Replication is the process that transfers data from an active master to a slave server, which reproduces the data stream to achieve, as best as possible, a faithful copy of the data in the master.

To check replication health, you may start with sampling the service, i.e. committing some Sentinel value in the master and retrieving it from the slave.

Sentinel data: Tap tap… Is this thing on?
If you want to make sure that replication is working, the easiest test is using replication itself to see if data is being copied across from the master to the slaves. The method is easy:

1. Make sure that the data you want to see is NOT in the master or in the slave. If you skip this step, you may think that replication is working, while in fact it may not.
2. Either create a table …

Download MariaDB 10.1.6

Release Notes Changelog What is MariaDB 10.1?

MariaDB APT and YUM Repository Configuration Generator

The MariaDB project is pleased to announce the immediate availability of MariaDB 10.1.6. This is a Beta release.

See the Release Notes and …

My latest post is online on the Booking.com blog: Evaluating MySQL Parallel Replication Part 3: Benchmarks in Production.  In this post, I present benchmark results on MariaDB 10.0 parallel replication on four Booking.com production workloads.

This post is also the opportunity to promote my two talks at Percona Live Europe, taking place in Amsterdam from September 21 to 23:

Binlog Servers at

Both MySQL and MariaDB have been busy, each introducing new features, sometimes creating the same feature, often with different syntax.

This is sometimes good for users, who have a wide choice. And sometimes it is bad, as once you are used to the deployment and syntax of one flavor, it is hard to switch to a different one. This problem is enhanced if you are dealing with an application, MySQL Sandbox, that needs to work well with all flavors.

The latest releases of MySQL Sandbox (3.0.51 to 3.0.55) have been necessary to solve minor and major troublesome points with MySQL 5.7.8 and MariaDB 10.1.

The current version (3.0.55) can install all the newest releases, including replication with MySQL 5.7.8 which suffers from a compatibility bug (better explored in a separate article). …

The schedule is out for Percona Live Europe: Amsterdam (September 21-23 2015), and you can see it at: https://www.percona.com/live/europe-amsterdam-2015/program.

From MariaDB Corporation/Foundation, we have 1 tutorial: Best Practices for MySQL High Availability – Colin Charles (MariaDB)

And 5 talks:

1. Using Docker for Fast and Easy Testing of MariaDB and MaxScale – Andrea Tosatto (Colt Engine s.r.l.) (I expect Maria Luisa is giving this talk together – …

There is nothing more to be said:

SELECT
gen.TABLE_SCHEMA
, gen.TABLE_NAME
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
) as COLUMN_NUM
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY != ""
) as INDEX_NUM_ALL
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "PRI"
) as INDEX_NUM_PRI
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "UNI"
) as INDEX_NUM_UNI
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "MUL"
) as INDEX_NUM_MUL

from …

This Log Buffer Edition cuts through the crowd and picks some of the outstanding blog posts from Oracle, SQL Server and MySQL.

Oracle:

• Continuous Delivery (CD) is a software engineering approach in which teams keep producing valuable software in short cycles and ensure that the software can be reliably released at any time.
• Query existing HBase tables with SQL using Apache Phoenix.
• Even though WebLogic with Active GridlLink are Oracle’s suggested approach to deploy Java applications that use Oracle Real Applications Clusters (RAC), …

MariaDB 10.0.20 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.20/

This is the eleventh GA release of MariaDB 10.0, and 21st overall release of MariaDB 10.0.

There were no major functionality changes, but there was one security fix, 6 crashing bugs fixed, some general upstream fixes, and quite a few bug fixes, so let me cover the highlights:

• Security Fix: Client command line option –ssl-verify-server-cert (and MYSQL_OPT_SSL_VERIFY_SERVER_CERT option of the client API) when used together with –ssl will ensure that the established connection is SSL-encrypted and the MariaDB server has a valid certificate. This fixes CVE-2015-3152.
• Crashing …

MariaDB 5.5.44 was recently released (it is the latest MariaDB 5.5), and is available for download here:

https://downloads.mariadb.org/mariadb/5.5.44/

This is a maintenance release, and no major changes, so there are only several noteworthy items (but one of those being a security fix and five potential crashing bug):

• Security Fix: Client command line option –ssl-verify-server-cert (and MYSQL_OPT_SSL_VERIFY_SERVER_CERT option of the client API) when used together with –ssl will ensure that the established connection is SSL-encrypted and the MariaDB server has a valid certificate. This fixes CVE-2015-3152.
• Crashing Bug: mysql_upgrade crashes the server with REPAIR VIEW ( …

MariaDB 10.1.5 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.1.5/

This is the 3rd beta, and 6th overall, release of MariaDB 10.1. There were not many major changes in this release, but a few notable items, as well as many overall bugs fixed (I counted 306).

Since it’s beta, I’ll only cover the major changes and additions, and omit covering general bug fixes (feel free to browse them all here).

To me, these are the highlights:

• New status variables: New status variables Binlog_group_commit_trigger_count, …