Search Results for: replication time

Replication of the NOW() function (also, time travel)

Notice the result of the NOW() function in the following query. The query was run on a real database server and I didn’t change the clock of the server or change anything in the database configuration settings.

You may proceed to party like it is 1999. How can the NOW() function return a value […]

Making HAProxy 1.5 replication lag aware in MySQL

HAProxy is frequently used as a software load balancer in the MySQL world. Peter Boros, in a past post, explained how to set it up with Percona XtraDB Cluster (PXC) so that it only sends queries to available nodes. The same approach can be used in a regular master-slaves setup to spread the read load across […]

MySQL Tutorials: A time to learn at Percona Live 2015

The many hours of intensive tutorials, led by some of the top minds in MySQL, have always been a major draw each year to the Percona Live MySQL Conference and Expo. And 2015’s event will be no exception. Percona Live 2015 runs April 13-16 in Santa Clara, Calif. and the first day is dedicated to […]

Typical misconceptions on Galera Replication for MySQL

Even if a Galera node looks like a regular MySQL server, the underlying replication mechanism is very different. This implies some changes in the way you have to configure the Galera nodes. Here are some of the most common misconceptions about Galera when using Percona XtraDB Cluster. Q: Why should I enable binary logging as […]

MySQL ring replication: Why it is a bad option

I’ve recently worked with customers using replication rings with 4+ servers; several servers accepting writes. The idea behind this design is always the same: by having multiple servers, you get high availability and by having multiple writer nodes, you get write scalability. Alas, this is simply not true. Here is why. High Availability Having several […]

Galera replication – how to recover a PXC cluster

Galera replication for MySQL brings not only the new, great features to our ecosystem, but also introduces completely new maintenance techniques. Are you concerned about adding such new complexity to your MySQL environment? Perhaps that concern is unnecessarily. I am going to present here some simple tips that hopefully will let fresh Galera users prevent […]

Measuring failover time for ScaleArc load balancer

ScaleArc hired Percona to benchmark failover times for the ScaleArc database traffic management software in different scenarios. We tested failover times for various clustered setups, where ScaleArc itself was the load balancer for the cluster. These tests complement other performance tests on the ScaleArc software – sysbench testing for latency and testing for WordPress acceleration. […]

Semi-Sync replication performance in MySQL 5.7.4 DMR

I was interested to hear about semi-sync replication improvements in MySQL’s 5.7.4 DMR release and decided to check it out.  I previously blogged about poor semi-sync performance and was pretty disappointed from semi-sync’s performance across WAN distances back then, particularly with many client threads. The Test The basic environment of these tests was: AWS EC2 […]

Row-based replication, MySQL 5.6 upgrades and temporal data types

Whither your rollback plan? MySQL 5.6 upgrades are in full swing these days and knowing how to safely upgrade from MySQL 5.5 to 5.6 is important. When upgrading a replication environment, it’s important that you can build a migration plan that safely allows for your upgrade with minimal risk — rollback is often a very […]