Profiling Zebra's initial sync performance

[arya2]

Motivation

It may make it easier to:

• Narrow down what may have caused a performance regression
• Improve the effectiveness of a quick test for sampling initial sync performance that can be run for every PR update

Possible Design

• Log to a file

• Add a feature flag for enabling extra logs during validation when:

  • semantic validation of blocks/transactions start, progress, or finish
  • contextual validation of blocks/transactions start, progress, or finish
  • blocks are written to disk

• Process the logs into a performance profile

• Add a test for comparing a new profile to the previous profile

  • This test could fail if the entire sync or any steps are far slower than expected