PostgreSQL User group NL Adyen Meetup 2022

Dear all,

It’s been a long, long time but we are happy to invite you to the "PostgreSQL User Group NL" meetup of November 2022 with a great line-up and a perfect venue: Adyen in Amsterdam!

Next to some interesting headliners in this meetup we offer the opportunity to participate in the Lightning Talks. If you have anything to share on the subject of PostgreSQL, please let us know and we are happy to give you the floor.

This Meetup will be held at the office of Adyen Simon Carmiggeltstraat office close to Central Station. We are going to have some food and drinks. Many thanks to Adyen for their hospitality!!

Let’s meet on Tuesday November 15th!

Gerard en Feike

Agenda:

17:30 - 18:30
Arrive, food and drinks

18:30 - 18:35
Opening & Welcome

18.35 - 19.20
UNDERSTANDING POSTGRES HOT UPDATES PLUS USING PROMETHEUS AND GRAFANA TO TRACK AND TUNE ISSUES

By Derk van Veen started as a java developer in 2010 but slowly transposed to being a full time DBA from 2015. I really enjoyed working with PostgreSQL and I switched to being a full time PostgreSQL DBA at Adyen. I am having a great time at Adyen working with PostgreSQL and lots of critical data.

At Adyen we have invested heavily and built upon the Postgres database engine, generally this has worked very well for us. Occasionally Postgres Write Amplification can be a technical challenge at Adyen, fortunately this does not happen often, unfortunately when it does happen it is around critical, high volume workloads.

So we have been working on using Prometheus and Grafana to track and tune issues around Write Amplification, which can normally be relatively easily addressed by tuning FillFactor and/or tweaking application design.
As well as the tooling (Prometheus and Grafana based dashboards), we have developed "awareness training" for our Developer teams, to ensure we proactively tackle any Write Amplification issues.

This presentation starts with the technical background, covering why Postgres Write Amplification can happen, the sorts of workloads which are likely to hit this sort of issue and how we can sometimes mitigate this by tuning FillFactor and/or tweaking application design. Next we talk about monitoring, specifically how to proactively monitor for this, starting with the Postgres standard metrics `pg_stat_user_tables` and then using the Prometheus Postgres exporter and Grafana to track key long term trends.

The aim of the talk is to share best practice and lessons learnt for managing Postgres from Adyen. We want to share this with the broader Postgres community, as we think our DBAs will find this useful and also we're looking for feedback and further possible enhancements.

Finally in terms of coverage, this talk relates to 5 of the topics

• PostgreSQL internals hacking << The 1st half of the presentation dives into Postgres internals
• Tools and utilities << The 2nd half of the presentation is about using open-source monitoring tools (Prometheus and Grafana) to proactively and iteratively monitor and tune Postgres.
• Tuning and performance improvements << better tuning FillFactor and awareness of how HOT Updates work, has been a major win for us in 2022, we are pushing Postgres to its limits and beyond!
• Administering large scale PostgreSQL installations << tables with billions of UPDATEs per day?
• Case studies and/or success stories of PostgreSQL deployments (or interesting failures) << vacuum was really struggling to keep up, we have massively cut the vacuum costs through tuning FillFactor and/or
  tweaking application design.

19.20-20.00
EXPLORING LINUX MEMORY USAGE AND IO PERFORMANCE FOR POSTGRESQL
By: Frits Hoogland – developer advocate at Yugabyte, where he works on cloud native open source technology and performance challenges. H

Linux and containers are similar in that they provide operating system resources such as memory and storage. These resources—along with CPU and networking— are key factors to achieve optimal application performance. However, many cloud native applications rely on high performance disk IO to function properly.

In this session, we’ll explore how memory allocation at the container or operating system level influences the performance of buffered disk IO. We’ll also examine Linux memory details and the different ways to perform disk IO. From there, we’ll walk through a number of examples that reveal the dynamics of buffered IOs, with an emphasis on how these change with changes in memory usage, and can lead to spectacular performance differences.

Understanding these dynamics are important to any cloud native application that is dependent on disk IO and has performance requirements.

20:00 – 20:15
Lightning Talks

20.15
Wrap up and get together with refreshments