PM00028: USING LOCAL OS API IN SOLARIS HANGS WHEN THERE ARE MULTIPLE THREADS ATTEMPTING TO GET GROUPS FOR USERS.

Fixes are available

APAR status

Closed as program error.

Error description

Reviewed the native_stdout.log and it was found that there are
multiple threads attempting to get groups for users. The
platform specific code for the Solaris version of the user
registry was examined and it was determined that when multiple
threads are attempting to access the group database, the
position kept by the Operating System for the database can be
reset when each thread attempts to load the database. Since
the position for the group database in Solaris is shared by
all the threads in the process, all the threads using the
group database can get their groups processing reset each time
a new thread initializes the group database.

In addition to the database reinitialization, it was found that
when a thread closes group data base then performance can be
affected for further requests per the endgrent() function
documentation.

The following is sample list of the threads attempting to get
groups,

"SoapConnectorThreadPool : 2" daemon prio=3 tid=0x018fe248
nid=0x4e runnable [0xbd67d000..0xbd67fa70]
at
com.ibm.ws.security.registry.unix.UnixRegistryImpl.ntv_getGroups
ForUser(Native Method)
...

"SoapConnectorThreadPool : 1" daemon prio=3 tid=0x01238f08
nid=0x4d runnable [0xbe47d000..0xbe47faf0]
at
com.ibm.ws.security.registry.unix.UnixRegistryImpl.ntv_getGroups
ForUser(Native Method)
...

"SoapConnectorThreadPool : 0" daemon prio=3 tid=0x00c48410
nid=0x4c runnable [0xbd77d000..0xbd77fb70]
at
com.ibm.ws.security.registry.unix.UnixRegistryImpl.ntv_getGroups
ForUser(Native Method)

Local fix

A temporary workaround is to remove the primary gid for the user
from the /etc/passwd file. This will short circuit the search.

Problem summary

****************************************************************
* USERS AFFECTED:  All users of IBM WebSphere Application      *
*                  Server V6.1 and V7.0                        *
****************************************************************
* PROBLEM DESCRIPTION: For WebSphere Application Server,       *
*                      using LocalOS in Solaris hangs when     *
*                      there are multiple threads attempting   *
*                      to obtain the groups for a user in      *
*                      the LocalOS registry.                   *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
For WebSphere Application Server, the application server can
cause a hang while accessing the LocalOS registry from
multiple threads. The operating system calls to open the
password and group files reset a process wide counter
everytime that they are invoked. When this happens from
multiple threads, the call to obtain a user or group from the
password or group file can get in an indeterminate state thus
causing a hang.

Problem conclusion

The code was modified to serialize access to the password and
group files.

The fix for this APAR is currently targeted for inclusion in
fix packs 6.1.0.31 and 7.0.0.11.  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
PM00028
Reported component name
WEBS APP SERV N
Reported component ID
5724H8800
Reported release
61S
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2009-10-29
Closed date
2010-01-26
Last modified date
2010-01-26

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

R61S PSY
UP
R700 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
29 December 2021

Tips

PM00028: USING LOCAL OS API IN SOLARIS HANGS WHEN THERE ARE MULTIPLE THREADS ATTEMPTING TO GET GROUPS FOR USERS.

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

R61S PSY

R700 PSY

Document Information

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