Question: How can you force a Redis slave to sync with its master?
Answer
To force a Redis slave to sync with its master, you can use the SLAVEOF
command. This command makes a server a replica (or slave) of another server (the master), implementing a master-replica model.
If a Redis instance is already a replica of some master, and you want to force a new synchronization, you need to first break the existing replication and then re-establish it. Here's how you can do that:
redis-cli SLAVEOF NO ONE redis-cli SLAVEOF master_host master_port
In this script, master_host
and master_port
should be replaced with the hostname and port number of your master Redis instance.
Please note, these commands will cause the current Redis instance to stop accepting write queries until the synchronization process completes. Additionally, if your data set is large, the synchronization may take a while.
Another way to force a resynchronization is by using the DEBUG RELOAD
command, which unloads and reloads the database again. However, this technique is not recommended for production environments as it blocks the server during the operation.
redis-cli DEBUG RELOAD
Remember to use these commands cautiously, especially in a production environment. Inappropriate use can lead to data loss or service interruption.
Was this content helpful?
Other Common Redis Questions (and Answers)
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