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Sveta SmirnovaPercona’s Principal Support Engineer, Sveta Smirnova presents the webinar MySQL Test Framework for Troubleshooting on April 12, 2018, at 10:00 am PDT (UTC-7) / 1:00 pm EDT (UTC-4). MySQL Test Framework (MTR) provides a unit test suite for MySQL. MySQL Server developers and contributors write the tests in the framework, and use them to ensure the build […]
In this blog, I will provide answers to the Q & A for the Performance Schema for MySQL Troubleshooting webinar. First, I want to thank everybody for attending my March 1, 2018, webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I was unable to answer […]
Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Effective Testing for Live Applications on March 29, 2018, at 10:00 am PDT (UTC-7) / 1:00 pm EDT (UTC-4). When an application is hit with trouble in a live production environment, it is often difficult to: Repeat a problematic scenario without the risk of […]
In this post, I’ll discuss the fix for lp:1704195 (migrated to PS-2503), which prevents ANALYZE TABLE from blocking all subsequent queries on the same table. In November 2017, Percona released a fix for lp:1704195 (migrated to PS-2503), created by Laurynas Biveinis. The fix, included with Percona Server for MySQL since versions 5.6.38-83.0 and 5.7.20-18, stops ANALYZE TABLE from invalidating query and […]
In this blog, I will provide answers to the Q & A for the Basic Internal Troubleshooting Tools for MySQL Server webinar. First, I want to thank everybody for attending my February 15, 2018, webinar on troubleshooting tools for MySQL. The recording and slides for the webinar are available here. Below is the list of […]
Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Basic External MySQL Troubleshooting Tools on March 15, 2018 at 10:00 am PDT (UTC-7) / 1:00 pm EDT (UTC-4). In my troubleshooting webinar series, I normally like to discuss built-in instruments available via the SQL interface. While they are effective and help to understand […]
Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Performance Schema for MySQL Troubleshooting on Thursday, March 1, 2018, at 10:00 am PST (UTC-8) / 1:00 pm EST (UTC-5). Register Now Performance Schema, first introduced in version 5.5, is a really powerful tool. It is actively under development, and each new version provides […]
In this blog, I will provide answers to the Q & A for the Troubleshooting MySQL Crashes webinar. First, I want to thank everybody for attending our January 25, 2018, webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I was unable to answer fully during […]
Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents “Basic Internal Troubleshooting Tools for MySQL Server” on Thursday, February 15, 2018, at 10:00 am PST (UTC-8) / 1:00 pm EST (UTC-5). Register Now MySQL Server has many built-in troubleshooting tools. They are always available and can provide many insights on what is […]
Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Troubleshooting MySQL Crashes on January 25, 2018, at 10:00 am PST (UTC -8) / 1:00 pm EST (UTC -5). Register Now This webinar is for every MySQL user! In this talk, I won’t focus on how to analyze core files, read the source […]
In this blog, we’ll look at a mystery around setting the MySQL open_file_limit variable in MySQL and Percona Server for MySQL. MySQL Server needs file descriptors to run. It uses them to open new connections, store tables in the cache, create temporary tables to resolve complicated queries and access persistent ones. If mysqld is not […]
In this post, we will discuss the best way to update an InnoDB table manually. As a support engineer, I often see situations when the cardinality of a table is not correct. When InnoDB calculates the cardinality of an index, it does not scan the full table by default. Instead it looks at random pages, as […]
In this blog post, we’ll discuss migrating data from encrypted Amazon MySQL RDS to encrypted Amazon Aurora. One of my customers wanted to migrate from an encrypted MySQL RDS instance to an encrypted Aurora instance. They have a pretty large database, therefore using mysqldump or a similar tool was not suitable for them. They also wanted to setup […]
In this blog post, we’ll look at MyRocks and the LOCK IN SHARE MODE. Those who attended the March 30th webinar “MyRocks Troubleshooting” might remember our discussion with Yoshinori on LOCK IN SHARE MODE. I did more tests, and I can confirm that his words are true: LOCK IN SHARE MODE works in MyRocks. This quick example demonstrates this. The initial setup:
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CREATE TABLE t ( id int(11) NOT NULL, f varchar(100) DEFAULT NULL, PRIMARY KEY (id) ) ENGINE=ROCKSDB; insert into t values(12345, 'value1'), (54321, 'value2'); |
In session 1:
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session 1> begin; Query OK, 0 rows affected (0.00 sec) session 1> select * from t where id=12345 lock in share mode; +-------+--------+ | id | f | +-------+--------+ | 12345 | value1 | +-------+--------+ 1 row in set (0.01 sec) |
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In this blog, we will provide answers to the Q & A for the TokuDB Troubleshooting webinar. First, we want to thank everybody for attending the March 22, 2017 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that we were unable to answer during the […]
In this blog, I will provide answers to the Q & A for the Troubleshooting Issues with MySQL Character Sets webinar. First, I want to thank everybody for attending the March 9 MySQL character sets troubleshooting webinar. The recording and slides for the webinar are available here. Below is the list of your questions that […]
In this blog, I will provide answers to the Q & A for the Troubleshooting MySQL Access Privileges Issues webinar. First, I want to thank everybody for attending the February 23 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer […]
In this blog post, I’ll look for the bottleneck that prevented the performance in my previous post from achieving better results. The powerful machine I used in the tests in my previous post has a comparatively slow disk, and therefore I expected my tests would hit a point when I couldn’t increase performance further due to the disk speed. […]
In this blog post, we’ll look at a workaround for MySQL bug 72804. Recently I worked on a ticket where a customer performed a point-in-time recovery PITR using a large set of binary logs. Normally we handle this by applying the last backup, then re-applying all binary logs created since the last backup. In the middle of the […]
In this blog post, we’ll look at Performance Schema benchmarks for OLTP Read/Write workloads. I am in love with Performance Schema and talk a lot about it. Performance Schema is a revolutionary MySQL troubleshooting instrument, but earlier versions had performance issues. Many of these issues are fixed now, and the default options work quickly and […]