swebhdfs and livy

#1

Hello,
I m trying to use the Secured WebHDFS node in order to then use the Create Spark Context with livy, but it is not clear how this node has to be setup, I m having this error message Unexpected HTTP response: code=404 != 200, op=GETFILESTATUS, message=Not Found (IOException) but it s unclear where I can set up the url for connecting .
Is there a way we can have acces to the source code of this node so I can understand what is the purpose of all the parameter ?

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#2

Hi @jclaude,
welcome to the community.

Could you give me some context to the cluster setup? Are you sure you have WebHDFS enabled in the cluster?

The URL is given with the host name in the configuration of the node. With the host name and the given port we create the connection URL.
You can test your settings by clicking the “Test Connection” Button in the Secured HDFS node.

best Mareike

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#3

Hi Mareike,
Yes webhdfs is up and working I can use it thru any webbrowser thru this url
https://HOSTNAME:8443/gateway/default/webhdfs/v1/tmp?op=LISTSTATUS

The error I mention previously is happening when I click on the button, error 404 means bad url so I suspect that this is second part of the url that is incorrect, but I don’t know how to set it up properly on the node ?

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#4

@jclaude
the KNIME Big Data Extensions do not support KNOX gateway access yet. A possible workaround could be to use the REST nodes in KNIME to directly work with the KNOX REST API for webHDFS.

best Mareike

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