Scale factor to workingset size lookup for tiny databases
Read More → Category: Databases
Use the following SQL to drop the tables and indexes in the HammerDB TPC-H schema, so that you can re-load it.
Read More →Some versions of HammerDB (e.g. 3.2) may induce imbalanced NUMA utilization with SQL Server. This can easily be observed with Resource monitor. When NUMA imbalance occurs one of the NUMA nodes will show much larger utilization than the other. E.g. The cause and fix is well documented on this blog. In short HammerDB issues a…
Read More →HammerDB is a great tool for running Database benchmarks. However it is very easy to create an artificial bottleneck which will give a very poor benchmark result. When setting up HammerDB to run against even a moderate modern server, it is important to avoid displaying the client transaction outputs in the HammerDB UI. In my…
Read More →Nutanix X-Ray is well known for being able to model IO/Storage workloads, but what about workloads that are CPU bound? X-Ray can run Ansible scripts on the X-Ray worker VMs, and by doing so we are able to provision almost any application. For our purposes we are going to use Postgres DB and the built-in…
Read More →The vertica vioperf tool is used to determine whether the storage you are planning on using is fast enough to feed the vertica database. When I initially ran the tool, the IO performance reported by the tool and confirmed by iostat was much lower than I expected for the storage device (a 6Gbit SATA device…
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 →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”…
Read More →TL;DR It’s pretty easy to get 1M SQL TPM running a TPC-C like workload on a single Nutanix node. Use 1 vDisk for Log files, and 6 vDisks for data files. SQL Server needs enough CPU and RAM to drive it. I used 16 vCPU’s and 64G of RAM. Running database servers on Nutanix is an…
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