Hi,

1) stop the slave threads on B and C

2) stop writes to A using FLUSH TABLES WITH READ LOCK.

2.1) set read_only=true on A to prevent any writes if the read lock is
accidently released

2.2) get A's coordinates with SHOW MASTER STATUS

3) issue START SLAVE UNTIL ... on B using the coordinates from A's SHOW
MASTER STATUS

4) issue SHOW MASTER STATUS ON B

5) START SLAVE UNTIL ... on C using the coordinates from B

6) Issue SHOW MASTER STATUS on C

7) Issue CHANGE MASTER TO on A with coordinates from C

8) Issue CHANGE MASTER TO on C with coordinates from A (captured in step
2.2)

10) Release READ LOCK (with UNLOCK TABLES) on A

11) A should remain read_only to prevent unexpected writes to it

12) send writes to C

--Justin

On Thu, Oct 25, 2012 at 11:47 AM, Sabika M <sabika.makhd...@gmail.com>wrote: