example: using prometheus tags in custom metrics

[mathetake]

Signed-off-by: Takeshi Yoneda [email protected]

resolves #245

[mathetake]

@peterj @eitansuez maybe you guys are interested in this ? 😉

[eitansuez]

wonderful. thank you!

[hochuenw-dd]

Hi @mathetake, it seems in this example, we are running the wasm VM in each worker thread. Does the SDK automatically aggregate the counter metric if Envoy runs multiple worker threads? If not, do we need to run it in the main thread?
Thanks!

[mathetake]

All the metrics are aggregated by Envoy, so you don t need to care about that

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On Sun, Jun 12, 2022 at 12:09 Hochuen ***@***.***> wrote: Hi @mathetake <https://github.com/mathetake>, it seems in this example, we are running the wasm VM in each worker thread. Does the SDK automatically aggregate the counter metric if Envoy runs multiple worker threads? If not, do we need to run it in the main thread? Thanks! — Reply to this email directly, view it on GitHub <#246 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADHDJ6MTPTLZTMVMPFZALILVOVIGNANCNFSM5NQYFRDQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[hochuenw-dd]

I see. Thank you for the quick response! @mathetake
I was reading https://github.com/tetratelabs/proxy-wasm-go-sdk/blob/main/doc/OVERVIEW.md#terminology,

Wasm Service is a type of plugins running in a singleton VM (i.e. only one instance exists in the Envoy main thread). It is mainly used for doing some extra work in parallel to Network or Http Filters such as aggregating metrics, logs, etc. Sometimes, such a singleton VM itself is also called Wasm Service.

It does mention aggregating metrics in Wasm service, I'm curious what is the use case that we might have to aggregate metrics using Wasm Service?