So today we look at an aspect of capacity management or planning and how it relates to MySQL and its Logging.  For this blog I’m primarily going to look at MySQL’s binary logs. They have a tendency to grow, and will continue to if not held in check.  Happily, they tend to be easy to… Read More »

In this article, I will show you how it’s possible to perform an online migration from a 3 members Galera cluster setup (in this case I’m using PXC 5.7.14) to a 3 members MySQL Group Replication cluster setup (MySQL Community 5.7.17).

Don’t forget that before adopting Group Replication as database backend, you should validate that your application do match GR requirements and limitations. When this is validated, you can start !

So first, let’s have a look at the current situation:

We have an application (sysbench 0.5), reading and writing to a Galera Cluster ( …

As stated in the MySQL Cluster documentation:

Partition.  This is a portion of the data stored by the cluster. There are as many cluster partitions as nodes participating in the cluster. Each node is responsible for keeping at least one copy of any partitions assigned to it (that is, at least one replica) available to the cluster.

According to my understanding for the previous paragraph, if we have a cluster of 6 datanodes we should have 6 partitions for each NDB table. I claim that this is not true for all cases – at least, after the introduction of ndbmtd (Multi-Threaded Daemon) in MySQL Cluster 7.2 .
In this post, I’ll do some …

Percona announces the release of Percona XtraDB Cluster 5.7.16-27.19 on December 15, 2016. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.7.16-27.19 is now the current release, based on the following:

• Percona Server 5.7.16-10
• Galera Replication library 3.19
• wsrep API version 26

All Percona software is open-source and free.

…

Welcome to a new series of blogs: Percona Live featured tutorial speakers! In these blogs, we’ll highlight some of the tutorial speakers that will be at this year’s Percona Live conference. We’ll also discuss how these tutorials can help you improve your database environment. Make sure to read to the end to get a special Percona Live 2017 registration bonus!

In this Percona Live featured tutorial, we’ll meet Giuseppe Maxia, Quality Assurance Architect at VMware. His tutorial is on MySQL Document Store: SQL and NoSQL United. MySQL 5.7 introduced document store, which allows asynchronous operations …

After MySQL installation, If you don’t have any enterprise level / any GUI interface for monitoring, backup then one of the option is, write your own scripts to automate these tasks.
In this Blog post, we are going to see few monitoring and backup scripts with covering common security issues.

• Credential security
• mysql_config_editor and Credential security
• Monitoring scripts
• backup scripts

Credential security

Following is a simple script, which will monitor MySQL service. In case MySQL …

How to solve mysqld service restart problem for above error?

Problem :
I was adding shell and home directory for mysql user,executed following cmd,

shell> usermod -m -d /home/mysql -s /bin/bash mysql

If mysql is running and process running with mysql , we need to stop mysql otherwise it will throw an error like usermod: user mysql is currently used by process 27768

After stopping MySQL service and adding shell and homedir for mysql user, at the time mysqld service startup it started throwing error.

shell> service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
Shell> systemctl status mysqld.service

● mysqld.service - MySQL Server
Loaded: loaded …

In this blog post, we’ll discuss the differences between row store and column store databases.

Clients often ask us if they should or could be using columnar databases. For some applications, a columnar database is a great choice; for others, you should stick with the tried and true row-based option.

At a basic level, row stores are great for transaction processing. Column stores are great for highly analytical query models. Row stores have the ability to write data very quickly, whereas a column store is awesome at aggregating large volumes of data for a subset of columns.

One of the benefits of a columnar database is its crazy fast query speeds. In some cases, queries that took minutes or hours are completed in seconds. This makes columnar databases a good choice in a query-heavy …

Percona announces the release of Percona XtraDB Cluster 5.6.34-26.19 on December 14, 2016. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.6.34-26.19 is now the current release, based on the following:

• Percona Server 5.6.34-79.1
• Galera Replication library 3.19
• wsrep API version 26

All Percona software is open-source and free. Details of this …

Any DBA who has administered a busy master knows how fast the disk space occupied by binary logs may grow.  DBAs have no control on this: the growth depends on the workload, and the workload depends on many factors, e.g.:

- application changes (the applications start writing more due to code changes) - traffic changes (the peak season arrive, your workload doubles in size) - infrastructure changes (the devops add more servers) - business changes (new business flows adds to existing workload)
So either you have being thoughtful and have planned in advance for a large enough storage space (to handle the increase in number of binary logs), or,  sooner or later, you will face the usual dilemma - how many retention days dare you give up to accommodate for the binlog growth?
In my case, I was very thoughtful, but the boss didn't listen and gave me servers with very limited binlog storage space and, more important, …