Consequently, Continuent needs additional talented staff.
We are currently looking for a person who would be a good fit for our “Database Clustering Technical Sales & Support Engineer” position, in the US Pacific timezone.
If you know someone who would be a good fit for this role and our company’s culture, please send them our way.
Co-Author: Rafael Alvarez
When you look up the word idempotence in wikipedia you get the following definition: Idempotence is the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application.
When I think of idempotence in the sense of how IT operations work, the very first thing that comes to mind is Ansible. In Ansible you have a yml file that represents a state you want the target host to be in. For example, I can use the yum module to ensure that MySQL is installed on my RHEL virtual machine. When the playbook is run, it checks if MySQL is installed. If not, it will install it. It is installed, then it will ignore that …
[Read more]Parallel replication has been around for a few years now but is still not that commonly used. I had a customer where the master had a very large write workload. The slave could not keep up so I recommended to use parallel slave threads. But how can I measure if it really helps and is working?
At my customer the
slave_parallel_workers
was 0. But how big should I increase it, maybe to 1? Maybe to 10? There is a blog post about how can we see how many threads are actually used, which is a great help.
We changed the following variables on the slave:
slave_parallel_type = LOGICAL_CLOCK; slave_parallel_workers = 40; slave_preserve_commit_order = ON;
40 threads sounds a lot, right? Of course, this is workload specific: if the transactions are independent it might be …
[Read more]Your database cluster contains your most business-critical data and therefore proper performance under load is critical to business health. If response time is slow, customers (and staff) get frustrated and the business suffers a slow-down.
If the database layer is unable to keep up with demand, all applications can and will suffer slow performance as a result.
To prevent this situation, use load tests to determine the throughput as objectively as possible.
In the sample load.pl script below, increase load by
increasing the thread quantity.
You could also run this on a database with data in it without polluting the existing data since new test databases are created to match each node’s hostname for uniqueness.
Note: The examples in this blog post assume that a Connector is …
[Read more]
Error Message: ERROR 1396 (HY000): Operation CREATE USER failed
for 'admin'@'%'
Generic Error Message:Operation %s failed for %s
Error Scenario:Operation CREATE USER failed
Operation DROP USER failed
Reason:The reason for this error is, you are trying to do some
user operation but the user does not exist on the MySQL system.
Also, for drop user, the user details are stored somewhere in the
system, even though, you have already dropped the user from MySQL
server.
Resolution:Revoke all access granted to the user, drop the user,
and run FLUSH PRIVILEGE command to remove the caches. Now
create/drop/alter the user, it will work.
REVOKE ALL ON *.* FROM 'user'@'host';DROP USER
'user'@'host';FLUSH PRIVILEGES;
Grant Tables:The following tables will help you in identifying
the user related informations (as of MySQL 5.7):
mysql.user: User accounts, global privileges, and other
non-privilege …
For Percona Live Europe this year, I got accepted a workshop on query optimization and a 50-minute talk covering TLS for MySQL at Large Scale, talking about our experiences at the Wikimedia Foundation.
Workshop
The 3-hour workshop on Monday, titled Query Optimization with MySQL 8.0 and MariaDB 10.3: The Basics is a beginners’ tutorial–though dense in content. It’s for people who are more familiar with database storage systems other than InnoDB for MySQL, MariaDB or Percona Server. Or who, already familiar with …
[Read more]You all heard about that today AWS announced that RDS is started to support GTID Transactions. I’m a great fan of RDS but not for GTID. Since RDS has better settings and configurations to perform well. Many of you people read about the AWS What’s new page regarding GTID. But here we are going to talk about the actual benefits and drawbacks.
RDS supports GTID on MySQL 5.7.23 or later. But AWS released this version on Oct10 (two days before). So, for now, this is the only version which supports GTID.
NOTE: GTID supports only for RDS, its not
available for Aurora. It may support in future)
Update : 27 March 2019:
Aurora MySQL 5.7 supports GTID. Find the relavent
link below.
Before configuring the GTID, lets have a look at what is GTID?
The first four steps on how to start a Software Quality Team for MySQL Cluster from ground up
On June 2018, the first ever re-organization of the Oracle MySQL
Cluster group occurred. As in other companies, there’s a moment
when a larger group is broken down into smaller teams each owning
a part of the overall process/code-base/tasks. While in some
cases the new teams are just a formalization of an
already-existent informal structure, in others a new team emerges
to answer specific long-term needs.
In MySQL Cluster group, such team was the Quality Team which I
have become responsible for. The long-term needs were getting the
grips on testing infrastructure, ensure reliable test execution
and reporting, and evolve current infrastructure to support
developers in creating better tests.
As soon as the team was formed, the first challenge was to define
the first steps to start this team. Here are the first four steps
our …
There are a number of options for generating ID values for your tables. In this post, Alexey Mikotkin of Devart explores your choices for generating identifiers with a look at auto_increment, triggers, UUID and sequences.
AUTO_INCREMENT
Frequently, we happen to need to fill tables with unique identifiers. Naturally, the first example of such identifiers is PRIMARY KEY data. These are usually integer values hidden from the user since their specific values are unimportant.
When adding a row to a table, you need to take this new key value from somewhere. You can set up your own process of generating a new identifier, but MySQL comes to the aid of the user with the AUTO_INCREMENT column setting. It is set as a column attribute and allows you to generate unique integer identifiers. As an example, consider the …
[Read more]I have done many automations MySQL Automations with Rundeck. This blog series will explain about the DevOps In MySQL with Rundeck. Rundeck is one of my favourite Automation tools. Here we are going to see how can we install and configure rundek on a CentOS server with mysql as a backend. Even I like Jenkins, …
The post RunDeck Series 1 – Install And Configure RunDeck 3.0 On CentOS 7 appeared first on SQLgossip.
