long totalRequestSize = buf.length;
int offset = 0;
// Here we read in the header. We avoid having pb
// do its default 4k allocation for CodedInputStream. We force it to use backing array.
CodedInputStream cis = CodedInputStream.newInstance(buf, offset, buf.length);
int headerSize = cis.readRawVarint32();
offset = cis.getTotalBytesRead();
RequestHeader header = RequestHeader.newBuilder().mergeFrom(buf, offset, headerSize).build();
offset += headerSize;
int id = header.getCallId();
if (LOG.isTraceEnabled()) {