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Displaying posts with tag: Percona Toolkit (reset)
Optimizing MySQL for Zabbix


This blog post was inspired by my visit at the annual Zabbix Conference in Riga, Latvia this year, where I gave a couple of talks on MySQL and beyond.

It was a two day single-track event with some 200 participants, a number of interesting talks on Zabbix (and related technologies) and really well-organized evening activities. I was amazed how well organized the event was and hope to be invited to speak there next year as well.   (Just in case you’re not sure what Zabbix is, it is an enterprise-class open source distributed monitoring solution for networks and applications)

I must secretly confess, it was also the first conference …

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Data inconsistencies on MySQL replicas: Beyond pt-table-checksum

Percona Toolkit’s pt-table-checksum is a great tool to find data inconsistencies between a MySQL master and its replicas. However it is sometimes not enough to know that there are inconsistencies and let pt-table-sync fix the issue: you may want to know which exact rows are different to identify the statements that created the inconsistency. This post shows one way to achieve that goal.

The issue

Let’s assume you have 2 servers running MySQL 5.5: db1 the master and db2 the replica. You want to upgrade to MySQL 5.6 using an in-place upgrade and to play safe, you will upgrade db2 (the slave) first. If all goes well you will promote it and upgrade db1.

A good thing to do after upgrading db2 is to check for potential data …

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Percona Toolkit for MySQL with MySQL-SSL Connections

I recently had a client ask me how to use Percona Toolkit tools with an SSL connection to MySQL (MySQL-SSL). SSL connections aren’t widely used in MySQL due to most installations being within an internal network. Still, there are cases where you could be accessing MySQL over public internet or even over a public “private” network (ex: WAN between two colo datacenters). In order to keep packet sniffers at bay, the connection to MySQL should be encrypted.

If you are connecting to Amazon RDS from home or office (ie: not within the AWS network) you better be encrypted!

As there is already a MySQL Performance Blog post on how to setup MySQL SSL connections, we can skip that and dive right in.

As you probably know, the mysql client …

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How to avoid hash collisions when using MySQL’s CRC32 function

Percona Toolkit’s  pt-table-checksum performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master – and the tool pt-table-sync synchronizes data efficiently between MySQL tables.

The tools by default use the CRC32. Other good choices include MD5 and SHA1. If you have installed the FNV_64 user-defined function, pt-table-sync will detect it and prefer to use it, because it is much faster than the built-ins. You can also use …

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MySQL Replication: ‘Got fatal error 1236′ causes and cures

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to make sure that data transfers smoothly, and to do so you need to act promptly regarding replication errors to continue data synchronization. Here on the Percona Support team, we often help customers with replication broken-related issues. In this post I’ll highlight the top most critical replication error code 1236 along with the causes and cure. MySQL replication error “Got fatal error 1236” can be triggered by multiple reasons and I will try to cover all of them.

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Percona Toolkit 2.2.11 for MySQL is now available

Percona is pleased to announce the availability of Percona Toolkit 2.2.11.  Released on Sept. 25, Percona Toolkit is a collection of advanced command-line tools to perform a variety of MySQL server and system tasks that are too difficult or complex for DBAs to perform manually. Percona Toolkit, like all Percona software, is free and open source.

This release contains bug fixes for pt-query-digest, pt-mysql-summary, pt-stalk, as well as other tools and is the current GA (Generally Available) stable release in the 2.2 series. Downloads are available here and from the  …

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Syncing MySQL slave table with pt-online-schema-change

I recently encountered a situation in which after running Percona Toolkit’s pt-table-checksum on a customer system, 95% of the table on the MySQL master was different on the MySQL slave. Although this table was not a critical part of the infrastructure, from time to time, writes to the table from the master would break replication. Additionally, this table has about 6 million rows, and running pt-table-sync would take sometime. Rebuilding the slave from backup of the master would not be an easy option as well since the slave acts as an archive where it has a lot more data than the master.

So how did we solve it? With pt-online-schema-change and a NOOP ALTER.

pt-online-schema-change --alter 'ENGINE=INNODB' D=dbname,t=tblname

How is it …

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MySQL 101: Monitor Disk I/O with pt-diskstats

Here on the Percona Support team we often ask customers to retrieve disk stats to monitor disk IO and to measure block devices iops and latency. There are a number of tools available to monitor IO on Linux. iostat is one of the popular tools and Percona Toolkit, which is free, contains the pt-diskstats tool for this purpose. The pt-diskstats tool is similar to iostat but it’s more interactive and contains extended information. pt-diskstats reports current disk activity and shows the statistics for the last second (which by …

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OpenStack’s Trove: The benefits of this database as a service (DBaaS)

In a previous post, my colleague Dimitri Vanoverbeke discussed at a high level the concepts of database as a service (DBaaS), OpenStack and OpenStack’s implementation of a DBaaS, Trove. Today I’d like to delve a bit further into Trove and discuss where it fits in, and who benefits.

Just to recap, Trove is OpenStack’s implementation of a database as a service for its cloud infrastructure as a service (IaaS). And as the mission statement declares, the Trove project seeks to provide a scalable and reliable cloud database service providing functionality for both relational and non-relational database engines. With the current release of Icehouse, the technology has begun to show maturity providing both stability and a rich feature set.

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Release Candidate Packages for Red Hat Enterprise Linux 7 and CentOS 7 now available

The Percona team is pleased to announce the Release Candidate for Percona Software packages for Red Hat Enterprise Linux 7 and CentOS 7.

With more than 1 million downloads and thousands of production deployments at small, mid-size and large enterprises, Percona software is a industry leading distribution that enhances the performance, scale, management and diagnosis of MySQL deployments.

This new packages bring the benefits of Percona Software to developers and administrators that are using Red Hat Enterprise Linux 7 and CentOS 7.

The new packages are available from our testing repository. The packages included are: :

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