PK69410: NULLPOINTEREXCEPTION IN JSPEXTENSIONSERVLETWRAPPER.TRANSLATEJSP

Fixes are available

APAR status

Closed as program error.

Error description

The problem occurs only in a WebSphere application server for
z/OS running with multiple servants.  When JSPs are compiled on
the fly in this environment, the runtime code manages the case
where both servants may try to access a single JSP to compile it
concurrently by allowing one servant to lock the JSP file while
it compiles.  If the instance arises where two requests for a
JSP needing to be compiled at the same time, and are routed to
separate servant regions, the following NullPointerException is
likely to occur:
java.lang.NullPointerException
at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
            translateJsp(JSPExtensionServletWrapper.java:404)
at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
      _checkForTranslation(JSPExtensionServletWrapper.java:366)
at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
      checkForTranslation(JSPExtensionServletWrapper.java:262)
at com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.
      handleRequest(JSPExtensionServletWrapper.java:151)
at com.ibm.ws.jsp.webcontainerext.JSPExtensionProcessor.
      handleRequest(JSPExtensionProcessor.java:255)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(
                                             WebApp.java:3174)
...
The above exception is thrown in the servant who is attempting
to compile the JSP after another servant has already obtained
a lock on the JSP file.  In addition to the NullPointerException
the JSP in question is likely to be flagged as permanently
unavailable for the life of the servant region, so that all
requests coming to the servant for the JSP will fail with 500
errors (UnavailableExceptions will be thrown to the client).

Local fix

As a preventative measure, you can bypass this issue by
precompiling JSPs before or during application deployment.
If you find yourself currently experiencing
UnavailableExceptions due to this issue, a recycle of the server
or servant region will be required to recover from this problem.

Problem summary

****************************************************************
* USERS AFFECTED:  All users of WebSphere Application Server   *
*                  V6.0.1 for z/OS                             *
****************************************************************
* PROBLEM DESCRIPTION: When JavaServer Pages (JSP) are         *
*                      compiling at runtime on a z/OS server   *
*                      that is running with multiple           *
*                      servants, a NullPointerException may    *
*                      occur.                                  *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The problem occurs only in a WebSphere z/OS server running
with multiple servant regions.  When JSPs are compiled on the
fly in this environment, the JSP Container manages the case
where both servant regions may try to access a single JSP to
compile it concurrently by allowing one servant to lock the
JSP file while it compiles.  If the instance arises where two
requests for a JSP need to be compiled at the same time, and
are routed to separate servant regions, there is a small
window in which a NullPointerException is likely to occur:
java.lang.NullPointerException

at
com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.transl
ateJsp(JSPExtensionServletWrapper.java:404)
at
com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper._check
ForTranslation(JSPExtensionServletWrapper.java:366)
at
com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.checkF
orTranslation(JSPExtensionServletWrapper.java:262)
at
com.ibm.ws.jsp.webcontainerext.JSPExtensionServletWrapper.handle
Request(JSPExtensionServletWrapper.java:151)
....................

Problem conclusion

The JSP Container has been modified to cause a servant region
to retry obtaining the lock on a JSP file before compiling it.
This retry will expire after 120 seconds.  If the compilation
time is expected to be longer, a user can increase the retry
time by setting the webcontainer's custom property:

com.ibm.ws.jsp.zosFileLockRetrying = 120 (default)

The custom property is not case sensitive.

Please refer to the following technote for instructions on
enabling WebContainer custom properties:
http://www.ibm.com/support/docview.wss?rss=180&uid=swg21284395

APAR PK69410 requires changes to documentation.

NOTE: Periodically, we refresh the documentation on our
Web site, so the changes might have been made before you
read this text. To access the latest on-line
documentation, go to the product library page at:

http://www.ibm.com/software/webservers/appserv/library

The following Changes to the z/OS version of the
WebSphere Application Server Version 6.0.x Information
Center.

The following description of the
com.ibm.ws.jsp.zosFileLockRetrying Web conatiner
custom property will be added to the topic "Web
container custom properties:"

Extending the wait time when two servants need to
concurrently compile the same JSP

When JavaServer Pages files (or user-defined JSP files)
are complied in an environment that has multiple servants,
the JSP container uses locking to prevent both servants
from trying to concurrently compile the same JSP file.
If two requests for a JSP need to be compiled at the same
time, and are routed to separate servants, the JSP
container locks the JSP file until the compilation for
the first servant completes. If the second servant has to
wait for more than 120 seconds for the lock to be
released, the request for the JSP fails.

If you expect the compilation time for any of your JSP
files to be more than 120 seconds, specify, in seconds,
a value greater than 120 for the
com.ibm.ws.jsp.zosFileLockRetrying custom property. The
new setting should extend the wait time, such that the
new wait time prevents a JSP request from failing in
situations where two requests for the same JSP file need
to be handled at approximately the same time, but the
requests are routed to different servants.

APAR PK69410 currently targeted for inclusion in Service
Level (Fix Pack) 6.0.2.33 of WebSphere Application Server V6.1
for z/OS.

Please refer to URL:
//www.ibm.com/support/docview.wss?rs=404&uid=swg27006970
for Fix Pack availability.

Temporary fix

Comments

APAR Information

APAR number
PK69410
Reported component name
WEBSPHERE FOR Z
Reported component ID
5655I3500
Reported release
601
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-07-22
Closed date
2008-09-15
Last modified date
2009-03-03

APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:

PK75090 PK75949

Fix information

Fixed component name
WEBSPHERE FOR Z
Fixed component ID
5655I3500

Applicable component levels

R601 PSY UK43592
UP09/02/11 P F902

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":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SS7K4U","label":"WebSphere Application Server for z\/OS"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.0.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
28 December 2021

Tips

PK69410: NULLPOINTEREXCEPTION IN JSPEXTENSIONSERVLETWRAPPER.TRANSLATEJSP

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R601 PSY UK43592

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.

Document Information

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