Cherry-pick mrtheb/kafka-python 2b016b69

Set FetchRequest MaxBytes value to bufsize instead of fetchsize (=MinBytes)

kafka/consumer.py

@@ -359,7 +359,10 @@ class SimpleConsumer(Consumer):
         fetch_size = self.fetch_min_bytes
 
         while True:
-            req = FetchRequest(self.topic, partition, offset, fetch_size)
+            # use MaxBytes = client's bufsize since we're only
+            # fetching one topic + partition
+            req = FetchRequest(
+                self.topic, partition, offset, self.client.bufsize)
 
             (resp,) = self.client.send_fetch_request([req],
                                     max_wait_time=self.fetch_max_wait_time,

kafka/util.py

@@ -38,7 +38,8 @@ def read_short_string(data, cur):
 
 def read_int_string(data, cur):
     if len(data) < cur + 4:
-        raise BufferUnderflowError("Not enough data left")
+        raise BufferUnderflowError(
+            "Not enough data left to read string len (%d < %d)" % (len(data), cur + 4))
 
     (strLen,) = struct.unpack('>i', data[cur:cur + 4])
     if strLen == -1:
@@ -46,7 +47,8 @@ def read_int_string(data, cur):
 
     cur += 4
     if len(data) < cur + strLen:
-        raise BufferUnderflowError("Not enough data left")
+        raise BufferUnderflowError(
+            "Not enough data left to read string (%d < %d)" % (len(data), cur + strLen))
 
     out = data[cur:cur + strLen]
     return (out, cur + strLen)
@@ -68,7 +70,6 @@ def group_by_topic_and_partition(tuples):
     return out
 
 
-
 class ReentrantTimer(object):
     """
     A timer that can be restarted, unlike threading.Timer