Bug 761848 (GLUSTER-116) - Replicate: Need inode number from first subvolume on fresh lookup
Summary: Replicate: Need inode number from first subvolume on fresh lookup
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: GLUSTER-116
Product: GlusterFS
Classification: Community
Component: replicate
Version: mainline
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Shehjar Tikoo
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Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2009-07-08 06:26 UTC by Shehjar Tikoo
Modified: 2009-08-12 06:02 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Environment:
Last Closed:
Regression: RTP
Mount Type: ---
Documentation: ---
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Description Shehjar Tikoo 2009-07-08 06:26:37 UTC
We know that replicate needs to do a lookup from multiple subvolumes on a fresh lookup request. It is possible that the inode number returned in this new lookup is different from the ino returned to the previous lookup for the same file.

This behaviour can break things for tools like unfs3 which depend on the same inode number, in order to map file handles to files.

Right now, libglusterfsclient works around this by avoiding the pruning of inodes. This has its limits since the memory consumption by the inode table will constantly increase.

This is not a bug but I think more of a feature required for a narrow bunch of tools. I am alright with having an option in replicate that forces it to return inode from one particular sub-volume when this option is set. In other cases, it does sound like a better idea to keep the current behaviour of round-robin'ing or load-balancing the fresh lookups among the various subvolumes.

Comment 1 Shehjar Tikoo 2009-07-10 05:03:41 UTC
Fix committed to release-2.0 branch.
http://git.savannah.gnu.org/cgit/gluster.git/commit/?h=release-2.0&id=b23c9fcc8a16b8c4a4b1814ff5035a18f03da0f4

Pending on mainline.


I'll defer changing the status till the time when I've done some tests with unfs3
and libglusterfsclient.

Comment 2 Anand Avati 2009-07-16 03:14:45 UTC
PATCH: http://patches.gluster.com/patch/722 in master (Return inode number always from the first up subvolume in AFR.)

Comment 4 Shehjar Tikoo 2009-07-23 09:53:43 UTC
In recent tests using unfs3, booster and replicate and distribute, I do not see any failures due to stale file handles. This is with version 0.5 of unfs3booster and the patches that will be part of 2.0.5 release.


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