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How does MySQL Replication really work?

While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the …

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Is there room for more MySQL IO Optimization?

I prefer to run MySQL with innodb_flush_method=O_DIRECT in most cases – it makes sure there is no overhead of double buffering and I can save the limited amount of file system cache I would normally …

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MySQL 5.6.7-RC in tpcc-mysql benchmark

MySQL 5.6.7 RC is there, so I decided to test how it performs in tpcc-mysql workload from both performance and stability standpoints. I can’t say that my experience was totally flawless, I bumped into two …

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Recovery deleted ibdata1

Recently I had a case when a customer deleted the InnoDB main table space – ibdata1 – and redo logs – ib_logfile*. MySQL keeps InnoDB files open all the time. The following recovery technique is …

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Comparing Percona XtraDB Cluster with Semi-Sync replication Cross-WAN

I have a customer who is considering Percona XtraDB Cluster (PXC) in a two colo WAN environment.  They wanted me to do a test comparing PXC against semi-synchronous replication to see how they stack up against …

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Troubleshooting MySQL Memory Usage

One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you …

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How to Monitor MySQL with Percona’s Nagios Plugins

In this post, I’ll cover the new MySQL monitoring plugins we created for Nagios, and explain their features and intended purpose. I want to add a little context. What problem were we trying to solve …

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Getting MySQL Core file on Linux

Core file can be quite helpful to troubleshoot MySQL Crashes yet it is not always easy to get, especially with recent Linux distributions which have security features to prevent core files to be dumped by …

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MySQL performance on EC2/EBS versus RDS

A while ago I started a series of posts showing benchmark results on Amazon EC2 servers with RAID’ed EBS volumes and MySQL, versus RDS machines. For reasons that won’t add anything to this discussion, I …

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MySQL Connection Timeouts

Sometimes on very busy MySQL server you will see sporadic connection timeouts, such as Can’t connect to MySQL server on ‘mydb’ (110). If you have connects timed in your application you will see some successful …

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