redis persistence

rdb and aof persistence strategies can coexist

Both persistence strategies are recommended

redis preferentially loads the aof file to restore data

1. rdb (redis database)

The data in memory during the time period is written to disk.Snapshot storage.

Fork a child process for persistence.Write/read temporary files.The main process does not perform IO operations.

Suitable for large-scale data recovery, the integrity of data recovery is poor.

2. aof (append only file)

Log each write operation, only append files.The command is executed once according to the log file during recovery.

redis rewrites the aof file, 64m, not too big.

aof saves more complete data.Worst loss of 2s data.

Frequent IO, rewrite.

3. Master-Slave Replicate

Solve the problem of frequent IO and high overhead of aof.