With the recent release of Percona XtraDB Cluster, I am increasingly being asked about MySQL’s semi-synchronous replication. I find that there are often a number of misconceptions about how semi-synchronous replication really works. I think it is very important to understand what guarantees you actually get with semi-synchronous replication, and what you don’t get.

The first thing to understand is that despite the name, semi-synchronous replication is still asynchronous. Semi-synchronous is actually a pretty bad name, because there is no strong coupling between a commit on the master and a commit on the replicas. To understand why, let’s look at what truly synchronous replication means. In truly synchronous replication, when you commit a transaction, the commit does not complete until all replicas have also committed successfully. …

TokuDB® v5.2, the latest version of Tokutek’s flagship storage engine for MySQL and MariaDB, is now available.

This version offers performance enhancements over previous releases, especially for multi-client scale up and point queries, and extends the cases where ALTER TABLE is non-blocking, in particular adding Hot Column Rename.

TokuDB v5.2 maintains all our established advantages: fast trickle load, fast bulk load, fast range queries through clustering indexes, hot schema changes, great compression, no fragmentation, and full MySQL compatibility for ease of installation. See our benchmark page for details.

Multi-client workloads

In TokuDB v5.2, we have reworked our locking scheme to better support multi-client workloads, and as always, we have focused on large databases. How did we do? Let’s check out some …

Many of us know what it's like to work at an open source company. About 6 weeks ago I started my job as a Senior MySQL DB Admin/Architect (DBA but the "A" stands for both) at Mozilla. And I have to say, working for an open company is a lot different from working for an open source company.

There's so much more that's, well, open.

I can point to the Bugzilla bugs database, where all our ticket tracking is done. It's open to the public, although on the systems side we mark a lot of bugs private because they contain important information like hostnames and IP addresses and what ports are open vs. not.

Or I could point to my director's quest to make the IT department more open - one that I think is possible, …

Last week I was faced to a strange problem while benchmarking MySQL 5.6: some of my user sessions become "frozen" periodically and finally my whole test was not valid..

More in-depth analyze shown that:

• sessions are "frozen" when executing a SELECT statement..
• sessions are not really frozen, but waiting on read!..
• the read seems to be a kind of long read, involving many I/O operations..
• all makes think that query is execution a full table scan (200M rows, 40GB table) and ignoring indexes, so instead of 1ms I have >5min response time..

But the problem is completely "random" - it's not happening all of the time and not in all users sessions. And every time I'm executing EXPLAIN for any given "wrong" query - it's always giving me a right execution plan.. So, seems that something is going wrong on the time when queries are executed concurrently, and not when I'm …

Keith Larson and I will be at SCaLE at the LAX Hilton Friday until Sunday. Yes, we have swag and want to get your feedback. Don’t forget the Friday night BOF session.

And we also will be at the San Francisco MySQL Users Group where I will present Goldilocks and the Three Queries — MySQL EXPLAIN Explained on Wednesday the 25th.

In between, we will be attending the Oracle Leaders Summit. This is an unique event where the leaders of the users groups of various Oracle Family Products meet to discuss better ways of organizing user communities. This year we are lucky to have MySQL leaders from Asia, Europe and the Americas attending.

…

Taxonomy upgrade extras: monitoringmonitornewsperformance monitornewslettermpmmaas

On January 9th FromDual launched its Monitoring as a Service (MaaS) solution for MySQL.
This service is based on the Performance Monitor for MySQL (mpm) v0.8 and …

In MySQL you can restrict users to connect only via SSL settings. HeidiSQL's user manager now adds support for these settings, which include cipher, subject and issuer. You can also select X509 certificate, in which case cipher etc. do not matter. To get this new feature, you just need to update to the latest build (see Help > Check for updates).

In MySQL you can restrict users to connect only via SSL settings. HeidiSQL's user manager now adds support for these settings, which include cipher, subject and issuer. You can also select X509 certificate, in which case cipher etc. do not matter. To get this new feature, you just need to update to the latest build (see Help > Check for updates).

Read the original article at The Problem with Startup Bootcamps

Scanning Crains NY Business recently, I saw an article on 'starting up' in 54 hours.  It's the brainchild of Marc Nager, Clint Nelsen and Franck Nouyrigat called Startup Weekend. Startup bootcamps seem to be the current extra-curricular activity of choice these days. Wharton is also getting in on it with their Innovation Tournament. Then there is the …

Backing up binary logs are essential part of creating good backup infrastructure as it gives you the possibility for point in time recovery. After restoring a database from backup you have the option to recover changes that happend after taking a backup. The problem with this approach was that you had to do periodic filesystem level backups of the binary log files which could still lead to data loss depending on the interval you back them up.
Recently in MySQL 5.6, mysqlbinlog got a new feature addition that supports connecting to remote MySQL instances and dumping binary log data to local disks ( http://dev.mysql.com/doc/refman/5.6/en/mysqlbinlog-backup.html ). This can be used as a foundation of our live binary log backups.

The wrapper script below will connect to the remote server specified in the config and ensure mysqlbinlog utility …