Long time ago I wrote a blog post that we started using Semi-Synchronous replication in production at Facebook. We are running our own MySQL facebook-5.6 branch, which added many replication (including Semisync) patches. Some of them were also merged with WebScaleSQL.

 Recently I heard from people from community that they were suffering from Semisync performance issues in official MySQL 5.6. I took some time to review our previous MySQL bug reports, then realized that some important bugs were either still "verified" or inefficiently fixed. Two most affecting bug reports were …

I’ll be presenting Undrop for InnoDB data recovery toolkit on Percona Live 2015. The conference takes place in Santa Clara on 13-16 April.

You may wonder why do I care if I plan to drop none of my production databases. To name few reasons:

• Taxes, death and data loss are inevitable
• Good knowledge of how InnoDB stores data on disk help to design fast and scalable databases
• The toolkit can be used to troubleshoot bugs in InnoDB.

So bookmark the session, it’s going to be a great discussion.

Undrop for InnoDB | Percona Live MySQL Conference 2015

The post Presenting Undrop for InnoDB Toolkit on Percona Live 2015 appeared first on …

January 27, 2015 By Severalnines

Unlike standard MySQL server and MySQL Cluster, the way to start a MySQL/MariaDB Galera Cluster is a bit different. Galera requires you to start a node in a cluster as a reference point, before the remaining nodes are able to join and form the cluster. This process is known as cluster bootstrap. Bootstrapping is an initial step to introduce a database node as primary component, before others see it as a reference point to sync up data.

How does it work?

When Galera starts with the bootstrap command on a node, that particular node will reach Primary state (check the value of wsrep_cluster_status). The remaining nodes will just require a normal start command and they will automatically look for existing Primary Component (PC) in the cluster and join to form a cluster. Data synchronization then happens through either incremental state transfer (IST) or …

In this blog post, we will discuss MySQL performance on eXFlash DIMMs. Earlier we measured the IO performance of these storage devices with sysbench fileio.

Environment

The benchmarking environment was the same as the one we did sysbench fileio in.

CPU: 2x Intel Xeon E5-2690 (hyper threading enabled)
FusionIO driver version: 3.2.6 build 1212
Operating system: CentOS 6.5
Kernel version: 2.6.32-431.el6.x86_64

In this case, we used a separate machine for testing which had a 10G ethernet connection to this server. This server executed sysbench. The client was not the bottleneck in this case. The environment is described in greater detail at the end of the blog post.

Sysbench OLTP write workload

…

Mon, 2015-01-26 09:59chris.calender

I ran into this error today while working with ROLES, bundled privileges for a group of users (a nice addition in MariaDB 10.0):

ERROR 1959 (OP000) Invalid role specification

The manual suggests that this error occurs "if a role that doesn't exist, or to which the user has not been assigned, is specified".

However, I ran into a case where the role was created and assigned properly (examine SHOW GRANTS for user in question).

In this case, the problem was just due to a bug that affected remote connections on older …

Taxonomy upgrade extras: BackupRestoreRecoverymysqldumppoint-in-time-recoverypitr

Sometimes we face the situation where we have a full MySQL database backup done with mysqldump and then we have to restore and recover just one single table out of our huge mysqldump file.
Further our mysqldump backup was taken hours ago so we want to recover all the changes on that table since our backup was taken up to the end.

In this blog article we cover all the steps needed to achieve this goal …

Today is my last day at Tokutek. On Monday I'm starting a new opportunity as VP/Technology at CrunchTime!. If you are a web developer, database developer, or quality assurance engineer in the Boston area and looking for a new opportunity please contact me or visit the CrunchTime! career page.

I've really enjoyed my time at VoltDB and Tokutek. Working for Mike Stonebraker (at VoltDB) was on my career "bucket list" and in these past 3.5 years at Tokutek I've experienced the awesomeness of the MySQL ecosystem and the surging NoSQL database …

For months when speaking with customers I have been positioning Percona Cloud Tools (PCT) as a valuable tool for the DBA/Developer/SysAdmin but only recently have I truly been able to harness the data and make a technical recommendation to a customer that I feel would have been very difficult to accomplish otherwise.

Let me provide some background: I was tasked with performing a Performance Audit for one of our customers (Performance Audits are extremely popular as they allow you to have a MySQL Expert confirm or reveal challenges within your MySQL environment and make your database run faster!) and as part of our …

Following on from my earlier proposal to change Replication + InnoDB settings, in the MySQL team, we are proposing to make the following additional changes to defaults in MySQL 5.7:

Fri, 2015-01-23 15:14markusmakela

MaxScale’s filter system is very flexible and enables a new way of interacting with queries. The upcoming firewall filter shows just one of the many ways that you can control and manage the flow of queries through MaxScale.

The firewall filter is meant to offer finer and more varied control over queries and their execution. The main idea of the filter is to work as a base to build and improve upon and to show just how that can be done with MaxScale.

The filter provides a variety of ways to control which kinds of queries get executed. The simplest ones block queries that happen during a certain time range or do a certain operation. The more complex ones can match queries using a regular expression, check for the existence of a WHERE clause in the query or deny the query on the basis of the current session’s query speed. These rules can be applied to specific users or network ranges or …