Profile-Guided Optimization

Profile-Guided Optimization (PGO) is a compiler optimization technique where a program is optimized based on the runtime profile.

According to the tests , we see improvements of up to 15% more processed log events per second on some Vector workloads. The performance benefits depend on your typical workload - you can get better or worse results.

More information about PGO in Vector you can read in the corresponding GitHub issue .

How to build Vector with PGO?

There are two major kinds of PGO: Instrumentation and Sampling (also known as AutoFDO). In this guide, is described the Instrumentation PGO with Vector. In this guide we use cargo-pgo for building Vector with PGO.

• Install cargo-pgo .
• Check out the Vector repository.
• Go to the Vector source directory and run cargo pgo build. It will build the instrumented Vector version.
• Run instrumented Vector on your test load like cargo pgo run -- -- -c vector.toml and wait for some time to collect enough information from your workload. Usually, waiting several minutes is enough (but your case can be different).
• Stop Vector instance. The profile data will be generated in the target/pgo-profiles directory.
• Run cargo pgo optimize. It will build Vector with PGO optimization.

A more detailed guide on how to apply PGO is in the Rust documentation .