Performance evaluation of the agent

[vigneshshanmugam]

This will be an ongoing task that we will be working on at regular intervals to improve the overall performance of the agent and also continuously adding metrics to the benchmark runner that would help us identify bottlenecks introduced by the agent going forward

• [ ] Add onload event handler delay introduced by the agent. For page-load transactions we do a lot of processing on the onload event and we could measure that time and use it in benchmarks

[saurabhnanda]

@vigneshshanmugam please let me know if this is not the right place to ask such questions.

I'm trying to understand what the current benchmarks really mean, especially:

• Total CPU Time
• Agent CPU Time

Do the numbers given at https://github.com/elastic/apm-agent-rum-js/blob/15760cf0929c292dca83cda3eeefa433cec91e71/packages/rum/test/benchmarks/BENCHMARKS.md mean that the RUM agent is adding a 10-17 second overhead?

[rainydayDY]

I have a question that page-load trigger too early，if my website render too lower，the 'largest-contentful-paint' doesn't trigger, or only trigger once, but the page-load trigger, the 'largest-contentful-paint' time will not correct const sendPageLoadMetrics = () => { // to make sure PerformanceTiming.loadEventEnd has a value setTimeout(() => tr.removeTask(PAGE_LOAD)) } There's something wrong with that logic

[paulb-elastic]

Issue for the "...page load trigger too early..." problem raised separately under https://github.com/elastic/apm-agent-rum-js/issues/1162 and fixed in https://github.com/elastic/apm-agent-rum-js/pull/1190