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Displaying posts with tag: administration (reset)
JSON Output of the pmm-admin list Command

In this blog post, we’ll look at Percona Monitoring and Management’s pmm-admin list command.

The pmm-admin list command shows all monitoring services you have added using the pmm-admin add command. Starting with version 1.4.0, Percona Monitoring and Management (PMM) also lists external monitoring services when you run pmm-admin list, i.e., those services that monitor the backends not supported out of the box (such as PostgreSQL databases).

In the output, the external monitoring services appear at the bottom:

The tabular output of the pmm-admin list commandJSON Output for …

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Use Docker To Explore MySQL 5.7.8-rc

Recently I have been using Ansible and Vagrant to test the MySQL 5.7 release candidates but several of you asked about using Docker. The hardest part of this process will be installing Docker on your operating system of choice and that is fairly easy. I am using Ubuntu 14.04 LTS and the installation was a wget command.

Next comes the magic. Docker will download the MySQL 5.7.8-rc image if it is not already loaded locally and then start it.
docker run -p 3306:3306 --name mysql -e MYSQL_ROOT_PASSWORRD=secret -d mysql:5.7.8-rc
The quick translation of the above is that we are telling Docker to set up a container named mysql on port 3306 using a password of secret, run all this as a daemon using MySQL version 5.7.8-rc.

And MySQL 5.7.8-rc is running. But to find it you will have to ask Docker where the server is running.

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Ansible and Loading MySQL Databases Part II

Loading databases on virtual systems is not as straight forward as it should be. Last time the foundation for using Ansible was set down on our quest to be able to have fully functional database servers on virtual servers automatically. But that prompted a few of you to remind me that you do not always need Ansible.

Without Ansible
You can have Vagrant do the work. Modify the vagrant file to run a script to run a script when provisioned, such as
config.vm.provision :shell,path: ""
and create the shell script.

# example setup script for LAMP stack on Vagant box
sudo apt-get -y update
sudo apt-get -y install apache2 php5 libapache2-mod-php5
## …
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MySQL Fabric and Sharding

Last time we set up a High Availability server farm with MySQL Fabric. Now it is time to set up sharding. I will be using the good old World database and sharding the City table on the ID field. There are 4,079 cities in this table and they will be split in two. So one shard, that we will call CityLow will have the records 2,000 and below and the other records at 2,001 and above will be called CityHigh. We also need a global group for setting up sharding that will be called CityGlobal.

Sadly, the first step is to remove the previous setup with mysqlfabric manage teardown. This will remove the fabric database from the Fabric controller. Fabric itself has to be stopped with mysqlfabric manage stop. The command mysqlfabric manage setup will set up a fresh, clean fabric database. And …

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MySQL Workbench 6.2: New Migration Source and Sync Feature

MS Access Migration

MS Access support was added to the Migration Wizard in MySQL Workbench 6.2, joining MS SQL Server, Sybase ASE, Sybase SQL Anywhere, PostgreSQL, SQLite and “Generic ODBC” as migration sources. You can read more about it in How-To: Guide to Database Migration from MS Access using MySQL Workbench.

Include Model Scripts in Forward Engineering and Synchronization

Workbench modeling has always supported attaching SQL script files to the model, usually for documentation/organization purposes. You can now include these attachments to the output script when performing forward engineering or synchronization.

Resume data copy …

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MySQL Workbench 6.2: Fabric and Client Connection Browser

MySQL Fabric Support

MySQL Fabric servers can now be added to the Workbench home screen. When clicked, these connections will dynamically query the Fabric server and individual connections for all the managed MySQL servers will be created. You can then connect to each instance as usual. 

Metadata Lock Browser

MySQL uses metadata locking to manage access to objects (tables, triggers, and so forth). Sometimes that can be puzzling, as your query may block waiting on an object being manipulated by another connection from maybe another user. The Client Connections list was updated to take advantage of the metadata lock information provided in the performance_schema starting in MySQL 5.7.3, to show …

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Containing your MySQL Instances

Virtual servers for MySQL are popular but are they the answer? Should we be containing our instances instead. An Updated Performance Comparison of
Virtual Machines and Linux Containers
is an interesting study of using containers over VMs by four brilliant folk from IBM Research in Austin. There are several benefits to containers that are detailed in the study.

So what is wrong with VMs? IBM has been using them since the 1970s. Well, VMs have a static number of virtual CPUs (vCPU) and a fixed amount of RAM that bound performance. And each vCPU can only use up to one real CPUs of clock cycles. Since each VM is a Linux process, resource management like the scheduler come into play.

Containers? They are built on the kernel namespaces. A container acts like its own little Linux box but …

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Changes in MySQL 5.6.20

The MySQL Release Notes should be part of any DBA’s regular reading list. The Changes in MySQL 5.6.20 came out last week and there are some interesting goodies.

  • MySQL now includes DTrace support on Oracle Linux 6 or higher with UEK kernel.
  • A new system variable binlog_impossible_mode controls what happens if the server cannot write to the binary log, for example, due to a file error.
  • The mysqlhotcopy utility is now deprecated and will be removed in a future version of MySQL

5.6.20 has a slew of bug fixes, functionality changes, and notes.

So why should you be reading the changes on a regular basis? There isa goldmine of information in them. For instance, if you use blobs, consider this: …

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MySQL APT Repository

THe MySQL APT Repository provides an easy and convenient way to get the latest MySQL software. My test server was need of a refresh so I put on a fresh install of Ubuntu 14.04 and downloaded mysql-apt-config_0.2.1-1ubuntu14.04_all.deb.

sudo dpkg -i mysql-apt-config_0.2.1-1ubuntu14.04_all.deb
[sudo] password for dstokes:
Selecting previously unselected package mysql-apt-config.

You will get a choice to install MySQL 5.6 or the latest 5.7 DMR.

sudo apt-get update Pulls the latest information from the repository for the various packages.

sudo apt-get install mysql-server Installs the server and will start it running. And then a quick sudo apt-get install mysql-workbench to get me where i needed to be.

There is a detailed information at …

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Foreign Keys and MySQL

Foreign Keys are often a mystery to new DBAs in the MySQL world. Hopefully this blog will clear some of this up.

In this example, we will have a table for employee data and a table for the data on offices. First we need the two tables.
CREATE TABLE employee (
-> e_id INT NOT NULL,
-> name CHAR(20),
-> PRIMARY KEY (e_id)
-> );

CREATE TABLE building (
-> office_nbr INT NOT NULL,
-> description CHAR(20),
-> e_id INT NOT NULL,
-> PRIMARY KEY (office_nbr),
-> FOREIGN KEY (e_id)
-> REFERENCES employee (e_id)

Those who do not use Foreign Keys will not be familiar with the last four lines of the building table. The trick is that there are two e_id columns, one in each table. In the employee table

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