[IOTDB-373] [Distributed] Query coordinating

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Labels: distributed
• Assignee: Unassigned
• Reporter: Tian Jiang
• Created: 17/Dec/19 12:38
• Updated: 30/Oct/20 02:55

Description

When using more than one replicas, query options are enriched and complicated. To ensure load balancing, we may have to choose the node with lowest load to perform the query, which requests knowing the load of each node and a formula to rank the nodes based on their status.

We can also issue the same query to multiple replicas and pick up the fastest one to respond to the user as MapReduce has done. But this may result in resource wasting unless we feasibly support quick query cancellation.

In a word, we should decide which replica(s) to serve a query and what information we need to collect to make the decision.

Issue Links

• is a child of: IOTDB-68 IoTDB supports distributed version