We sometimes receive challenging requests… this is a story about one of those times.

The customer has implemented a sharding solution and would like us to review alternatives or improvements. We analyzed the possibility of using ProxySQL as it looked to be a simple implementation. However, as we had 200 shards we had to implement 200 rules — the first shard didn’t have much overload, but the latest one had to go through 200 rules and took longer.

My first idea was to use FLAGIN and FLAGOUT creating a B-Tree, but the performance was the same. Reviewing the code, I realized that the rules were implemented as a list, which means that, in the end, all the rules were going to be processed until hit with the right one and FLAGIN is used just to filter out.

At that point, I asked, what could I do? Is it possible to implement it differently? What is the performance impact?

One Problem, Two Solutions

I …

ProxySQL brings a lot of value to your MySQL infrastructures such as Caching or Connection Multiplexing but it does not come free — your database needs to go through additional processing traffic which adds some overhead. In this blog post, we’re going to discuss where this overhead comes from and measure such overhead. 

Types of Overhead and Where it Comes From 

There are two main types of overhead to consider when it comes to ProxySQL — Network Overhead and Processing Overhead. 

Network Overhead largely depends on where you locate ProxySQL. For example, in case you deploy ProxySQL on the separate host (or hosts) as in this diagram: 

The application will have added network latency for all requests, compared to …

PlanetScaleDB is a sharded database built on Vitess. Learn key sharding concepts and apply them using our quickstart demo and sample app for rating puppies written in Rust.

Recently I posted about checkpointing in MySQL, where MySQL showed interesting “wave” behavior.

Soon after Dimitri posted a solution with how to fix “waves,” and I would like to dig a little more into proposed suggestions, as there are some materials to process.

This post will be very heavy on InnoDB configuration, so let’s start with the basic configuration for MySQL, but before that some initial environment.

I use MySQL version 8.0.21 on the hardware as described here. 

As for the storage, I am not using some “old dusty SSD”, but production available Enterprise-Grade Intel SATA SSD …

This is the announcement blogpost and this is my overview taken from medium:

The one where MySQL 8.0 lands on Google Cloud SQL

Ada Doglace and Lily Grace (lilygrams). Photo by Anthony Ferrara.

There are many things that makes me happy. Puppies (see picture), food, wine and databases… (not particularly in that order). And things that makes me even happier such as a well designed schema and proper usage of ORM (Object Relational Mapping).

MySQL was the database I used to love to hate. It grew on me and the fact that long strides were made to make it more consistent and more modern kept me away from …

InnoDB ReplicaSet was introduced from MySQL 8.0.19. It works based on the MySQL asynchronous replication. Generally, InnoDB ReplicaSet does not provide high availability on its own like InnoDB Cluster, because with InnoDB ReplicaSet we need to perform the manual failover. AdminAPI includes the support for the InnoDB ReplicaSet. We can operate the InnoDB ReplicaSet using the MySQL shell. 

• InnoDB cluster is the combination of MySQL shell and Group replication and MySQL router
• InnoDB ReplicaSet is the combination of MySQL shell and MySQL traditional async replication and MySQL router

Why InnoDB ReplicaSet?

• You can manually perform the switchover and failover with InnoDB ReplicaSet
• You can easily add the new node to your replication environment. InnoDB ReplicaSet helps with data provisioning (using MySQL clone plugin) and setting up the replication.

In this …

Presentation of some of the new features of MySQL 8.0.21 released on July 13th, 2020.

The post MySQL 8.0.21 New Features Summary first appeared on dasini.net - Diary of a MySQL expert.

PMM (Percona Monitoring and Management) is a great community tool for monitoring your OSDB (MySQL, PostgreSQL, MongoDB) fleet. It’s feature rich, and it’s built and distributed as open-source based on several de-facto industry standard tools such as Grafana and Prometheus. In the second half of last year, major version 2 was released and whereas the major components remained mostly the same, some significant architectural changes were made, but this is out-of-scope for this post.

Upgrading to PMM2 is basically the same as starting from scratch with a fresh install; it requires re-adding all your servers, which can be a painful process if you have a large fleet of instances. For servers where you have OS level access, you can just install the PMM2 agent, but for RDS there is no access to the OS so another approach is required. In this blog, I will focus on getting a large number of RDS instances added.

Adding RDS instances …

Oftentimes, we need to replicate between Amazon Aurora and an external MySQL server. The idea is to start by taking a point-in-time copy of the dataset. Next, we can configure MySQL replication to roll it forward and keep the data up-to-date.

This process is documented by Amazon, however, it relies on the mysqldump method to create the initial copy of the data. If the dataset is in the high GB/TB range, this single-threaded method could take a very long time. Similarly, there are ways to improve the import phase (which can easily take 2x the time of the export).

Let’s explore some tricks to significantly improve the speed of this process.

Preparation Steps

The first step is to enable binary logs in Aurora. Go to the Cluster-level parameter group and make sure binlog_format …

     VIEWs have been a handy feature of MySQL for many years but do you know about the WITH CHECK OPTION clause?  The WITH CHECK OPTION clause is used for a updatable views to prohibit the changes to those views that would produce rows which are not included in the defining query.

    VIEW Definition    Since a lot of SQL novices read my blog, I'd like to start with the definition of a view "Views are stored queries that when invoked produce a result set. A view acts as a virtual table" according the MySQL Manual.
SQL > CREATE VIEW x_city AS             SELECT     Name,                        …