abhishekrb19 opened a new issue, #19018: URL: https://github.com/apache/druid/issues/19018
### Motivation We have high throughput and high QPM in some environments and we use query prioritization strategy to prioritize some query workloads over others. However, the query prioritization and [routing](https://druid.apache.org/docs/latest/configuration/#query-routing) strategy is currently only configurable on the Brokers/Historical servers. Peons launch with a default server priority of 0, meaning all peon servers are eligible to serve all queries, regardless of the strategy defined on the Brokers. As a result, workload isolation doesn't apply here since real-time servers aren't segmented by priority in the same way as Historicals and Brokers. ### Proposed changes To enable priority-aware replica allocation for Peon servers, we can introduce a new supervisor spec property, `serverPriorityToReplica`. This allows the existing Broker-side prioritization strategy to extend naturally to Peons without additional architectural changes. For example, `serverPriorityToReplica: {"1": 2, "0": 1}` will launch 2 CliPeon servers with priority 1 and 1 CliPeon server with priority 0. In this setup: - Tasks with `serverPriority = 1` would have higher fault tolerance and availability - Tasks with `serverPriority = 0` would have a single replica and lower fault tolerance This will work with the following Broker configurations and provide isolation: ```properties druid.broker.select.tier=custom druid.broker.select.tier.custom.priorities=[0] ``` or a different isolated broker that will route queries to Peons with priority 1: ```properties druid.broker.select.tier=custom druid.broker.select.tier.custom.priorities=[1] ``` ### Operational impact None. By default, this property when unspecified will be null. Operators using the existing `replicas` configuration will continue to work as before, with all replicas assigned to the default server priority 0. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
