Hi Lana. Looks like you may have run into this bug as well:
http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2027 James Burnash, Unix Engineering -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Lana Deere Sent: Friday, October 29, 2010 5:06 PM To: [email protected] Subject: [Gluster-users] concurrent write and read to the same file GlusterFS 3.1.0, distributed volumes, rdma transport, CentOS 5.4/5.5. I was doing "tail -f" on a log file while the program generating it was running and noticed some strange behavior. I wasn't able to reproduce exactly the same strange behavior, but here is some which did reproduce for me reliably. This is a small perl program producing a bit of output every few seconds: $| = 1; for ($i=0; $i < 100; ++$i) { printf("This is line $i\n"); sleep(3); } If I run it with output sent to a gluster volume, perl foo.pl > bar it works fine: "bar" has the right content after the script terminates, or if I kill the script while it runs "bar" has a valid partial output. While the perl script is running, if I log into a different host which can see that volume and do "tail -f bar" that also works fine: every few seconds, the next line of output appears. However, while the perl script is running if I do "tail -f bar" from the same host as the script is running on, it will print me the current end of the file but then it will hang without producing any subsequent output. This is true whether or not I have a tail running on a different host concurrently. The tail on the same host as the script will correctly notice that the file was reset if I kill and restart the perl script while leaving the tail running. Then it prints the first line, but at that point it hangs again. Anyone else seeing this? Any ideas what might be reasons why? Thanks! .. Lana ([email protected]) _______________________________________________ Gluster-users mailing list [email protected] http://gluster.org/cgi-bin/mailman/listinfo/gluster-users DISCLAIMER: This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this in error, please immediately notify me and permanently delete the original and any copy of any e-mail and any printout thereof. E-mail transmission cannot be guaranteed to be secure or error-free. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. NOTICE REGARDING PRIVACY AND CONFIDENTIALITY Knight Capital Group may, at its discretion, monitor and review the content of all e-mail communications. http://www.knight.com _______________________________________________ Gluster-users mailing list [email protected] http://gluster.org/cgi-bin/mailman/listinfo/gluster-users
