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MySQL QA Episode 12: My server is crashing... Now ...

My server is crashing… Now what? This special episode in the MySQL QA Series is for customers or users experiencing a crash. A crash? Cheat sheet: https://goo.gl/rrmB9i Sever install & crash. Note this is as a demonstration: do …

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The MySQL query cache: Worst enemy or best friend?

During the last couple of months I have been involved in an unusually high amount of performance audits for e-commerce applications running with Magento. And although the systems were quite different, they also had one …

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PXC - Incremental State transfers in detail

IST Basics State transfers in Galera remain a mystery to most people.  Incremental State transfers (as opposed to full State Snapshot transfers) are used under the following conditions: The Joiner node reports Galera a valid …

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MySQL QA Episode 11: Valgrind Testing: Pro's, Con'...

Today’s episode is all about Valgrind – from the pro’s to the con’s, from the why to the how! This episode will be of interest to anyone who is or wants to work with Valgrind on …

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Percona XtraBackup 2.2.12 is now available

Percona is glad to announce the release of Percona XtraBackup 2.2.12 on August 3, 2015. Downloads are available from our download site or Percona Software Repositories. Percona XtraBackup enables MySQL backups without blocking user queries, …

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Checkpoint strikes back

In my recent benchmarks for MongoDB, we can see that the two engines WiredTiger and TokuMX struggle from periodical drops in throughput, which is clearly related to a checkpoint interval – and therefore I correspond …

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MySQL QA Episode 10: Reproducing and Simplifying: ...

Welcome to the 10th episode in the MySQL QA series! Today we’ll talk about reproducing and simplifying: How to get it Right. Note that unless you are a QA engineer stuck on a remote, and …

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Why base64-output=DECODE-ROWS does not print row e...

Lately I saw many cases when users specified option --base64-output=DECODE-ROWS  to print out a statement representation of row events in MySQL binary logs just to get nothing. Reason for this is obvious: option --base64-output=DECODE-ROWS  does …

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Multi-source replication in MySQL 5.7 vs Tungsten ...

MySQL 5.7 comes with a new set of features and multi-source replication is one of them. In few words this means that one slave can replicate from different masters simultaneously. During the last couple of …

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MySQL QA Episode 9: Reducing Testcases for Experts...

Welcome to MySQL QA Episode 9. This episode will go more in-depth into reducer.sh: Reducing Testcases for Experts: multi-threaded reducer.sh We will explore how to use reducer.sh to do true multi-threaded testcase reduction – a world’s …

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InnoDB Posts

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Using Cgroups to Limit MySQL and MongoDB memory us...

Quite often, especially for benchmarks, I am trying to limit available memory for a database server (usually for MySQL, but recently for MongoDB also). This is usually needed to test database performance in scenarios with …

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Update on the InnoDB double-write buffer and EXT4 ...

In a post, written a few months ago, I found that using EXT4 transactions with the “data=journal” mount option, improves the write performance significantly, by 55%, without putting data at risk. Many people commented on …

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Insight for DBAs Posts

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MySQL Quality Assurance: A Vision for the Future b...

Welcome to the final – but most important – episode in the MySQL QA Series. In it, I present my vision for all MySQL Quality Assurance – for all distributions – worldwide. Episode 13: A Better …

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MySQL QA Episode 12: My server is crashing... Now ...

My server is crashing… Now what? This special episode in the MySQL QA Series is for customers or users experiencing a crash. A crash? Cheat sheet: https://goo.gl/rrmB9i Sever install & crash. Note this is as a demonstration: do …

Read More