while (!responderClosed && dfsClient.clientRunning && !isLastPacketInBlock) {
// process responses from datanodes.
try {
// read an ack from the pipeline
long begin = Time.monotonicNow();
ack.readFields(blockReplyStream);
long duration = Time.monotonicNow() - begin;
if (duration > dfsclientSlowLogThresholdMs
&& ack.getSeqno() != Packet.HEART_BEAT_SEQNO) {
DFSClient.LOG
.warn("Slow ReadProcessor read fields took " + duration