postgres Archives | n0derunner

Notes on tuning postgres for cpu and memory benchmarking

Published: October 18, 2024 (Updated: October 18, 2024) in Postgres, Database Performance, tpc-c, hammerDB, postgres, tuning, benchmarking by gary. Leave a Comment on Notes on tuning postgres for cpu and memory benchmarking.

Recently I wanted to measure the impact of NUMA placement and Hugepages on the performance of postgres running in a VM on a Nutanix node. To do this I needed to drive postgres to do real transactions but have very little jitter/noise from the filesystem and storage. After reading a lot of blogs I came […]

Understanding Concurrency Parameters in pgbench

Published: January 12, 2021 (Updated: September 7, 2022) in Postgres, postgres, pgbench, concurrency by gary. Leave a Comment on Understanding Concurrency Parameters in pgbench.

How to use the “jobs” and “clients” parameters in pgbench without going crazy.

Postgres pgbench scale-factors and WSS

Published: August 11, 2020 (Updated: April 2, 2021) in Postgres, postgres, pgbench by gary. Leave a Comment on Postgres pgbench scale-factors and WSS.

Scale factor to workingset size lookup for tiny databases

How to measure database scaling & density on Nutanix HCI platform.

Published: March 27, 2020 (Updated: November 5, 2022) in Nutanix, database, postgres, scaling, density by gary. Leave a Comment on How to measure database scaling & density on Nutanix HCI platform..

How can database density be measured? How does database performance behave as more DBs are consolidated? What impact does running the CVM have on available host resources? tl;dr The cluster was able to achieve ~90% of the theoretical maximum. CVM overhead was 5% for this workload.

Measuring CPU performance with X-Ray and pgbench.

Published: October 1, 2019 (Updated: January 3, 2023) in X-Ray, x-ray, postgres, pgbench, cpu by gary.

An X-ray workload for measuring application density

Impact of Data locality on DB workloads.

Published: July 23, 2019 (Updated: October 8, 2020) in Nutanix, nutanix, postgres by gary.

Do database workloads benefit from data locality?

View from Nutanix storage during Postgres DB benchmark

Published: June 28, 2019 (Updated: March 15, 2020) in Nutanix, Postgres, postgres, database by gary.

Following on from the previous [1] [2] experiments with Postgres & pgbench. A quick look at how the workload is seen from the Nutanix CVM. The Linux VM running postgres has two virtual disks: One is taking transaction log writes. The other is doing reads and writes from the main datafiles. Since the database size […]

Benchmarking with Postgres PT2

Published: June 28, 2019 (Updated: March 15, 2020) in Postgres, benchmarks, database, postgres by gary.

In this example we run pgbench with a scale factor of 1000 which equates to a database size of around 15GB. The linux VM has 32G RAM, so we don’t expect to see many reads. Using prometheus with the Linux node exporter we can see the disk IO pattern from pgbench. As expected the write […]

Benchmarking with Postgres PT1

Published: June 28, 2019 (Updated: March 15, 2020) in Postgres, postgres, database, benchmarks by gary.

In this example, we use Postgres and the pgbench workload generator to drive some load in a virtual machine. Assume a Linux virtual machine that has Postgres installed. Specifically using a Bitnami virtual appliance. Once the VM has been started, connect to the console Allow access to postgres port 5432 – which is the postgres […]

Install a bitnami image to Nutanix AHV cluster.

Published: June 28, 2019 (Updated: June 28, 2019) in Nutanix, benchmark, nutanix, database, postgres, ahv by gary.

One of the nice things about using public cloud is the ability to use pre-canned application virtual appliances created by companies like Bitnami. We can use these same appliance images on Nutanix AHV to easily do a Postgres database benchmark Step 1. Get the bitnami image wget https://bitnami.com/redirect/to/587231/bitnami-postgresql-11.3-0-r56-linux-debian-9-x86_64.zip Step 2. Unzip the file and convert […]

Performance gains for postgres on Linux with hugepages

Published: March 7, 2019 (Updated: September 7, 2022) in Postgres, postgres, tuning, hugepages, linux by gary.

For this experiment I am using Postgres v11 on Linux 3.10 kernel. The goal was to see what gains can be made from using hugepages. I use the “built in” benchmark pgbench to run a simple set of queries. Since I am interested in only the gains from hugepages I chose to use the “-S” […]