Analysis of the principle of Redis Master-Slave synchronization (experiment)
redis master-slave synchronization principle
During the synchronization process,
The master creates the RDB file only on the first synchronization and uses it as a base for synchronization.
All subsequent synchronizations are performed by incremental command transfer (AOF).
Environment Description:
master: 192.168.2.100 Do not open RDB and AOF
slave: 192.168.2.200 Open RDB and AOF
Configuration information:
master：
# vim etc/redis.conf
#save 600 5 //disable RDB
appendonly no //disable AOF
requirepass 123456 //Specify authentication password
slave：
# vim etc/redis.conf
save 600 5 //disable RDB
appendonly yes //disable AOF
appendfilename "appendonly.aof" //Specify an AOF file
appendfsync everysec //Force writes to disk once per second
no-appendfsync-on-rewrite no //command appends are not performed during log rewriting
auto-aof-rewrite-percentage 100 //overwrite when current AOF exceeds previous AOF size by 100%
auto-aof-rewrite-min-size 64mb //log rewrite minimum
slaveof 192.168.2.100 6379 //Specify main library IP and port
masterauth 123456 //Specify the login password for the master library
Start redis:
master：# redis-server etc/redis.conf
slave：# redis-server etc/redis.conf
Observe synchronization:
master：
# redis-cli -a 123456
127.0.0.1: 6379> info replication //Check whether the master-slave relationship is correct
127.0.0.1: 6379> keys * //At this time, there is no RDB file in the master installation directory.
(empty list or set)
127.0.0.1:6379> set name zhagnsan //create key
OK
# ll /usr/local/redis-3.0.6-6379 //generate an RDB file to use as a basis for synchronization with slave
-rw-r--r-- 1 root root 35 May 20 21:59 dump_6379.rdb
slave：
# redis-cli
127.0.0.1: 6379> info replication //Check whether the master-slave relationship is correct
127.0.0.1: 6379> keys * //data synchronized
1) "name"
127.0.0.1:6379> get name
"zhagnsan"
# ll /usr/local/redis-3.0.6-6379 //directory to generate RDB files and AOF files
-rw-r--r-- 1 root root 60 May 20 21:59 appendonly.aof
-rw-r--r-- 1 root root 18 May 20 21:58 dump.rdb
master：
# redis-cli -a 123456
127.0.0.1:6379> set age 26 //add 2 keys
OK
127.0.0.1:6379> set home beijing
OK
# ll /usr/local/redis-3.0.6-6379 //RDB file size unchanged
-rw-r--r-- 1 root root 35 May 20 21:59 dump_6379.rdb
slave：
# redis-cli
127.0.0.1: 6379> keys * //data synchronized
1) "age"
2) "name"
3) "home"
# ll /usr/local/redis-3.0.6-6379 //Discovery: RDB file size unchanged, only AOF changed
-rw-r--r-- 1 root root 126 May 20 22:00 appendonly.aof
-rw-r--r-- 1 root root 18 May 20 21:58 dump.rdb
Summary: During data synchronization, master creates RDB files only on the first synchronization,
All subsequent synchronizations are synchronized by incremental transmission commands.
