What is FindCoordinator?
The first step before any group or transaction operation: locates the group coordinator or transaction coordinator. A COORDINATOR_NOT_AVAILABLE response means the __consumer_offsets or __transaction_state partition leader is still being elected; retry with backoff.
Wire Diagram
Request Header · flexible
message_size
int32 · 4B
api_key
int16 · 2B
api_version
int16 · 2B
correlation_id
int32 · 4B
client_id
string (compact)
tagged
var
FindCoordinatorRequest v3
Key
string (compact)
KeyType
int8 · 1B
tagged
var
Schema & Example
Schema { "Key": string, "KeyType": int8 }
Example { "Key": "retention.ms", "KeyType": 1 }