In this blog post, I’ll look at how you can analyze MySQL audit logs (Percona Server for MySQL) with ClickHouse and ClickTail.

Audit logs are available with a free plugin for Percona Server for MySQL (https://www.percona.com/doc/percona-server/LATEST/management/audit_log_plugin.html). Besides providing insights about activity on your server, you might need the logs for compliance purposes.

However, on an active server, the logs can get very large. Under a sysbench-tpcc workload, for …

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  …

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 …

Overview

I find far too often that MySQL error and slow query logs are unaccounted for.  Setting up log rotation helps make the logs manageable in the event that they start to fill up and can help make your troubleshooting of issues more efficient.

Setup

All steps in the examples below are run as the root user. The first step is to setup a user that will perform the log rotation.  It is recommended to only give enough access to the MySQL user for the task that it is performing.

Create Log Rotate MySQL User

mysql > CREATE USER 'log_rotate'@'localhost' IDENTIFIED BY '<ENTER PASSWORD HERE>';
mysql > GRANT RELOAD,SUPER ON *.* to 'log_rotate'@'localhost';
mysql > FLUSH PRIVILEGES;</pre>

The next step is to setup the MySQL authentication config as root.  Here are two methods to set this up.  The first method will be the more secure method of …

Recently I blogged about the new default authentication plugin in MySQL 8.0 and I got some comments complaining that this new authentication plugin is breaking half of applications.

So first of all, if you are using an old connector or a connector (like the one for Go) not yet supporting caching_sha2_passwordas authentication plugin, you are still able to use the old one. If you have created a new user for your application not supporting the new authentication method, you just have to run the …

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 …

We’re excited to announce a major update to our tutorial “Database Load Balancing for MySQL and MariaDB with ProxySQL”

ProxySQL is a lightweight yet complex protocol-aware proxy that sits between the MySQL clients and servers. It is a gate, which basically separates clients from databases, and is therefore an entry point used to access all the database servers.

In this new update we’ve…

• Updated the information about how to best deploy ProxySQL via ClusterControl
• Revamped the section “Getting Started with ProxySQL”
• Added a new section on Data Masking
• Added new frequently asked questions (FAQs)

Load balancing and high availability go …

In this blog post, we’ll look at how you can verify query performance using ProxySQL.

In the previous blog post, I showed you how many information can you get from the “stats.stats_mysql_query_digest” table in ProxySQL. I also mentioned you could even collect and graph these metrics. I will show you this is not just theory, it is possible.

These graphs could be very useful to understand the impact of the changes what you made on the query count or execution time.

I used our all-time favorite benchmark tool called Sysbench. I was running the following query:

UPDATE sbtest1 SET c=? WHERE k=?

There was no index on “k” when I started the test. During the test, I …

In this post, We will learn how to handle online schema change if the table has triggers.

In PXC, an alter can be made directly ( TOI ) on tables with less than a 1G ( by default) , but on a 20GB or 200GB table we need some downtime to do ( RSU ).

Pt-osc is a good choice for Percona Cluster/Galera. By default percona toolkit’s pt-online-schema-change will create After “insert / update / delete” triggers for maintaining the sync between the shadow and the original table.

pt-online-schema-change process flow:

Check out the complete slides for effective MySQL administration here

If the tables has triggers already then pt-osc wont work well in …

In this blog post, we’ll look at what is needed when migrating MySQL users to Amazon RDS. We’ll discuss how we can transform MySQL user grants and make them compatible with Amazon RDS.

In order to deliver a managed service experience, Amazon RDS does not provide shell access to the underlying operating system. It also restricts access to certain procedures that require advanced privileges.

Every MySQL instance has some users with ALL PRIVILEGES, and you can’t directly migrate these users to Amazon RDS because it does not support following privileges for regular users.

• SUPER – Enable use of other administrative operations such as CHANGE MASTER TO, KILL, PURGE BINARY …