Regards community,
I want to deploy a cluster of Cassandra DB on EC2 -AWS.
I followed these tutorials without problem: http://datascale.io/how-to-create-a-cassandra-cluster-in-aws/ http://datascale.io/how-to-create-a-cassandra-cluster-in-aws-part-2/
However my nodes (instances), can't be accessed from outside (DataStax DevCenter App / Linux CLI), although they have public IP and that the security group have the necessary ports open.
> The specified host(s) could not be reached. All host(s) tried for
> query failed (tried: /52.91.81.107:9042
> (com.datastax.driver.core.TransportException: [/52.91.81.107:9042]
> Cannot connect)) [/52.91.81.107:9042] Cannot connect My configuration
> file cassandra.yaml of node1:
cluster_name: ‘DataScale Demo Cluster’
seeds: “Public IP Node 1,Public IP Node 2”
broadcast_address: Public IP Node 1
listen_address:
I have doubts if I also need to modify the rpc_address (default localhost)?
Any suggestions?
Thank you so much
The listen_address and rpc_address should both be the private IP address.
Clients will then be able to access the cluster via the public IP address.
Related
I try to build Cassandra cluster with 3 nodes
On node 1 i've got a trouble when i try use cqlsh:
Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})
In cassandra.yaml i dont't see strings with ip 127.0.0.1, i wrote there correct parametres (in my mind)
cluster_name: 'cassandra_cluster'
seeds: "node_public_ip_1,node_public_ip_2,node_public_ip_3"
listen_address: node_public_ip_1
rpc_adress: node_public_ip_1
in cassandra-topology.properties:
`# Cassandra Node IP=Data Center:Rack`
node_public_ip_1=dc1:rac1
node_public_ip_2=dc1:rac1
node_public_ip_3=dc1:rac1
What i do wrong?
Thanks!
When you run cqlsh without specifying the host, it defaults to localhost (127.0.0.1). You need to specify the client IP address (rpc_address) of the node you want to connect to when running cqlsh.
Also, the standard recommendation for multi-homed servers is to use the private IP for internal cluster comms and the public IP for client connections. This means that in cassandra.yaml you would configure:
listen_address: private_ip
rpc_address: public_ip
Since the seeds are used for seeding cluster communication, you would also configure the seeds list with the nodes' private IP addresses.
Finally, if you're using the old PropertyFileSnitch, you should also configure cassandra-topology.properties with the nodes' private IP addresses.
However, PFS is really old and in almost all cases our recommendation is to use GossipingPropertyFileSnitch since it has all the benefits of being able to expand the cluster in the future without any downsides as I've explained in this post -- https://community.datastax.com/questions/8887/.
It is also a lot simpler to manage GPFS since you only need to set a single node's DC and rack configuration in cassandra-rackdc.properties without having to reconfigure all the nodes whenever you add/remove nodes from the cluster.
When you do switch to GPFS, you should delete cassandra-topology.properties on the nodes to prevent any gossip issues in the future as I've explained in this post -- https://community.datastax.com/questions/4621/. Cheers!
Try run the "nodetool status" and "nodetool describecluster" on both nodes of this cluster to identify the IP used by nodes.
and try connect passing the host/ip. like:
cqlsh <host> <port> -u <user> -p <password>
I would like to know about configuration parameters of cassandra.yaml namely,
listen_address
broadcast_address
rpc_address
broadcast_rpc_address
on individual nodes in a particular scenario.
Scenario: 6-node cluster with respective private IPs but only one node has a public IP.
Requirement: remote python application to access the cluster
What I have tried on each node:
listen_address: respective private IP
broadcast_address: blank
rpc_address: blank
except on node with public ip as 0.0.0.0
broadcast_rpc_address: blank except on node with public ip as its public ip
I tried issuing from my application Cluster(['public ip'], port=9042) but I received the warning which eventually led to shutting down my application:
WARNING:cassandra.cluster:Failed to create connection pool for new
host 192.xxx.xx.3:
I recommend adding two interfaces to each machine.
One of them is listen_address
and one for the rpc_address.
in this approach, you don't use as broadcast_rpc_address.
but, if you use for public ip you have to put a general address for all nodes. Only one of them can not have a public address.
Problem while Creating cluster using cassandra:-
I follow the below steps for creating a Cassandra cluster:-
1.Installed cassandra in 3 Windows-7 PCs.
PC IPAddress-127.0.0.1,127.0.0.2,127.0.0.3
2.Modified the cassandra.yaml file as below.
cluster_name: 'MyCluster'
num_tokens: 256
seed_provider: - seeds: "127.0.0.1"
listen_address: 127.0.0.1,127.0.0.2,127.0.0.3
rpc_address: 0.0.0.0
3.start the Cassandra in all the above 3 PCs.
but I am not getting more than 1 Node in Node tool. I can see only one node.
