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ECV Health Monitor is not working properly in F5 LTM

Hi, We have same physical server where different applications are running . for example HC-HH and HC-APP. These two application can be accessed by URLS http://lmjedwmsap1.jeddah.cpksa.local:7778/forms/frmservlet?config=wmshcrdc-hh and http://lmjedwmsap1.jeddah.cpksa.local:7778/forms/frmservlet?config=wmshcrdc.

Now we are trying to configure ECV monitor and assign them to Pool to monitor members .

ECV Monitor settings are as below

Type = HTTP Interval = 5 seconds Timeout = 16 seconds Send string = GET /forms/frmservlet?config=wmshcrdc-hh HTTP/1.1\r\nHost:\r\nConnection: close\r\n\r\n Receive string = 200 OK Monitor port = 7778 But it is now working perfectly . Pool members are showing healthy ( green ) even if the particular application is down .

Can anybody assist where is the issue ???/

Regds...Indrajit

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USER ACCEPTED ANSWER & F5 ACCEPTED ANSWER

I guess the bigger question would be what constitutes being "down"? Many applications will "fail", while the web server is still functional. You're looking for a 200 OK response, so that's likely what you're getting. There are generally a few ways to troubleshoot an HTTP monitor:

  1. Command line cURL is a great way to test an HTTP request and corresponding response:

    curl -v http://x.x.x.x:7778/forms/frmservlet?config=wmshcrdc-hh
    
  2. Tcpdump the monitor itself. This will allow you to see the monitor's request and the server's response:

    tcpdump -lnni 0.0 -Xs0 port 7778 and host x.x.x.x
    
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Comment made 22-Mar-2014 by Indrajit Basak 94
Thanks Kevin for quick answer . Actually we want to monitor the application not the web server . So in that case what should be the "receive string " parameter setting in monitor configuration . How to find it out ? I believe 200 Ok is the receive string for generic web application . So in our case it is not the correct settings . Can you help on this Regds....Indrajit
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USER ACCEPTED ANSWER & F5 ACCEPTED ANSWER

Thanks Kevin for quick answer . Actually we want to monitor the application not the web server . So in that case what should be the "receive string " parameter setting in monitor configuration . How to find it out ?

I believe 200 Ok is the receive string for generic web application . So in our case it is not the correct settings .

Can you help on this

Regds....Indrajit

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USER ACCEPTED ANSWER & F5 ACCEPTED ANSWER

200 OK is the generic (good) response string for ANY HTTP web server. I would start by trying the cURL command above. That should show you what the application response actually looks like. Find something in the payload of the response, preferably near the top, that definitively indicates a good application response. You may also want to try the same cURL command with a "down" application to see the differences.

