The setup consists of write-behind on dht. write behind has flush-behind turned on and has a window-size configured to 4MB.

write behind is showing under-par performance. This is evident in a booster set-up, where the application is doing large number of small-sized writes. Attached is the valgrind report of the dd on booster doing 1 million writes each of 140 bytes. The report shows the application spending lots of time in traversing the request-queue in write-behind.

PATCH: http://patches.gluster.com/patch/1433 in master (performance/write-behind: fine-tune logic of wb_mark_winds)

PATCH: http://patches.gluster.com/patch/1434 in master (performance/write-behind: Aggregate adjacent contiguous write-buffers into single iobuf.)

PATCH: http://patches.gluster.com/patch/1435 in master (performance/write-behind: remove redundant traversal of write-requests in the wind list in wb_ sync.)

PATCH: http://patches.gluster.com/patch/1437 in master (performance/write-behind: reduce list-traversal during wb_mark_unwinds)

PATCH: http://patches.gluster.com/patch/1436 in master (performance/write-behind: reduce traversal of request list during wb_mark_winds.)

PATCH: http://patches.gluster.com/patch/1438 in master (performance/write-behind: add option "enable-trickling-writes".)

PATCH: http://patches.gluster.com/patch/1424 in release-2.0 (performance/write-behind: fine-tune logic of wb_mark_winds)

PATCH: http://patches.gluster.com/patch/1425 in release-2.0 (performance/write-behind: Aggregate adjacent contiguous write-buffers into single iobuf.)

PATCH: http://patches.gluster.com/patch/1427 in release-2.0 (performance/write-behind: remove redundant traversal of write-requests in the wind list in wb_sync.)

PATCH: http://patches.gluster.com/patch/1426 in release-2.0 (performance/write-behind: reduce list-traversal during wb_mark_unwinds)

PATCH: http://patches.gluster.com/patch/1428 in release-2.0 (performance/write-behind: reduce traversal of request list during wb_mark_winds.)

PATCH: http://patches.gluster.com/patch/1429 in release-2.0 (performance/write-behind: add option "enable-trickling-writes".)

Created attachment 74 [details]
text shaping patch for mc-4.5.42

callgrind report for recital after optimization

PATCH: http://patches.gluster.com/patch/1446 in master (performance/write-behind: reduce usage of iov_length.)

PATCH: http://patches.gluster.com/patch/1447 in master (performance/write-behind: store the current window size in wb_file.)

PATCH: http://patches.gluster.com/patch/1448 in master (performance/write-behind: store currently aggregated data size in wb_file)

PATCH: http://patches.gluster.com/patch/1443 in release-2.0 (performance/write-behind: reduce usage of iov_length.)

PATCH: http://patches.gluster.com/patch/1444 in release-2.0 (performance/write-behind: store the current window size in wb_file.)

PATCH: http://patches.gluster.com/patch/1445 in release-2.0 (performance/write-behind: store currently aggregated data size in wb_file)

PATCH: http://patches.gluster.com/patch/1838 in master (performance/write-behind: Add enable-trickling-writes to volume_options.)