pgbench paramaters for concurrency control pgbench offers two parameters for controlling the concurrency in the benchmark. Namely: -j for ‘jobs’. The number of pgbench threads to run. -j, –jobs=NUM number of threads (default: 1) -c for ‘clients’. The number of “postgres” processes to run. -c, –client=NUM number of concurrent database clients (default: 1) Here are…
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Scale factor to workingset size lookup for tiny databases
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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. Experiment setup The goal was to establish how database…
Read More → An X-ray workload for measuring application density
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Do database workloads benefit from data locality?
Read More →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…
Read More →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…
Read More →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…
Read More →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…
Read More →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”…
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