Limits

Ruvio runs a shard’s commands on one thread, so a command that walks a lot of data holds up every client of that shard. These bounds keep one call short. They are fixed in the server unless a setting is named.

Command	Bound	What happens past it
SCAN, HSCAN, SSCAN, ZSCAN	COUNT at most 10000	A larger COUNT is lowered to 10000. A scan call may return fewer keys than COUNT (or none) and still not be finished; keep calling with the returned cursor until it is 0.
KEYS	100000 keys in the database	The command answers an error; use SCAN.
ZPOPBYSCORE	10000 members per call	At most 10000 members are popped; call again for the rest.

SMEMBERS, HGETALL, LRANGE and similar commands read the whole answer on the shard thread before the reply is sent. For a collection with many thousands of members use SSCAN, HSCAN, ZSCAN or a ranged LRANGE instead. The reply buffer of a connection is limited as well, and a client that does not read its replies is disconnected when the buffer is full; see docs/CONFIGURATION.md.