Introduction

The early architecture of Uber consisted of a monolithic backend application written in Python that used Postgres for data persistence. Since that time, the architecture of Uber has changed significantly, to a model of microservices and new data platforms. …

The post Why Uber Engineering Switched from Postgres to MySQL appeared first on Uber Engineering Blog.

[this is a repost of my http://shardquery.com blog post, because it did not syndicate to planet.mysql.com]

As work on WarpSQL (Shard-Query 3) progresses, it has outgrown MySQL proxy.  MySQL proxy is a very useful tool, but it requires LUA scripting, and it is an external daemon that needs to be maintained.  The MySQL proxy module for Shard-Query works well, but to make WarpSQL into a real distributed transaction coordinator, moving the proxy logic inside of the server makes more sense.

The main benefit of MySQL proxy is that it allows a script to "inject" queries between the client and server, intercepting the results and possibly sending back new results to the client.  I would like similar functionality, but inside of the server.

For example, I would like to implement new SHOW commands, and these commands do not need to be …

[this is a repost of my http://shardquery.com blog post, because it did not syndicate to planet.mysql.com]

As work on WarpSQL (Shard-Query 3) progresses, it has outgrown MySQL proxy.  MySQL proxy is a very useful tool, but it requires LUA scripting, and it is an external daemon that needs to be maintained.  The MySQL proxy module for Shard-Query works well, but to make WarpSQL into a real distributed transaction coordinator, moving the proxy logic inside of the server makes more sense.

The main benefit of MySQL proxy is that it allows a script to "inject" queries between the client and server, intercepting the results and possibly sending back new results to the client.  I would like similar functionality, but inside of the server.

For example, I would like to implement new SHOW commands, and these commands do not need to be …

As work on WarpSQL (Shard-Query 3) progresses, it has outgrown MySQL proxy.  MySQL proxy is a very useful tool, but it requires LUA scripting, and it is an external daemon that needs to be maintained.  The MySQL proxy module for Shard-Query works well, but to make WarpSQL into a real distributed transaction coordinator, moving the proxy logic inside of the server makes more sense.

The main benefit of MySQL proxy is that it allows a script to “inject” queries between the client and server, intercepting the results and possibly sending back new results to the client.  I would like similar functionality, but inside of the server.

For example, I would like to implement new SHOW commands, and these commands do not need to be implemented as actual MySQL SHOW commands under the covers.

For example, for this blog post I made a new example command called “SHOW PASSWORD”

Percona announces the GA release of Percona XtraBackup 2.4.4 on July 25th, 2016. You can download it from our download site and from apt and yum repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an …

Networking is critical in MySQL, it is a fundamental resource to manage access to the server from client applications and other replication peers. The behaviour of a containerized MySQL service is determined by how the MySQL image is spawned with “docker run” command. With Docker single-host networking, a MySQL container can be run in an isolated environment (only reachable by containers in the same network), or an open environment (where the MySQL service is totally exposed to the outside world) or the instance simply runs with no network at all.

In the previous two blog posts, we covered the basics of running MySQL in a container and how to build a custom MySQL image. In today’s post, we are going to cover the basics of how Docker …

Decoding binary protocols in python

Decoding binary protocols like the MySQL Client/Server Protocol or MySQL's new X Protocol involves taking a sequence of bytes and turning them into integers.

In python the usually workhorse for this task is struct.unpack()

It takes a sequence of bytes and a format-string and returns a tuple of decoded values.

In the case of the MySQL Client/Server protocol the integers are (mostly) little-endian, unsigned and we can use:

In the previous blog post we explained how to create schemas and collections. In this one we are going to explain how to work with collections: adding, updating and deleting documents.

The following code demonstrates how to add a single document to an existing collection:

var mysqlx = require('mysqlx');
mysqlx.getSession({
  host: 'host',
  port: '33060',
  dbUser: 'root',
  dbPassword: 'my pass'
}).then(function (session) {
  var schema = session.getSchema('mySchema');
  var coll = schema.getCollection('myColl');
  var newDoc = { name: 'Test Name', description: 'Test Description' };

  coll.add(newDoc).execute().then(function (added) {
    console.log('Document(s) added: '
                + added.getAffectedItemsCount());
    session.close();
  })
  .catch(function (err) {
    console.log(err.message);
    console.log(err.stack); …

Recently I upgraded some MySQL databases from 5.6 to 5.7, but -- for boring reasons unique to my environment -- I had to leave one replica on version 5.6. I knew there was a chance that the 5.7 -> 5.6 replication wouldn't work, but I decided to try it out to see if (and why) it would fail. Once I upgraded the master, replication failed, so I checked the error log on the replica and found these messages:

[ERROR] Slave I/O: Found a Gtid_log_event or Previous_gtids_log_event when @@GLOBAL.GTID_MODE = OFF. Error_code: 1784 [ERROR] Slave I/O: Relay log write failure: could not queue event from master, Error_code: 1595

The error surprised me a little bit since I'm not using GTIDs in that replication topology. I asked around a bit, and Kenny Gryp hypothesized that I might be experiencing MySQL bug #74683, which was fixed in version 5.6.23. Since my …

We may sometimes require to get few days ago records from table like last 2 days last 3 days last 10 days or last 15 days etc Most of developer choose other logic but we can easily get using mysql queryusing CURDATE and INTERVALIn this example mysql query i have one table elements and colu