Redis RDB local backup script

This python script redis_backup.py will create local Redis RDB-snapshot backups using the bgsave command to a given directory:

0. Issue a bgsave command
1. Wait for bgsave to finish successfully
2. Copy the newly created RDB file to the backup directory
3. Verify MD5 checksum
4. Remove old .rdb files if the backup directory is too crowded

Environment Requirement

0. Python 2.7
1. Python modules: redis
2. A redis instance running locally. You should always rsync the local backup directory to other servers to maximize the data safety.

Running the script

The script can be run with no arguments:

$ python reids_backup.py
backup begin @ 2015-03-28 18:30:43.828446
backup dir:    	/opt/work/RedisBackup/backups
backup file:   	redis_dump_%Y-%m-%d_%H%M%S
max backups:   	10
redis port:    	6379
bgsave timeout:	60 seconds
connected to redis server localhost:6379
redis rdb file path: /opt/src/redis-2.8.19/dump.rdb
redis bgsave... ok
backup /opt/work/RedisBackup/backups/redis_dump_2015-03-28_183044(port_6379).rdb created. 18 bytes, checksum ok!
backup successful! time cost: 0:00:01.005492

If everything goes well, this will create a RDB backup file in the ./backups directory.