Monitor performance

[letmaik]

We should define some performance metrics and monitor them similar to how CCF does in their repository.

Metrics could be:

• Throughput on POST /entries
  • did:web using cached resolution
  • X.509
• Throughput on GET /entries/<txid>/receipt
  • Cached historical transaction
• Latency as time to receipt following POST /entries
  • Uncached did:web, requires at minimum two calls to POST /entries, followed by one or more GET /entries/<txid>/receipt until receipt is ready
  • Cached did:web, requires one call to POST /entries, followed by one or more GET /entries/<txid>/receipt
  • X.509, same as cached did:web
  • Note: Measuring latency is tricky as it relies on some parameters like CCF's tree signing interval (configurable) and the client delay between retries both for POST /entries in the case of uncached did:web and for receipt fetching.
• Memory usage after inserting a large number of entries
  • Single issuer
  • Many issuers
  • With/without prefix tree

Using a small claim payload size for now is probably fine, like 1 KB.