doc: afr-statistics command documentation

Change-Id: I44ae593c319a3ad2f724e1d8e9557d94c4200765
BUG: 1086748
Signed-off-by: Venkatesh Somyajulu <vsomyaju@redhat.com>
Reviewed-on: http://review.gluster.org/7791
Reviewed-by: Humble Devassy Chirammal <humble.devassy@gmail.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

1 files changed, 142 insertions, 0 deletions

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+##gluster volume heal <volume-name> statistics
+
+##Description
+In case of index self-heal, self-heal daemon reads the entries from the
+local bricks, from /brick-path/.glusterfs/indices/xattrop/ directory.
+So based on the entries read by self heal daemon, it will attempt self-heal.
+Executing this command will list the  crawl statistics of self heal done for
+each brick.
+
+For each brick, it will list:
+1. Starting time of crawl done for that brick.
+2. Ending time of crawl done for that brick.
+3. No of entries for which self-heal is successfully attempted.
+4. No of split-brain entries found while self-healing.
+5. No of entries for which heal failed.
+
+
+
+Example:
+a) Create a gluster volume with replica count 2.
+b) Create 10 files.
+c) kill brick_1 of this replica.
+d) Overwrite all 10 files.
+e) Kill the other brick (brick_2), and bring back (brick_1) up.
+f) Overwrite all 10 files.
+
+Now we have 10 files, which are in split brain. Self heal daemon will crawl for
+both the bricks, and will count 10 files from each brick.
+It will report 10 files under split-brain with respect to given brick.
+
+Gathering crawl statistics on volume volume1 has been successful
+------------------------------------------------
+
+Crawl statistics for brick no 0
+Hostname of brick 192.168.122.1
+
+Starting time of crawl: Tue May 20 19:13:11 2014
+
+Ending time of crawl: Tue May 20 19:13:12 2014
+
+Type of crawl: INDEX
+No. of entries healed: 0
+No. of entries in split-brain: 10
+No. of heal failed entries: 0
+------------------------------------------------
+
+Crawl statistics for brick no 1
+Hostname of brick 192.168.122.1
+
+Starting time of crawl: Tue May 20 19:13:12 2014
+
+Ending time of crawl: Tue May 20 19:13:12 2014
+
+Type of crawl: INDEX
+No. of entries healed: 0
+No. of entries in split-brain: 10
+No. of heal failed entries: 0
+
+------------------------------------------------
+
+
+As the output shows, self-heal daemon detects 10 files in split-brain with
+resept to given brick.
+
+
+
+
+##gluster volume heal <volume-name> statistics heal-count
+It lists the number of entries present in
+/<brick>/.glusterfs/indices/xattrop from each-brick.
+
+
+1. Create a replicate volume.
+2. Kill one brick of a replicate volume1.
+3. Create 10 files.
+4. Execute above command.
+
+--------------------------------------------------------------------------------
+Gathering count of entries to be healed on volume volume1 has been successful
+
+Brick 192.168.122.1:/brick_1
+Number of entries: 10
+
+Brick 192.168.122.1:/brick_2
+No gathered input for this brick
+-------------------------------------------------------------------------------
+
+
+
+
+
+
+##gluster volume heal <volume-name> statistics heal-count replica \
+  ip_addr:/brick_location
+
+To list the number of entries to be healed from a particular replicate
+subvolume, listing any one child of that replicate subvolume in the command,
+will list the entries for all the childrens of that replicate subvolume.
+
+Example:           dht
+             /              \
+            /                \
+         replica-1         replica-2
+         /    \               /    \
+     child-1  child-2   child-3   child-4
+    /brick1   /brick2   /brick3   /brick4
+
+gluster volume heal <vol-name> statistics heal-count ip:/brick1
+will list  count only for child-1 and child-2.
+
+gluster volume heal <vol-name> statistics heal-count ip:/brick3
+will list count only for child-3 and child-4.
+
+
+
+1. Create a volume same as mentioned in the above graph.
+2. Kill Brick-2.
+3. Create some files.
+4. If we are interested in knowing the number of files to be healed from each
+   brick of replica-1 only, mention any one child of that replica.
+
+gluster volume heal volume1 statistics heal-count replica 192.168.122.1:/brick2
+
+output:
+-------
+Gathering count of entries to be healed per replica on volume volume1 has \
+been successful
+
+Brick 192.168.122.1:/brick_1
+Number of entries: 10                                <--10 files
+
+Brick 192.168.122.1:/brick_2
+No gathered input for this brick                     <-Brick is down
+
+Brick 192.168.122.1:/brick_3
+No gathered input for this brick                     <--No result, as we are not
+                                                        interested.
+
+Brick 192.168.122.1:/brick_4                         <--No result, as we are not
+No gathered input for this brick                        interested.
+
+