LISTSERV 16.5 - XROOTD-L Archives

Hello, XRootD experts,

We operated a CMS Tier-2 Center for CERN's CMS experiments.

All CMS Tier-2 centers participating in this experiment must pass a monitoring system called SAM3.

We are constantly experiencing one of the problems in this checking process.

At a problematic test, it checked the remote data accessibility through global redirector of CMS/

It is set to download only a part of the file, so the actual amount transferred is very small, about a few MB.

Therefore, the task is configured to finish within 240 seconds (4 minutes).

I have found that this test is successful in some cases and that some tasks fail.

When I looked at the failed jobs, I noticed that the following job redirection through the Global Redirector.

After finding the final XRootD Server, it re-scanned the redirector server from Global XRootD Redirector again.

We were able to see that it restarted without any distinguish message.

- T2_BE_IIHE

cmsxrootd.fnal.gov:1094 -> cms-xrd-global.cern.ch:1094 -> xrootd.ba.infn.it:1094 -> maite.iihe.ac.be:1095 -> maite.iihe.ac. be: 1094 -> [2001: 6a8: 1080 :: b: 92]: 20341 -> cmsxrootd.fnal.gov:1094 -> cms-xrd-global.cern.ch:1094 -> ......

The only information we know that one packet can be lost when going out of our center.

When I tried to send a packet to the sites through the "MTR" program, I could see that only one packet disappeared.

I suspect that this one packet makes a rescanning from the beginning point.

If you have any information to resolve this problem, please let me know how to that.

Regards,