How do I move a redis database from one server to another?

Save a snapshot of the database into a dump.rdb by either running BGSAVE or SAVE from the command line. This will create a file named dump.rdb in the same folder as your redis server. See a list of all server commands.

Copy this dump.rdb to the other redis server you want to migrate to. When redis starts up, it looks for this file to initialize the database from.

If you have the connectivity between servers it is better to set up replication (which is trivial, unlike with SQL) with the new instance as a slave node - then you can switch the new node to master with a single command and do the move with zero downtime.

It is also possible to migrate data using the SLAVEOF command:

SLAVEOF old_instance_name old_instance_port 

Check that you have receive the keys with KEYS *. You could test the new instance by any other way too, and when you are done just turn replication of:

SLAVEOF NO ONE 

Since Redis 5.0 is recommended to use REPLICAOF as SLAVEOF is deprecated - see manual

Nowadays you can also use MIGRATE, available since 2.6.

I had to use this since I only wanted to move the data in one database and not all of them. The two Redis instances live on two different machines.

If you can't connect directly to Redis-2 from Redis-1, use ssh port binding:

 ssh [email protected] -L 1234:127.0.0.1:6379 

A small script to loop all the keys using KEYS and MIGRATE each key. This is Perl, but hopefully you get the idea:

 foreach ( $redis_from->keys('*') ) { $redis_from->migrate( $destination{host}, # localhost in my example $destination{port}, # 1234 $_, # The key $destination{db}, $destination{timeout} ); } 

See http://redis.io/commands/migrate for more info.

Key elements of a zero-downtime migration is:

• replication (http://redis.io/commands/SLAVEOF)
• possibility to write into a slave during application switching (CONFIG SET slave-read-only no)

In short:

1. setup a target redis (empty) as slave of a source redis (with your data)
2. wait for replication finish
3. permit writes to a target redis (which is currently slave)
4. switch your apps to a target redis
5. wait for finish datastream from master to slave
6. turn a target redis from master to slave

Additionally redis have options which allows to disable a source redis to accept writes right after detaching a target:

• min-slaves-to-write
• min-slaves-max-lag

This topic covered by

• http://redis.io/topics/admin#upgrading-or-restarting-a-redis-instance-without-downtime

Very good explanation from RedisLabs team https://redislabs.com/blog/real-time-synchronization-tool-for-redis-migration (use web.archive.org)

And even their interactive tool for migrate: https://github.com/RedisLabs/redis-migrate

source_host=xxx source_port=6379 source_db=10 source_auth=xxx target_host=yyyyy target_port=6379 target_db=12 target_auth=yyyyy redis-cli -a $source_auth -h $source_host -p $source_port -n $source_db keys \* | while read key; do echo "redis-cli -h $source_host -p $source_port -a $source_auth -n $source_db MIGRATE $target_host $target_port "" $target_db 5000 COPY AUTH $target_auth KEYS $key" redis-cli -h $source_host -p $source_port -a $source_auth -n $source_db MIGRATE $target_host $target_port "" $target_db 5000 COPY AUTH $target_auth KEYS $key done 

I's pretty good with my case, tested it.

To check where the dump.rdb has to be placed when importing redis data,

start client

$ redis-cli 

and

then

redis 127.0.0.1:6379> CONFIG GET * 1) "dir" 2) "/Users/Admin" 

Here /Users/Admin is the location of dump.rdb that is read from server and therefore this is the file that has to be replaced.

you can also use rdd

it can dump & restore a running redis server and allow filter/match/rename dumps keys

I also want to do the same thing: migrate a db from a standalone redis instance to a another redis instances(redis sentinel).

Because the data is not critical(session data), i will give https://github.com/yaauie/redis-copy a try.

The simple way I found to export / Backup Redis data (create dump file ) is to start up a server via command line with slaveof flag and create live replica as follow (assuming the source Redis is 1.2.3.4 on port 6379):

/usr/bin/redis-server --port 6399 --dbfilename backup_of_master.rdb --slaveof 1.2.3.4 6379 

I just published a command line interface utility to npm and github that allows you to copy keys that match a given pattern (even *) from one Redis database to another.

You can find the utility here:

https://www.npmjs.com/package/redis-utils-cli

Problem: Redis in Cloud, or local, data migration from server1 to server2, using dump.rdb file not working

My Solution:

Step 1. create the dump file, dump.rdb:

Run the create dump command in redis-cli: BGSAVE

Identify the dump dir, command in redis-cli: config get dir response e.g: /data

Step 2. Copy the dump.rdf file from the source to the destination redis server (k8s container with redis or local redis server, use config get dir to identify the folder path)

Step 3. Disable AOF(append only file). Redis uses 2 systems for storing data. One that uses a file to keep records (dump.rdb), or an event sourcing system, style called AOF. AOF is used by default. For migration using a dump file, we need to disable the AOF system. For this, create a text file: redis.config and add a single line:

appendonly no

Step 4. Start the redis server with the config file as command argument. In order to specify a config file run the server with the config file:

redis-server /path/to/redis.conf

Step 5. Validation- Redis will automatically load the dump file. Connect to redis and query for keys, or check the logs for the number of imported entries (e.g keys loaded: 6513):

 1:M 23 May 2024 05:56:20.243 * RDB age 4002 seconds 1:M 23 May 2024 05:56:20.243 * RDB memory usage when created 7.22 Mb 1:M 23 May 2024 05:56:20.629 * Done loading RDB, keys loaded: 6513, keys expired: 0. 

PS: also a good article: https://www.digitalocean.com/community/tutorials/how-to-back-up-and-restore-your-redis-data-on-ubuntu-14-04

Good Luck !