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

Question

I currently have a live redis server running on a cloud instance and I want to migrate this redis server to a new cloud instance and use that instance as my new redis server

Answer 1

you can also use rdd

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

Answer 2

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

Answer 3

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.

Answer 4

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

Answer 5

First, create a dump on server A.

A$ redis-cli
127.0.0.1:6379> CONFIG GET dir
1) "dir"
2) "/var/lib/redis/"
127.0.0.1:6379> SAVE
OK

This ensures dump.rdb is completely up-to-date, and shows us where it is stored (/var/lib/redis/dump.rdb in this case). dump.rdb is also periodically written to disk automatically.

Next, copy it to server B:

A$ scp /var/lib/redis/dump.rdb myuser@B:/tmp/dump.rdb

Stop the Redis server on B, copy dump.rdb (ensuring permissions are the same as before), then start.

B$ sudo service redis-server stop
B$ sudo cp /tmp/dump.rdb /var/lib/redis/dump.rdb
B$ sudo chown redis: /var/lib/redis/dump.rdb
B$ sudo service redis-server start

The version of Redis on B must be greater or equal than that of A, or you may hit compatibility issues.

Answer 6

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.