In operation, we may need to copy one redis db to another. rdb is an awesome mechanism but if you're migrating things in/out of services like ElastiCache. It's just not on-the-fly.

Other people suggested some good approaches. Here are some ready-to-use codes in python.

Common Usages

# copy redis1/db0 -> redis2/db0 (dryrun)
redis-cp.py redis1 redis2 --dryrun --verbose

# copy redis1/db3 ->redis2/db3 (dryrun)
redis-cp.py redis1 redis2 --dryrun --verbose --db 3

# copy redis1/db1 ->redis2/db3 (dryrun)
redis-cp.py redis1 redis2 --dryrun --verbose --sdb 1 --ddb 3

Advanced Usages

# running two redis servers locally (different port) for testing/develop
redis-cp.py redis1 redis2 --sport 6379 --dport 7777

# change batch size (default is 100, which is just a random pick)
redis-cp.py redis1 redis2 --batch 500