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Displaying posts with tag: Insight for DBAs (reset)
How to Build Percona Server for MySQL From Sources

Lately, the number of questions about how to build Percona software has been increased. More and more people try to add their own patches, add some modifications, and build software by themselves. But this raises the question of how to do this in the same way as Percona does, as sometimes the compiler flag can make a drastic impact on the final binary.

First of all, let’s talk about the stages of compiling software.

I would say that at the beginning you need to prepare the build environment, install all the needed dependencies, and so on. For each version, the dependency list would be different. How do you get the correct dependency list? You can get all build requirements from the spec file (on rpm-based systems) or from the control file( on deb-based systems).

The next stage is to get the source code of Percona …

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MySQL Monitoring and Reporting Using the MySQL Shell

MySQL Shell is the advanced MySQL client, which has many excellent features. In this blog, I am going to explain the MySQL shell commands “\show” and “\watch”. Both commands are very useful to monitor the MySQL process. It provides more insights into the foreground and background threads as well. 

Overview

“\show” and “\watch” are the MySQL shell commands, which can be executed using the Javascript (JS), Python (Py), and SQL interfaces. Both commands are providing the same information, but the difference is you can refresh the results when using the command “\watch”. The refresh interval is two seconds. 

  • \show: Run the specified report using the provided options and arguments.
  • \watch: Run the specified report using the provided options and arguments, and refresh the results at regular intervals.

Below are the available options you can use with the “\show” …

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MySQL 5.6 and Percona Server for MySQL 5.6 are End of Life

MySQL 5.6.51 is the last release of the MySQL 5.6 series. Oracle will no longer provide updates or security fixes for this version.

Following Percona’s Release Lifecycle policies, the Percona Server for MySQL 5.6 series has reached End of Life (EOL) as well, and we will no longer provide public builds for bugs and security fixes.

We recommend that you upgrade to MySQL 5.7 or Percona Server for MySQL 5.7, or for the latest features, MySQL 8.0 or Percona Server for MySQL 8.0.

Suppose you have not upgraded because you have off-the-shelf applications that also must be upgraded and require 5.6, or you have other …

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Various Types of InnoDB Transaction Isolation Levels Explained Using Terminal

The goal of this blog post is to explain the various types of transaction isolation levels available in MySQL. After reading the blog, you will be able to explain dirty reads, non-repeatable reads, and the concept of phantom rows as well.

What is the Isolation Level in MySQL?

Isolation (I) is one of the properties from ACID. It defines how each transaction is isolated from other transactions and is a critical component of application design. As per the SQL:1992 standard, InnoDB has four types of Isolation levels. Below, I have listed the types in order, and each transaction isolation level provides better consistency compared to the previous one.

  • READ-UNCOMMITTED
  • READ-COMMITTED
  • REPEATABLE-READ – ( MySQL’s DEFAULT )
  • SERIALIZABLE

You can change the isolation level using the variable “transaction_isolation” at runtime. As transaction isolation changes can …

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Webinar February 24: What’s Old Is New, What’s Coming Is Here – Percona Offerings for MySQL 5.6 and DBaaS in PMM

Join Brian Walters and Brandon Fleisher for an interactive discussion around new service and software offerings coming from Percona.

Oracle has decided that MySQL 5.6 will reach its end of life in February 2021. This means there will be no more updates and, more importantly, no more security fixes for discovered vulnerabilities. Yikes! Did you know you have options? Did you know Percona can solve this problem? Tune in to find out how.

Choosing a database-as-a-service (DBaaS) provider can be a daunting challenge. Not ready to move to DBaaS in the public cloud? Or, are you constrained to on-prem deployment due to regulations or other market conditions? Tune-in to learn how Percona is bringing the benefits of simplified DBaaS deployment to the on-prem, private cloud, and hybrid datacenter.

This interactive webinar will be conducted in a roundtable forum style. Bring your interests, bring …

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Percona XtraBackup 8 Enables –lock-ddl by Default

Percona XtraBackup 8.0.23 enables the “lock-ddl” option by default to ensure any DDL events do not corrupt the backups. Any DML events continue to occur, and only DDL events are blocked.

