MySQL replication isn’t perfect and sometimes our data gets out of sync, either by a failure in replication or human intervention. We are all familiar with Percona Toolkit’s pt-table-checksum and pt-table-sync to help us check and fix data inconsistencies – but imagine the following scenario where we mix regular replication with the Tungsten Replicator:

We have regular replication going from master (db1) to 4 slaves (db2, db3, db4 and db5), but also we find that db3 is also master of db4 and db5 using Tungsten replication for 1 database called test. This setup is currently working this way because it was deployed some time ago when multi-source replication was not possible using regular MySQL replication. This is now a working feature in …

There are tools like pt-kill from the percona tool kit that may print/kill the long running transactions at MariaDB, MySQL or at Percona data instances, but a lot of backup scripts are just some simple bash lines.
So checking for long running transactions before the backup to be executed seems to be a step that is missed a lot.

Here is one line that might be just added in every bash script before the backup to be executed
Variant 1. Just log all the processlist entries and calculate which ones were running longer than TIMELIMIT:

$ export TIMELIMIT=70 && echo "$(date) : check for long runnig queries start:" >> /tmp/processlist.list.to.kill && mysql -BN -e 'show processlist;' | tee -a /tmp/processlist.list.to.kill | awk -vlongtime=${TIMELIMIT} '($6>longtime){print "kill "$1";"}' | tee -a /tmp/processlist.list.to.kill

Variant 2: Log all the processlist, calculate the calculate which processes …

About 2 weeks ago Oracle published the MySQL 5.7.7-labs-json version which includes a very interesting feature called “Generated columns” (also know as Virtual or Computed columns). MariaDB has a similar feature as well: Virtual (Computed) Columns.

The idea is very simple: if we store a column

`FlightDate` date

in our table we may want to filter or group by year(FlightDate), month(FlightDate) or even dayofweek(FlightDate). The “brute-force” approach: use the above Date and Time MySQL functions in the query; however it will prevent MySQL from using an index (see below). Generated columns will allow you to declare a “Virtual”, non-stored column …

A few years back Deva wrote about how to use tcpdump on very busy hosts. That post sparked my interest about exploring how to measure the impact of tcpdump on very busy hosts. In this post, I wanted to highlight how much of an impact there really is and what options you have to make the query collection much more effective.

Some things you need to know:

• The test is a sysbench read-only workload, 8 tables, 8 threads, 1000000 rows each with 16G of buffer pool. Dataset fully in memory.
• sysbench is ran on the same host, on 1Gbps connection, sysbench can saturate the network and therefore affect my network test with netcat so I decided to run locally.
• There are 13 tests, 5 minutes each with 1 minute interval, varying on how the dump file is captured.
  • First one as …

Open Query is supporting the mysql-cli Kickstarter project (for MySQL and MariaDB) by Amjith Ramanujam who already successfully completed a similar tool for PostgreSQL.

It is a new MySQL client with Auto-Completion and Syntax Highlighting. From the info provided, it’s Python based, thus portable, and can be installed without root access. Could be a very useful tool. The good old mysql command line client does lack some things, yet a relatively low-level command line client is often useful for remote tasks (as opposed to graphical tools) so we reckon it’s good that this realm gets a bit of attention!

Can we output content of a mariaDB table into JSON using the CONNECT Storage Engine ? MariaDB and MySQL are not currently JSON friendly databases. The usage of JSON in MySQL is almost inexistent with the excetion of the explain JSON output and of MariaDB dynamic column dump. There also exist a few udf (in [...]

Itchy Ninja Software is pleased to announce the release of Analyst for MySQL v1.1. Revolutionize the way you work and administrate MySQL, MariaDB, Galera, and Percona XtraDB installations.

Make More Efficient Use of Your Time

Gathering all of the metrics to diagnose a database installation is a very time consuming process, and many simply do not have the experience to know where to begin. With Analyst for MySQL, you will be able to get your hands on hundreds of metrics within moments. It really takes all of the guesswork, as well as tedious long sessions of writing queries out of managing a MySQL database server.

Cross-Platform

Not only can you run the program on Windows, Mac, or Linux, you can also generate server reports from each of those platforms as well! No need to install anything on the server at any time. All diagnostics are run from your laptop or desktop machine. The …

Because interactivity with the trainer (our classes are not dry lectures) and discussions are an important and intrinsic part of our teaching approach, we’ve long tracked development of technologies for online training, but previously were not satisfied.

High costs of various corporate offerings would negatively impact our pricing, given the relatively small scale use and our purposely small classes. The student system requirements would often be problematic – obviously students use different operating systems (Windows, Mac, Linux) and we cannot prescribe that people use a particular OS.

Big Blue Button has long looked like it had the right potential, and it’s now developed to a point where were happy with it. For more tech and practical details, see our Interactive Online Training page.

After our successful trial runs, we have the following …

This time it is nothing like a linkt to another Blog:  Galera on Mesos

Ok as a fact I was kinda involved. Even the work is done by Stefan all alone. We meat for a day in a coworking space and discussed about Galera and Mesos.
In the end Stefan produced this incredible blogpost and pushed Mesos forward.
Whats the fun about this post?
We already now Galera is already the standard in a lot of architectures. For example OpenStack. Doing consultant work for Docker also I encourage to use Galera for all this infrastructures Docker runs on. 
Mesos is about to run easy on 1000 nodes. It has a nice abstraction of nodes and framework. Companies like Airbnb, Paypal, eBay, Groupon use Mesos. Having a Galera poc for Mesos is going to make it likely to …

From time to time we detect query patterns that are not well fitted to the BTree+ structures provided by InnoDB. One such situation is when you need to traverse a hierarchy (tree) or graph structure with many nodes. Specialist databases exist for this such as Neo4J. However there exists a simple solution in the form of  OQGraph which is distributed with MariaDB and is documented here.

The OQGRAPH engine is based on an original idea by Open Query founder Arjen Lentz, and was developed in-house with Antony Curtis at Open Query.

A …