Working with Proxy Plug-in Issues

Working with Proxy Plug-in Issues

Before we understand how to deal with the proxy plug-in we need to understand what these proxy plugin are, how are they different from web servers, where they are present, etc. Let’s try to discuss each of these in details.

Introduction to Proxy Plug-in: Proxy Plug-in are mainly used to re-direct the requests to the application server based on the configurations specified inside plug-in config file.

The advantages of using the proxy plug-in are as follows:

1)      Re-direction of requests

2)      Load Balancing of requests

3)      Serves the static data (using the proxy cache)

Please find the below pictorial representation of a dynamic application server architecture containing the Proxy plug-in:

fig (a): proxy plug-in inside the dynamic application server architecture

Following are the list of proxy servers supported by Oracle BEA:-

1)      IIS plug-in

2)      Apache plug-in

3)      Netscape/SunOne plug-in

As we can observe from the above pic, the proxy plug-in is always available inside the webservers.  (They are different reasons for this)

 

 

 

Working with Proxy Plug-in related issues:

Following are most of the common problems/issues seen while working with the proxy plug-ins:

1)      Uneven Load balancing of the HTTP requests

2)      Frequent or unexpected session failover

3)      Unexpected http status codes in HTTP responses like 400, 404, 500, 503, etc for which the diagnosing at the weblogic server didn’t gave any clue.

*Note: for most of these issues updating of your existing plug-in will resolve the issue.

Enable the following debug flags inside the proxy sever plug-in config files to get more information about the issue:

1)      Set Debug=”ALL” :  Enabling these debug flag will give more traces of the following information:

a)      Headers sent to and from client.

b)      Headers sent to and from WLS.

c)      Information and error messages

2) Set DebugConfigInfo=”ON”: Enabling this flag will help the plug-in to log the following information:

a)      Returns the config information and runtime statistics to the browser

b)      Responds to the request that contain the string _WebLogicBridgeConfig

c)      Append the string _WebLogicBridgeConfigPath at the end of the URL.

Following is the example on how to use _WebLogicBridgeConfig:– http://hostname:portNo/contextPath/servletPath/pathInfo_WebLogicBridgeConfig

Executing the above URL will give the output that contains the complete information about the proxy plug-in like number if requests handled, max response time, min response time, time out, etc

Note:  Enabling any of the above parameters would require a server restart.

After enabling the above debug flags the output would by default routed to the following files depending up on the OS we are using:

1)      UNIX( related OS): /tmp/wlproxy.log

2)      Windows (related OS): C:\TEMP\wlproxy.log

 

Depending up on the Web Server we are using the proxy plug-in file name could be any of these two:

1)      Apache HttpServer: httpd.conf file

2)      Iplanet/SunOne: obj.conf file

3)      Microsoft IIS: iisProxy.Ini

8 comments

  1. Sankar, Good explanation…

    I have few questions. Is there any other way how we can send the request to WLS server if servers are in clustered environment?

    In the above post, WLS proxy plugin will determine for which server the request should go. Just assume if we do not have proxy plux, then how we can send the request?

    Also is it possiable to run the cluster mechanism with out WLS proxy?

    Please help.

  2. Sankar,

    Correct me if i am wrong,

    Gopal,

    You can use below location handler to direct request to perticular cluster or single managed servers

    Example

    SetHandler weblogic-handler
    WebLogicCluster a:7005,b:7007,c:7009
    Idempotent ON
    KeepAliveEnabled On
    WLSocketTimeoutSecs 8
    KeepAliveSecs 20
    PathTrim /pivot

    here in the above example when you hit http://www.cat.com/abc the request will directed to cluster which has a,b,c managed servers.

    Thanks,
    Ravi

  3. Hi Team,

    I have apache query, i m getting the following error while including the weblogic 10.3 plugin in Apache ,, do you have any idea how to solve this ,,, hope u wil reply
    ++++++++++++++++++++++++++++++++++++++++++++
    httpd: Syntax error on line 129 of E:/InstalledPrgs/apache_webserver/conf/httpd.conf: Cannot load E:/InstalledPrgs/apache_webserver/modules/mod_wl_20.so into se
    rver: The specified module could not be found.

  4. Hello

    I have a big problem. All the configurations explained here, works fine to me if I use another name to wlproxy.log file, for example, wlproxy.log.tes. I was watching wlproxy.log is written by two proccess. One is the sun one instance, but, I dont know who is the second proccess.

    could you have any opinion about that?

    Greetings

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