Top 60 Oracle Blogs

Recent comments

High CPU usage in docker-proxy with chatty database application? Disable userland-proxy!

Or just keep database and application co-located :)

It is well-known from the get-go, but very often overlooked because of ignorance or laziness: the database application must be co-located with the database server. Row-by-row roundtrips between the application and the database are expensive. Not only due to the network latency, but also because of the many CPU cycles wasted to switch the context between the two engines, or the two processes, and maybe the two servers.

In modern architectures, with microservices and containers, this means that a business service must be implemented in one microservice containing the business logic and the business data. Separating the application and the database into two microservices is a wrong design, non-efficient, non-scalable, and also non-green because of the unnecessary CPU usage.


I was building a new demo for this, as in the previous post, where I compare running the procedural code in the client or the server side of the database. When I was running my database in a Docker container, I’ve seen that the bad performance I wanted to show was even worse than expected:

  • the symptom was high CPU usage in “docker-proxy” process
  • the cause was that I’m using the default Docker userland proxy

Here is the related Twitter thread. Thanks to @G_Ceresa, @ochoa_marcelo, and @ofirm for the quick replies about the cause and solution: