Fix (APAR): PK96410 Status: Fix Release: 7.0.0.7, 7.0.0.5, 7.0.0.3 Operating System: AIX,Linux,Linux pSeries,Linux zSeries,Solaris,Windows Supersedes Fixes: CMVC Defect: PK96410 Byte size of APAR: 3679154 Date: 2009-09-30 Abstract: Intermittent error reading status line with HTTP proxy Description/symptom of problem: PK96410 resolves the following problem: ERROR DESCRIPTION: Intermittent error reading status line with HTTP proxy LOCAL FIX: N/A PROBLEM SUMMARY USERS AFFECTED: Users of IBM HTTP Server with mod_proxy_http configured PROBLEM DESCRIPTION: "proxy: error reading status line from remote server" appears in the error log intermittently RECOMMENDATION: Apply this fix if mod_proxy_http is configured When mod_proxy_http is using keepalive for pooled back end connections, a race condition can occur where the back end server decides to close the connection at about the same time that mod_proxy_http sends a new HTTP request on this same connection. The proxied request can fail and HTTP status code 502 may appear at the browser. "proxy: error reading status line from remote server" appears in the IHS error log. This problem is described by PR 37770 in Apache bugzilla https://issues.apache.org/bugzilla/show_bug.cgi?id=37770 PROBLEM CONCLUSION: IBM HTTP Server is updated with the fix for rev. 657443 from Apache httpd 2.2.x. Basically when this race condition occurs, IBM HTTP Server will close the front end connection to the browser which knows how to retry in this situation. This fix is scheduled for inclusion in IBM HTTP Server fix pack 7.0.0.9. Directions to apply fix: Special Instructions: None NOTE: The user must: * For V6, have Administrative rights in Windows, or be the Actual Root User in a UNIX environments. * For V7, logged in with the same authority level when unpacking a fix, fix pack or refresh pack. * For V6, be at V6.1.0.13 or newer of the Update Installer and for V7, 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 Certain iFixes may require a newer version of the Update Installer and the Update Installer will inform you during the installation process if a newer version is required.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 For detailed instructions to Extract the Update Installer see the following Technote: http://www.ibm.com/support/docview.wss?rs=180&uid=swg21205400 Note that there are two different methods for delivering iFixes, depending on the contents. The fix may be delivered either as a single file with a .pak extension (such as 6.1.0.11-WS-WAS-IFPK12345.pak) or a single file with a .zip extension (such as 6.1.0.11-WS-WAS-IFPK12345.zip) which then contains one or more files with a .pak extension. 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) Stop IBM HTTP Server 3) 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) Please note that in the future, if a Feature Pack is installed or uninstalled, a different set of iFixes will be needed. Use the Update Installer again at that time, with the maintenance directory location where these maintenance packages are stored, to determine the required interim fixes for the new WebSphere and Feature Pack(s) combination. 9) For V7, 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. 10) Restart IBM HTTP 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) Stop IBM HTTP Server 1) Start Update Installer 2) Enter the installation location of the WebSphere product you want to remove the fix. 3) Select "Uninstall maintenance package" operation. 4) Enter the file name of the maintenance package to uninstall (PKxxxxx.pak). 5) UnInstall maintenance package. 7) Restart IBM HTTP Server Directions to re-apply fix: 1) Stop IBM HTTP Server. 2) Follow the Fix instructions to apply the fix. 3) Restart IBM HTTP Server. 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