2 posts tagged with "tools"

This blog post has been authored by José Dapena Paz (Igalia), with contributions from Jason Williams (Bloomberg), Ashley Claymore (Bloomberg), Rob Palmer (Bloomberg), Joyee Cheung (Igalia), and Shu-yu Guo (Google).

In this post about V8 heap snapshots, I will talk about some performance problems found by Bloomberg engineers, and how we fixed them to make JavaScript memory analysis faster than ever.

The problem​

Bloomberg engineers were working on diagnosing a memory leak in a JavaScript application. It was failing with Out-Of-Memory errors. For the tested application, the V8 heap limit was configured to be around 1400 MB. Normally V8’s garbage collector should be able to keep the heap usage under that limit, so the failures indicated that there was likely a leak.

The past three months have been an awesome learning experience for me as I've joined the V8 team (Google London) as an intern, and have been working on a new tool called Indicium.

This system analyzer is a unified web interface to trace, debug and analyse patterns of how Inline Caches (ICs) and Maps are created and modified in real-world applications.

V8 already has a tracing infrastructure for ICs and Maps which can process and analyse IC events using the IC Explorer and Map events using Map Processor. However, previous tools didn't allow us to analyze maps and ICs holistically and this is now possible with system analyzer.