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Displaying posts with tag: Linux (reset)
Creating a Test Lab Using VirtualBox / NAT networking

My job is almost completely reliant upon my ability to perform work in lab of virtual machines. Almost every action plan I write is tested locally. When I need to troubleshoot an issue for a client one of the most common first steps I’ll perform is attempting to recreate the issue in a virtual environment so I can work on it there without the risk of impacting client data.

I believe that having a place to test and grow your skills is an absolute necessity for anyone working in the IT field today regardless of your specialization, even if you’re an IT generalist. But every now and then I hear about individuals who have issues with their virtual machines or with the virtual environment provided by their employer, so I figured this was a good time to share my method of creating a virtual lab. More specifically, one that allows you to do virtual work on a commodity laptop, one that won’t break down if you lose connectivity, one that …

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MySQL Health Check Script

Ever get called out for a MySQL issue only to realize that there was no issue?  It was a false alarm from the monitor.  We sure have and it’s frustrating, especially at 3:00 or 4:00 in the morning!

Many DBAs work in an environment where there is some sort of first level support that gets assigned tickets first.  Unfortunately, many of the times these groups are, shall we say, less than skilled in MySQL.  As a result, they quickly escalate the ticket onto the primary on-call DBA, even when there is really nothing wrong.

Much of the time, there are multiple types of MySQL topology in these environments: standalone, galera cluster, replication, etc.  Writing large runbooks with detailed test cases can be a daunting process and one that will cause many first-level support engineers to give up and simply escalate the issue anyway.

In an effort to avoid undue call outs, we developed a simple bash …

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[Reprint]Injection MySQL – Function

Reprint a PDF for MySQL Injection Test

MySQL Error Based SQL Injection Using EXP

Log Buffer #435: A Carnival of the Vanities for DBAs

Sun of database technologies is shining through the cloud technology. Oracle, SQL Server, MySQL and various other databases are bringing forth some nifty offerings and this Log Buffer Edition covers some of them.

Oracle:

  • How to create your own Oracle database merge patch.
  • Finally the work of a database designer will be recognized! Oracle has announced the Oracle Database Developer Choice Awards.
  • Oracle Documents Cloud Service R4: Why You Should Seriously Consider It for Your Enterprise.
  • Mixing Servers in a Server …
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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: "setup.sh"
and create the setup.sh shell script.

#!/bin/bash
#
# 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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Ansible and Loading MySQL Databases Part I

Automation software like Puppet, Chef, and Ansible can quickly load software on virtual servers. But how do you get your MySQL database instances loaded on these new servers? And how do you do it securely? Lets start with a fairly common pairing.

Ansible and Vagrant work very well together and the documentation for getting both to work together is rather extensive. BTW the newest version VirtualBox is 5.0 was recently released with a large number of improvements. Follow the documentation at their respective sites to get VirtualBox, Vagrant, and Ansible installed.

The linchpin is the Vagrantfile which controls how Vagrant starts the server. Inside this file we pull in an Ansible playbook.

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How to create a rock-solid MySQL database backup & recovery strategy

Have you ever wondered what could happen if your MySQL database goes down?

Although it’s evident such a crash will cause downtime – and surely some business impact in terms of revenue – can you do something to reduce this impact?

The simple answer is “yes” by doing regular backups (of course) but are you 100% sure that your current backup strategy will really come through when an outage occurs? And how much precious time will pass (and how much revenue will be lost) before you get your business back online?

I usually think of backups as the step after HA fails. Let’s say we’re in M<>M replication and something occurs that kills the db but the HA can’t save the day. Let’s pretend that the UPS fails and those servers are completely out. You can’t failover; you have to restore data. Backups are a key piece of “Business Continuity.” Also factor in the frequent need to restore data that’s been …

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Using Cgroups to Limit MySQL and MongoDB memory usage

Quite often, especially for benchmarks, I am trying to limit available memory for a database server (usually for MySQL, but recently for MongoDB also). This is usually needed to test database performance in scenarios with different memory limits. I have physical servers with the usually high amount of memory (128GB or more), but I am interested to see how a database server will perform, say if only 16GB of memory is available.

And while InnoDB usually respects the setting of innodb_buffer_pool_size in O_DIRECT mode (OS cache is not being used in this case), more engines (TokuDB for MySQL, MMAP, WiredTiger, RocksDB for MongoDB) usually get benefits from OS cache, and Linux kernel by default is generous enough to allocate as much memory as available. There I should note that while TokuDB (and TokuMX for MongoDB) supports DIRECT mode (that is bypass OS cache), we found there is a performance gain if OS cache is used for compressed pages.

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9 easy performance tips for your Linux environment

For the majority of us who have grown accustomed to a Windows environment over the years, Linux can seem like another world. In essence, Linux is a free open-source operating system that has gained increasing popularity since its release in 1991. Linux is based on the whole Unix ecosystem of operating systems that grew out of Bell Laboratories in the early 1970s. Linux has been around for almost 25 years and grew immensely in the late 1990s and early 2000s when it became associated with the LAMP web development stack; Linux stands for the ‘L’ in the acronym of popular tools, along with Apache, MySQL, and PHP/Perl/Python.

 

 

 

 

The main difference that …

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MySQL Incremental Backup - Point In Time Backup and Recovery of InnoDB and MyIsam Databases

Mysql Incremental Backup is a complete incremental backup script for MyISAM and InnodB databases using the MySQL binary log so that the backup process does not affect running databases. This tutorial describes the installation of the MysqlIncrementalBackup script and helps to troubleshoot issues that may arise during setup.

Showing entries 31 to 40 of 1228
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