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https://issues.apache.org/jira/browse/KAFKA-1715?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14369322#comment-14369322
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Adrian Preston commented on KAFKA-1715:
---------------------------------------
Hi [~joestein], I found this bug via the 'newbie' label - and so I hope you
don't mind if (as a newbie) I ask for a bit of advice on how best to resolve
the problem.
To confirm my understanding: it sounds like there are situations where a broker
can advertise a hostname in ZooKeeper that resolves to an address which isn't
reachable by clients and/or the other brokers in the cluster? Looking at the
code (in KafkaHealthcheck) it appears that the hostname supplied to ZooKeeper
is either:
# taken from the 'advertised.host.name' property,
# taken from the 'host.name' property, or
# as a last resort, obtained by calling
InetAddress.getLocalHost.getCanonicalHostName.
For situations where a user has specified the 'advertised.host.name' or
'host.name' properties, I think the user must take on the remedial work of
updating server.properties with new values. So the question I've been
pondering is: "is there a better way to pick a default than calling
InetAddress.getLocalHost.getCanonicalHostName?" - and I don't think there is.
The Java network libraries provide the ability to enumerate local addresses and
query various attributes of an address (e.g. "is this a loopback address?" -
but I can't think of a heuristic that is a guaranteed improvement. More over,
I'd be worried that anything I did come up with would introduce "exciting" new
failure modes - when it encountered an obscure network configuration.
Thus the best resolution I can come up with is to log the hostname advertised
in ZooKeeper - so that this information is easily accessible to anyone
troubleshooting a connectivity problem. Optionally Kafka could also log a
warning if Java reports that this hostname resolves to a loopback address.
What do you think?
> better advertising of the bound and working interface
> -----------------------------------------------------
>
> Key: KAFKA-1715
> URL: https://issues.apache.org/jira/browse/KAFKA-1715
> Project: Kafka
> Issue Type: Bug
> Reporter: Joe Stein
> Labels: newbie
> Fix For: 0.8.3
>
>
> As part of the auto discovery of brokers and meta data messaging we should
> try to advertise the interface that is bound and working better.
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