Problem: The DB on the brick is been accessed by CTR, for write and tier migrator, for read and write. The write from tier migrator is reseting the heat counters after a cycle. Since we are using sqlite, two connections trying to write would cause a db lock contention. As a result CTR used to fail to update the db. Solution: Using the same db connection of CTR for reseting the heat counters. 1) Introducted a new IPC FOP for CTR 2) After the query do a ipc syncop to the underlying client xlator associated to the brick. 3) CTR in brick will catch the IPC FOP and cleat the heat counters. Change-Id: I53306bfc08dcdba479deb4ccc154896521336150 BUG: 1260730 Signed-off-by: Joseph Fernandes <josferna@redhat.com> Reviewed-on: http://review.gluster.org/12031 Tested-by: NetBSD Build System <jenkins@build.gluster.org> Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Dan Lambright <dlambrig@redhat.com> Tested-by: Dan Lambright <dlambrig@redhat.com>