CanalInstance canalInstance = canalInstances.get(clientIdentity.getDestination());
PositionRange<LogPosition> positionRanges = null;
positionRanges = canalInstance.getMetaManager().removeBatch(clientIdentity, batchId); // 更新位置
if (positionRanges == null) { // 说明是重复的ack/rollback
throw new CanalServerException(
String.format(
"ack error , clientId:%s batchId:%d is not exist , please check",
clientIdentity.getClientId(), batchId));
}