Common questions

What happens when redis key expires?

What happens when redis key expires?

Keys with an expire When a key has an expire set, Redis will make sure to remove the key when the specified amount of time elapsed. The key time to live can be updated or entirely removed using the EXPIRE and PERSIST command (or other strictly related commands).

How do I know when my redis key expires?

Redis TTL command is used to get the remaining time of the key expiry in seconds.

  1. Return Value. Integer value TTL in milliseconds, or a negative value. TTL in milliseconds.
  2. Syntax. Following is the basic syntax of Redis TTL command.
  3. Example. First, create a key in Redis and set some value in it.

How long can a redis value be?

512 Megabytes
Redis Strings are binary safe, this means that a Redis string can contain any kind of data, for instance a JPEG image or a serialized Ruby object. A String value can be at max 512 Megabytes in length.

How does redis handle TTL?

How does Redis Stores the expiration time? Redis stores the expiration information as absolute Unix timestamps in milliseconds (for Redis versions >2.6). So the time flows even when the Redis server is not active. This means that the keys will expire surely whenever the Redis server becomes active again.

How do I find my Redis key value?

Redis TYPE command is used to get the data type of the value stored in the key.

  1. Return Value. String reply, data type of the value stored in the key or none.
  2. Syntax. Following is the basic syntax of Redis TYPE command. redis> TYPE KEY_NAME.
  3. Example. First, create some keys in Redis and set some values in it.

What is time to live in Redis?

Time to live (TTL) is an integer value that specifies the number of seconds until the key expires. Redis can specify seconds or milliseconds for this value. When an application attempts to read an expired key, it is treated as though the key is not found.

How do I find my redis key value?

What is time to live in redis?

How many values can Redis?

Redis can handle up to 232 keys, and was tested in practice to handle at least 250 million keys per instance. Every hash, list, set, and sorted set, can hold 232 elements. In other words your limit is likely the available memory in your system.

How many requests can Redis handle?

Redis can handle many connections, and by default, Redis has a maximum number of client connections set at 10,000 connections. You can set the maximum number of client connections you want the Redis server to accept by altering the maxclient from within the redis. conf file.

How does expire work in Redis version 2.1.3?

In Redis versions prior 2.1.3 altering a key with an expire set using a command altering its value had the effect of removing the key entirely. This semantics was needed because of limitations in the replication layer that are now fixed. EXPIRE would return 0 and not alter the timeout for a key with a timeout set.

What happens when you delete a Redis key?

Redis keys are persistent by default, meaning that the Redis server will continue to store them unless they are deleted manually. There may, however, be cases where you’ve set a key but you know you will want to delete it after a certain amount of time has passed; in other words, you want the key to be volatile.

What happens when a timeout is set on a Redis key?

Set a timeout on key. After the timeout has expired, the key will automatically be deleted. A key with an associated timeout is often said to be volatile in Redis terminology. The timeout will only be cleared by commands that delete or overwrite the contents of the key, including DEL, SET, GETSET and all the *STORE commands.

How to expire keys in Redis you DigitalOcean?

To demonstrate this, run the following two commands. The first creates a string key named key_melon with a value of “cantaloupe”, and the second sets it to expire after 450 seconds: If the timeout was set successfully, the expire command will return (integer) 1. If setting the timeout failed, it will instead return (integer) 0.

Share this post