How to configure Cassandra in GCP to remotely connect?

Question

I am following the below steps to install and configure Cassandra in GCP. It works perfectly as long as working with Cassandra within GCP.

$java -version
$echo "deb http://downloads.apache.org/cassandra/debian 40x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.sources.list
$curl https://downloads.apache.org/cassandra/KEYS | sudo apt-key add -
$sudo apt install apt-transport-https
$sudo apt-get update
$sudo apt-get install cassandra
$sudo systemctl status cassandra
//Active: active (running)
$nodetool status
//Datacenter: datacenter1
$tail -f /var/log/cassandra/system.log

$find /usr/lib/ -name cqlshlib
##/usr/lib/python3/dist-packages/cqlshlib
$export PYTHONPATH=/usr/lib/python3/dist-packages
$sudo nano ~/.bashrc
//Add 
export PYTHONPATH=/usr/lib/python3/dist-packages
//save
$source ~/.bashrc
$python --version
$cqlsh
//it opens cqlsh shell

But I want to configure Cassandra to remotely connect.

I tried the following 7 different solutions.

But still I am getting the error.

1.In GCP,
VPC network -> firewall -> create
IP 0.0.0.0/0
port tcp=9000,9042,8088,9870,8123,8020, udp=9000
tag = hadoop
Add this tag in VMs
2.rm -Rf ~/.cassandra
3.sudo nano ~/.cassandra/cqlshrc
[connection]
hostname = 34.72.70.173
port = 9042
4. cqlsh 34.72.70.173 -u cassandra -p cassandra
5. firewall - open ports
https://stackoverflow.com/questions/2359159/cassandra-port-usage-how-are-the-ports-used
9000,9042,8088,9870,8123,8020,7199,7000,7001,9160
6. Get rid of this line: JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname=localhost"
Try restart the service: sudo service cassandra restart
If you have a cluster, make sure that ports 7000 and 9042 are open within your security group.
7. you can set the environment variable $CQLSH_HOST=1.2.3.4. Then simply type cqlsh.
https://stackoverflow.com/questions/20575640/datastax-devcenter-fails-to-connect-to-the-remote-cassandra-database/20598599#20598599
sudo nano /etc/cassandra/cassandra.yaml
listen_address: localhost
rpc_address: 34.72.70.173
broadcast_rpc_address: 34.72.70.173
sudo service cassandra restart
sudo nano ~/.bashrc
export CQLSH_HOST=34.72.70.173
source ~/.bashrc
sudo systemctl restart cassandra
sudo service cassandra restart
sudo systemctl status cassandra
nodetool status

Please suggest how to get rid of the following error

Connection error: ('Unable to connect to any servers', {'127.0.0.1:9042': ConnectionRefusedE
rror(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})

score 0 · Answer 1 · answered Jul 21 '21 at 08:39

This indicates that when you ran cqlsh, you didn't specify the public IP:

Connection error: ('Unable to connect to any servers', \
  {'127.0.0.1:9042': ConnectionRefusedError(111, "Tried connecting to [('127.0.0.1', 9042)]. \
  Last error: Connection refused")})

When running Cassandra nodes on public clouds, you need to configure cassandra.yaml with the following:

listen_address: private_IP
rpc_addpress: public_IP

The listen address is the what Cassandra nodes use for communicating with each other privately, e.g. gossip protocol.

The RPC address is what clients/apps/drivers use to connect to nodes on the CQL port (9042) so it needs to be set to the nodes' public IP address.

To connect to a node with cqlsh (a client), you need to specify the node's public IP:

$ cqlsh <public_IP>

Cheers!

How to configure Cassandra in GCP to remotely connect?

1 Answers1