Hi Karl, all On 10/15/07, Karl Czajkowski <[EMAIL PROTECTED]> wrote: > When this is going on, how many connections are showing up under > netstat, i.e. in various TIMED_WAIT states? Is it possible that your > pool of 1000 sockets is being exhausted and leading to more rapid > re-use of existing sockets?
No, during these tests I have been the soul user of the machine. It is a vmware 64bit CentOS 5 guest running in a Windows Server 2003 host that I have been configuring as the grid front end for a recently acquired cluster. > A little googling on socket reuse revealed some problems discussed > with web and POP mail servers where source socket addresses were being > reused while a server still had a TIME_WAIT entry for the same address > from an older connection (on the same host pair)... I have previously looked at what was going on using netstat and only saw globus connections in the 43000:44000 range. > It might help for others if you mentioned the operating system(s) and > version(s) of the endpoints in question (in order to understand if there > are any known TCP/IP quirks there). Yes, sorry I meant to add that but hit send in a hurry. I mentioned the server OS above, the server is running GT4.0.5 (I followed the quickstart). The client machine is a Fedora Core 5 box with GT4.0.2 WS clients. The iptables on the server is up to date with the current repos. > As I think you are looking at packets created by the TCP stack on the > OS and not packets crafted by Globus Toolkit software, I wonder if you > are really just seeing an underlying OS bug or misconfiguration that > is being tickled due to, e.g., fast connection rates with a certain > file staging workload. It is certainly a possibility that this is an artifact being introduced elsewhere in the communications, it could be a bug in the netfilter state tracking code. However, as I mentioned I have never had any other trouble with the state module and I figure it would be a more thoroughly exercised bit of code than globus. I guess I could test that reasonably easily by tcpdump-ing the client activity too and matching the outgoing packets there, however I wouldn't expect to find any differences as this is all on the input chain and nothing to do with any nat transformations. I'm happy to provide for logs/data if you can think of anything that would help shed more light. Cheers, -Blair -- In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite. - Paul Dirac
