The X Protocol

For the MySQL Document Store we developed a new protocol to lay out a solid foundation for the features we’ll implement over the next years.

Building a Protocol with Async APIs in mind

Asynchronous APIs are all about executing other work while a task gets blocked.

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Based on messages, we create mysql replication platforms , using async message to build strong distributed subscription system.

read this PDF : http://www.vmcd.org/docs/MySQL_async_message.pdf

Percona Live is a Christmas in MySQL world. It’s time when all friends and family gather over a glass of beer. Everyone is talking about achievements of the last year and make New Year resolutions for a next one.

There will be two talks from TwinDB this year. One is about data recovery and one – about backups.

The data recovery talk is a kind of traditional talk. I will briefly cover InnoDB files format so you know where to look for data. I will show how to recover data from two most popular accidents: InnoDB tablespace corruption and DROP TABLE or DROP DATABASE. Data recovery is impossible without table structure recovery. I will show how to get the structure from an .frm file or from InnoDB dictionary (think of DROP TABLE when the .frm file is gone). We made a drastic improvement in user …

In this blog post, we will discuss how to deal with jumbo chunks in MongoDB.

You are a MongoDB DBA, and your first task of the day is to remove a shard from your cluster. It sounds scary at first, but you know it is pretty easy. You can do it with a simple command:

db.runCommand( { removeShard: "server1_set6" } )

MongoDB then does its magic. It finds the chunks and databases and balances them across all other servers. You can go to sleep without any worry.

The next morning when you wake up, you check the status of that particular shard and you find the process is stuck:

"msg" : "draining ongoing",
"state" : "ongoing",
"remaining" : {
"chunks" : NumberLong(3),
"dbs" : NumberLong(0)

There are three chunks that for some reason haven’t been migrated, so the

removeShard

In this blog post we’ll discuss a caveat when downloading MariaDB MaxScale binaries.

Following the previous performance results in my last two posts on sysbench and primary keys (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/), I wanted to measure overhead from proxies servers like ProxySQL and MaxScale.

Unfortunately, I found that MaxScale binaries are not available without registering on the …

MySQL 5.7.12 is the fourth stable (GA) release of the MySQL 5.7 series. It brings with it the usual bug fixes and incremental enhancements that you would expect with a point release. Except this time things are a little bit different.…

In this blog, we will examine the differences between GCache and Record-Set Cache in Percona XtraDB Cluster.

In Percona XtraDB Cluster (PXC), there is the concept of GCache and Record-Set cache (which can also be called transaction write-set cache). The use of these two caches is often confusing if you are running long transactions, as both of them result in the creation of disk-level files. Let’s understand what their main differences are.

Record-Set Cache

• When you run a long-running transaction on any particular node, it will try to append a key for each row that it tries to modify (the key is a unique identifier for the row {db,table,pk.columns}). This information is cached in out-write-set, which is then sent to the group for …

In this blog, we’ll discuss how the Percona XtraDB Cluster threading model works.

Percona XtraDB Cluster (PXC) creates a different set of threads to service its operations. These threads are in addition to existing MySQL threads. Let’s understand what these threads are and how they’re used. There are three main groups of threads:

1. Applier thread(s)
   1. Applier threads are meant to apply write-sets that the node receives from other nodes (through cluster). (write-message is directed through

      gcv_recv_thread

      .)
   2. The number of applier threads is controlled using the

      wsrep_slave_thread

       configuration. (The default value is 1, so at least one wsrep applier thread …

This blog post will discuss the issues and solutions for MySQL Data at Rest encryption.

Data at Rest Encryption is not only a good-to-have feature, but it is also a requirement for HIPAA, PCI and other regulations.

There are three major ways to solve data encryption at rest:

1. Full-disk encryption
2. Database-level (table) encryption
3. Application-level encryption, where data is encrypted before being inserted into the database

I consider full disk encryption to be the weakest method, as it only protects from someone physically removing the disks from the server. Application-level encryption, on the other hand, is the best: it is the most flexible method with almost no overhead, and it also solves data in-flight encryption. Unfortunately, it is not always possible …

And the first two Database Performance Team characters are . . .

The last blog introduced the Database Performance Team. The Database Performance Team is comprised of our services experts, who work tirelessly every day to guarantee the performance of your database. Percona’s services team is made up of superheroes that make sure your database is running at peak performance. Now we’re ready to reveal the identity of the first two team members.

The first is funny, friendly, quick-witted, supporting, fast and courteous – but still able to get the job done with amazing competence. Who is this champion?

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