The thanos-query be configured to use the service for all instances or the service separated by shards

[debuggedme]

Why does the store need to be accessed by shard, while Prometheus-sidecar does not, and instead needs to access all replicas of all shards and then deduplicate?

[dosubot[bot]]

The difference between the sidecar and store gateway in Thanos lies in their roles and data handling:

• Sidecar: It connects to a Prometheus instance, reading its data for querying or uploading to cloud storage. It deduplicates data from Prometheus HA pairs by accessing all replicas of all shards, using external labels to identify and remove duplicates. This ensures a consistent view of metrics across all Prometheus instances.

• Store Gateway: It serves metrics from a cloud storage bucket, querying historical data stored in shards. The store gateway is accessed by shard to efficiently retrieve and serve this historical data.

The store is accessed by shard because it deals with data organized in shards within the cloud storage, optimizing retrieval and querying. In contrast, the Prometheus-sidecar accesses all replicas to deduplicate data, ensuring aggregated and consistent data from multiple Prometheus instances ^[1][2].

To continue talking to Dosu, mention @dosu.

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[debuggedme]

@dosu
Prometheus can also be deployed in a sharded mode.

[dosubot[bot]]

Hey @debuggedme! I see you're diving deep into Prometheus deployment strategies. While I can help with technical questions, bug fixes, and engineering insights, this particular query is a bit outside my wheelhouse. If you think I should tackle this, feel free to reach out to the Dosu Team. They'll know what to do! 😊

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[debuggedme]

https://github.com/thanos-io/kube-thanos/blob/v0.29.0/examples/all/manifests/thanos-query-deployment.yaml#L55-L57

I find it a bit strange that if everything is deployed in a sharded manner, the query rules are different.

[debuggedme]

@fpetkovski @yeya24

[MichaHoffmann]

Sidecars usually have Prometheus servers beside them and own their data. As a result two sidecars will not have the same data and the data needs to be deduplicsted - i.e if the Prometheus servers formed an HA pair.
Stores own the data in their buckets which comes from many sidecars or receivers or other sources. They don't need to be sharded but for performance reasons often are. They usually are operated as HA deployment that is registered as endpoint group since every store in the HA deployment has same data as all own the data in the bucket.

[MichaHoffmann]

Technically all data in querier is deduplicated as the querier doesn't really know which series the endpoints where it gets it's data from own ( outside of their external labels )

[debuggedme]

@MichaHoffmann Yes, I want to know if the Prometheus server is running in shard mode, should the exposed service be based on the shard's service (svc) or all instances services (svc) and then deduplicated by labels?

- --store=dnssrv+_grpc._tcp.thanos-sidecar-0.thanos.svc.cluster.local
- --store=dnssrv+_grpc._tcp.thanos-sidecar-1.thanos.svc.cluster.local
- --store=dnssrv+_grpc._tcp.thanos-store-0.thanos.svc.cluster.local
- --store=dnssrv+_grpc._tcp.thanos-store-1.thanos.svc.cluster.local

or

- --store=dnssrv+_grpc._tcp.thanos-sidecar(-headless).thanos.svc.cluster.local
- --store=dnssrv+_grpc._tcp.thanos-store(-headless).thanos.svc.cluster.local

I think both approaches might work. I'd like to know which one is more recommended.

What I don't understand is that the Prometheus server is configured based on services that retain all instances and deduplicate them according to labels, whereas the store-gateway is configured based on services for different shards in https://github.com/thanos-io/kube-thanos/blob/v0.29.0/examples/all/manifests/thanos-query-deployment.yaml#L55-L57.

- --store=dnssrv+_grpc._tcp.thanos-sidecar(-headless).thanos.svc.cluster.local
- --store=dnssrv+_grpc._tcp.thanos-store-0.thanos.svc.cluster.local
- --store=dnssrv+_grpc._tcp.thanos-store-1.thanos.svc.cluster.local

If my understanding is incorrect, please provide guidance.