I am new to using Redis and I am playing around a little bit with it. I have noticed that after a little time, let's say 10 minutes all the keys that I inserted just go away.
I just did the default installation showed in the documentation. I didn't configure anything with a redis.config. Is there any configuration that I need to do so my data can persist?
Environment
Redis Server
Redis server v=6.2.6 sha=00000000:0 malloc=jemalloc-5.1.0 bits=64 build=557672d61c1e18ba
Redis-cli
redis-cli 6.2.6
Ubuntu 18.08 VM.
I have also been using redisInsight to insert the keys.
there are two mechanisms for persisting the data to disk:
snapshotting
append-only file (aof)
if you want to use snapshotting, you need to add the following settings in redis.conf file
dir ./path_for_saving_snapshot
dbfilename "name_of _snapshot.rdb"
save 60 1000
with this configuration, redis will dump the data to disk every 60 seconds if at least 1,000 keys changed in that period.
if you want to use aof, you need to add the following settings in redis.conf file
appendonly yes
appendfilename "your_aof_file.aof"
appendfsync everysecond
everysecond is the default FYSNC policy. you have also other options.
You can configure your Redis instance to use either of the two mechanisms or a combination of both.
Related
I'm importing an old Redis backup in order to browse its databases.
However upon launching Redis with the imported dump.rdb a lot of data is missing.
My guess is because Redis immediately expires all the old keys.
Is there a configuration setting to prevent Redis from expiring anything?
Redis doesn't do that, but you can try setting the server's clock to some time in the distant past before loading the RDB.
I want to delete all keys from redis cluster by using fast process. I know how to delete the keys by using "redis-cli FLUSHALL". But this command can be slow when the data set is large. I heard that all keys can be cleared from redis cache by re-starting the redis service. I am testing this process on my local mac laptop. I am performing following steps:-
Setting many number of keys on my local redis server by using example command redis-cli SET mykey1 "Hello"
Then Re-starting the redis service "brew services restart redis" in the hope that all keys will be deleted when the service will be back up
Then getting the keys by giving "redis-cli KEYS '*'" command
I still see the keys after step-3
The keys are gone only when I give this command--> redis-cli FLUSHALL? How I can clear the keys by re-starting the redis service locally on my mac laptop first then I will try on QA servers?
You see the keys after restart because there is either RDB or AOF persistence enabled. See https://redis.io/topics/persistence.
RDB is enabled by default. To disable persistence, you need to edit your redis.conf or start as redis-server --save "" --appendonly no
See Is there a way to flushall on a cluster so all keys from master and slaves are deleted from the db on how to use redis-cli to send the command to all cluster nodes.
As dizzyf indicates, use FLUSHALL ASYNC to have the deletion performed in the background. This will create fresh hash maps for each database, while the old ones are deleted (memory reclaimed) progressively by a background thread.
In redis 4.0 and greater, the FLUSHALL ASYNC command was introduced, as a way to delete all the keys in a non-blocking manner. Would this solve your issue?
https://redis.io/commands/flushall
Thank you for links. These were very helpful. I was able to achieve the result by making changes to my redis.conf file with--> redis-server --save "" and --appendonly no. So after these changes, when I now re-start redis service nothing is saved.
How to disable Save for some DBs and allow for the others in the Redis
You cannot. An RDB snapshot is a single file that contains the data of all dbs.
You can send a FLUSHDB on the dbs you do not want to restore after the RDB is loaded.
If you'll use a dedicated Redis process for each db you could configure each one differently with a dedicated redis.conf file, and a SAVE and BGSAVE commands will only create a snapshot of the Redis process it was issued on.
I have a Redis server with maxmemory 512MB and maxmemory-policy allkeys-lru but once the server has filled up after a day of usage, I can't add any more items:
redis 127.0.0.1:6379[3]> set foooo 123
(error) OOM command not allowed when used memory > 'maxmemory'.
IMHO that never should happen with the LRU policy.
I copied some server info to this Pasebin: http://pastebin.com/qkax4C7A
How can I solve this problem?
Note: I'm trying to use maxmemory because my Redis server is continously eating up memory even though nearly all keys have an expire setting and because FLUSHDB does not release system memory - perhaps this is related..
In the end I'm trying to use Redis as a cache.
Your info output suggests that a lot of your server's memory is taken by Lua scripts:
used_memory_lua:625938432
Note that Lua scripts remain in memory until the server is restarted or SCRIPT FLUSH is called. It would appear as if you're generating Lua scripts on the fly...
Im using redis 2.8.3 server to store key value pairs in redis.
redis.conf
port 6378
bind 127.0.0.1
databases 16
After restarting the redis-server
redis-server /home/redis.conf
Im loosing all the keys which i have already stored in redis.Can anyone help me to solve this.
If you run a 'BGSAVE' before you shut down the server does that help?
The shutdown script should always run that....
Use this configuration settings, which will help you to sync data using a background process:
# appendfsync always
appendfsync everysec
# appendfsync no
to prevent removing data from redis after restarting redis service in windows, you should update redis.windows-service.conf.
Redis SAVE command is used to create backup of current redis database
Save the DB on disk: save seconds changes
Will save the DB if both the given number of seconds and the given
number of write operations against the DB occurred
In the example below the behaviour will be to save:
after 1sec if at least 1 key changed
after 100sec if at least 50 keys changed
like in the following example, in SNAPSHOTTING section:
################################ SNAPSHOTTING ################################
save 1 1
save 100 50
after making changes, restart redis service,
you can download last version of redis for windows