Messages stop routing when sending system is bounced

[Gena Gill]

We have a system that sends orders to the interface engine.  When they bounce the interface on their side, the connection is lost in my cloverleaf engine, then I can see it go back to up status, but no messages will come through until I stop and start the thread on my side.

This is the only thread I have where I have to do this, and everything is set up the same as the others.  This also didn’t happen before we “upgraded” the sending system.  The other vendor is blaming my cloverleaf engine for the problem.

Does anyone have any ideas on what could be causing this, or if it really is on the cloverleaf engine, and even if it isn’t if there’s some way that I could set something up that would stop and start that thread on my engine whenever it lost connectivity from the other system?

Topic

[Todd Lundstedt]

Check your Cloverleaf servers’s netstat output for connections on that port after it “goes back up”

Windows:

netstat -an | findstr

Unix/AIX:

netstat -an | grep

Verify the connection is coming from the IP address of the sending system.  If it is, and if the sending systems interface program is still down, they have something else running and acting as an interface on their server.  If the IP address is coming from some other system, check that system to see why it is trying to communicate with Cloverleaf.  Perhaps their “old” version is still running interface programs.

If you didn’t mention that you see the connection go down, and then go back up (instead of just staying up) when they stop their outbound to Cloverleaf, I would suspect their interface shutdown methods don’t disconnect correctly, and the Cloverleaf “server” thread continues to think the connection is up and good.  But, because you mentioned you see the connection go down, I suspect some other program on that sending system, or a program on some other system is configured to use your threads IP/Port for interface communication (just with no data to send, hence the supposition it’s their old version).

[Gena Gill]

That makes a lot of sense.  I emailed the vendor to ask for some time to do some focused testing.  

As soon as I read your post, I had an “Ah-Ha” moment.  I have a suspicion that they may have pointed test to this prod port.

[Gena Gill]

They had the interfaces still active from the old server on their side, so both the old and the new were trying to connect at the same time.  They got that shut down, and it looks like we no longer have a conflict.

Thanks for your help!

[Todd Lundstedt]

You’re welcome, Gena.  That actually happens far more often, here, then anyone would like… sometimes, you just want to bean a vendor in the head, ask them “what, exactly, were you thinking?”, and then hand them their sign (referencing Bill Engvall’s comedy routine).  😆

I am glad you got it all figured out.

[Author]

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