In this blog post, we’ll discuss the possible reasons for MySQL “Got an error reading communication packet” errors, and how to address them.

In Percona’s managed services, we often receive customer questions on communication failure errors – where customers are faced with intermittent “Got an error reading communication packets” messages. I thought this topic deserved blog post so we can discuss possible reasons for this error, and how to remedy this problem. I hope this will help readers on how to investigate and resolve this problem.

First of all, whenever a communication error occurs it increments the status counter for either Aborted_clients or …

Replication between Tungsten clusters

The process I will describe in this post will allow you to configure replication between Tungsten clusters. The most common use case I have seen for this is a dedicated ETL cluster.

The setup will look like this:

So we will have a composite datasource (compositeprod) composed of east and west clusters, and two ETL clusters, one on each side.

The described setup allows failover or switchover within a single datacenter (e.g. db1.east -> db2.east) or to the Disaster Recovery Site, (e.g. db1.east -> db1.west) for the core cluster.

At the time of this article’s publication it is not possible to replicate between two composite clusters, so each ETL cluster needs to be standalone. This feature is expected for Tungsten 5.0 release.

We will install a standalone replicator on the ETL hosts to bring data in …

MySQL Sandbox 3.1.07 adds several options to execute shell or SQL commands during the sandbox installation.

Figure 1: MySQL Sandbox states and where you can run the hooks

There are 3 options to run shell commands, 2 to run SQL queries, and 2 to run SQL files.

## Shell commands
--pre_start_exec=command  : runs 'command' after the installation, before the server starts
--pre_grants_exec=command : runs 'command' after the server starts, before loading the grants.
--post_grants_exec=command : runs 'command' after the loading the grants.

## SQL statements
--pre_grants_sql=query : runs 'query' before loading the grants.
--pre_grants_file=filename : runs SQL file 'filename' before loading the grants.
--post_grants_sql=query : runs 'query' …

Just a few days ago, I presented at the MariaDB Roadshow in London, and I had a lot of fun. While I had canned slides, I did know the topic intimately well, so it was good to get further in-depth. In addition, we had these MasterMind sessions, basically the place to get one-on-one time with Anders/Luisa/or me, I noticed that pretty much everyone said they were buying services afterwards (which more or less must mean the event was rather successful from that standpoint!).

In addition to that, I was happy to see that from attendee feedback, I did have the highest averages – thank you!

So here’s to repeating this in Paris next week — Gestion des données pour les applications vitales – …

We’ve been learning for many years how to run Linux for databases, but over time we realized that many of our lessons learned apply to many other server workloads. Generally, server process will have to interact with network clients, access memory, do some storage operations and do some processing work – all under supervision of the kernel.

Unfortunately, from what I learned, there’re various problems in pretty much every area of server operation. By keeping the operational knowledge in narrow camps we did not help others. Finding out about these problems requires quite intimate understanding of how things work and slightly more than beginner kernel knowledge.

Many different choices could be made by doing empiric tests, sometimes with outcomes that guide or misguide direction for many years. In our work we try to understand the reasons behind differences that we observe in random poking at a problem.

In order …

Security these days is bigger than ever. This statement needs no proof. It seems like it is getting easier and easier to get access to ‘secure data’. As system grows it becomes really hard to secure all endpoints. This is why encrypting data is now the hot topic in the database world.…

Okay, I will admit that I grew up professionally without package management. Well, we did have SSCS and RCS under Unix and a lot of very brilliant shells scripts but nothing modern programmers would deign to touch. Then came Linux Torvalds (and why hasn't he been given a Nobel prize?!?!) and I blundered into the Redhat world with their RPM package manager. RPMS are great but over time I was seduced by Ubuntu and became and became an apt-get fiend.

Now I need to do a demo of the new MySQL 5.7.12 Document store features on an RPM based distro, Oracle 7.1. I could have used a Vagrant or Docker image but ended up using VirtualBox. You can even use a fresh install on hardware even though that seems to be becoming passe in a virtual & containerized world. So if you are following along please adjust to your platform.

After installing the latest and greatest Virtualbox from VirtualBox.org, I pulled the ISO image from …

Overview

Cloud storage is becoming more and more popular for offsite storage and DR solutions for many businesses. This post will help with those people that want to perform this process for MySQL backups directly into Amazon S3 Storage. These steps can probably also be adapted for other processes that may not be MySQL oriented.

Steps

In order to perform this task we need to be able to stream the data, encrypt it, and then upload it to S3. There are a number of ways to do each step and I will try and dive into multiple examples so that way you can mix and match the solution to your desired results.  The AWS S3 CLI tools that I will be using to do the upload also allows encryption but to try and get these steps open for customization, I am going to do the encryption in the stream.

1. Stream MySQL backup
2. Encrypt the stream
3. Upload the stream to AWS S3

Step 1 : …

In this blog post, we’ll discuss ProxySQL versus MaxScale for OLTP RO workloads.

Continuing my series of READ-ONLY benchmarks (you can find the other posts here: https://www.percona.com/blog/2016/04/07/mysql-5-7-sysbench-oltp-read-results-really-faster/ and https://www.percona.com/blog/2016/03/28/mysql-5-7-primary-key-lookup-results-is-it-really-faster), in this post I want to see how much overhead a proxy adds. At this

In my opinion, there are only two solid proxy software options for MySQL at the moment: ProxySQL and MaxScale. In the past, there was also MySQL Proxy, but it is pretty much dead for now. Its replacement, MySQl Router, is still in the very early stages …

Removing users in MySQL is an easy task, but there are some drawbacks to check carefully before dropping a user. Not taking these possible issues into consideration can render your application unusable.

First it is important to understand the concept of user in MySQL. A user has three main functions: authentication, privileges and resources. This is different from other databases: in MySQL users don’t own objects. An object belongs to a database and there is no direct relationship between objects and users. This simplifies the process of deleting a user because no objects will be erased.

But users, as I wrote before, have an associated set of privileges that define what database sessions can do, and the privileges applied both in stored programs and view execution.

At the same time, procedures, functions, triggers, and views have two possible security contexts: invoker and definer. If they are created using the invoker …