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https://issues.apache.org/jira/browse/KAFKA-691?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Maxime Brugidou updated KAFKA-691:
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    Attachment: KAFKA-691-v1.patch

Here is a first draft (v1) patch.

1. Added the consumer property "producer.metadata.refresh.interval.ms" defaults 
to 600000 (10min)

2. The metadata is refreshed every 10min (only if a message is sent), and the 
set of topics to refresh is tracked in the topicMetadataToRefresh Set (cleared 
after every refresh) - I think the added value of refreshing regardless of 
partition availability is to detect new partitions

3. The good news is that I didn't touch the Partitioner API, I only changed the 
code to use available partitions if the key is null (as suggested by Jun), it 
will also throw a UnknownTopicOrPartitionException("No leader for any 
partition") if no partition is available at all

Let me know what you think about this patch. I ran a producer with that code 
successfully and tested with a broker down.

I now have some concerns about the consumer: the refresh.leader.backoff.ms 
config could help me (if i increase it to say, 10min) BUT the rebalance fails 
in any case since there is no leader for some partitions

I don't have a good workaround yet for that, any help/suggestion appreciated.
                
> Fault tolerance broken with replication factor 1
> ------------------------------------------------
>
>                 Key: KAFKA-691
>                 URL: https://issues.apache.org/jira/browse/KAFKA-691
>             Project: Kafka
>          Issue Type: Bug
>    Affects Versions: 0.8
>            Reporter: Jay Kreps
>         Attachments: KAFKA-691-v1.patch
>
>
> In 0.7 if a partition was down we would just send the message elsewhere. This 
> meant that the partitioning was really more of a "stickiness" then a hard 
> guarantee. This made it impossible to depend on it for partitioned, stateful 
> processing.
> In 0.8 when running with replication this should not be a problem generally 
> as the partitions are now highly available and fail over to other replicas. 
> However in the case of replication factor = 1 no longer really works for most 
> cases as now a dead broker will give errors for that broker.
> I am not sure of the best fix. Intuitively I think this is something that 
> should be handled by the Partitioner interface. However currently the 
> partitioner has no knowledge of which nodes are available. So you could use a 
> random partitioner, but that would keep going back to the down node.

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