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Comment made 26-Mar-2014 by Indrajit Basak 94
Hi Kevin , Below are the outputs of the command for both working and non working application . Can you pls suggest what can be the receive string [root@RYDWMSLB01:Active:Standalone] config # curl -v http://172.26.200.92:7778/forms/frmservlet?config=wmscprdc-hh * About to connect() to 172.26.200.92 port 7778 (#0) * Trying 172.26.200.92... connected * Connected to 172.26.200.92 (172.26.200.92) port 7778 (#0) > GET /forms/frmservlet?config=wmscprdc-hh HTTP/1.1 > User-Agent: curl/7.19.7 (i686-redhat-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8y zlib/1.2.3 libidn/0.6.5 > Host: 172.26.200.92:7778 > Accept: */* > < HTTP/1.1 200 OK < Date: Wed, 26 Mar 2014 08:37:29 GMT < Server: Oracle-Application-Server-10g/10.1.2.2.0 Oracle-HTTP-Server < Content-Length: 2899 < Cache-Control: private < Content-Type: text/html < <HTML> <!-- FILE: base.htm (Oracle Forms) --> <!-- --> <!-- This is the default base HTML file for running a form on the --> <!-- web using a generic APPLET tag to include Forms applet. --> <!-- --> <!-- IMPORTANT NOTES: --> <!-- Default values for all the variables which appear below --> <!-- (enclosed in percent characters) are defined in the servlet --> <!-- configuration file (formsweb.cfg). It is preferable to make --> <!-- changes in that file where possible, rather than this one. --> <!-- --> <!-- This file will be REPLACED if you reinstall Oracle Forms, so --> <!-- you are advised to make your own version if you want to make --> <!-- want to make any modifications. You should then set the --> <!-- baseHTML parameter in the Forms Servlet configuration file --> <!-- (formsweb.cfg) to point to your new file instead of this one. --> <HEAD><TITLE>Oracle Application Server Forms Services</TITLE></HEAD> <BODY > <COMMENT id="forms_plugin_info" appcodebase="/forms/java" apparchive="frmall.jar" appheight="600" appwidth="750"> </COMMENT> <!-- Forms applet definition (start) --> <NOSCRIPT> <!-- Forms applet definition (end) --> </BODY> </HTML> * Connection #0 to host 172.26.200.92 left intact ******************************** Working Application ************************** [root@RYDWMSLB01:Active:Standalone] config # curl -v http://172.26.200.92:7778/forms/frmservlet?config=cpwmsrdc * About to connect() to 172.26.200.92 port 7778 (#0) * Trying 172.26.200.92... connected * Connected to 172.26.200.92 (172.26.200.92) port 7778 (#0) > GET /forms/frmservlet?config=cpwmsrdc HTTP/1.1 > User-Agent: curl/7.19.7 (i686-redhat-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8y zlib/1.2.3 libidn/0.6.5 > Host: 172.26.200.92:7778 > Accept: */* > < HTTP/1.1 200 OK < Date: Wed, 26 Mar 2014 08:41:20 GMT < Server: Oracle-Application-Server-10g/10.1.2.2.0 Oracle-HTTP-Server < Content-Length: 2934 < Cache-Control: private < Content-Type: text/html < <HTML> <!-- FILE: base.htm (Oracle Forms) --> <!-- --> <!-- This is the default base HTML file for running a form on the --> <!-- web using a generic APPLET tag to include Forms applet. --> <!-- --> <!-- IMPORTANT NOTES: --> <!-- Default values for all the variables which appear below --> <!-- (enclosed in percent characters) are defined in the servlet --> <!-- configuration file (formsweb.cfg). It is preferable to make --> <!-- changes in that file where possible, rather than this one. --> <!-- --> <!-- This file will be REPLACED if you reinstall Oracle Forms, so --> <!-- you are advised to make your own version if you want to make --> <!-- want to make any modifications. You should then set the --> <!-- baseHTML parameter in the Forms Servlet configuration file --> <!-- (formsweb.cfg) to point to your new file instead of this one. --> <HEAD><TITLE>Retail Warehouse Managment System - RDC RIYADH (All CP Concepts)- PROD - 1</TITLE></HEAD> <BODY > <COMMENT id="forms_plugin_info" appcodebase="/forms/java" apparchive="frmall.jar" appheight="685" appwidth="950"> </COMMENT> <!-- Forms applet definition (start) --> <NOSCRIPT> <!-- Forms applet definition (end) --> </BODY> </HTML> * Connection #0 to host 172.26.200.92 left intact * Closing connection #0
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USER ACCEPTED ANSWER & F5 ACCEPTED ANSWER

This is a tough one. The outputs you're displaying look almost identical. Is there some HTML content that in the working site and not in the non-working site?

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Comments on this Answer
Comment made 26-Mar-2014 by Indrajit Basak 94
This is the only output of the above command . <HEAD><TITLE>Retail Warehouse Managment System - RDC RIYADH (All CP Concepts)- PROD - 1</TITLE></HEAD> this is the line i found different in working and non working application . But if put <HEAD><TITLE>Retail Warehouse Managment System - RDC RIYADH (All CP Concepts)- PROD - 1</TITLE></HEAD> in receive string , immediately the pool member is down . Not sure about the syntax if i am put correctly or any other issue . Any suggestion .
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