Downsampling in query service?

[yurishkuro]

It seems we have the wrong scope of these flags, what meaning do they have for the query service?

$ SPAN_STORAGE_TYPE=memory go run ./cmd/query help
...
      --downsampling.hashsalt string               Salt used when hashing trace id for downsampling.
      --downsampling.ratio float                   Ratio of spans passed to storage after downsampling (between 0 and 1), e.g ratio = 0.3 means we are keeping 30% of spans and dropping 70% of spans; ratio = 1.0 disables downsampling. (default 1)
...

[jpkrohling]

I can schedule some time to track this down.

[joe-elliott]

The query service adds storageFactory flags here:

jaeger/cmd/query/main.go

Line 144 in e677384

storageFactory.AddFlags,

which adds the downsampling flags here:

jaeger/plugin/storage/factory.go

Line 170 in e677384

func (f *Factory) AddFlags(flagSet *flag.FlagSet) {

A quick git blame suggests it has been this way for years. We could split these methods into AddReaderFlags and AddAllFlags? If that makes sense I'll submit a PR.

[yurishkuro]

We could split these methods into AddReaderFlags and AddAllFlags

+1

However, when archive storage is configured query can also write