In this blog, I discuss a MongoDB administration checklist designed to help MySQL DBAs.

If you are MySQL DBA, starting MongoDB administration is not always an easy transition. Although most of the concepts and even implementation are similar, the commands are different. The following table outlines the typical MySQL concepts and DBA tasks (on the left) to corresponding MongoDB ones (on the right). If you happen to be a MongoDB DBA and want to learn MySQL administration, you can use the same table looking from right to left.

I’ve also created a webinar, MongoDB administration for MySQL DBA, that explains the above concepts. You can download the slides to use as a reference.

Don’t forget …

In this blog, I intend to present the MySQL Enterprise Monitor (MEM), and also to present a multi-machine vagrant setup by adding a vagrant-hostmanager plugin to configure the /etc/hosts on the VMs. To start, I begin by installing the hostmanager plugin on my mac where I manage my environments. [crayon-58c2f17573ee8441268854/] OK, so that was easy.… Read More »

In this blog, I will provide answers to the Q & A for the Troubleshooting locking issues webinar.

First, I want to thank you for attending the May, 12 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: Do you have the links to those other info sources?

A: Yes, they are listed in the “More Information” slide. In the PDF, all the links are active. If you speak Russian, you can also check …

I have a few upcoming speaking engagements in June 2016:

• Nerdear.la – June 9-10 2016 – Buenos Aires, Argentina – never been to this event but MariaDB Corporation are sponsors and I’m quite excited to be back in Buenos Aires. I’m going to talk about the MySQL ecosystem in 2016.
• SouthEast LinuxFest – June 10-12 2016 – Charlotte, NC, USA – I have a few talks here, a bit bummed that I’m going to be missing the speaker dinner, but I expect this to be another great year. Learn about MariaDB Server/MySQL Security Essentials, the MySQL ecosystem in 2016, and about distributions from the view of a package.
• NYC MySQL Meetup – June 27 2016 – New York, USA – I’m …

New versions of systemd (like in Ubuntu 16.04) are able to configure pid Cgroups (ulimit -u via Cgroups) using TasksMax.

Check the commit implementing TaksMax.

Author: Lennart Poettering <lennart@poettering.net>
Date:   Fri Nov 13 19:28:32 2015 +0100

    core: enable TasksMax= for all services by default, and set it to 512

    Also, enable TasksAccounting= for all services by default, too.

    See:

    http://lists.freedesktop.org/archives/systemd-devel/2015-November/035006.html

But not we’ve got silly defaults:

$ systemctl show -p TasksMax docker
TasksMax=512

$ systemctl show -p TasksMax mysql
TasksMax=512

So if you use Docker or MySQL most likely you are going to have trouble without really putting load on your server.

Just set TasksMax for your service.

TasksMax=infinity

Feel free to configure that setting fitting …

This post shows you how to add the menu option and GUI to set users and groups. It’s quite a bit easier than mastering all the command-line syntax. It makes setting up the required user and group accounts for an Oracle Enterprise or MySQL database solution much easier.

You add the utility by calling the yum (Yellowdog Updater, Modified) utility like this:

yum installed -y system-config_users

You should see the following:

Loaded plugins: langpacks
adobe-linux-x86_64                                       |  951 B     00:00     
ol7_UEKR3                                                | 1.2 kB     00:00     
ol7_latest                                               | 1.4 kB     00:00     
Resolving Dependencies
--> Running transaction check
---> Package system-config-users.noarch 0:1.3.5-2.el7 will be installed
--> Processing …

Sandisk (FusionIO) and Nexenta are working together to build this SDS solution.

Infiniflash is a very large SDS production, which manages for very large DW system who requires large storage space and also high IOPS.

We test infiniflash system ,read this Infiniflash_benchmark

In this blog, we’ll discuss the ramifications of the Galera Error Failed to Report Last Committed (Interrupted System Call).

I have recently seen this error with Percona XtraDB Cluster (or Galera):

[Warning] WSREP: Failed to report last committed 549684236, -4 (Interrupted system call)

It was posted in launchpad as a bug in 2013: https://bugs.launchpad.net/percona-xtradb-cluster/+bug/1434646

My colleague Przemek replied, and explained it as:

Reporting the last committed transaction is just a part of the certification index purge process. In case it fails for some reason (it occasionally does), the cert index purge may be a little delayed. But it does not mean the transaction was not applied successfully. This is a warning after all.

If we look up this error in the source code, we realize …

In this blog, we will discuss MySQL 5.7 asynchronous query execution using the X Plugin.

Overview

MySQL 5.7 supports X Plugin / X Protocol, which allows (if the library supports it) asynchronous query execution. In 2014, I published a blog on how to increase a slow query performance with the parallel query execution. There, I created a prototype in the bash shell. Here, I’ve tried a similar idea with NodeJS + mysqlx library (which uses MySQL X Plugin).

TL;DR version: By using the MySQL X Plugin with NodeJS I was able to increase query performance 10x (some query rewrite required).

X Protocol and NodeJS

Here are the steps required:

1. First, we will need to …

Awhile ago I found myself analyzing a MySQL fabric installation to understand why a group member was occasionally being marked as FAULTY even when the server was up and running and no failures were observed.  

         
                         server_uuid     address  status       mode weight
------------------------------------ ----------- ------- ---------- ------
ab0b0653-6121-11c5-55a0-007543445454 mysql1:3306 PRIMARY READ_WRITE    1.0
f34dd331-2432-11f4-a2d3-006754678533 mysql2:3306 FAULTY  READ_ONLY     1.0

Upon reviewing mysqlfabric logs, I found the following warnings were being logged from time to time:

[WARNING] 1442221217.920115 - FailureDetector(xc_grp_1) - Server (f34dd331-2432-11f4-a2d3-006754678533) in group (xc_grp_1) is unreachable

Since I was not clear under which circumstances a server is marked as FAULTY, I decided to review MySQL Fabric code (Python) to better …