Re: Can an sms-service be configured to retry http delivery after failure to post a url ?

Peter Farmer wrote:

> Hi,
> 
> I have been scanning the user doco and reading the mail archives, but havent 
> been able to find an answer . I hope that someone on the list can set me 
> straight. We have set up kannel to channel MO SMS's to a 3rd parties web 
> application servers. Which works quite well. The target http server has other 
> users apart from our sms gateway, and we occassionally have incoming messages 
> blocked from being delivered because of connection limits being reached on 
> the target.  Obviously there may be various other resource or operational 
> reasons why our attempts to transfer sms's to a system not under our control 
> could  fail (in essence we get a 4xx, 5xx http status reply, or no response 
> at all) . 
> What we require to happen in this circumstance is not to send a delivery 
> report to the sending phone number reporting the failure , but for the smsbox 
> to queue the message and retry posting it a later date (i.e a store & forward 
> mechanism) and then just expire quietly after a designated retry period. Is 
> this possible with the existing kannel system or am i up for some late night 
> coding to my own sms-box extensions  ? 
> There appears to be a qeueing facility for the reverse operation of sending 
> sms's submitted to an smsbox via http.  So there is a message storing 
> mechanism that might be used . But I see no way to key into that based on a 
> http response code. The sms-box can handle http redirect responses (30x) 
> autonomously, so i have some hope that I could configure/extend kannel to 
> respond appropriately to other http request response code. 
> 
> Thanks for your input in advance

now, we have "at least" an HTTP request retry mechanism inside of smsbox, that 
helps dealing with "HTTP server not available" issues. To have a persistant 
queue of MO messages that should get transported to the application layer you 
need store-file support inside smsbox. Which is not supported in the raw Kannel.

See 'http-request-retry' and 'http-queue-delay' config directives gor smsbox group.

@Alex, any intention from your side to put this on official cvs, or should we go 
ahead any addopt it from the private tree?

BTW, this brings again a more semantical question to the top. Should a 
"messaging node" try infinitly to deliver a message to the next node (the 
application layer in this case)? I don't think so. Actually it's the "fault" of 
the next node, if the HTTP server breaks and responds with HTTP 500. IMO, a node 
inside a communication path is not required to "cover" errors of the 
participating nodes. But I guess this is a "system architecture" religious question.

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