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How to Diagnose and Debug a HTTP 503 Error in a Portal Environment (Doc ID 751101.1)

Last updated on JULY 08, 2019

Applies to:

Portal - Version to [Release 10gR2]
Information in this document applies to any platform.


The purpose of this document is to give some guidance when Users or Systems Administrators encounter HTTP 503 errors.

HTTP 503 is the standard HTTP error that means "Service Unavailable."

503 error is a generic error which can be caused by many situations.
A 503 error can be displayed in any or all of the following locations:-

A root cause error may be displayed with the 503 which will be more helpful in determining exactly what the issue might be.

A 503 may not cause any obvious user error, or might be simply resolved by a browser refresh. It can be a temporary issue or a permanent problem.

For these reasons finding the root cause can be extremely difficult.

There are a number of notes written about different types of 503 errors which may be encountered.  This note aims to act as a Master Note to finding the possible reasons for your particular situation.

Examples of where a 503 error may occur

Browser Errors

Service Temporarily Unavailable


Error: The listener returned the following Message: 503 Service Temporarily Unavailable

Apache error log errors

[Thu Jun 15 15:21:21 2006] [error] [client <IP_ADDRESS>] [ecid: <ECID>] mod_plsql: /pls/portal/portal.home HTTP-503 ORA-28000 Proxy log On failed. Please verify that you have specified correct connectivity information i.e. username, password & connect-string in the DAD

J2EE application.log
eg <Midtier Oracle Home>/j2ee/OC4J_Portal/application-deployments/portal/OC4J_Portal_default_island_1/application.log

06/06/15 15:26:37 portal: id=<ECID> Invalid status code encountered : status=503 reason=Service Temporarily Unavailable name=content-fetcher22 label=pageMeta url=https://<HOSTNAME>:<SSL_PORT>/pls/portal/!<PAGE_ID> time=83ms content=<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<TITLE>503 Service Temporarily Unavailable</TITLE>
<H1>Service Temporarily Unavailable</H1>
The server is temporarily unable to service your
request due to maintenance downtime or capacity
problems. Please try again later.
<ADDRESS>Oracle-Application-Server-10g/ Oracle-HTTP-Server Server at Port 7778</ADDRESS>

Note: If the debugging level in the PPE is not high, then a 503 error may not actually be displayed in any logs. Instead the error seen might just be a "Stall timeout reached". Increase the debug level to see if a 503 is actually being generated.

Questions and Answers

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In this Document
 Examples of where a 503 error may occur
Questions and Answers
 Step 1 - Find All Reported Errors
 Step 2 - Search Knowledge Base For Similar Issues
 Step 3 - Apply Solutions From Any Relevant Knowledge Base Notes
 Step 4 - Determine in which layer the error originated
 Step 5 - Raise A Service Request
 Performance Related
 Unable to Access Portal At All
 Relating To Database Portlets
 Relating To Java Portlets
 HA Architecture
 SSO protected JSPs

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