chore: update Fluent Bit status in readme

[l2dy]

Fluent Bit 1.7.0 has introduced multi-threading support. See fluent/fluent-bit#1567.

[bits-bot]

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[binarylogic]

@l2dy I took some time to look into Fluentbit's multi-threading support because I was curious. I had a difficult time finding the actual change that introduced this. I then realized this was an opt-in setting that must be perfectly balanced across all outputs to saturate all cores. Again (#10542), this does not embody the essence of the feature matrix, which is that the tool will vertically scale practically to enable the aggregator use case.

This is a great example of why we built Vector! 😄

[l2dy]

Meanings of each feature is unclear to me though. For example:

⚠ = Not interoperable, metrics are represented as structured logs

What software to interoperate with if only Vector is "interoperable"?

metrics are represented as structured logs

No longer true for Fluent Bit since v1.8, see https://fluentbit.io/announcements/v1.8.1/.

For a long time our community have asked for native metrics support. Despite Fluent Bit has metrics collectors for CPU, Disk I/O, Network, Memory and others the data payload was handled as a simple structured log, that is called ‘logs as metrics’. Now we are introducing ‘native metrics’.

[l2dy]

I then realized this was an [opt-in setting that must be perfectly balanced across all outputs to saturate all cores]

Fluentd requires similar configuration: flush_thread_count and Multi Process Workers. In this case, both are not as good as Vector is.