Optimistic Execution of MSET

[suxb201]

The MSET command comes with the CO::IDEMPOTENT flag, which implies the following scenario:

• k1 = old
• k2 = old

When executing:

• MSET k1 new k2 new
• MGET k1 k2

We expect MGET to return either old old or new new. However, is it possible that it could return old new or new old?

Consider the following execution sequence (assuming no inline execution):

• shard1: MGET k1(in txq); MSET k1(enqueue)
• shard2: MSET k2(optimistic); MGET k2(enqueue)

In this scenario, MGET might return old new. Is this correct, or am I misunderstanding something?

[romange]

You are absolutely right with you question, the only thing is that MSET does not have CO::IDEMPOTENT flag. MGET has :)