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Displaying posts with tag: database (reset)
MySQL High Availability Framework Explained – Part II

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 MySQL semisynchronous replication configuration, the master …

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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 …

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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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Pager for the New MySQL Shell

I love the new shell but the one thing I missed from the old shell was the ability to use a pager like more or less to throttle the output of the screen.  Low and behold the engineers have added paging in MySQL Shell 8.0.13!!

Turn Paging On
Things can scroll off the screen quickly and pagination programs keep the output to small chunks.  To pick the more program as you pagination program, simply enter \pager more or for less enter \pager less

See the first illustration

How to turn paging on and off with the MySQL Shell 8.0.13

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A Tale of Two JSON Implementations - MySQL and MariaDB

JSON has proven to be a very import data format with immense popularity. A good part of my time for the last two or so years has been dedicated to this area and I even wrote a book on the subject.  This is a comparison of the implementations of handling JSON data in MySQL and MariaDB. I had requests from the community and customers for this evaluation.

JSON Data Types Are Not All Equal
MySQL added a JSON data type in version 5.7 and it has proven to be very popular.  MariaDB has  JSON support  version 10.0.16 but is actually an alias to a longtext data type so that statement based replication from MySQL to MariaDB is possible.

MySQL stores  JSON documents are …

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Quickly Load JSON Data into The MySQL Document Store with util.importJson

With new MySQL Shell 8.0.13 comes a new way to quickly load JSON data sets very quickly.  In a past blog and in several talks I have shown how to use the shell with the Python mode to pull in the data.  But now there is a much faster way to load JSON

Load JSON Quickly Start a copy of the new shell with mysqlsh. Connect to your favorite server \c dave@localhost and then create a new schema session.createSchema('bulk'). Then point you session to the schema just created with \use bulk.  Version 8.0.13 has a new utility function named importJson that does the work.  The first argument is the path to the data set (here the MongoDB restaurant collection) and the second allows you to designate the schema and collection where you wish to have the data stored.  In this example the data set was in the downloads directory of my laptop and I wanted to put it in the newly created 'bulk' schema …

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The Future Of The Application Stack

Containers are eating the world. If you have built and deployed an application in production over the last few years, the odds are that you have deployed your code in containers. You might have created and deployed individual containers (Docker, Linux LXC, etc.) directly in the beginning, but quickly switched over to a container orchestration technology like Kubernetes (K8s) or Swarm when you needed to coordinate multi-node deployments and high availability (HA). In this container-driven world, what will the future of the application stack look like? Let’s start with what we need from this “future” application stack.

What Do We Need From This Future Application Stack?

  1. Cloud Agnostic

    We …

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MySQL Books - 2018 has been a very good year

Someone once told me you can tell how healthy a software project is by the number of new books each year.  For the past few years the MySQL community has been blessed with one or two books each year. Part of that was the major shift with MySQL 8 changes but part of it was that the vast majority of the changes were fairly minor and did not need detailed explanations. But this year we have been blessed with four new books.  Four very good books on new facets of MySQL.

Introducing the MySQL 8 Document Store is the latest book from Dr. Charles Bell on MySQL.  If you have read any other of Dr. Chuck's book you know they are well written with lots of examples.  This is more than a simple introduction with many intermediate and advanced concepts covered in detail.

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Upgrading MySQL to 8.0.12 with Audit plugin.

As a spin-off from the previous post,, I thought that it would be good to see how well the Audit plugin upgrades to MySQL 8. The big change in auditing is that the tables change from MyISAM to InnoDB, so keep your eyes open.

I’m using the previously used instance in version 5.7.18.


Before we do anything, let’s make sure auditing will be in place when we restart the instance with 8.0.12:

Uncomment the plugin-load & audit-log params we had originally commented out. After all, this is something we should have done in the last post (apologies!):

vi my_audit.cnf:

Restart the 5.7 instance so we upgrade from a rebooted / ‘as real as can be …

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Hibernate database catalog multitenancy

Introduction As I explained in this article, multitenancy is an architectural pattern which allows you to isolate customers even if they are using the same hardware or software components. There are multiple ways you can achieve multitenancy, and in this article, we are going to see how you can implement a multitenancy architecture using the … Continue reading Hibernate database catalog multitenancy →

The post Hibernate database catalog multitenancy appeared first on Vlad Mihalcea.

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