Partnering to participate knowledge sharing for the community of Database Administrators.

In continuation to the community contribution with knowledge gained out of experience and networking, Mydbops IT Solutions, conducted its 4th Database Meetup on Saturday, 3rd of August, 2019. Here was the first time, that we had changed our venue. With the like-minded sponsor in M/s.Zenefits Technologies India Pvt. Ltd. They played a role of a perfect host for all of us as attendees. Their venue was a perfectly equipped to suit the knowledge sharing exercise.

Key note by Mr.Ramesh Aithal, Head of Engineering at Zenefits was build on statistics, of how the Industry is taking shape and the galore of opportunities in the coming days. The attendees from multiple companies were a great …

To set correct system variable values is the essential step to get the correct server behavior against the workload.
In MySQL, we have many System variables that can be changed at runtime, and most of them can be set at the session or global level.

To change the value of a system variable at the global level in the past, users needed to have SUPER privileges. Once the system variable value is modified as global, the server will change this behavior for the session, and obviously as global scope.

For instance, one of the most commonly adjusted variables is probably max_connections.

If you have max_connection=100 in your my.cnf or as the default value, and during the day as DBA you notice that it is not enough, it is easy just to add new connections on the fly with the command:

SET GLOBAL …

Introduction In this article, we are going to see how we can limit the SQL query result set to the Top-N rows only. Limiting the SQL result set is very important when the underlying query could end up fetching a very large number of records, which can have a significant impact on application performance. Why limit the number of rows of a SQL query? Fetching more data than necessary is the number one cause of data access performance issues. When a given business use case is developed, the amount of data available... Read More

The post How to limit the SQL query result set to Top-N rows only appeared first on Vlad Mihalcea.

ProxySQL 2.0.5, released by ProxySQL, is now available for download in the Percona Repository along with Percona’s proxysql-admin tool.

ProxySQL is a high-performance proxy, currently for MySQL and database servers in the MySQL ecosystem (like Percona Server for MySQL and MariaDB). It acts as an intermediary for client requests seeking resources from the database. René Cannaò created ProxySQL for DBAs as a means of solving complex replication topology issues.

This release includes ProxySQL 2.0.5 which fixes many bugs and introduces a number of features …

To set correct system variable values is the essential step to get the correct server behavior against the workload.  

In MySQL we have many System variables that can be changed at runtime, most of them can be set at session or at global scope. 

To change the value of a system variable at global level in the past user need to have SUPER privileges. Once the system variable value is modified as global, the server will change his behavior for the session, and obviously as global scope. For instance, one of the most commonly adjusted variables is probably max_connections. If you have max_connection=100 in your my.cnf or as default value, and during the day as DBA you notice that the number of them is not enough, it is easy just to add new connections on the fly, the command:

SET GLOBAL MAX_CONNECTIONS=500;

Will do the work. But here is the issue. We had changed a GLOBAL value, that apply to the whole …

To set correct system variable values is the essential step to get the correct server behavior against the workload.  

In MySQL we have many System variables that can be changed at runtime, most of them can be set at session or at global scope. 

To change the value of a system variable at global level in the past user need to have SUPER privileges. Once the system variable value is modified as global, the server will change his behavior for the session, and obviously as global scope. For instance, one of the most commonly adjusted variables is probably max_connections. If you have max_connection=100 in your my.cnf or as default value, and during the day as DBA you notice that the number of them is not enough, it is easy just to add new connections on the fly, the command:

SET GLOBAL MAX_CONNECTIONS=500;

Will do the work. But here is the issue. We had changed a GLOBAL value, that apply to the whole …

MySQL Memory Calculator

Check out the “MySQL Memory Calculator” added to my blog page, which will be helpful to calculate MySQL memory usage during tuning of MySQL memory parameters. https://www.abhinavbit.com/p/mysql-memory-calculator.html

Photo by Kelly Sikkema on  …

Overview The Skinny

Part of the power of Tungsten Clustering for MySQL / MariaDB is its intelligent MySQL Proxy, known as the Tungsten Connector. The Tungsten Connector has built-in read-write splitting capabilities, and it is also possible to configure different algorithms which select the appropriate slave (i.e. Round-Robin or Lowest-Latency).

The Question Recently, a customer asked us:

How do we best share the load between read-only slaves? Currently, there appears to be an imbalance, with most of the read-only queries reaching just one slave. What may we do to improve this situation?

This customer noticed that a couple of long …

When somebody wants to migrate from a single MySQL instance to a full HA solution using MySQL InnoDB Cluster, the best solution to reduce the downtime is to use asynchronous replication and switch database only once at a certain point in time when everything is ready. This is almost what I explained already in this post.

The most difficult part was related to the provisioning of the existing data to the new cluster members. A backup (physical or logical) was required. It should have been restored on every nodes and we had to be sure to not mess up with the GTIDs.

This is not more the case since MySQL 8.0.17 ! Now we can use the CLONE plugin to start the cluster provisioning too.

The current situation

…

Percona is glad to announce the release of Percona XtraBackup 8.0.7 on August 7, 2019. You can download it from our download site and apt and yum repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an open source solution, it …