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 …

In this blog post, we’ll look at how to turn on binlog encryption in Percona Server for MySQL.

Why do I need this?

As you probably know, Percona Server for MySQL’s binlog contains sensitive information. Replication uses the binlog to copy events between servers. They contain all the information from one server so that it can be applied on another. In other words, if somebody has access to a binlog, it means they have access to all the data in the server. Moreover, said person (or, “Hacker”) could create a clone copy of our server by just making a replica of it. In the end, they have access to our binlog. This shows how important protecting a binlog really is – leakage of binlogs not only make a particular table/tablespace or a group of tables accessible to a hacker, but literally the whole server …

Please join Percona Technical Account Manager Tim Sharp, as he presents How Percona Maintains Optimal Customer Health on Thursday, March 8, 2018 at 11:00 am PST (UTC -8) / 2:00 pm EST (UTC -5).

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How do you guarantee optimal database performance for your critical applications and services? Proactive monitoring and intervention is one way.

Percona Technical Account Managers (TAM) are expert DBAs that provide proactive assistance to our Managed Service customers – helping to guarantee performance, …

In this post I’ll look at some of our recent work for benchmark enthusiasts: a TPCC-like workload for Sysbench (version 1.0 or later).

Despite being 25 years old, the TPC-C benchmark can still provide an interesting intensive workload for a database in my opinion. It runs multi-statement transactions and is write-heavy. We also decided to use Sysbench 1.0, which allows much more flexible LUA scripting that allows us to implement TPCC-like workload.

For a long time, we used the tpcc-mysql (https://github.com/Percona-Lab/tpcc-mysql) tool for performance evaluations of MySQL and Percona Server for MySQL, but we recognize that the tool is far from being intuitive and simple to use. So we hope the adaptation for Sysbench will …

Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Performance Schema for MySQL Troubleshooting on Thursday, March 1, 2018, at 10:00 am PST (UTC-8) / 1:00 pm EST (UTC-5).

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Performance Schema, first introduced in version 5.5, is a really powerful tool. It is actively under development, and each new version provides even more instruments for database administrators.

Performance Schema is complicated. It is also not free: it can slow down performance if you enable certain …

In this blog post, I’ll look at how you can analyze raw MySQL query logs with ClickHouse.

For typical query performance analyses, we have an excellent tool in Percona Monitoring and Management. You may want to go deeper, though. You might be longing for the ability to query raw MySQL “slow” query logs with SQL.

There are a number of tools to load the MySQL slow query logs to a variety of data stores. For example, you can find posts showing how to do it with LogStash. While very flexible, these solutions always look too complicated and limited in functionality to me.   

By far the best solution to parse and load MySQL slow query logs (among multiple log types supported) is Charity …

In this blog post,  I’ll look at how to catch slow and frequent queries with ProxySQL.

More and more people are using ProxySQL because it is a great tool and it can help DBAs a lot. But many people do not realize that it is more powerful than it looks. It has many features and possibilities. I am going to show you one of my favorite “tricks” / use cases.

There are plenty of blog posts explaining how ProxySQL works. I am not going to that again. Instead, let’s jump straight to the point. There is a table in ProxySQL called “stats.stats_mysql_query_digest”. It is one of my favorite tables because it basically records all the queries that were running against ProxySQL. Without collecting any queries on the MySQL server, I can find …

In this blog post, I’ll look at how to execute a MySQL single table Point-In-Time Recovery.

I recently wrote a blog post describing a different way of doing Point-In-Time Recovery (PITR). If you want to know the step by step, please visit the mentioned blog post. Here is a quick summary of the approach:

1. Restore the backup on the desired server
2. Create a fake master
3. Copy all relevant binlogs to the fake master
4. Configure server from the first step as a slave from a fake master

In addition to the above steps, there is a similar approach …