MySQL 8.0.13 improves replication lag monitoring by extending the instrumentation for transaction transient errors. These temporary errors, which include lock timeouts caused by client transactions executing concurrently as the slave is replicating, do not stop the applier thread: instead, they cause a transaction to retry.…
Category Archives: Replication
Group Replication: coping with unreliable failure detection
Failure detection is a cornerstone of distributed systems as it determines which components are working properly or not, allowing it to tackle both network and host instabilities and failures. Like many other distributed systems, Group Replication (GR) requires a majority of correctly operating group members to work properly.…
On-demand primary election
Having a server acting as a primary with multiple secondaries is the most common setup when using Group Replication. Until now though, there was no way to change the current primary member while the group was running without causing some sort of disruption.…
Setting up MySQL Group Replication with MySQL Docker images
MySQL Group Replication (GR) is a MySQL Server plugin that enables you to create elastic, highly-available, fault-tolerant replication topologies. Groups can operate in a
single-primary mode with automatic primary election, where only one server accepts updates at a time. Alternatively, groups can be deployed in multi-primary mode, where all servers can accept updates, even if they are issued concurrently.…
Protecting your data – Part II: Preventing unwanted data changes on Group Replication members by asynchronous replication channels
Further to our earlier blog post about Fail-safe enhancements to Group Replication, where we discussed enhancements against data modification in members which are not ONLINE, we now present here additional changes to protect data from being accidentally modified by asynchronous replication channels.…
Performance Improvements in MySQL 8.0 Replication
MySQL 8.0 became Generally Available (GA) on April 19th, a great moment for us working on MySQL at Oracle. It is now a “fully grown adult” packed with new features, and improvements to existing features, as described here.
This blog post focuses on the impact of replication performance improvements that went into MySQL 8.0.…
Reading the log positions of a snapshot consistently
MySQL 8.0.11 introduced a new performance schema table named log_status, which provides consistent information about MySQL server instance log positions from replication and transactional storage engines.
Used in conjunction with other MySQL 8.0 feature (the backup lock), this new feature will allow backup tools to take backup with minimal impact in DML throughput, but ensuring consistent snapshot with respect to GTIDs, replication, binary logs and transactional storage engine logs.…
Taking advantage of new transaction length metadata
MySQL 8.0.2 introduced a small yet powerful per transaction metadata information containing the transaction length in binary logs.
MySQL binary logs are being used for many other things than MySQL replication or backup/recovery: replicate to Hadoop; replicate to other databases, such as Oracle; capture data change (CDC) and extract-transform-load (ETL); record change notification for cache invalidation; change tracking for differential backups; etc.…
MySQL 8.0: New Features in Replication
It is with extreme delight and a big smile on our face that we share the news that a new major MySQL release has been declared Generally Available (GA). The road to MySQL 8 was pretty eventful, sometimes painful and sometimes hard, always challenging, but nonetheless a great ride and an extremely rewarding journey for the engineers that have worked on it.…
One year of MySQL Replication Contributions
Since January 2017, the MySQL Replication Team has been involved in processing many Community Contributions !
We are really happy to receive contributions (and not only in the replication team), but this also implies a lot of work from our engineers, as more than resolving a bug or developing a new feature, code contributions need to be analyzed, the code needs to be understood and validated.…