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502 Proxy Error And Sigsegv When Sending Post Request To Portal Through Webcache (Doc ID 1309710.1)

Last updated on APRIL 16, 2021

Applies to:

Web Cache - Version and later
Information in this document applies to any platform.


There is a 502 Proxy Error displayed in the browser, when users try to submit portlet page in Oracle Portal through webcache. Portlet displayes Java EE application implemented using Struts framework.

This error occurs after upgrading Oracle Portal 10g to Oracle Portal 11g. Let me know,

1. The request to the Portal includes a very large POST as can be seen in Data Collection record. The web cache trace dump references a large POST body similar to the one shown below (although you may not see this specific content with "@@POST_BODY_TOO_LARGE" in the trace dump):

- Tracedump
<TraceDump Header="Generated by Oracle Web Cache on Mon Jan 3 16:35:58 2011 - Build 100402.1900"
Version="11g (" Label="Build 100402.1900" Date="2011-01-03 16:35:59">
Error Number: 0
Signal Code: SEGV_MAPERR
Faulting Address: 0xb9bb94

<cache_documentT MemAddr = "0x131b9028">
<SiteName = "<FQHN>:80">
<URI = "/portal/page/portal/<MYAPP>/MySites_Page">
<Method = "POST">
<PostBody = "@@POST_BODY_TOO_LARGE">
<MultiVersion = "Not Valid">
<Compressed = "No">

2. Error message "Proxy error - Request could not be processed. Invalid response received by proxy or gateway server" is seen in browser when accessing a particular page in Oracle Portal. The reason for this error is a crash of the web cache as can be seen from the Web Cache event log :

[2011-01-04T12:55:47+01:00] [webcache] [ERROR:1] [WXE-09720] [diagnostics] [ecid: <ECID>,0:1] [req-info: ] [client: <CLIENT_IP>] [host: <FQHN>] [url: /portal/page/portal/<MYAPP>/MySites_Page]
[2011-01-04T12:55:47+01:00] [webcache] [ERROR:1] [WXE-13601] [diagnostics] [ecid: <ECID>,0:1] Signal SIGSEGV caught
[2011-01-04T12:55:47+01:00] [webcache] [NOTIFICATION:1] [WXE-12816] [logging] [ecid: ] reqlogdump: 1 0 11331 1 frontend 2 ...
[2011-01-04T12:55:47+01:00] [webcache] [NOTIFICATION:1] [WXE-12816] [logging] [ecid: ] reqlogdump: 2 1 13900 0 utl 1 ...
3. This error occurs after upgrading Oracle Portal 10g to Oracle Portal 11g.

4. The Problem is just with this particular POST request on single page inside portlet . i.e. "/portal/page/portal/<MYAPP>/MySites_Page". But on the other side the default web cache welcome page works fine.

5. As per dump generated, the POST body is quit long because it seems including a large number of URL parameters in the body. example of HTTP Headers in browser is shown below:

POST /portal/page/portal/<MYAPP>/MySites_Page HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/, application/x-ms-xbap, application/x-ms-application, application/, application/, application/msword, */*
Referer: http://<FQHN>/portal/page/portal/<MYAPP>/MySites_Page
Accept-Language: en-us
Content-Type: application/x-www-form-urlencoded
UA-CPU: x86
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET CLR 1.1.4322)
Host: <HOST>
Content-Length: 9791
Connection: Keep-Alive
Cache-Control: no-cache
Cookie: oracle.uix=0^^GMT+1:00^p; ORA_PORTAL_SESSION_portal=...; OHS-<FQHN>.com-80=...;JSESSIONID=...
eventId=91866130&eventSummaryValue=&summaryTotal=&monthlyTotal=&91866140-min=null&91866140-max=null&eventId=91866140&eventSummaryValue=&summaryTotal=&monthlyTotal=&137880-min=null&137880-max=null&eventId=137880&eventSummaryValue=&summaryTotal=&monthlyTotal=&137890-min=null&137890-max=null&eventId=137890&eventSummaryValue=&summaryTotal=&monthlyTotal=&137900-min=null&137900-max=null&eventId=137900&eventSummaryValue=&summaryTotal=&monthlyTotal=&136090-min=null&136090-max=null&eventId=136090&eventSummaryValue=&summaryTotal=&monthlyTotal=&95738580-min=0&95738580-max=1&eventId=95738580&eventSummaryValue=HTTP/1.1 502 Proxy Error
Date: Mon, 03 Jan 2011 15:35:58 GMT
Content-Length: 237
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1

<title>502 Proxy Error</title>
<h1>Proxy Error</h1>
<p>Request could not be processed.Invalid response received by proxy or gateway server.</p>




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