如何使用python从gcloud集群连接Cassandra

Question

We try to connect cluster using bash script using Jupyter notebook :

!gcloud compute --project "project_name" ssh --zone "us-central1-a" "cassandra-abc-m"

After that we try to connect using :

import cql
con= cql.connect(host="127.0.0.1",port=9160,keyspace="testKS")

cur=con.cursor()
result=cur.execute("select * from TestCF")

How to inter-connect both? Kindly help me for it.

Answer 1

As I understand the question, you are SSHing out to a Google Compute (GCP) instance (running Cassandra) and are then trying to run a Python script to connect to the local node. I see two problems in your cql.connect line.

First, Cassandra does not use port 9160 for CQL. CQL uses port 9042. I find this point confuses people so much, that I recommend not setting port= at all . The driver will use the default, which should work.

Secondly, if you deployed Cassandra to a GCP instance, then you probably changed listen_address and rpc_address . This means Cassandra cannot bind to 127.0.0.1 . You need to use the value defined in the yaml's rpc_address (or broadcast_rpc_address ) property.

$ grep rpc_address cassandra.yaml
rpc_address: 10.19.17.5

In my case, I need to specify 10.19.17.5 if I want to connect either locally or remote.

tl;dr;

1. Don't specify the port.
2. Connect to your external-facing IP address, as 127.0.0.1 will never work.