How do you solve replication lag?
To mitigate replication lag for large operations we use batching. We never apply a change to 100,000 rows all at once. Any big update is broken into small segments, subtasks, of some 50 or 100 rows each. As an example, say our app needs to purge some rows that satisfy a condition from a very large table.
How does MySQL master slave replication work?
Replication works as follows: Whenever the master’s database is modified, the change is written to a file, the so-called binary log, or binlog. The slave has another thread, called the SQL thread, that continuously reads the relay log and applies the changes to the slave server.
How to delay slave replication in MySQL support?
The answer for this problem is a delayed slave replication, It’s actually you are intentionally lagging MySQL slave to a master by few minutes / hours so that you have always a MySQL instance far from damage. There are two ways to do this, 1. MySQL delayed slave replication , 2.
When to use row based replication in MySQL?
Row-based replication allows extra columns to exist at the end of the table, so as long as it is able to write the first columns it will be fine. First apply the change to all slaves, then failover to one of the slaves and then apply the change to the master and attach that as a slave.
When to stop slave thread in row based replication?
When row based replication detects data drift, it will stop the slave thread to prevent making things worse. Then there is a method in between these two: mixed mode replication.
Why does MySQL replication stall the replication stream?
This has to do with the fact that a DDL change will most of the time lock a table and only release this lock once the DDL change has been applied. It even gets worse once you start replicating these DDL changes through MySQL replication, where it will in addition stall the replication stream.