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Battle for Synchronous Replication in MySQL: Galera vs. Group Replication

 | February 24, 2017 |  Posted In: Group Replication, High-availability, Insight for DBAs, Insight for Developers, MySQL, Percona XtraDB Cluster, Replication

Group Replication

In today’s blog post, I will briefly compare two major synchronous replication technologies available today for MySQL. Synchronous Replication Thanks to the Galera plugin, founded by the Codership team, we’ve had the choice between asynchronous and synchronous replication in the MySQL ecosystem for quite a few years already. Moreover, we can choose between at least three […]

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Galera warning “last inactive check”

 | June 2, 2016 |  Posted In: Percona XtraDB Cluster, XtraDB Cluster

Managing Replication

In this post, we’ll discuss the Galera warning “last inactive check” and what it means. Problem I’ve been working with Percona XtraDB Cluster quite a bit recently, and have been investigating various warnings. I came across this one today: [Warning] WSREP: last inactive check more than PT1.5S ago (PT1.51811S), skipping check This warning is related […]

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Galera Error Failed to Report Last Committed (Interrupted System Call)

 | May 27, 2016 |  Posted In: MySQL, Percona XtraDB Cluster, XtraDB Cluster

In this blog, we’ll discuss the ramifications of the Galera Error Failed to Report Last Committed (Interrupted System Call). I have recently seen this error with Percona XtraDB Cluster (or Galera): [Warning] WSREP: Failed to report last committed 549684236, -4 (Interrupted system call) It was posted in launchpad as a bug in 2013: https://bugs.launchpad.net/percona-xtradb-cluster/+bug/1434646 My […]

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How Big Can Your Galera Transactions Be

 | October 26, 2015 |  Posted In: Percona XtraDB Cluster

While we should be aiming for small and fast transactions with Galera, it is always possible at some point you might want a single large transaction, but what is involved? First, this is supposed to be controlled by two settings, wsrep_max_ws_rows  and wsrep_max_ws_size . The first variable is not yet enforced and has no effect – see […]

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Optimizing Percona XtraDB Cluster for write hotspots

 | June 3, 2015 |  Posted In: InnoDB, Insight for DBAs, MySQL, Percona XtraDB Cluster

Some applications have a heavy write workload on a few records – for instance when incrementing a global counter: this is called a write hotspot. Because you cannot update the same row simultaneously from multiple threads, this can lead to performance degradation. When using Percona XtraDB Cluster (PXC), some users try to solve this specific […]

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