I have been reading through old mails for this list and the wiki and i am confused on what machine would do the writes for an afr setup. Say I have two "servers" (192.168.0.10, 192.168.0.11) with configs ------------- volume locks type features/posix-locks subvolumes brick end-volume volume brick type storage/posix option directory /mnt/raid/gfs end-volume volume server type protocol/server subvolumes brick option transport-type tcp/server # For TCP/IP transport option client-volume-filename /etc/glusterfs/glusterfs-client.vol option auth.ip.brick.allow 192.168.0* option auth.ip.brick-ns.allow 192.168.0* end-volume ------------ and one client (192.168.0.20) with config ------------ ### Add client feature and attach to remote subvolume of server1 volume brick1 type protocol/client option transport-type tcp/client # for TCP/IP transport option remote-host 192.168.0.10 # IP address of the remote brick option remote-subvolume brick # name of the remote volume end-volume ### Add client feature and attach to remote subvolume of brick1 volume brick2 type protocol/client option transport-type tcp/client # for TCP/IP transport option remote-host 192.168.0.11 # IP address of the remote brick option remote-subvolume brick # name of the remote volume end-volume ### Add AFR feature to brick1 volume afr1 type cluster/afr subvolumes brick1 brick2 end-volume ### Add IO Threads volume iothreads type performance/io-threads option thread-count 4 option cache-size 32MB subvolumes afr1 end-volume ### Add IO Cache volume io-cache type performance/io-cache option cache-size 32MB # default is 32MB option page-size 1MB #128KB is default option option priority *.php:3,*.htm:2,*:1 # default is '*:0' option force-revalidate-timeout 2 # default is 1 subvolumes iothreads end-volume ### Add writebehind feature volume writebehind type performance/write-behind option aggregate-size 1MB option flush-behind on subvolumes io-cache end-volume ### Add readahead feature volume readahead type performance/read-ahead option page-size 256kB option page-count 16 # cache per file = (page-count x page-size) subvolumes writebehind end-volume ------------ So when my client machine copies a 10 megabyte file, does the client send this file to server1 and server2, or do the servers figure this out? Is there server side afr? My question is along the lines of what happens if i have 10 servers (data nodes) and 2 clients, how can i move the load of copying files from clients to servers? or is this even possible? I would think that in a mail cluster setup, i would not want my mail servers having the extra load of handling the afr, i would think it should send a write to one server and the server handles replicating? Or am I totally not understanding something?
