Backup Data

Overview

Ardb uses standard Redis command SAVE/BGSAVE to backup data store, and use extended command IMPORT to restore data store.

Backup

• SAVE [redis|ardb|backup]

  SAVE would block the current thread until all data backuped. The backup data would be saved in a file located in 'backup-dir' configured in ardb.conf.
  The format argument indicates that snapshot type saved. 'redis' format is redis's rdb format, 'ardb' format is ardb's own format which is storage engine independent, while 'backup' format depends on the storage engine backend, currently only RocksDB could save 'backup' format.
  And about the performance, 'redis' is always slowest, 'ardb' is a little faster, while 'backup' is much faster that the others.

           127.0.0.1:36379> keyscount *          
           (integer) 128410113             
           (132.19s)                 
           127.0.0.1:36379> save backup               
           OK                   
           (10.71s)               
           127.0.0.1:36379> save ardb            
           OK             
           (176.38s)          
           127.0.0.1:36379> save redis          
           OK          
           (236.21s)    
  

• BGSAVE [redis|ardb|backup]

BGSAVE would do the almost same thing for SAVE command except that it's executed in a background thread which does not block any thread for the client connection.

Restore

• IMPORT path

IMPORT is a command that would restore data from backup data file which generated by SAVE/BGSAVE. And like Save command, the 'backup' format data could be imported fastest.

Example:

             127.0.0.1:36379> import backup/rocksdb-redis-snapshot.1464851634
             OK
             (381.04s)
             127.0.0.1:36379> import backup/rocksdb-ardb-snapshot.1464851425
             OK
             (173.63s)
             127.0.0.1:36379> import backup/rocksdb-backup-snapshot.1464851409
             OK
             (4.70s)