FLUSHALLDelete every key on every shard.
| Syntax | FLUSHALL |
| Group | server |
| Arity | -1 |
| Since | 1.0.0 |
| Flags | write |
| Complexity | O(S) fan-out; per shard O(N/S) clear plus WATCH invalidation plus a feed-generation bump |
| Redis compatibility | differs: ASYNC / SYNC are accepted and ignored (the flush is always synchronous per shard), and it bumps the CDC feed generation, so live FEED cursors get a resync error |