Question

I have a Redis set called userids with over 100,000 entries in it.

When I run

redis-cli smembers userids | grep 12288357681

it returns a value like: 1324. 12288357681

This means that redis found the userid in the set.

But when I run:

redis-cli sismember userids 12288357681

it returns this: (integer) 0

This means that redis DID NOT find the userid in the set.

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How is this possible? Am I using the sismember function incorrectly?

Answer 1

Perhaps the value stored in your set is 1324. 12288357681 instead of just 12288357681 ?

Check the below tests:

niloct@ubuntu:~$ redis-cli
redis 127.0.0.1:6379> sadd userids 12288357681
(integer) 1
redis 127.0.0.1:6379> exit
niloct@ubuntu:~$ redis-cli smembers userids | grep 12288357681
12288357681
niloct@ubuntu:~$ redis-cli sismember userids 12288357681
(integer) 1

Note the output of grep, it is different from yours.