4

I am trying to configure Cassandra with Drill. I used the same approach given on the link: https://drill.apache.org/docs/starting-the-web-ui/.

I used the following code for New Storage Plugin:

 {
  "type": "cassandra",
  "hosts": [
    "127.0.0.1"
  ],
  "port": 9042,
  "username": "<username>",
  "password": "<password>",
  "enabled": false
}

I have attached the Screenshot here.

But I'm getting the following error:

Please retry: Error (invalid JSON mapping)

How can I resolve this?

Abhishek Kumar
  • 53
  • 6

2 Answers2

3

All the code :

  1. Git: https://github.com/yssharma/drill/tree/cassandra-storage
  2. Patch: https://gist.github.com/yssharma/2581ae8a97c559b2677f

1. Get Drill: Lets get the Drill source

$ git clone https://github.com/apache/drill.git

2. Get Cassandra Storage patch/Download the Patch file from:

https://reviews.apache.org/r/29816/diff/raw/

3. Apply the patch on top of Drill $ cd drill $ git apply --check ~/Downloads/DRILL-92-CassandraStorage.patch $ git apply ~/Downloads/DRILL-92-CassandraStorage.patch

4. Build Drill with Cassandra Storage & export distribution to /opt/drill

$ mvn clean install -DskipTests
$ mkdir /opt/drill
$ tar xvzf distribution/target/*.tar.gz --strip=1 -C /opt/drill

5. Start Sqlline. That it we have finished with the Drill build and installation – and its time we can start using Drill.

$ cd /opt/drill
$ bin/sqlline -u jdbc:drill:zk=local -n admin -p admin
Drill-Sqlline

Hit ‘show schemas‘ to view existing schemas.

Drill-Sqlline-schemas

6. Drill Web interface You should be able to see the Drill web interface on localhost:8047, or whatever your host/port is.

Use this as your config:

 {
      "type": "cassandra",
      "config": {
        "cassandra.hosts": [
          "127.0.0.1",
          "127.0.0.2"
        ],
        "cassandra.port": 9042
      },
      "enabled": true
    }

Also, if this doesnt work, know that they are working on a plugin for it now: https://github.com/apache/drill/pull/1960

joe hoeller
  • 1,248
  • 12
  • 22
  • 4
    Adding some commentary will go a long way to explain why this solves the OP's question. Just a code dump alone is not that helpful. – SiKing Sep 22 '20 at 20:55
  • Sure, but all it seemed like he was missing the right json config based on his ask. Either way, i left something in full detail. – joe hoeller Sep 23 '20 at 21:23
  • 1
    The whole point of SO is not answering one person's question, but to have a repository of questions-answers for anybody that might be facing similar problems in the future. The extra commentary will serve those future visitors. Hence the entire voting system. See the [tour] for more info. – SiKing Sep 23 '20 at 21:40
  • Got it, that makes sense - thanks for explaining that because that is useful for answering future questions. – joe hoeller Sep 24 '20 at 22:16
1

I'll give an update here as well. We're doing some serious refactoring of the how Drill works with storage plugins. Specifically, we're working to incorporate the Calcite Adapter1 for Cassandra. The reason for this is that the hard part of storage plugins isn't the connection, it's the optimizations. Calcite already does query planning for Drill and already implemented a bunch of these adapters which means that the work of figuring out all the optimizations (AKA pushdowns) is largely done.

In the case of Cassandra/Scylla, this is particularly important because some filters should be pushed down to Cassandra, and some should absolutely not be pushed down. The adapters also include aggregate pushdowns--something which no Drill plugins currently do. Again the point of this is that once we commit this, the connector should work VERY will with Cassandra/Scylla. We have one for ElasticSearch that is very near completion and once that's done the Cassandra plugin is next. If you have any suggestions/comments or other feedback, please post on the pull request linked above.

** UPDATE 11 April 2021: Cassandra/Scylla Plugin Now Merged in Drill 1.19.0-SNAPSHOT **

cgivre
  • 513
  • 4
  • 21