On 11/19/2014 03:23 AM, Lindsay Mathieson wrote: > Just some basic question on the heal process, please just point me to the docs > if they are there :) > > - How is the need for a heal detected? I presume nodes can detect when they > can't sync writes to the other nodes. This is flagged (xattr?) for healing > when the other nodes are back up? > > - How is the master file chosen? quorum? latest write? Self heal is detection/healing is handled by AFR using extended attributes which keep track of the type of heal (data/meta-data/entry) and the direction of heal (i.e. what the sources and sinks are). More details can be found here :https://github.com/gluster/glusterfs/blob/master/doc/features/afr-v1.md > > - I have a three peer, two node/brick replica with server side quorum. The > third peer was added to give an odd number of peers for quorom, but it doesn't > participate in bricks. Does this make sense? it helps with deciding which node > is master for heals? Server quorum is useful for detecting split-brains due to graph change, etc but I guess it can still lead to data split-brains. Client quorum can be used to avoid data split-brains at the cost of availability. More information here: https://access.redhat.com/documentation/en-US/Red_Hat_Storage/2.1/html/Administration_Guide/ch10s10.html https://access.redhat.com/documentation/en-US/Red_Hat_Storage/2.0/html/Administration_Guide/sect-User_Guide-Managing_Volumes-Quorum.html http://www.gluster.org/community/documentation/index.php/Features/Server-quorum > > - diff heals. I'm guessing the nodes scan the file pairs block by block, > calculating a checksum for each block and comparing, if they don't match, the > master node block is replicated. That is correct. It scans in 128 kb chunks (configurable via the `cluster.self-heal-window-size` volume set option). > > - Synchronizing the compare over the network must be fun ... > > > - Is there anyway to display a file heal progress? it would make the process a > lot less anxiety inducing even if it was very slow. As of now, `gluster volume heal <volname> info` gives only the list of files that need healing. But yes, it would be nice to have some sort of a CLI to monitor the % progress of files that are currently under data self-heal. HTH, Ravi > > thanks, > > > > _______________________________________________ > Gluster-users mailing list > Gluster-users@xxxxxxxxxxx > http://supercolony.gluster.org/mailman/listinfo/gluster-users > _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://supercolony.gluster.org/mailman/listinfo/gluster-users
