WL#2788: Distributed LOCK TABLE for mysqld
Affects: Server-7.1 — Status: Assigned — Priority: Medium
To support online alter table one needs a mysqld table lock in each mysqld One ide to implement this is using a table: NDB$TABLE_LOCKS Each mysqld will have an event on NDB$TABLE_LOCKS When one needs the lock one inserts a row into the table and waits for all mysqld to update it's bit that the table is locked Note: one additional feature needed from event api is subscribing to API_FAIL_REP Locking: INSERT INTO NDB$TABLE_LOCK Wait for all alive API nodes to update it bits. Other mysqld: Wait for INSERT into NDB$TABLE_LOCK On event: lock table locally Update NDB$TABLE_LOCK with bit representing on nodeid Note: This will note safe guard against ndbapi programs... (i.e. we still need table locks inside kernel for some cases...)
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