Ensure that Oracle Web Cache has been configured to communicate with IIS, as Start IIS, and then access the following URL:

A Troubleshooting Oracle Web Cache A-1 A Troubleshooting Oracle Web Cache This appendix describes common problems that you might encounter when using Oracle Web Cache and explains how to solve them. It contains the following topics: ■ Section A.1, Problems and Solutions ■ Section A.2, Common Configuration Mistakes ■ Section A.3, Diagnosing Cache Content Results ■ Section A.4, Diagnosing Common Edge Side Includes ESI Syntax Errors ■ Section A.5, Impact of HTTP Traffic Changes ■ Section A.6, Need More Help? A.1 Problems and Solutions This section describes common problems and solutions. It contains the following topics: ■ Section A.1.1, No Response from Application Web Server Error ■ Section A.1.2, Load Issues on Oracle Web Cache Computer ■ Section A.1.3, Performance Degradation and Memory ■ Section A.1.4, Invalidation Timeouts in a Cache Cluster ■ Section A.1.5, Capacity Issues on Origin Server ■ Section A.1.6, Browsers Not Receiving Complete Responses ■ Section A.1.7, Browser Presenting a Page Not Displayed Error ■ Section A.1.8, ESI Errors with IBM Websphere Application Server ■ Section A.1.9, XML Parsing Errors of webcache.xml Appears in Event Viewer A.1.1 No Response from Application Web Server Error Problem If an 11g Release 1 11.1.1 Oracle Web Cache is reverse proxying 10g components, such as Oracle Portal, Oracle Forms Services, or Oracle Business Intelligence Discoverer, and SSL is enabled, the following browser error may return: No response from Application Web Server In addition, messages similar to the following appear in the event log: A-2 Oracle Fusion Middleware Administrators Guide for Oracle Web Cache [2009-02-11T03:44:55-08:00] [webcache] [ERROR:32] [WXE-11904] [security] [ecid: ] SSL handshake fails NZE-29024 [2009-02-11T03:44:55-08:00] [webcache] [WARNING:1] [WXE-11905] [security] [ecid: ] SSL additional information: The certificate sent by the other side could not be validated. This may occur if the certificate has expired, has been revoked, or is invalid for another reason. [2009-02-11T03:44:55-08:00] [webcache] [WARNING:1] [WXE-11905] [security] [ecid: ] SSL additional information: Remote IP [140.87.11.159]:9002 [2009-02-11T03:44:55-08:00] [webcache] [WARNING:1] [WXE-11905] [security] [ecid: ] SSL additional information: Local IP 152.68.64.152:2832 [2009-02-11T03:44:55-08:00] [webcache] [WARNING:1] [WXE-11906] [security] [ecid: ] SSL details: SSL error during handshake details: internal=The certificate sent by the other side could not be validated. This may occur if the certificate has expired, has been revoked, or is invalid for another reason. system=Success This error indicates that the wallet you selected for Oracle Web Cache contains a certificate that does not match the wallet used by the 10g components. Solution To resolve this problem, modify the wallet you specify for Oracle Web Cache to use the wallet you are using for the 10g components. See Section 5.4.3 . A.1.2 Load Issues on Oracle Web Cache Computer On UNIX operating systems, the top and uptime utilities report a higher than expected average load when the Oracle Web Cache computer is idle. Problem This effect occurs because Oracle Web Cache performs light maintenance work, even when it is idle. One operation Oracle Web Cache performs is garbage collection. During idle mode, the following effect occurs: ■ The uptime load—the average kernel scheduler queue length—is going to be longer. Oracle Web Cache increases the average queue length uptime output by approximately one. ■ The CPU load is still low because the work Oracle Web Cache performs is minimal. A.1.3 Performance Degradation and Memory Because Oracle Web Cache is an in-memory cache, it is best to deploy Oracle Web Cache on a dedicated computer to minimize paging. Unless the computer is dedicated to run Oracle Web Cache, ensure the maximum cache size does not exceed 20 percent of the total memory. This section describes workarounds to invalidation timeouts: ■ Problem 1: Paging ■ Problem 2: Oracle Web Cache Using Memory than the Maximum Cache Size Problem 1: Paging If the time taken to cache or invalidate objects increases, the computer may be paging. Paging can severely degrade performance.