In a MySQL 5.7 master-slave setup that uses the default semisynchronous replication setting for rpl_semi_sync_master_wait_point, a crash of the master and failover to the slave is considered to be lossless. However, when the crashed master comes back, you may find that it has transactions that are not present in the current master (which was previously a slave). This behavior may be puzzling, given that semisynchronous replication is supposed to be lossless, but this is actually an expected behavior in MySQL. Why exactly this happens is explained in full detail in the …[Read more]
By having appropriate indexes on your MySQL tables, you can greatly enhance the performance of SELECT queries. But, did you know that adding indexes to your tables in itself is an expensive operation, and may take a long time to complete depending on the size of your tables? During this time, you are also likely to experience a degraded performance of queries as your system resources are busy in index-creation work as well. In this blog post, we discuss an approach to optimize the MySQL index creation process in such a way that your regular workload is not impacted.
MySQL Rolling Index Creation
We call this approach a ‘Rolling Index Creation’ - if you have a MySQL master-slave replica set, you can create the index one node at a time in a rolling fashion. You should create the index only on the slave nodes so the master’s …[Read more]
Are you looking to get started with the world’s most popular open-source database, and wondering how you should setup your MySQL hosting? So many default to Amazon RDS, when MySQL performs exceptionally well on Azure Cloud. While Microsoft Azure does offer a managed solution, Azure Database, the solution has some major limitations you should know about before migrating your MySQL deployments. In this post, we outline the best way to host MySQL on Azure, including managed solutions, instance types, high availability replication, backup, and disk types to use to optimize your cloud database performance.
MySQL DBaaS vs. Self-Managed MySQL
The first thing to consider when weighing between self-management and a MySQL Database-as-a-Service …[Read more]
In Part I, we introduced a High Availability (HA) framework for MySQL hosting and discussed various components and their functionality. Now in Part II, we will discuss the details of MySQL semisynchronous replication and the related configuration settings that help us ensure redundancy and consistency of the data in our HA setup. Make sure to check back in for Part III where we will review various failure scenarios that could arise and the way the framework responds and recovers from these conditions.
What is MySQL Semisynchronous Replication?
Simply put, in a …[Read more]
In this three-part blog series, we will explain the details and functionality of a High Availability (HA) framework for MySQL hosting using MySQL semisynchronous replication and the Corosync plus Pacemaker stack. In Part I, we’ll walk you through the basics of High Availability, the components of an HA framework, and then introduce you to the HA framework for MySQL.
What is High Availability?
The availability of a computer system is the percentage of time its services are up during a period of time. It’s generally expressed as a series of 9′s. For example, the table below shows availability and the corresponding downtime measured over one year.
MySQL 5.6.25 was recently released (it is the latest MySQL 5.6, is GA), and is available for download here.
For this release, there are 2 “Functionality Added or Changed” items of note:
- Functionality Added/Changed: MySQL distributions now include an innodb_stress suite of test cases. Thanks to Mark Callaghan for the contribution. (Bug #76347)
- Functionality Added/Changed: my_print_defaults now masks passwords. To display passwords in cleartext, use the new –show option.
In addition to those, there were 55 other bug fixes:
- 10 InnoDB
- 8 Replication
- 3 Partitioning (one overlaps w/ an InnoDB bug fix)
- 35 Miscellaneous (and 6 of …