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diff --git a/Feature Planning/GlusterFS 3.7/Policy based Split-brain Resolution.md b/Feature Planning/GlusterFS 3.7/Policy based Split-brain Resolution.md new file mode 100644 index 0000000..f7a6870 --- /dev/null +++ b/Feature Planning/GlusterFS 3.7/Policy based Split-brain Resolution.md @@ -0,0 +1,128 @@ +Feature +------- + +This feature provides a way of resolving split-brains based on policies +from the gluster CLI. + +Summary +------- + +This feature provides a way of resolving split-brains based on policies. +Goal is to give different commands to resolve split-brains using +policies like 'choose a specific brick as source' and choose the biggest +files as source etc. + +Owners +------ + +Ravishankar N +Pranith Kumar Karampuri + +Current status +-------------- + +Feature completed. + +Detailed Description +-------------------- + +Till now, if there is a split-brain manual intervention is required to +resolve split-brain. But most of the times it so happens that files from +particular brick are chosen as source or the files with bigger file size +is chosen as source. This feature provides CLI that can be used to +resolve the split-brains in the system at that moment using these +policies. + +Benefit to GlusterFS +-------------------- + +It improves manageability of resolving split-brains + +Scope +----- + +### Nature of proposed change + +####Added new gluster CLIs: + +1.```gluster volume heal <VOLNAME> split-brain bigger-file <FILE>.``` + +Locates the replica containing the FILE, selects bigger-file as source +and completes heal. + +2.```gluster volume heal <VOLNAME> split-brain source-brick <HOSTNAME:BRICKNAME> <FILE>.``` + +Selects ```<FILE>``` present in ```<HOSTNAME:BRICKNAME>``` as source and completes +heal. + +3.```gluster volume heal <VOLNAME> split-brain <HOSTNAME:BRICKNAME>.``` + +Selects **all** split-brained files in ```<HOSTNAME:BRICKNAME>``` as source +and completes heal. + +Note: ```<FILE>``` can be either the full file name as seen from the root of +the volume (or) the gfid-string representation of the file, which +sometimes gets displayed in the heal info command's output. + +### Implications on manageability + +New CLIs are added to improve manageability of files in split-brain + +### Implications on presentation layer + +None + +### Implications on persistence layer + +None + +### Implications on 'GlusterFS' backend + +None + +### Modification to GlusterFS metadata + +None + +### Implications on 'glusterd' + +None + +How To Test +----------- + +Create files in data and metadata split-brain. Accessing the files from +clients gives EIO. Use the CLI commands to pick the source file and +trigger heal After the CLI returns success, the files should be +identical on the replica bricks and must be accessible again by the +clients + +User Experience +--------------- + +New CLIs are introduced. + +Dependencies +------------ + +None + +Documentation +------------- + +TODO: Add an md file in glusterfs/doc. + +Status +------ + +Feature completed. Main and dependency patches: + +<http://review.gluster.org/9377> +<http://review.gluster.org/9375> +<http://review.gluster.org/9376> +<http://review.gluster.org/9439> + +Comments and Discussion +----------------------- + +--- |