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ethirajesh · Posted: Fri Jul 22, 2011 4:28 am Post subject:

Hi I need your inputs on the below design where I retry a Webservice for certain number of times.

InputNode-->Compute-->HTTPRequest-->Mapping-->HTTPReply

In the above design I have HTTPInput node in separate flow, which checks the incoming request and route the request to the above mentioned flow(there are 4 such flows which is invoked based on the request coming in).

When Web service is down, I need to retry the request for 3 times. To acheive this, I have wired 'Failure' terminal of HTTPRequest to a Filter node to check the exception type. If the exception is not 'Parser', 'Messageexception' or 'User Exception' or 'The retry count is exceeds 3' I route this to True terminal which is wired to another Compute node (Through False I connect to it to Exception Hadler component). The 'out' of this is wired to the Input terminal of the COmpute node of the above message flow.

My Doubts are :

Note1: I tried saving retry count in MQRH2 header, but when the message is coming out from Failure terminal, this header is getting deleted automatically.

1) Is this is the right approach for retrying a webservice?
2) Since MQRFH2 header is getting deleted, I am gonna use Environment variable to hold the retry count.
3) Will this design makes other messages choked coming in during the Retry?

Note2:

During peak season the number of request will be around 25000.
The incoming request is of query string type and The HTTPRequest hits the webservice using 'GET' Method.

I am sorry for making my query too length.

Thanks
Rajesh Ethiraj