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PK99815; 7.0.0.5: Supercede the interim fix for PK94209

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Abstract

Slow application deployment resulting from zip file decompression overhead

Download Description

PK99815 resolves the following problem:

ERROR DESCRIPTION:
PK94209 corrects the following problem:
Improve application deployment performance by expanding nested archives to temporary storage when an access threshold is reached.

However, there was an error in the packaging of the interim fix for PK94209 which would cause the installation of subsequent interim fixes to fail. PK99815 supercedes PK94209 and repackages the interim fix to correct this problem.

LOCAL FIX:

PROBLEM SUMMARY

USERS AFFECTED:
All users of IBM WebSphere Application Server version 7.0

PROBLEM DESCRIPTION:
Slow application deployment resulting from zip file decompression overhead

RECOMMENDATION:
None

This update provides a performance enhancement by reducing the overhead of accessing entries in nested archives. Overhead is reduced by expanding the nested archive to a temporary
location, and by using that temporary copy of the nested archive for further accesses. For medium to large sized applications, without this update, the overall cost of accessing entries within nested archives can grow to be in excess of one hour.

Frequent access is made to entries within nested archives during the deployment of new enterprise application. The performance improvements provided by this update apply mostly
to application deployment operations.

Getting input streams for entries from within nested archives is expensive due to archive decompression overhead. A request for an input stream on an entry in a nested archive requires a scan and decompression from the beginning of that nested archive.

PROBLEM CONCLUSION:
This update provides a performance enhancement by enabling the extraction of temporary copies of nested archive files when repeated access is made to entries within the nested archives.

When obtaining an input stream for a entry from within a nested archive, for example, when loading the web module deployment descriptor, "web.xml" from a web module archive (WAR file) that is stored within enterprise application archive (EAR file), as long as the nested web module archive is left inside
the enterprise application archive, accessing the web module deployment descriptor requires first that the nested web module archive be accessed, then, second, that the entries of the nested web module archive be scanned and decompressed until the target web module deployment descriptor is reached.

When the number of entries which are accessed is small, or when the overall web module archive is small, the cost of the extra scan and decompression is relatively low, and is not a problem.

When the number of entries which are accessed is more than a few, or when the web module archive has more than a few tens of kilobytes (KB) of data, the cost of the access can grow to be large.

When the number of entries which are accessed is large, or when the web module archive is very large, the cost of the access can grow to be quite excessive. (Application deployment times in excess of an hour have been seen.)

This update causes the creation of new temporary files. To disable creation of the new temporary files, use the following custom JVM property setting:

com.ibm.config.eclipse.wtp.dynamic.expansion=false

**************************************************************
All the previous APAR text describes the problem corrected by PK94209. However, the interim fix for PK94209 had a packaging problem which would cause the installation of subsequent interim fixes to fail. This APAR, PK99815, supersedes PK94209 and repackages that interim fix only. There is no additional
code change made with this APAR.
**************************************************************

*** Note that there is no problem with PK94209 as shipped in any fix pack. The fix for PK94209 is currently targeted for inclusion in fix pack 7.0.0.7. Please refer to the Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

Prerequisites

Download the UpdateInstaller below to install this fix.

[{"PRLabel":"UpdateInstaller","PRLang":"US English","PRSize":"7250000","PRPlat":{"label":"AIX","code":"PF002"},"PRURL":"http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991"}]

Installation Instructions

Review the readme.txt for detailed installation instructions.

[{"INLabel":"Readme","INLang":"US English","INSize":"9815","INURL":"ftp://public.dhe.ibm.com/software/websphere/appserv/support/fixes/PK99815/readme.txt"}]
On
[{"DNLabel":"7.0.0.0-WS-WAS-IFPK99815","DNDate":"29 Oct 2009","DNLang":"US English","DNSize":"24184","DNPlat":{"label":"AIX","code":"PF002"},"DNURL":"https://www.ibm.com/support/fixcentral/quickorder?fixids=7.0.0.0-WS-WAS-IFPK99815&product=ibm%2FWebSphere%2FWebSphere+Application+Server&source=dbluesearch","DNURL_FTP":"ftp://public.dhe.ibm.com/software/websphere/appserv/support/fixes/PK99815/7.0.0.0-WS-WAS-IFPK99815.pak","DDURL":"http://public.dhe.ibm.com:7618;sw_websphere;appserv/support/fixes/PK99815/7.0.0.0-WS-WAS-IFPK99815.pak"}]

Technical Support

Contact IBM Support using SR (http://www.ibm.com/software/support/probsub.html), visit the WebSphere Application Server Support Web site (http://www.ibm.com/software/webservers/appserv/was/support/), or contact 1-800-IBM-SERV (U.S. only).

[{"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Component":"Performance and High CPU Utilization","Platform":[{"code":"PF002","label":"AIX"},{"code":"PF010","label":"HP-UX"},{"code":"PF012","label":"IBM i"},{"code":"PF016","label":"Linux"},{"code":"PF027","label":"Solaris"},{"code":"PF033","label":"Windows"}],"Version":"7.0;7.0.0.1;7.0.0.3;7.0.0.5","Edition":"Base;Network Deployment;Single Server","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
07 December 2019

UID

swg24024860