[KAFKA-1137] Problem of FetchRequest API

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 0.8.0
• Component/s: consumer
• Assignee: Neha Narkhede
• Reporter: aio
• Created: 21/Nov/13 02:56
• Updated: 04/Feb/14 21:12
• Resolved: 21/Nov/13 23:38

Description

We meet this problem when use Fetch API [0] in Node.js client [1]. The detail of the problem as follow:
Send 2 FetchRequest in sequence through one long polling socket connection, each request hold one different topic (topic1 and topic2), topic2 is sent after topic1,MaxWaitTime set 30s, MinBytes set 1 byte. As the protocol doc said, when topic has new produced message, Kafka server would write back response to the socket, but the fact is Kafka server write response only when the last topic (topic2) has new message, otherwise we have to wait 30s to get the fetchResponse of topic1.

I think Kafka server only approve the the MaxWaitTime in last FetchRequest of one socket connection, but why respond the new message in all topic when the last request have message.

[0] : https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-FetchRequest
[1] : https://github.com/SOHU-Co/kafka-node