APAR status
Closed as program error.
Error description
The web container component in WAS uses a class called
SimpleHashtable to store data in a hashed manner. The class
holds an array of HashtableEntries to store objects in it.
All classes creating those SimpleHashtables do so via a
default constructor that creates an array of
HashtableEntries with 127 array indices. We see quite a lot
of those objects in the heap having only very few references
and/or objects stored in the hashtable. Hence, a great deal of
memory is used by empty array indices.
Local fix Problem summary
****************************************************************
* USERS AFFECTED: Performance enchancement for *
* webContainer and Session components. *
****************************************************************
* PROBLEM DESCRIPTION: The web container and session *
* components in WAS *
* use a class called SimpleHashtable *
* to store data in a hashed manner. *
* The class holds an array of *
* HashtableEntries to store objects *
* in it. All classes creating those *
* SimpleHashtables do so via a default *
* constructor that creates an array of *
* HashtableEntries with 127 array *
* indices. In some cases, quite a lot *
* of those objects in the heap having *
* only very few references *
* and/or objects stored in the *
* hashtable. Hence, a great deal of *
* memory is used by empty array indices. *
****************************************************************
* RECOMMENDATION: *
****************************************************************
The default value for the SimpleHashtable was set too high.
Components like webContainer and Session depend on the
SimpleHadtable to hold their runtime objects. A large
SimpleHashtable may not be required.
Since the SimpleHastable is "growable", the initial size should
be set to a reasonable value.
Problem conclusion
During initialization of WebContainer and Session components,
set the default size of the SimpleHashtable to a smaller number
Temporary fix
testFix drivers posted to
pq99999 on 12/03/2003
Comments
APAR information |
APAR number |
PQ81539 |
Reported component name |
WAS ENTERPRISE |
Reported component ID |
5630A3700 |
Reported release |
00A |
Status |
CLOSED PER |
PE |
NoPE |
HIPER |
NoHIPER |
Special Attention |
NoSpecatt |
Submitted date |
2003-12-01 |
Closed date |
2004-01-07 |
Last modified date |
2004-01-07 |
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
Publications Referenced
Applicable component levels |
R003 PSY |
UP |
R00A PSY |
UP |
R00H PSY |
UP |
R00I PSY |
UP |
R00S PSY |
UP |
R00W PSY |
UP |
|