runProof Segmentation Violation & XrdProofConn error

Hi root-talk,

I was working on my own TSelector to loop over multiple large ntuples on my local machine ( Mac OS X 10.6.8 ) and save the output files via TProofOutputFile to a root file. I first encountered a segmentation violation after all the looping and file merging has been done but before Terminate() was executed. I am using a compiled program (TRint) to run the selector. However, I tested it as a macro as well - with the same result. I was able to reproduce this error when using the runProof(“ntuple”) tutorial. In the end, I was only able to get rid of it by connecting to the PROOF session via TProof* pr = TProof::Open("proof://localhost:40000/",""); instead of

After I managed to save the files locally using the workaround mentioned at [url]Cannot write object to file with TProofOutputFile and setting LOCALDATASERVER

all was running fine for one evening …

Now, suddenly I cannot connect to Proof at all anymore! My own Selector as well as the runProof(“ntuple”) example return the same error:

110819 11:19:17 001 Proofx-E: Conn::Connect: failed to connect to proof://patrick@localhost:40000// 110819 11:19:17 001 Proofx-E: XrdProofConn: XrdProofConn: severe error occurred while opening a connection to server [localhost:40000]

110819 10:57:43 001 Proofx-E: Conn::Connect: failed to connect to proof://patrick@localhost:11093// 110819 10:57:43 001 Proofx-E: XrdProofConn: XrdProofConn: severe error occurred while opening a connection to server [localhost:11093] getProof: could not get/start a valid session at proof://localhost:11093 runProof: could not start/attach a PROOF session
I tried all sorts of different combinations. Besides connecting to lite:// which results again in the segmentation violation above, nothing worked.

I hope you can help me out with this one and I am not wasting your time.
Please let me know if you need more input to trace the problem.

Thanks a lot for your help
Patrick

Hi again,

let me give you an update.

In the meantime I think I at least found a solution for the XrdProofConn problem. I always needed to kill all running proofserv.exe processes via

to be able to connect to a proof session again. Ergo, I had the feeling that opening or connecting to a Proof session collided with the previously opened one. Thus, I included

at the end of each session. It seems to do the trick cause I didn’t run into the same problem again since then. Your datasets keep being staged on the workers, of course.

However, the segmentation violation using ProofLite still persists but that’s nothing urgent which would keep me from working …

cheers
Patrick