Question: How can you check the Redis replication status?
Answer
You can check the status of Redis replication using the INFO command, particularly the INFO REPLICATION section. This command provides information about Redis's master or slave state along with other details such as connected slaves, master link status etc.
Here is an example of how to do this:
$ redis-cli
127.0.0.1:6379> INFO REPLICATIONThe output will provide a lot of useful information. If your instance is set as a master, it will show something similar to:
# Replication
role:master
connected_slaves:3
slave0:ip=127.0.0.1,port=6380,state=online,offset=1456,lag=1
slave1:ip=127.0.0.1,port=6381,state=online,offset=1456,lag=1
slave2:ip=127.0.0.1,port=6382,state=online,offset=1456,lag=1
master_replid:<some id>
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:1456
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:1456If your instance is set as a slave, it will show:
# Replication
role:slave
master_host:127.0.0.1
master_port:6379
master_link_status:up
master_last_io_seconds_ago:6
master_sync_in_progress:0
slave_repl_offset:184823
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:<some id>
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:184823
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:69868
repl_backlog_histlen:114956In this way, you can easily check the replication status of your Redis instances.
Was this content helpful?
Other Common Redis Questions (and Answers)
White Paper
Free System Design on AWS E-Book
Download this early release of O'Reilly's latest cloud infrastructure e-book: System Design on AWS.
Switch & save up to 80%
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement. Instantly experience up to a 25X boost in performance and 80% reduction in cost