Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
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.