consumer_load_aware

Load-aware sticky consumer example

This example demonstrates the sarama.SubscriptionUserDataBalanceStrategy interface (see issue #3505). A LoadAwareSticky strategy wraps the built-in sticky assignor and injects a fresh LoadSample (CPU percent, in-flight count, lag) into the member's JoinGroup subscription metadata on every rebalance cycle.

Plan and AssignmentData are delegated unchanged to the sticky strategy; this example deliberately keeps the assignor logic simple to focus on the per-cycle metadata hook. A production load-aware assignor would also implement its own Plan and decode each member's UserData on the leader to weight the assignment.

Run

$ go run . -brokers="127.0.0.1:9092" -topics="sarama" -group="example"

Files

• load_aware_sticky.go — the wrapper strategy that implements SubscriptionUserDataBalanceStrategy.
• main.go — minimal consumer group runner that wires the strategy in via Config.Consumer.Group.Rebalance.GroupStrategies.