Is it possible to get a Redis key even if it's expired(but still exists in Redis)?

Question

Since the Redis expires keys in passive and active way,

Is there any way to get a key even if its expire time has passed(but still exists in Redis)?

Do you mean just the key? Or also the value? See https://stackoverflow.com/questions/18328058/redis-2-8-notifications-get-value-instead-of-key-on-expire# — LeoMurillo, Dec 25 '19 at 14:03
Key and value. I checked it, it's interesting but isn't what i meaned. — Amin Shojaei, Dec 26 '19 at 05:30

score 2 · Answer 1 · answered Dec 25 '19 at 18:16

DEBUG OBJECT myKey will return info about the key even when it is expired timewise - if it has not been garbage-collected (actively-expired) or passively-expired (accessed) yet.

To test this, you can disable the background (active) expiring with DEBUG SET-ACTIVE-EXPIRE 0. Use carefully. Restore with DEBUG SET-ACTIVE-EXPIRE 1

Note the DEBUG OBJECT myKey returns the memory address, so if you really need to see the value, you'll have to explore the RAM contents.

> DEBUG OBJECT myKey
Value at:0x7fff70629920 refcount:1 encoding:embstr serializedlength:4 ...

DEBUG OBJECT myKey returns (error) ERR no such key if it has been expired already, actively or passively, or if it doesn't exist of course.

Thanks. Seems the best normal way is "shadow expiration key" https://stackoverflow.com/a/28647773/8712494 — Amin Shojaei, Dec 26 '19 at 05:35

score 1 · Accepted Answer · answered Dec 25 '19 at 14:33

1

No, there isn't. The key (and its value) will be expired automatically eventually, or upon trying to access it (i.e. passively or actively).

answered Dec 25 '19 at 14:33

Itamar Haber

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Is it possible to get a Redis key even if it's expired(but still exists in Redis)?

2 Answers2