redis-migrate-tool is a convenient and useful tool for migrating data between redis.

It is based on redis replication.

In the process of migrating data, the source redis also can provide services for users.

To build redis-migrate-tool:

$ cd redis-migrate-tool
$ autoreconf -fvi
$ ./configure
$ make
$ src/redis-migrate-tool -h

src/redis-migrate-tool -c rmt.conf -o log -d

Before run this tool, make sure your source redis machines have enough memory to generate rdb files.

If your source machines have no enough memory to generate rdb files at one time, you had better set threads small in the rmt.conf.

For example, if your source redis are all in one machine, and this machine only has free memory to generate one rdb file, you had better set threads to 2(one to read from source, anther to write to target) in the rmt.conf file.

Config file has three parts: source, target and common.

• type: The group redis type. Possible values are:
• single
• twemproxy
• redis cluster
• rdb file
• servers:: The list of redis address in the group. If type is twemproxy, this is same as the twemproxy config file. If type is rdb file, this is the file name.
• hash: The name of the hash function. Just for type is twemproxy. Possible values are:
• one_at_a_time
• md5
• crc16
• crc32 (crc32 implementation compatible with libmemcached)
• crc32a (correct crc32 implementation as per the spec)
• fnv1_64
• fnv1a_64
• fnv1_32
• fnv1a_32
• hsieh
• murmur
• jenkins
• hash_tag: A two character string that specifies the part of the key used for hashing. Eg "{}" or "$$". Hash tag enable mapping different keys to the same server as long as the part of the key within the tag is the same. Just for type is twemproxy.
• distribution: The key distribution mode. Just for type is twemproxy. Possible values are:
• ketama
• modula
• random

• threads: The max threads count can be used by redis-migrate-tool. Defaults to the cpu core count.
• step: The step for parse request. The higher the number, the more quickly to migrate, but the more memory used. Defaults to 1.
• mbuf_size: Mbuf size for request. Defaults to 512.
• noreply: A boolean value that decide whether to check the target group replies. Defaults to false.

For example, the configuration file shown below is to migrate data from single to twemproxy.

[source]
type: single
servers:
 - 127.0.0.1:6379
 - 127.0.0.1:6380
 - 127.0.0.1:6381
 - 127.0.0.1:6382

[target]
type: twemproxy
hash: fnv1a_64
hash_tag: "{}"
distribution: ketama
servers:
 - 127.0.0.1:6380:1 server1
 - 127.0.0.1:6381:1 server2
 - 127.0.0.1:6382:1 server3
 - 127.0.0.1:6383:1 server4

[common]
threads: 2
noreply: true
step: 10
mbuf_size: 1024

Migrate data from twemproxy to redis cluster.

[source]
type: twemproxy
hash: fnv1a_64
hash_tag: "{}"
distribution: ketama
servers:
 - 127.0.0.1:6379
 - 127.0.0.1:6380
 - 127.0.0.1:6381
 - 127.0.0.1:6382

[target]
type: redis cluster
servers:
 - 127.0.0.1:7379

[common]
step: 1
mbuf_size: 512

Migrate data from rdb file to redis cluster.

[source]
type: rdb file
servers:
 - /data/redis/dump1.rdb
 - /data/redis/dump2.rdb

[target]
type: redis cluster
servers:
 - 127.0.0.1:7379

[common]
threads: 1
noreply: false
step: 5
mbuf_size: 512

Copyright 2012 Deep, Inc.

Licensed under the Apache License, Version 2.0: https://www.apache.org/licenses/LICENSE-2.0