In this situation, queriers act as workers that pull jobs from the queue, execute them, and return the results to the query-frontend for aggregation.
We recommend that you run at least two query-frontend replicas for high-availability reasons.
Because the query-scheduler is a mandatory component when using the query-frontend, you must run at least one query-scheduler replica.
The following steps describe how a query moves through the query-frontend.
- A query-frontend receives a query.
- The query-frontend places the query in an queue by communicating with the query-scheduler, where it waits to be picked up by a querier.
- A querier picks up the query from the queue and executes it.
- A querier or queriers return the result to query-frontend, which then aggregates and forwards the results to the client.