeRegistry * * when grammar's unknown components * * cache fills up * **************************************************************** * RECOMMENDATION: * **************************************************************** Upon seeing an XML type that cannot be not found in TypeRegistry, TypeRegistry loads XML schema files to find definition of the type. However, if an XML type is not defined in any schema files, it is added to a cache to avoid loading schema files again next time when the same undefined type is observed. This optimization is done since schema loading operation can be time consuming. Where there are a large number of undefined types, the cache might overflow. When the cache overflows, a pruning algorithm cleans up items from the cache. This means TypeRegistry might load schema files for types that might have already been seen before. TypeRegistry gets locked when loading schemas and if there are many of schema loading requests, the threads have to wait and this can eventually cause thread starvation. The default size of the cache is 512. A warning is printed in the logs indicating the cache has overflowed.
Problem conclusion
New code has been put in to enable users to change the default cache size to a larger number using ' com.ibm.xml.xlxp.internal.s1.grammar.Grammar.UnresolvedComponent Cache.MAXIMUM_SIZE_EXPONENT' system property. The value of this system property should be a positive integer and the size is calculated with the following formula: 2^n (n being the property value). The default value for this property is "9" which means the cache size is "2^9 = 512". The fix for this APAR is currently targeted for inclusion in fix pack 8.5.5.15 and fix pack 9.0.0.11. Please refer to the Recommended Updates page for delivery information: http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix
Comments
APAR Information
APAR number
PH07141
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
850
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2019-01-11
Closed date
2019-02-28
Last modified date
2019-02-28
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
WEBS APP SERV N
Fixed component ID
5724H8800
Applicable component levels
R850 PSY
UP
Document Information
Modified date:
28 April 2022