[pkg/stanza] json_parser is a GC hot spot

[atoulme]

Component(s)

pkg/stanza

What happened?

Description

json_parser is a hot spot under high load as it allocates too many objects.

The problem is exacerbated by the json library used as it is not optimized to handle the creation of a []byte slice that is not preallocated, creating many copies as it is resized.

https://github.com/json-iterator/go/blob/71ac16282d122fdd1e3a6d3e7f79b79b4cc3b50e/iter_str.go#L35

Steps to Reproduce

Expected Result

Actual Result

Collector version

v0.103.0

Environment information

Environment

OS: (e.g., "Ubuntu 20.04")
Compiler(if manually compiled): (e.g., "go 14.2")

OpenTelemetry Collector configuration

No response

Log output

No response

Additional context

No response

[github-actions]

Pinging code owners:

• pkg/stanza: @djaglowski

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