Camunda BPM is an open-source workflow and decision automation platform. Camunda BPM ships with tools for creating workflow and decision models, operating deployed models in production, and allowing users to execute workflow tasks assigned to them.

By default, Camunda comes with an embedded database called H2, which works pretty decently within a Java environment with relatively small memory footprint. However, when it comes to scaling and high availability, there are other database backends that might be more appropriate.

In this blog post, we are going to deploy Camunda BPM 7.10 Community Edition on Linux, with a focus on achieving database high availability. Camunda supports major databases through JDBC drivers, namely Oracle, DB2, MySQL, …

Node.js and MySQL is one of the necessary binding needed for any web application. MySQL is one of the most popular open source database in world and efficient as well. Almost every popular programming language like Java or PHP provides driver to access and perform operations with MySQL.

In this tutorial i am trying to cover code for learning and code for production. So if you know this already and looking for ready made code for production. Click here to jump there directly.

Introduction:

Node.js is rich with number of popular packages registered at package registry called …

In this tutorial we'll learn how to build a React application that consumes a third-party REST API using the fetch() API. We'll also use Bootstrap 4 to style the UI.

We'll consume a third-party API available from this link.

We'll also see some basics of React such as:

The state object to hold the state of the app and the setState() method to mutate the state. The componentDidMount() life-cycle method for running code when the component is mounted in the DOM. How to embed JavaScript expressions in JSX using curly braces. How to render lists of data using the map() method and JSX and conditionally render DOM elements using the logical && operator.

React is the most popular UI library for building user interfaces built and used internally by Facebook.

React has many features such as:

Declarative: React makes it easy to build interactive UIs by creating views for each state in your application, …

Percona announces the release of Percona XtraDB Cluster Operator 0.3.0 early access.

The Percona XtraDB Cluster Operator simplifies the deployment and management of Percona XtraDB Cluster in a Kubernetes or OpenShift environment. It extends the Kubernetes API with a new custom resource for deploying, configuring and managing the application through the whole life cycle.

You can install the Percona XtraDB Cluster Operator on Kubernetes or OpenShift. While the operator does not support all the Percona XtraDB Cluster features in this early access release, instructions on how to install and configure it …

Distributed systems are hard – I just want to echo that. In MySQL, we have quite a number of options to run highly available systems. However, real fault tolerant systems are difficult to achieve.

Take for example a common use case of multi-DC replication where Orchestrator is responsible for managing the topology, while ProxySQL takes care of the routing/proxying to the correct server, as illustrated below. A rare case you might encounter is that the primary MySQL

node01

on DC1 might have a blip of a couple of seconds. Because Orchestrator uses an adaptive health check – not only the node itself but also consults its replicas – it can react really fast and promote the node in DC2.

Why is this problematic?

The problem occurs when

node01

resolves its temporary issue. A race condition could occur within ProxySQL that could mark it back as read-write. You can increase an …

MySQL 8.0 provides another way to handle JSON documents, actually in a "Not only SQL" (NoSQL) approach... In other words, if you need/want to manage JSON documents (collections) in a non-relational manner, with CRUD (acronym for Create/Read/Update/Delete) operations then you can use MySQL 8.0! Did you know that?

Why Choose MySQL Replication?

Some basics first about the replication technology. MySQL Replication is not complicated! It is easy to implement, monitor, and tune as there are various resources you can leverage - google being one. MySQL Replication does not contain a lot of configuration variables to tune. SQL_THREAD and IO_THREAD's logical errors aren't that hard to understand and fix. MySQL Replication is very popular nowadays and offers a simple way of implementing database High Availability. Powerful features such as GTID (Global Transaction Identifier) instead of the old-fashioned binary log position, or lossless Semi-Synchronous Replication make it more robust.

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A great way to install MySQL when you need to do quick tests is to use a sandbox tool. This allows you to perform all the installation steps with a single command making the whole process very simple, and it allows for automation of the test. Giuseppe Maxia (also known as the Data Charmer, @datacharmer on Twitter) has for many years maintained sandbox tools for MySQL, first with MySQL Sandbox and now with dbdeployer.

One of the most recent features of dbdeployer is the support for MySQL NDB Cluster. In this blog, I will take …

If you are using Galera replication, you know that schema changes may be a serious problem. With its current implementation, there is no way even a simple ALTER will be unobtrusive for live production traffic. It is a fact that with the default TOI alter method, Percona XtraDB Cluster (PXC) cluster suspends writes in order to execute the ALTER in the same order on all nodes.

For factual data structure changes, we have to adapt to the limitations, and either plan for a maintenance window, or use pt-online-schema-change, where interruptions should be very short. I suggest you be extra careful here, as normally you …

You say you want a Replication?

One of the best features of MySQL is the ability to use MySQL‘s built-in database replication feature to automatically replicate data from one server (source/master) to another (slave/replica). Group Replication was added in MySQL 5.7 as a way to provide a high-availability solution using a new variation of MySQL replication.

(In some earlier posts, I explained how to setup Group Replication using three MySQL database servers and how to …