I have installed datastax-community-64bit_2.0.3
So, Please help me to solve this problem. I need to create Cassandra cluster.
Thanks in Adavance,
Satya
You have follow all the steps for creating cluster,but you have to define firewall inbound rule for allowing the port.(by default these ports are not allowed by firewall).So after modifying the "cassandra.yaml" file,you have to set the port used in cassandra and datastax in your firewall,then start the cassandra service.
For adding port in firewall:
go to control panel->windows firewall->advanced setting->Inbound Rules->new Rule->select port and add all the ports require for the cassandra/datastax. google the require ports for cassandra/datastax.
The 127.x.x.x IP addresses you are using are all loopback device addresses. Traffic sent to those addresses never leaves your localhost. If you want the three hosts to discover each other you need to use IPs from some private IP address range. See this Wikipedia article for an overview. As your Windows workstations are networked, the IP number to use should be obvious from running ipconfig on the command line on each of the three workstations. Look for the output entry IPv4-Adress.
I created 3 instances with 3 Elastic IP addresses pointing to these instances.
I did a yum install of dsc:
dsc12.noarch 1.2.13-1 #datastax
And the /etc/cassandra/default.conf/cassandra.yaml has the:
- seeds: [Elastic IP list]
But when I start cassandra via "service cassandra start" I see in /var/log/cassandra/cassandra.log:
...
Exception encountered during startup: Unable to contact any seeds!
...
And sure enough "nodetool status" shows:
Failed to connect to '127.0.0.1:7199': Connection refused
BUT:
If I change the value of the seeds to use the "private IP" of the instance, cassandra starts just fine. I would expect it work just fine with the Elastic IP's, but it doesn't.
Do you know why that is?
The reason I want the Elastic IP's to work is that I know the IP address ahead of time, so that when I provision a machine with Puppet, I can pre-populate the seeds in cassandra.yaml file. I don't know the private IP address until after the machine has booted :(
This is almost a duplicate of: Cassandra on Amazon EC2 with Elastic IP addresses
I believe your problem comes from the seed IP's not being the same as the node's Broadcast IP's . To change this modify the following line in each of your Cassandra.yamls
# Address to broadcast to other Cassandra nodes
# Leaving this blank will set it to the same value as listen_address
broadcast_address: <node's elastic ip> #uncomment this line
I have installed Apache Cassandra on the remote Ubuntu server. How to allow remote access for an Apache Cassandra database? And how to make a connection?
Remote access to Cassandra is via its thrift port (although note that the JMX port can be used to perform some limited operations).
The thrift port is defined in cassandra.yaml by the rpc_port parameter, which defaults to 9160. Your cassandra node should be bound to the IP address of your server's network card - it shouldn't be 127.0.0.1 or localhost which is the loopback interface's IP, binding to this will prevent direct remote access. You configure the bound address with the rpc_address parameter in cassandra.yaml. Setting this to 0.0.0.0 says "listen on all network interfaces" which may or may not be suitable for you.
To make a connection you can use:
The cassandra-cli in the cassandra distribution's bin directory provides simple get / set / list operations and depends on Java
The cqlsh shell which provides CQL access to cassandra, this depends on Python
A higher level interface such as Apollo
For anyone finding this question now, the top answer is out of date.
Apache Cassandra's thrift interface is deprecated and will be removed in Cassandra 4.0. The default client port is now 9042.
As noted by Tyler Hobbs, you will need to ensure that the rpc_address parameter is not set to 127.0.0.1 or localhost (it is localhost by default). If you set it to 0.0.0.0 to listen on all interfaces, you will also need to set broadcast_rpc_address to either the node's public or private IP address (depending on how you plan to connect to Cassandra)
Cassandra-cli is also deprecated and Apollo is no longer active. Use cqlsh in lieu of cassandra-cli and the Java driver in lieu of Apollo.
I do not recommend making the JMX port accessible remotely unless you secure it properly by enabling SSL and strong authentication.
Hope this is helpful.
cassandra 3.11.3
I did the following to get mine working. Changes in cassandra.yaml :
start_rpc: true
rpc_address: 0.0.0.0
broadcast_rpc_address: ***.***.***.***
broadcast_rpc_address is the address of machine where cassandra is installed
seed_provider:
- class_name: ...
- seeds: "127.0.0.1, ***.***.***.***"
In seeds i added/appended the ip address of machine where cassandra was running.
I accessed it from windows using tableplus. In tableplus, I wrote the ip address of the cassandra machine, in the port section I wrote 9042 and used the username and password, which i used for ssh connection.
For anyone using Azure, the issue may be that you need to create a public ip address since the virtual ip points to the cloud service itself and not the virtual machine. You can find more info in this post