XLEN key
Returns the number of entries inside a stream. If the specified key does not exist the command returns zero, as if the stream was empty. However note that unlike other Redis types, zero-length streams are possible, so you should call TYPE or EXISTS in order to check if a key exists or not.
Streams are not auto-deleted once they have no entries inside (for instance after an XDEL call), because the stream may have consumer groups associated with it.
Integer reply: the number of entries of the stream at key.
"1541374488587-0" redis> XADD mystream * item 2 "1541374488588-0" redis> XADD mystream * item 3 "1541374488590-0" redis> XLEN mystream (integer) 3
© 2009–2018 Salvatore Sanfilippo
Licensed under the Creative Commons Attribution-ShareAlike License 4.0.
https://redis.io/commands/xlen