The occurrence of failures and crashes can compromise the high availability of your database system affecting your revenue and reputation. Therefore, it is fundamental to minimize downtime and have an efficient strategy for crash recovery.

Replication and failover are commonly applied to deal with those situations. However, other types of failures can also affect the recovery process. In fact, the occurrence of unanticipated faults can really be an headache! Thus, it is better to be prepared and implement a good fault-tolerant failover strategy.

Performing failover is not trivial. It requires the execution of several steps in order to ensure data consistency (i.e., no data loss) -- especially if the "best" candidate to become the new master is not the most up-to-date.

Note that, one might desire that the slave with the best hardware should become the new master. In this case, the candidate must be …

Percona Server version 5.6.13-60.6

Percona is glad to announce the fourth Release Candidate of Percona Server 5.6.13-60.6 (downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.6.13, including all the bug fixes in it, Percona Server 5.6.13-60.6 is the fourth RC release in the Percona Server 5.6 series. All of Percona‘s software is open-source and …

MySQL 5.7.2 features enhanced Multi-threaded slave which can be used to apply transactions in parallel even within a single database. Internal details of its working can be found in an earlier post. In this  post we will see how we can configure our replication slave to use this enhancement.
MySQL 5.7.2 has a new system variable  --slave-parallel-type which is dynamic. It can be set to the following values:

1. DATABASE  : (Default) Use the db partitioned MTS (1 worker per database)
2. LOGICAL_CLOCK:  Use logical clock based parallelization mode.

Apart from this the original option of --slave-parallel-workers=N is still valid and it sets that number of workers that we need to spawn. Also since the slave leverages the group of transactions that have …

IntroductionRe-applying binary logs generated from highly concurrent master on the slave has always been an area of focus. It is important for various reasons. First, in real-time systems, it becomes extremely important for the slave to keep up with the master. This can only be guaranteed if the slaves’ performance in reapplying the transactions from the binary log is similar (or at-least comparable) to that of master, which is accepting queries directly from multiple clients. Second, in synchronous replication scenarios, having a fast slaves, aids in reducing the response times as seen by the clients to the master. This can be made possible by applying transactions from the binary log in parallel. However if left uncontrolled, a simple round-robin multi-threaded applying will lead to inconsistency and the slave will no longer be the exact replica of the leader.
The infamous out of order commit problemThe Out of order execution of transaction …

Learn how Modernizing Medicine, an electronic medical records company, serves thousands of customers and leverages Continuent Tungsten to manage databases on Amazon AWS. Modernizing Medicine is as fast growing SaaS company, offering electronic medical records management solution for thousands of small and medium-sizes dermatology, ophthalmology, optometry, plastic surgery, cosmetic and

The MariaDB project is pleased to announce the immediate availability of MariaDB 5.5.33a. This is a Stable (GA) release. See the Release Notes and Changelog for detailed information on this release and the What is MariaDB 5.5? page in the AskMonty Knowledgebase for general information about the MariaDB 5.5 series.

Download MariaDB 5.5.33a

Release Notes Changelog …

“Will you expand the next webcast to 90 minutes? This one was too interesting to last only one hour” was one of the questions we got during the “Tuning MySQL for Great Product Performance: The Fundamentals, Updated for MySQL 5.6” webinar on August 27th.  The engineers on Q&A got a lot of good (and more technical) questions during the webcast.  For those of you who were unable to join us live, I’ve posted the questions and answers below, and you can listen to a recording of the webinar and get a .pdf of slides at this link.

The webinar was created specifically for the software and …

One of our customers sometimes observed lots of simple insertions taking far longer than expected to complete. Usually these insertions completed in milliseconds, but the insertions sometimes were taking hundreds of seconds. These stalls indicated the existence of a serialization bug in the Fractal Tree index software, so the hunt was on. We found that these stalls occurred when a big transaction was committing and the Fractal Tree index software was taking a checkpoint. This problem was fixed in both TokuDB 7.0.3 and TokuMX 1.0.3. Please read on as we describe some details about this bug and how we fixed it. We describe some of the relevant Fractal Tree index algorithms first.

What is a Big Transaction?

Each transaction builds a rollback log as it performs Fractal Tree index operations. The rollback log is maintained in memory until it gets too big and is spilled to the TokuDB rollback file. We define a small …

In this episode, we finish our series about the MySQL Utilities. Ear Candy is pt-stalk, and At the Movies is a fast parallel query engine.

MySQL Utilities part 5

Part 1 of MySQL Utilities
Part 2 of MySQL Utilities
Part 3 of MySQL Utilities
Part 4 of MySQL Utilities

mysqlrplcheck

[bugzilla2]$ mysqlrplcheck --master=root:PASS@bugzilla1 --slave=root:PASS@localhost:/var/lib/mysql/mysql.sock

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Oracle OpenWorld 2013 is just days away, and Pythian is once again everywhere at OOW. Pythian’s famous Annual Oracle Bloggers Meetup — one of your top favorite events of OpenWorld, is once again here at OOW.

Oracle:

As this year is heading to a close, it will complete 21 years of partnership between Intel and Oracle.

Have you started to pay closer attention to social, cloud, mobile, and/or big data technologies and trends?

NetBeans IDE 7.4 RC 1, released today, has a long list of features, including support for …