Showing entries 1 to 10 of 40744
10 Older Entries »
[Solved] MySQL User Operation - ERROR 1396 (HY000): Operation CREATE / DROP USER failed for 'user'@'host'

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 …

[Read more]
Percona Live Europe Tutorial: Query Optimization and TLS at Large Scale

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]
Identifying High Load Spots in MySQL Using Slow Query Log and pt-query-digest

pt-query-digest is one of the most commonly used tool when it comes to query auditing in MySQL®. By default, pt-query-digest reports the top ten queries consuming the most amount of time inside MySQL. A query that takes more time than the set threshold for completion is considered slow but it’s not always true that tuning such queries makes them faster. Sometimes, when resources on server are busy, it will impact every other operation on the server, and so will impact queries too. In such cases, you will see the proportion of slow queries goes up. That can also include queries that work fine in general.

This article explains a small trick to identify such spots using pt-query-digest and the slow query log. pt-query-digest is a component of …

[Read more]
Invitation to meet Galera Cluster developers at Oracle OpenWorld San Francisco

We will have a kiosk at Moscone Center, south exhibition hall, Oracle’s Data Management area number 123, close to high availability area and exits 16 and 18. Our kiosk number is DBA-P1.

Our CEO and Co-Founder Seppo Jaakola will host a presentation highlighting the main features of our upcoming Galera Cluster 4.0. The presentation will take place Monday, Oct 22, 1:00 p.m. – 1:20 p.m at the Exchange @ Moscone South – Theater 2. Seats are limited!

Come and meet us! Let’s discuss your MySQL high availability plan or your Galera Cluster deployment. If you want to set up a meeting with us please email to ínfo@galeracluster.com for a meeting request.

MySQL 2018 Community Reception

The 2018 MySQL Community Reception is October 23rd in a new venue at Samovar Tea, 730 Howard Street in San Francisco at 7:00 PM.   Right in the heart of the Moscone Center activities for Oracle OpenWorld and Oracle Code one activities.

The MySQL Community Reception is not part of Oracle OpenWorld or Oracle Code One (you do not need a badge for either event) but you do need to RSVP.  Food, drinks, and a really amazing group of attendees!   And there will be more than tea to drink.

Plus we have a few new surprises this year! 

Generating Identifiers – from AUTO_INCREMENT to Sequence

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]
Rundeck Series: Install And Configure RunDeck 3.0 On CentOS 7

Credit: RunDeck Rundeck is one of my favorite 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, but as a SYSadmin, I like the Rundeck a lot.You may think like both can do automation. But as …

The post Rundeck Series: Install And Configure RunDeck 3.0 On CentOS 7 appeared first on SQLgossip.

Mydbops Delighted to be part of Open Source India -2018

Mydbops has partnered with OSI days for the second consecutive year. OSI days is one of the Asia’s leading  open source conference.

Presentations on MySQL 

Topic        : Evolution of DBA’s in Cloud

Presenter : Manosh Malai ,Senior Devops / DB Consultant Mydbops

Kabilesh P R. Co-Founder / DB Consultant Mydbops

 

As Cloud is more widely adopted by industry now DBA’s should focus on ramping up their Skills on core optimisation and designing more scalable database. Our consultants emphasis the role of DBA in cloud environment and share their experience in handling large scale systems.

Topic : MySQL 8.0 = NoSQL + SQL

Presenter : …

[Read more]
Deploying MySQL on Kubernetes with a Percona-based Operator

In the context of providing managed WordPress hosting services, at Presslabs we operate with lots of small to medium-sized databases, in a DB-per-service model, as we call it. The workloads are mostly reads, so we need to efficiently scale that. The MySQL® asynchronous replication model fits the bill very well, allowing us to scale horizontally from one server—with the obvious availability pitfalls—to tens of nodes. The next release of the stack is going to be open-sourced.

As we were already using Kubernetes, we were looking for an operator that could automate our DB deployments and auto-scaling. Those available were doing synchronous replication using MySQL group replication or Galera-based replication. Therefore, we decided to write our own operator.

Solution architecture

The …

[Read more]
How to Fix ProxySQL Configuration When it Won’t Start

With the exception of the three configuration variables described here, ProxySQL will only parse the configuration files the first time it is started, or if the proxysql.db file is missing for some other reason.

If we want to change any of this data we need to do so via ProxySQL’s admin interface and then save them to disk. That’s fine if ProxySQL is running, but what if it won’t start because of these values?

For example, perhaps we accidentally configured ProxySQL to run on port 3306 and restarted it, but there’s already a production MySQL instance running on this port. ProxySQL won’t start, so we can’t edit the value that way:

2018-10-02 09:18:33 network.cpp:53:listen_on_port(): [ERROR] bind(): Address already in use

We could delete proxysql.db and have it reload the configuration files, but …

[Read more]
Showing entries 1 to 10 of 40744
10 Older Entries »