A DDL lock protects the definition of tables and views. With the “–lock-ddl” option disabled, Percona XtraBackup allows backups while concurrent DDL events continue to happen. These backups are invalid and fail at the Prepare stage. If DDL events have occurred without the backup user’s knowledge, they may be unaware the backup is corrupt.

MySQL 8.0 introduced “Lock Instance for Backup”. This backup lock is lightweight, and the performance for DML operations is almost the same with or without backup locks. This lock is not available in 5.7, because …

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Low Value in range_optimizer_max_mem_size Might Cause Full Table Scan

Although how range_optimizer_max_mem_size operates is explained in the official doc, it’s not a well-known variable and surely not a variable you need to modify under most circumstances. But from time to time we get some performance tickets related to this.

What problem does this variable cause if it is not properly sized? Let’s find out with an example!

Given the following table definition:

CREATE TABLE `joinit` (
  `i` int(11) NOT NULL AUTO_INCREMENT,
  `s` varchar(64) DEFAULT NULL,
  `t` time NOT NULL,
  `g` int(11) NOT NULL,
  PRIMARY KEY (`i`)
) ENGINE=InnoDB AUTO_INCREMENT=2490316 DEFAULT CHARSET=latin1

With ~2M rows

select count(*) from joinit ;
+----------+
| count(*) |
+----------+
|  2097152 |
+----------+

With the default value of  range_optimizer_max_mem_size = 8388608, the following …

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The MySQL Clone Wars: Plugin vs. Percona XtraBackup

Large replication topologies are quite common nowadays, and this kind of architecture often requires a quick method to rebuild a replica from another server.

The Clone Plugin, available since MySQL 8.0.17, is a great feature that allows cloning databases out of the box. It is easy to rebuild a replica or to add new nodes to a cluster using the plugin. Before the release of the plugin, the best open-source alternative was Percona XtraBackup for MySQL Databases.

In this blog post, we compare both alternatives for cloning purposes. If you need to perform backups, Percona XtraBackup is a better tool as it supports compression and incremental backups, among other features not provided by the plugin. The plugin supports compression only for network transmission, not for storage.

But one of the plugin’s strong points is simplicity. …

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MySQL 8.0.22: SHOW PROCESSLIST Version 2 – Now Available From PERFORMANCE_SCHEMA

The “SHOW PROCESSLIST” command is very famous and very useful for MySQL DBAs. It will help you to understand the ongoing thread activities and their current states. By default, the “show processlist” output details will be collected from the thread manager, and it needs the global mutex. From MySQL 8.0.22, we have an alternative way to get the process details from the PERFORMANCE_SCHEMA. It doesn’t need the global mutex. 🙂

Note: We also have the non-blocking SYS schema views “processlist” and “x$processlist”, which provide more complete information than the SHOW PROCESSLIST statement and the INFORMATION_SCHEMA.PROCESSLIST and PERFORMANCE_SCHEMA.PROCESSLIST. But, we can’t integrate this with the “SHOW PROCESSLIST” command.

In this blog, I am going to explain the complete details about the new processlist implementation using PERFORMANCE_SCHEMA.

“SHOW PROCESSLIST” Using Thread …

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Streaming MySQL Backups with Percona XtraBackup – Another Alternative

Today we are going to present you with another way to make a database copy between servers using our Percona XtraBackup utility.  What is the difference with many others existing on the web?  Not many, but they are interesting in terms of performance and availability.

We will combine the xbstream utility with the power of pigz and socat, to take advantage of the multi-processing in the case of having multiple processors, and at the same time, reduce the use of network bandwidth in cases where this component is a bottleneck.  So let’s explain each component:

socat: This stands for SOcket CAT. It is a utility for data transfer between two addresses.

What makes socat so versatile is the fact that an address can represent a network socket, any file descriptor, a Unix domain datagram or stream …

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