Fix (APAR): PM94437 Status: Fix Release: 7.0.0.29 Operating System: AIX,HP-UX,IBM i,Linux,Mac OS,Solaris,Windows,z/OS Supersedes Fixes: CMVC Defect: PM94437 Byte size of APAR: 200605 Date: 2013-12-06 Abstract: When an LDAP server goes down, all threads trying to communicate with the LDAP get blocked until the read times out. Description/symptom of problem: PM94437 resolves the following problem: ERROR DESCRIPTION:? When Ldap connection fails, VMM discards all the old contexts from the context pool and recreates a new pool. While this new pool is being created, all threads requesting access to Ldap are put in a 'wait' state. This APAR, minimizes the number of threads that wait on the Ldap Context pool creation to a user configured number. LOCAL FIX:? NONE PROBLEM SUMMARY:? USERS AFFECTED: All users of IBM WebSphere Application Server PROBLEM DESCRIPTION: When an LDAP server goes down, all threads trying to communicate with the LDAP get blocked until the read times out. RECOMMENDATION: None When an LDAP Server goes down, any new thread that tries to read from the server gets an exception. Virtual Member manager (VMM) then tries to recreate the LDAP Context Pool and during this creation all incoming threads are blocked. If a connection cannot be made for 120 seconds an exception is thrown and the threads are able to complete their processing. All requesting threads are, however, blocked for the duration until the exception is thown. PROBLEM CONCLUSION:? The code was modified to ensure that all threads are not blocked during this context pool recreation. You can configure if you want to minimize the number of threads blocked and also configure the exact number of threads blocked with the help of custom properties "minimizeContextPoolThreadBlock" and "maxThreadsToBlock". By default these values are "true" and "5". You can also customize to trace the bind timeout with a custom property named "bindTimeout". In order to set these properties, use the following commands: $AdminTask setIdMgrCustomProperty {-id -name minimizeContextPoolThreadBlock -value true} $AdminTask setIdMgrCustomProperty {-id -name maxThreadsToBlock -value 5} $AdminTask setIdMgrCustomProperty {-id -name bindTimeout -value } Here "LDAP_repos_ID" is the repository id of the LDAP configured in VMM. "millseconds" is to track the count of "quick" binds. Dump the updated statistic to the log. Also save the configuration after running the previous command using: $AdminConfig save The fix for this APAR is currently targeted for inclusion in fix packs 7.0.0.31, 8.0.0.8 and 8.5.5.2. Please refer to the Recommended Updates page for delivery information: http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980 Directions to apply fix: NOTE: Mark with an X the: 1) Release the fix applies to 2) The Editions that apply 3) And then DELETE THIS NOTE Fix applies to Editions: Release 7.0 __ Application Server (Express or BASE) __ Network Deployment (ND) __ Edge Components __ Developer Install Fix to all WebSphere installations unless special instructions are included below. Special Instructions: None NOTE: The user must: * Logged in with the same authority level when unpacking a fix, fix pack or refresh pack. * Be at V7.0.0.0 or newer of the Update Installer. Certain iFixes may require a newer version of the Update Installer and the Update Installer will inform you during the installation process if a newer version is required. This can be checked by reviewing the level of the Update Installer in file /updateinstaller/version.txt. The Update Installer can be downloaded from the following link: http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205991 1) If your iFix is delivered as a single file with a .pak extension, Copy the .pak file directly to the maintenance directory. If your iFix is delivered as a single file with a .zip extension, unzip the file into the maintenance directory. 2) Shutdown WebSphere Application Server. Manually execute setupCmdLine.bat in Windows or . ./setupCmdLine.sh in Unix from the WebSphere instance that maintenance is being applied to. 3) For IBM i users, use the update command to install and uninstall the interim fix. The IBM Information Center can provide additional details, if needed, on the use of this command. http://www14.software.ibm.com/webapp/wsbroker/redirect?version=compass&product=was-nd-iseries&topic=rins_update. For non-IBM i users, launch the Update Installer and click the Next button on the Welcome page. 4) Enter the directory path of the installation location of the WebSphere product you want to update, and click the Next button. 5) Select the "Install maintenance package" operation and click the Next button. 6) Enter the directory path of your maintenance directory where you have the maintenance packages (.pak files) and click the Next button. 7) The Available Maintenance Package to Install page should list all maintenance packages (.pak files) that it finds in the directory path provided in the previous step. The Update Installer will select the correct maintenance packages based on your system configuration and will not allow an invalid combination to be installed. Please keep the Update Installer recommendations and click the Next button and continue with the installation of the maintenance package. To determine why some maintenance packages have been identified as not applicable, see description in log found in /logs/tmp*/updatelogs.txt 8) For all platforms except Windows. In pre-install summary panel, use the "verify permission" feature to verify the user has permissions to apply updates to files associated with the selected maintenance. Correct any file permissions before clicking next to start the install. 9) Restart WebSphere Application Server. Directions to remove fix: NOTE: * The user must have Administrative rights in Windows, or be the Actual Root User in a UNIX environments. * FIXES MUST BE REMOVED IN THE ORDER THEY WERE APPLIED * DO NOT REMOVE A FIX UNLESS ALL FIXES APPLIED AFTER IT HAVE FIRST BEEN REMOVED * YOU MAY REAPPLY ANY REMOVED FIX Example: If your system has fix1, fix2, and fix3 applied in that order and fix2 is to be removed, fix3 must be removed first, fix2 removed, and fix3 re-applied. 1) Shutdown WebSphere Application Server. Manually execute setupCmdLine.bat in Windows or . ./setupCmdLine.sh in Unix from the WebSphere instance that uninstall is being run against. 2) Start Update Installer 3) Enter the installation location of the WebSphere product you want to remove the fix. 4) Select "Uninstall maintenance package" operation. 5) Enter the file name of the maintenance package to uninstall (PKxxxxx.pak). 6) UnInstall maintenance package. 7) Restart WebSphere Directions to re-apply fix: 1) Shutdown WebSphere Application Server. 2) Follow the Fix instructions to apply the fix. 3) Restart WebSphere Application Server. Additional Information: