Redis Persistent RDB

Two persistence mechanisms of RDB and AOF

Rdb:snapshot---the stored format is in binary format, is the default persistence mode, and periodically saves data from memory to disk by a pre-defined policy: Data file defaults to Dump.rdb

So there are two types of RDB storage mechanisms:

A. Clients can also use the Save or Bgsave command explicitly to start the snapshot save mechanism

B. Saving using a Save policy in a configuration file

Save: Saves the snapshot in the main thread and blocks all client requests (if there is a large amount of data in memory, it will block the customer request for a long time)

Bgsave: Asynchronously saved, the main process is not blocked, does not affect the client's request, and when it is saved, it will fork out a child process to write the in-memory snapshot to disk;

RDB disadvantage: In the event of an unexpected shutdown or power outage, data will be lost, the data is lost after the last snapshot

Default save (snapshot) policy

Save 900 1

Save 300 10

Save 60 10000

Save "": Empty inside quotation marks, indicating the ability to turn off the RDB

Stop-writes-on-bgsave-error Yes: The default is yes when an error occurs while the backup is stopped

Rdbcompression Yes: If the Rdb file is compressed to save space (compression consumes CPU), the default is Yes

Rdbchecksum Yes: Check code detection for RDB image file (for error detection), default Yes

Dbfilename Dump.rdb:rdb Storage file name, default is Dump.rdb

Dir:rdb File Save File location

This article is from the "burning Years of Passion" blog, please be sure to keep this source http://liuzhengwei521.blog.51cto.com/4855442/1931465

Redis Persistent RDB