[Gluster-users] Write-behind translator and network traffic.

[Rash]

Hey!

Using write-behind translator should improve small writes performance,
but using it in configuration with dht over two afrs shows to me almost
none improvement. When I'm watching networkt traffic (gluster works on
1Gb network) for every send packet there is one recieved:

10:05:20.205346 00:1e:c9:b9:bc:75 (oui Unknown) > 00:1e:c9:b9:bc:39 (oui Unknown), ethertype IPv4 (0x0800), length 189: n1.1019 > n2.6996: P 138505:138628(123) ack 71706 win 6533 <nop,nop,timestamp 517009620 517010547>
10:05:20.205583 00:1e:c9:b9:bc:39 (oui Unknown) > 00:1e:c9:b9:bc:75 (oui Unknown), ethertype IPv4 (0x0800), length 170: n2.6996 > n1.1019: P 71706:71810(104) ack 138628 win 3027 <nop,nop,timestamp 517010547 517009620>
10:05:20.205746 00:1e:c9:b9:bc:75 (oui Unknown) > 00:1e:c9:b9:bc:39 (oui Unknown), ethertype IPv4 (0x0800), length 126: n1.1019 > n2.6996: P 138628:138688(60) ack 71810 win 6533 <nop,nop,timestamp 517009620 517010547>
10:05:20.205801 00:1e:c9:b9:bc:39 (oui Unknown) > 00:1e:c9:b9:bc:75 (oui Unknown), ethertype IPv4 (0x0800), length 110: n2.6996 > n1.1019: P 71810:71854(44) ack 138688 win 3027 <nop,nop,timestamp 517010547 517009620>
10:05:20.205945 00:1e:c9:b9:bc:75 (oui Unknown) > 00:1e:c9:b9:bc:39 (oui Unknown), ethertype IPv4 (0x0800), length 158: n1.1019 > n2.6996: P 138688:138780(92) ack 71854 win 6533 <nop,nop,timestamp 517009620 517010547>
10:05:20.205994 00:1e:c9:b9:bc:39 (oui Unknown) > 00:1e:c9:b9:bc:75 (oui Unknown), ethertype IPv4 (0x0800), length 110: n2.6996 > n1.1019: P 71854:71898(44) ack 138780 win 3027 <nop,nop,timestamp 517010547 517009620>
10:05:20.206145 00:1e:c9:b9:bc:75 (oui Unknown) > 00:1e:c9:b9:bc:39 (oui Unknown), ethertype IPv4 (0x0800), length 126: n1.1019 > n2.6996: P 138780:138840(60) ack 71898 win 6533 <nop,nop,timestamp 517009620 517010547>
10:05:20.206211 00:1e:c9:b9:bc:39 (oui Unknown) > 00:1e:c9:b9:bc:75 (oui Unknown), ethertype IPv4 (0x0800), length 110: n2.6996 > n1.1019: P 71898:71942(44) ack 138840 win 3027 <nop,nop,timestamp 517010547 517009620>
10:05:20.207543 00:1e:c9:b9:bc:75 (oui Unknown) > 00:1e:c9:b9:bc:39 (oui Unknown), ethertype IPv4 (0x0800), length 168: n1.1020 > n2.6996: P 115271:115373(102) ack 61422 win 6161 <nop,nop,timestamp 517009620 517010525>
10:05:20.208136 00:1e:c9:b9:bc:39 (oui Unknown) > 00:1e:c9:b9:bc:75 (oui Unknown), ethertype IPv4 (0x0800), length 245: n2.6996 > n1.1020: P 61422:61601(179) ack 115373 win 19825 <nop,nop,timestamp 517010547 517009620>
10:05:20.208291 00:1e:c9:b9:bc:75 (oui Unknown) > 00:1e:c9:b9:bc:39 (oui Unknown), ethertype IPv4 (0x0800), length 66: n1.1020 > n2.6996: . ack 61601 win 6161 <nop,nop,timestamp 517009620 517010547>

In config there is:

volume wb
        type performance/write-behind
        option block-size 256kB
        option cache-size 2MB
        option flush-behind on
        subvolumes iot
end-volume

So shouldn't write-behind translator agregate these small writes in one
bigger - small packets in larger or larger window?

Regards

-- 
rash at konto pl