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Displaying posts with tag: replica set (reset)
The Best Way to Host MySQL on Azure Cloud

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 …

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MySQL High Availability Framework Explained – Part III: Failure Scenarios

In this three-part blog series, we introduced a High Availability (HA) Framework for MySQL hosting in Part I, and discussed the details of MySQL semisynchronous replication in Part II. Now in Part III, we review how the framework handles some of the important MySQL failure scenarios and recovers to ensure high availability.

MySQL Failure Scenarios Scenario 1 – Master MySQL Goes Down

  • The Corosync and Pacemaker framework detects that the master MySQL is no longer available. Pacemaker demotes the master resource and tries …
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MySQL Tutorial – Understanding The Seconds Behind Master Value

In a MySQL hosting replication setup, the parameter Seconds_Behind_Master (SBM), as displayed by the SHOW SLAVE STATUS command, is commonly used as an indication of the current replication lag of the slave. In this blog post, we examine how to understand and interpret this value in various situations.

Possible Values of  Seconds Behind Master

The value of SBM, as explained in the  MySQL documentation, depends on the state of the MySQL slave in general, and the states of MySQL slave SQL_THREAD and IO_THREAD in particular. While IO_THREAD connects with the master and reads the updates, SQL_THREAD applies these updates on the slave. Let’s examine the possible values of SBM during different states of the MySQL Slave.

When SBM Value is Null

  • SBM is …
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Highly Available Redis Clusters with Automated Sharding Launches at ScaleGrid

PALO ALTO, Calif., January 24, 2019 – ScaleGrid, a rising leader in the Database-as-a-Service (DBaaS) space, has just announced support for Redis Clusters on their fully managed Redis hosting plans. Redis Cluster is the native sharding implementation available within Redis, an open-source in-memory data structure project, that allows you to automatically shard across multiple Redis nodes without having to rely on external tools and utilities.

ScaleGrid is no novice when it comes to deploying and managing complex, sharded clusters in the cloud, as they have provided one of the most powerful sharding tools for their MongoDB hosting solutions since 2013.

With the introduction of Redis Clusters at ScaleGrid, Redis users can now easily create sharded clusters …

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MySQL High Availability Framework Explained – Part II: Semisynchronous Replication

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 …

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Slow MySQL Start Time in GTID mode? Binary Log File Size May Be The Issue

Have you been experiencing slow MySQL startup times in GTID mode? We recently ran into this issue on one of our MySQL hosting deployments and set out to solve the problem. In this blog, we break down the issue that could be slowing down your MySQL restart times, how to debug for your deployment, and what you can do to decrease your start time and improve your understanding of GTID-based replication.

How We Found The Problem

We were investigating slow MySQL startup times on a low-end, disk-based MySQL 5.7.21 deployment which had GTID mode enabled. The system was part of a master-slave pair and was under a moderate write load. When restarting during a scheduled maintenance, we …

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MySQL High Availability Framework Explained – Part I

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.

Availability %
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Data Integrity and Performance Considerations in MySQL Semisynchronous Replication

MySQL semisynchronous replication provides improved data integrity because when a commit returns successfully, it’s known that the data exists in at least two places – the master and its slave. In this blog post, we review some of the MySQL hosting configurations that influence the data integrity and performance aspects of semisynchronous replication. We’ll be using InnoDB storage engine and GTID-based replication in a 3-node replica set (master and 2 slaves), which will ensure there is redundancy in the slaves. This means that if there are issues with one slave, we can fall back on the other.

Configurations Applicable to Both Master and Slave Nodes

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Showing entries 1 to 8