afr: Add throttled background client-side heals

Backport of: http://review.gluster.org/13207

If a heal is needed after inode refresh (lookup, read_txn), launch it in
the background instead of blocking the fop (that triggered refresh)
until the heal happens.

afr_replies_interpret() is modified such that the heal is
launched only if atleast one sink brick is up.

Max. no of heals that can happen in parallel is configurable via the
'background-self-heal-count' volume option. Any number greater than that
is put in a wait queue whose length is configurable via
'heal-wait-queue-leng' volume option. If the wait queue is also full,
further heals will be ignored.

Default values:  background-self-heal-count=8, heal-wait-queue-leng=128

Change-Id: I9a134b2c29d66b70b7b1278811bd504963aabacc
BUG: 1313312
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/13564
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

0 files changed, 0 insertions, 0 deletions