Github user ggevay commented on the pull request:
https://github.com/apache/flink/pull/581#issuecomment-94310035
Thank you for your comments. I am very sorry for not replying earlier, but
I was extremely busy this week with other things. I will try to address the
issues that you mentioned:
> It supports only java.io.Serializable types. This is a bit inconsistent
with the current type handling and serialization in Flink. Some types that work
in all other parts do not work here.
Sorry, I will fix this.
> It does not work in a cluster. It sends "localhost" as the name to the
worker who should send the data back. In any non-local setup, this cannot work.
It doesn't send "localhost". It sends
InetAddress.getLocalHost().getHostName(), which will be some real hostname of
the machine. (Something like the "hostname" Linux command would give.)
> It requires the worker to be able to connect to the client. This may be
tricky, when the client and workers do not run both in the cluster.
If I put this in "contrib", as you suggested later, is it then an
acceptable assumption that the worker should be able to connect to the client,
or should I find some other way to make the connection?
> Selecting the proper interface that opens the port for data communication
is actually quite tricky.
I will modify the code to open the server in a way that it listens on all
interfaces. (Actually, it already does that. bind(null) binds the socket to
0.0.0.0 (which means to listen on all interfaces), according to the JDK source
code. But the Java API documentation doesn't say this explicitly, so I will use
the ServerSocket constructor instead (with null as bindAddr), for which the
documentation agrees with the source that it will listen on all interfaces.) I
will also take a look at how the TaskManager does this.
> What about reworking this as a library function and add it to
flink-contrib?
OK, I will make the modification.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
