@soloestoy I wonder why this.

Background: some users are actually relying on this - touching every key w/ KEYS or SCAN - to force expiry.

Hi @itamarhaber , I know that people use KEYS or SCAN to force expire, but I think KEYS is not a good choice, it's already too complex and slow, and expire will make KEYS slower down, moreover we have to propagate expire to AOF and slave, that will make AOF buffer and SLAVE output buffer grow too fat.

Hello folks, I think that KEYS should remain like it is, showing the set of keys that exist. Not doing that would depart from the semantics from a product point of view, like:

EXPIRE foo 1
Wait 5 seconds
KEYS *
... foo ...

So I would not modify KEYS... However I've another solution for people that are in need of such capability. I'll follow up shortly.

Hello folks, I think that KEYS should remain like it is, showing the set of keys that exist. Not doing that would depart from the semantics from a product point of view

Hi @antirez , I mean KEYS still remains its behavior, would not show the expired keys:

EXPIRE FOO 1
Wait 5 seconds
KEYS *
nil

KEYS only check TTL, but do not delete it...

Oh ok, that makes sense, and I like the refactoring going there in db.c, let me check the code better.

I'm merging @soloestoy, changing only one thing. Just an subjective hint, matter of taste, but see the following code:

    if (!keyIsExpired(db,key)) {
        return 0;
    } else if (server.masterhost != NULL) {
        /* If we are running in the context of a slave, return ASAP:
         * the slave key expiration is controlled by the master that will
         * send us synthesized DEL operations for expired keys.
         *
         * Still we try to return the right information to the caller,
         * that is, 0 if we think the key should be still valid, 1 if
         * we think the key is expired at this time. */
        return 1;
    }

It becomes much obvious once you remove the useless else/if

    if (!keyIsExpired(db,key)) return 0;
    
    if (server.masterhost != NULL) {
        /* If we are running in the context of a slave, return ASAP:
         * the slave key expiration is controlled by the master that will
         * send us synthesized DEL operations for expired keys.
         *
         * Still we try to return the right information to the caller,
         * that is, 0 if we think the key should be still valid, 1 if
         * we think the key is expired at this time. */
        return 1;
    }