On Wed, Sep 21, 2016 at 01:47:34AM -0400, Raghavendra Gowdappa wrote: > Hi all, > > [1] might have implications across different components in the stack. Your reviews are requested. > > <commit-msg> > > rpc : Change the way client uuid is built > > Problem: > Today the main users of client uuid are protocol layers, locks, leases. > Protocolo layers requires each client uuid to be unique, even across > connects and disconnects. Locks and leases on the server side also use > the same client uid which changes across graph switches and across > file migrations. Which makes the graph switch and file migration > tedious for locks and leases. > As of today lock migration across graph switch is client driven, > i.e. when a graph switches, the client reassociates all the locks(which > were associated with the old graph client uid) with the new graphs > client uid. This means flood of fops to get and set locks for each fd. > Also file migration across bricks becomes even more difficult as > client uuid for the same client, is different on the other brick. > > The exact set of issues exists for leases as well. > > Hence the solution: > Make the migration of locks and leases during graph switch and migration, > server driven instead of client driven. This can be achieved by changing > the format of client uuid. > > Client uuid currently: > %s(ctx uuid)-%s(protocol client name)-%d(graph id)%s(setvolume count/reconnect count) > > Proposed Client uuid: > "CTX_ID:%s-GRAPH_ID:%d-PID:%d-HOST:%s-PC_NAME:%s-RECON_NO:%s" > - CTX_ID: This is will be constant per client. > - GRAPH_ID, PID, HOST, PC_NAME(protocol client name), RECON_NO(setvolume count) > remains the same. > > With this, the first part of the client uuid, CTX_ID+GRAPH_ID remains > constant across file migration, thus the migration is made easier. > > Locks and leases store only the first part CTX_ID+GRAPH_ID as their > client identification. This means, when the new graph connects, > the locks and leases xlator should walk through their database > to update the client id, to have new GRAPH_ID. Thus the graph switch > is made server driven and saves a lot of network traffic. What is the plan to have the CTX_ID+GRAPH_ID shared over multiple gfapi applications? This would be important for NFS-Ganesha failover where one NFS-Ganesha process is stopped, and the NFS-Clients (by virtual-ip) move to an other NFS-Ganesha server. Will there be a way to set CTX_ID(+GRAPH_ID?) through libgfapi? That would allow us to add a configuration option to NFS-Ganesha and have the whole NFS-Ganesha cluster use the same locking/leases. Thanks, Niels > > Change-Id: Ia81d57a9693207cd325d7b26aee4593fcbd6482c > BUG: 1369028 > Signed-off-by: Poornima G <pgurusid@xxxxxxxxxx> > Signed-off-by: Susant Palai <spalai@xxxxxxxxxx> > > </commit-msg> > > [1] http://review.gluster.org/#/c/13901/10/ > > regards, > Raghavendra > _______________________________________________ > Gluster-devel mailing list > Gluster-devel@xxxxxxxxxxx > http://www.gluster.org/mailman/listinfo/gluster-devel
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