What is WriteTxnMarkers?
After EndTxn, the transaction coordinator sends this internally (never user code) to write COMMIT or ABORT markers to every partition in the transaction. Consumers in read_committed mode are unblocked partition-by-partition as markers arrive, so a slow partition can delay consumption even if all others are done.
Wire Diagram
Response Header · flexible
message_size
int32 · 4B
correlation_id
int32 · 4B
tagged
var
WriteTxnMarkersResponse v1
tagged
var
ProducerId
int64 · 8B
tagged
var
Name
string (compact)
tagged
var
PartitionIndex
int32 · 4B
ErrorCode
int16 · 2B
tagged
var
Schema & Example
Schema { "Markers": [{ "ProducerId": int64, "Topics": [{ "Name": string, "Partitions": [{ "PartitionIndex": int32, "ErrorCode": int16 }] }] }] }
Example { "Markers": [{ "ProducerId": 0, "Topics": [{ "Name": "orders", "Partitions": [{ "PartitionIndex": 3, "ErrorCode": 0 }] }] }] }