[omniORB] Help needed to interpret COMM_FAILURE

[Renzo Tomaselli]

Duncan,
    is there any behavior which might affect a sending in a way that 
connection would be closed on either side while sending a very long 
message ? I mean > 1 Gigabyte message, which takes quite a number of 
seconds.
Client/server timeouts are left to their defaults,  and the same for 
in/outConScanPeriod (120/180).
Is it possible that on either side a connection is considered idle, and 
thus closed even while sending the message ? This would explain our 
troubles, I should just increase in/outConScanPeriod.
Thanks,

Renzo

Duncan Grisby wrote:

>On Friday 25 November, Renzo Tomaselli wrote:
>
>  
>
>>    this sound interesting. We too had an apparently random problem,
>>appearing as a COMM_FAILURE_MarshalArguments instead.
>>This occurs while the involved client manages to send very large
>>messages (e.g. several hundred megabytes) to the server, co-located on
>>the same Win host.
>>We initialize maxMsgSize to be 1 gigabyte, but we have never seen
>>MARSHAL_MessageSizeExceedLimitOnClient as a minor, as one would expect
>>in case of overflow failures.
>>    
>>
>
>The main time you can see COMM_FAILURE when a message size is exceeded
>is when a server is returning a message that is larger than its own
>message size limit. In that case, it starts sending the reply message,
>but when it is part way through, it discovers that the message is larger
>than permitted. It's too late to send an exception to the client, so it
>has to drop the connection. The client sees that as a
>COMM_FAILURE_UnmarshalReply.
>
>That isn't directly what is happening to you, but there are two related
>possibilities. If your clients are multi-threaded and you have set the
>oneCallPerConnection parameter to false, several client threads can be
>sharing a connection. In that case, if the server drops the connection
>for one call, other calls will see COMM_FAILURES, and could see
>COMM_FAILURE_MarshalArguments.
>
>Alternatively, when a client detects that it has exceeded its message
>size on sending, it too closes the connection it is using, so the server
>doesn't sit waiting for the end of a request that will never come.
>Again, if client threads are sharing a connection, you can see
>COMM_FAILUREs in other threads.
>
>I don't think either of those situations are actually what you're
>seeing, so I'm not sure what's going on. Are you able to get traces
>from traceLevel 25 when it goes wrong?
>
>Cheers,
>
>Duncan.
>
>  
>