question Re: How to load data from cassandra into NIFI in Support Questions

How to load data from cassandra into NIFI

adib_elaraki — Sun, 18 Aug 2019 09:28:49 GMT

Hello,

I want to use the querycassandra processor, but i'm facing some troubles. I'm trying to do some very basic actions which is selecting all rows from a table and then send them to another ExcecuteStream processor(java program).

Here is the table :

Here is the processor configuration. I've also added the port 9042 to the HDP sandbox both from the port forwarding table and the start_sandbox script:

username/password: cassandra

a global schema showing the error:

all host(s) tried for query failed (tried: /127.0.0.1:9042 (com.datastax.driver.core.exceptions.TransportException:[/127.0.0.1] Cannot connect)

Re: How to load data from cassandra into NIFI

mqureshi — Sat, 20 May 2017 00:23:10 GMT

@amine adi

So Cassandra is running on same node as Nifi? Is that right?

Re: How to load data from cassandra into NIFI

adib_elaraki — Sat, 20 May 2017 00:26:14 GMT

Cassandra is running on my linux host, and nifi is installed as a service in my HDP sandbox.

Re: How to load data from cassandra into NIFI

ssahi — Sat, 20 May 2017 04:52:23 GMT

@amine adi

I'm guessing that the ports are closed. If you are using the HDP Sandbox, the Sandbox is now Dockerized within the VM. You may want to add the Cassandra ports that you are using do both the VirtualBox Port Forwarding Section, and, you'll also have to edit some of the Docker scripts. Fortunately, there is a very good step by step tutorial here: https://community.hortonworks.com/articles/65914/how-to-add-ports-to-the-hdp-25-virtualbox-sandbox.html

As always, if you find this post useful, don't forget to "accept" the answer.

Re: How to load data from cassandra into NIFI

adib_elaraki — Sat, 20 May 2017 20:30:56 GMT

Thanks @Sonu Sahi for your reply, but i've already done this and the error persist 😕

Re: How to load data from cassandra into NIFI

mqureshi — Sun, 21 May 2017 11:49:17 GMT

@amine adi

For nifi "127.0.0.1" is its own host. Not your linux host. How do you connect to linux host from your sandbox? For example if you want to scp a file from your sandbox to your linux host, what ip address/host name wil you use? Use that instead of 127.0.0.1 from Nifi to connect to Cassandra.

Re: How to load data from cassandra into NIFI

adib_elaraki — Sun, 18 Aug 2019 09:28:24 GMT

here are my interface configuration both from my linux host, and my hortonworks sandbox where nifi belongs:

Thanks again !