In this blog post, we’ll look at how to migrate to Amazon RDS using Percona XtraBackup.

Until recently, there was only one way to migrate your data from an existing MySQL instance into a new RDS MySQL instance: take and restore a logical backup with mysqldump or mydumper. This can be slow and error-prone. When Amazon introduced Amazon Aurora MySQL, you could use Percona XtraBackup to take an online physical backup of your database and restore that into a new Aurora instance. This feature is now available for RDS MySQL as well. Using Percona XtraBackup instead of a logical backup can save a lot of time, especially …

In this blog post, we’ll look at the performance of multi-source replication with GTID.

Multi-Source Replication is a topology I’ve seen discussed recently, so I decided to look into how it performs with the different replication concepts. Multi-source replication use replication channels, which allow a slave to replicate from multiple masters. This is a great way to consolidate data that has been sharded for production or simplify the analytics process by using the same server. Since multiple masters are taking writes, care is needed to not overlook the slave. The traditional replication concept uses the binary log file name, and the position inside that file.

This was the standard until the release of global transaction identifiers (GTID). I have set up a test environment to validate which concept would perform better, and be a better choice for use in this topology.

SETUP

My test suite …

In this blog post, we’ll discuss some of the options available when purging binary logs. We’ll look at how to safely purge them when you have slaves in your topology and want to avoid deleting any binary log that still needs to be applied.

We generally want to ensure that, before purging the binary logs from the master, all logs were applied to the slaves to avoid halting them. The example error below is a classic case of a binary log purged before being applied on the slave:

Last_IO_Errno: 1236
Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: ‘Could not open log file’

MySQL offers some options to purge of binary logs. One of them is executing the PURGE BINARY LOGS command. The  …

Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Effective Testing for Live Applications on March 29, 2018, at 10:00 am PDT (UTC-7) / 1:00 pm EDT (UTC-4).

When an application is hit with trouble in a live production environment, it is often difficult to:

• Repeat a problematic scenario without the risk of making things worse
• Find which query or sequence of actions caused the issue
• Prepare a dataset to share with the support team that they can use to investigate the problem

At the same time, it is not possible to solve troubles without understanding what caused them. This is why it is necessary to clearly …

In this post, I’ll discuss the fix for lp:1704195 (migrated to PS-2503), which prevents

ANALYZE TABLE

 from blocking all subsequent queries on the same table.

In November 2017, Percona released a fix for lp:1704195 (migrated to PS-2503), created by Laurynas Biveinis. The fix, included with Percona Server for MySQL since versions 5.6.38-83.0 and 5.7.20-18, stops

ANALYZE …

Please join Percona’s Principal Architect in Architecture & Projects, Yves Trudeau, as he presents ZFS with MySQL on Wednesday, March 28, 2018, at 7:00 am PDT (UTC -7) / 10:00 am EDT (UTC -4).

Are you curious about ZFS? Would you like to learn how to setup and configure ZFS? What about ZFS with MySQL?

ZFS on Linux has matured a lot. It offers unique features that are extremely compelling for use with a database server like MySQL.

During this webinar, we’ll review the main characteristics of ZFS, and walk through the configuration of ZFS and MySQL in order to provide good performance levels and superior ease-of-management. We will also cover aspects like backups using snapshots, cloning snapshots to create local slaves, the …

In this post, we’ll look at the MySQL 8.0 innodb_dedicated_server variable.

MySQL 8.0 introduces a new variable called innodb_dedicated_server. When enabled, it auto tunes innodb_buffer_pool_size, innodb_log_file_size and innodb_flush_method at startup (if these variables are not explicitly defined in my.cnf).

The new MySQL 8.0 variable automatically sizes the following variables based on the RAM size of the system:

innodb_buffer_pool_size:

• • <1G: 128M(default value if innodb_dedicated_server is OFF)
  • <=4G: Detected Physical RAM * 0.5
  • >4G: Detected Physical RAM * 0.75

innodb_log_file_size: …

In this blog post, we’ll look at how Percona XtraDB Cluster (PXC) executes FLUSH and LOCK handling.

Introduction

Percona XtraDB Cluster is a multi-master solution that allows parallel execution of the transactions on multiple nodes at the same point in time. Given this semantics, it is important to understand how Percona XtraDB Cluster executes statements regarding FLUSH and LOCK handling (that operate at node level).

The section below enlist different flavors of these statements and their PXC semantics

FLUSH TABLE WITH READ LOCK

• FTWRL is normally used for backup purposes.
• Execution of this command establishes a global level …

From time to time I see pattern matching queries with conditions that look like this: “where fieldname like ‘%something%’ “. MySQL cannot use indexes for these kinds of queries, which means it has to do a table scan every single time.

(That’s really only half true — there are the FullText indexes. In another blog post I will cover FullText indexes as well.)

I recently was trying to find a solution, and my friend Charles Nagy reminded me of Trigrams. Let me show you the Trigram of the name Daniel:

daniel:
dan
ani
nie
iel

But how is this useful?

Let me show you an example. You have the following email …

In this blog post, we’ll look at how to navigate some of the complexities of multi-source GTID replication.

GTID replication is often a real challenge for DBAs, especially if this has to do with multi-source GTID replication. A while back, I came across a really interesting customer environment with shards where multi-master, multi-source, multi-threaded MySQL 5.6 MIXED replication was active. This is a highly complex environment that has both pros and cons, introducing risks as a trade-off for specific customer requirements.

This is the set up of part of this environment:

I started looking into this setup when a statement broke replication between db1 and db10. Replication broke due to a statement executed on a schema that was not present on db10. This also …