Halil Ozan Akgul

Halil Ozan Akgul

CITUS BLOG AUTHOR PROFILE

Computer engineer, Citus developer, Postgres lover, piano player, plant grower—all while working at Microsoft.

halilozanakgul

PUBLISHED ARTICLES
Halil Ozan Akgul

Monitor distributed Postgres activity with citus_stat_activity & citus_lock_waits

Written by By Halil Ozan Akgul | July 21, 2022 Jul 21, 2022

We released Citus 11 in the previous weeks and it is packed. Citus went full open source, so now previously enterprise features like the non-blocking aspect of the shard rebalancer—and multi-user support—are all open source for everyone to enjoy. One other huge change in Citus 11 is now you can query your distributed Postgres tables from any Citus node, by default.

When using Citus to distribute Postgres before Citus 11, the coordinator node was your application’s only point of contact. Your application needed to connect to the coordinator to query your distributed Postgres tables. Coordinator node can handle high query throughput, about 100K per second but your application might need even more processing power. Thanks to our work in Citus 11 you can now query from any node in the Citus database cluster you want. In Citus 11 we sync the metadata to all nodes by default, so you can connect to any node and run queries on your tables.

Running queries from any node is awesome but you also need to be able to monitor and manage your queries from any node. Before, when you only connected the coordinator, using Postgres’ monitoring tools was enough but this is not the case anymore. So in Citus 11 we added some ways to observe your queries similar to you would do in a single Postgres instance.

Keep reading
Halil Ozan Akgul

Citus Tips for Postgres: How to alter distribution key, shard count, & more

Written by By Halil Ozan Akgul | May 3, 2021 May 3, 2021

Citus is an extension to Postgres that lets you distribute your application’s workload across multiple nodes. Whether you are using Citus open source or using Citus as part of a managed Postgres service in the cloud, one of the first things you do when you start using Citus is to distribute your tables. While distributing your Postgres tables you need to decide on some properties such as distribution column, shard count, colocation. And even before you decide on your distribution column (sometimes called a distribution key, or a sharding key), when you create a Postgres table, your table is created with an access method.

Previously you had to decide on these table properties up front, and then you went with your decision. Or if you really wanted to change your decision, you needed to start over. The good news is that in Citus 10, we introduced 2 new user-defined functions (UDFs) to make it easier for you to make changes to your distributed Postgres tables.

Keep reading
Halil Ozan Akgul

Citus Tips: How to undistribute a distributed Postgres table

Written by By Halil Ozan Akgul | February 6, 2021 Feb 6, 2021

Once you start using the Citus extension to distribute your Postgres database, you may never want to go back. But what if you just want to experiment with Citus and want to have the comfort of knowing you can go back? Well, as of Citus 9.5, now there is a new undistribute_table() function to make it easy for you to, well, to revert a distributed table back to being a regular Postgres table.

If you are familiar with Citus, you know that Citus is an open source extension to Postgres that distributes your data (and queries) to multiple machines in a cluster—thereby parallelizing your workload and scaling your Postgres database horizontally. When you start using Citus—whether you’re using Citus open source or whether you’re using Citus as part of a managed service in the cloud—usually the first thing you need to do is distribute your Postgres tables across the cluster.

Keep reading

Page 1 of 1