Here are the questions I'd ask and steps I'd take to find out what is going on:
1) Is cMem the name of the collective or member? Can you switch it back and forth to see if it makes any difference?
2) When you say "I am able to connect thru SDK connection" do you mean you can connect to the collective using PI SDK Connection Manager? Do you try connecting to the collective in SDK connection? What if you try connecting to the troubled member explicitly instead of the collective?
3) When your code fails to connect can you see any trace of connection attempt in the SDK logs of any of the PI servers?
Thanks for replying
We got it solved. Actually server was not accepting any new connection from any client application. It was working fine with existing connection though.
Don’t know why server was doing that but it was production one and we want it up as soon as possible.
We restarted server and solved it.
OK glad it worked out but I wish we knew what was happening!