If you are thinking of using ProxySQL in our Percona XtraDB Cluster environment, I’ll explain how to use ProxySQL 2 for failover tasks.

How to Test

ProxySQL uses the “weight” column to define who is the WRITER node. For this example, I’ll use the following list of hostnames and IPs for references:

+-----------+----------------+
| node_name | ip             |
+-----------+----------------+
| pxc1      | 192.168.88.134 |
| pxc2      | 192.168.88.125 |
| pxc3      | 192.168.88.132 |
+-----------+----------------+

My current WRITER node is the “pxc1” node, but how can I see who is the current WRITER? It’s easy, just run the following query:

proxysql> select hostgroup_id, comment, hostname, status, weight from runtime_mysql_servers;

This is the output: …

A database proxy is a wonderful tool that is able to provide significant functionality across various use cases. For example, a seamless master role switch to another node for maintenance; transparency with read and write connections; or providing automatic, intelligent database load balancing.

In the MySQL world, these proxies provide a single entry point into MySQL databases for the calling client applications. Or put differently, the proxy is a middle layer sitting between a MySQL database and an application. The application connects to a proxy, which then forwards connections into the database.

Good proxies make MySQL database clusters appear like single databases by hiding the “behind-the-scenes-plumbing” from the application. One example of this allows a master failover to occur which “hides” the promotion of the new master from the client. These types …

ProxySQL and Orchestrator are usually installed to achieve high availability when using MySQL replication. On a failover (or graceful takeover) scenario, Orchestrator will promote a slave, and ProxySQL will redirect the traffic. Depending on how your environment is configured, and how long the promotion takes, you could end up in a scenario where you need manual intervention.

In this post, we are going to talk about some considerations when working with ProxySQL in combination with pt-heartbeat (part of Percona Toolkit), with the goal of making your environment more reliable.

Why Would We Want pt-heartbeat With ProxySQL?

If you have intermediate masters, the seconds_behind_master metric is not good enough. Slave servers that are attached to intermediate masters will report the seconds_behind_master relative to their own …

MySQL query rewrite for ClickHouse using ProxySQL  Introduction

ProxySQL in September 2017 announced support for ClickHouse as backend. ProxySQL is a popular open source, high performance and protocol-aware proxy server for MySQL and its forks. ClickHouse is an open source column-oriented database management system capable of real time generation of analytical data reports using SQL queries. To support ClickHouse as a backend, ProxySQL acts as a data bridge between MySQL protocol and ClickHouse protocol, allowing MySQL clients to execute queries in ClickHouse through it. ClickHouse’s SQL query syntax is different than MySQL’s syntax, and migrating application from MySQL to ClickHouse isn’t just a matter of changing connections endpoint but it also requires modifying some queries. This needs development time, but not always possible. One of ProxySQL most widely used feature is indeed the ability of …

Use ClickHouse like MySQL with ProxySQL Introduction

We have several customers on ClickHouse now for both columnar database analytics and archiving MySQL data, You can access data from ClickHouse with clickhouse-client but this involves some learning  and also limitations technically. Our customers are very comfortable using MySQL so they always preferred a MySQL client for ClickHouse query analysis and reporting, Thankfully ProxySQL works as a optimal bridge between ClickHouse and MySQL client, This indeed was a great news for us and our customers worldwide. This blog post is about how we can use MySQL client with ClickHouse.

Installation

• https://github.com/sysown/proxysql/releases/  (**Download the package starting with clickhouse )
• Dependencies installation:
  • yum -y install …

While we’ve had MySQL Group Replication support in ProxySQL since version 1.3 (native as of v1.4), development has continued in subsequent versions. I’d like to describe a scenario of how latency can affect ProxySQL in a MySQL Group Replication environment, and outline a few new features that might help mitigate those issues. Before we dive into the specifics of the discussion, however, let’s take a quick overview of ProxySQL and Group Replication for those who may not be familiar.

MySQL Group Replication

Similar in functionality to Percona XtraDB Cluster or Galera, MySQL Group Replication is the only synchronous native HA solution for MySQL*. With built-in automatic distributed recovery, conflict detection, and group membership, MySQL GR provides a completely native HA solution for MySQL environments.

The schedule of the preFOSDEM Day is now available !

We had a lot of proposals to deal with. Also this is a MySQL event where we, the MySQL Team has the possibility to show to you, our Community, all what we have working on to improve MySQL but also new stuff. We also invite some of our friends from the MySQL Community to talk about their experience.

I think we did a good selection and propose you new content. We are extremely happy to have Saverio Miroddi from TicketSolve talking about MySQL 8.0, Uber talking about InnoDB Cluster, and Facebook about Binlog.

As you can see, we will have 2 rooms, where one will be dedicated mostly to SQL and Optimizer topics but also tutorials.

You can also see that this year we also want to put some spot lights to MySQL NDB Cluster. You will see what is it, how is it used and what’s new. We will also have 2 community speakers sharing their MySQL NDB knowledge: Giuseppe Maxia, …

TL;DR – We encountered multiplexing issues with ProxySQL and after going around in circles for a while we found that the impact of mysql-auto_increment_delay_multiplex and mysql-connection_delay_multiplex_ms was not documented. Read the blog post why you should check these values in your configuration and check how your codebase handles last insert identifiers!

At my present company we are using a multi-layer ProxySQL setup to route our traffic to the appropriate database cluster’s primary or replica hosts. For this post it doesn’t matter whether you run a single or a multi-layer setup, have many backend servers configured or not, so I’ll simplify our architecture to a single ProxySQL layer where the application connects to all three proxies evenly:

The reason for having N+2 proxies is that this ensures us that we can retain high availability after failure of a single node. I’ve also added a …

It’s not uncommon these days for us to use a high availability stack for MySQL consisting of Orchestrator, Consul, and ProxySQL. You can read more details about this stack by reading Matthias Crauwels’ blog post How To Autoscale ProxySQL In The Cloud as well as Ivan Groenwold’s post on MySQL High Availability With ProxySQL, Consul And Orchestrator. But the high-level concept is simply that Orchestrator will monitor the state of the MySQL replication topology and report changes to Consul which in turn can update ProxySQL hosts using a tool called consul-template.

Until now we’ve typically implemented the ProxySQL portion of this stack using an autoscaling group of sorts due to the high levels of CPU usage that can be associated with …

In this post, we will explore one approach to MySQL high availability with ProxySQL, Consul and Orchestrator.

This is a follow up to my previous post about a similar architecture but using HAProxy instead. I’ve re-used some of the content from that post so that you don’t have to go read through that one, and have everything you need in here.

Let’s briefly go over each piece of the puzzle:

– ProxySQL is in charge of connecting the application to the appropriate backend (reader or writer).

It can be installed on each application server directly or we can have an intermediate connection layer with one or more ProxySQL servers. The former probably makes sense if you have a small number of application servers; as the number grows, the latter option becomes more attractive. Another scenario for the …