Details
-
Bug
-
Resolution: Fixed
-
Minor
-
None
-
None
-
master
-
3
-
9223372036854775807
Description
Finally, we found a commit and root cause of 25% metadata performance regression.
(File creation into single shared directory) This regression introduced on middle of lustre-2.5 and lustre-2.6 and this regression are still exist.
After our investigation with "git bisect" the follwoing patch caseus perforamnce regression.
5f3e926ac9ff8ad134ad920d0e8545e16395ef3b is the first bad commit commit 5f3e926ac9ff8ad134ad920d0e8545e16395ef3b Author: wang di <di.wang@intel.com> Date: Wed Jul 31 00:00:40 2013 -0700 LU-3529 lod: create striped directory 1. Add "lfs setdirstripe -i -c" to create striped directory. 2. client send create request to the master MDT, which will allocate FIDs and create slaves. for all of slaves. 3. Client needs to revalidate slaves during intent getattr and open request. 4. lmv_stripe_md will include attributes(size, nlink etc) from all of stripe, which will be protected by UPDATE lock. client needs to merge these attributes when update inode. 5. send create request to the MDT where the file is located, which can help creating master stripe of striped directory. Signed-off-by: wang di <di.wang@intel.com> Change-Id: I7ac560e39dcb415e310dc5e6ade531d76227ffae Reviewed-on: http://review.whamcloud.com/7196 Tested-by: Jenkins Tested-by: Maloo <hpdd-maloo@intel.com> Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Reviewed-by: John L. Hammond <john.hammond@intel.com>
Here is test configuration
1 x MDS (2 x E5-2690 v3, 128GB memory)
32 x Client(2 x CPU E5-2650, 128GB memory)
4 x OSS and 40 OST
RHEL6.5
- mpirun -np 128 -ppn 4 -hostfile ./hostfile.32 mdtest -n 5000 -v -d /scratch/mdtest.out -p 30 -i 3 -F
[e19b51372ad94818a7a79b1fbae5b55c665ba59f] LU-4196 build: Reenable OFED-3.5 support on SLES11 SUMMARY: (of 3 iterations) Operation Max Min Mean Std Dev --------- --- --- ---- ------- File creation : 88017.734 82493.520 84509.613 2489.825 File stat : 151997.740 142649.444 148656.020 4256.270 File read : 162847.716 154605.697 158734.759 3364.809 File removal : 84993.971 78063.127 80600.677 3118.973 Tree creation : 3692.169 2931.030 3262.108 318.519 Tree removal : 51.245 47.758 49.678 1.446 V-1: Entering timestamp...
[5f3e926ac9ff8ad134ad920d0e8545e16395ef3b] LU-3529 lod: create striped directory SUMMARY: (of 3 iterations) Operation Max Min Mean Std Dev --------- --- --- ---- ------- File creation : 66695.074 66242.158 66524.596 201.138 File stat : 152026.405 143681.866 148948.529 3741.740 File read : 165470.364 163291.085 164307.211 895.740 File removal : 86953.641 82117.776 84285.373 2005.726 Tree creation : 4165.148 2841.669 3603.150 558.417 Tree removal : 59.119 52.690 55.581 2.664 V-1: Entering timestamp...
Even no DNE, we are losing 25% performance regression.