Apache Cassandra remote access - cassandra

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For anyone finding this question now, the top answer is out of date.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Cassandra-cli is also deprecated and Apollo is no longer active.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

Related

How do I limit access to Cassandra from specific hosts?

I'm trying to control the access to Cassandra database so it can be accessed from specific hosts only (deny the access from not configured hosts ), I have the following configurations in cassandra.yaml file:-
start_rpc: true
rpc_address: 0.0.0.0
broadcast_rpc_address: x.x.x.x
rpc_port:9160
Are these configurations are correct or there is something missing? AND is there another way to access Cassandra from specific hosts?

Not sure which version of Cassandra you are using, but 9160 is for thrift protocol connections. It's been deprecated in Cassandra 3.0, and removed in Cassandra 4.0.
If it were me, I'd be closing that avenue of access by setting start_rpc: false.
All client connection requests should be using the CQL native binary protocol on port 9042 (9142 if client-to-node SSL is used in v4.0+).
control the access to Cassandra database so it can be accessed from specific hosts only
For this, your best option would be to filter with iptables on each node. Here's a resource which details how to do that. Basically, you'll need to ACCEPT connections to/from each IP address, on each node in the cluster:
Allow incoming connections from 192.168.0.1, only on port 9042:
iptables -A INPUT -s 192.168.0.1 --dport 9042 -j ACCEPT
Allow outgoing connections back to 192.168.0.1:
iptables -A OUTPUT -d 192.168.0.1 -j ACCEPT

I want to echo Aaron's comments. Thrift was deprecated and replaced by CQL in 2012. Support for Thrift in the Cassandra tools was dropped in 2014 (CASSANDRA-8358) and the Thrift RPC server was disabled by default since Cassandra 2.2 (CASSANDRA-9319).
Development on Thrift clients also ceased nearly 10 years ago. Nate McCall who is the current Chair of the Cassandra project and author of the Hector client closed it down in 2015 in preference for the Java driver so I wouldn't use Thrift anymore.
Instead of the Thrift server, you should configure the CQL native transport server. These are the properties you should focus on in cassandra.yaml:
listen_address: private_ip
rpc_address: public_ip
native_transport_port: 9042
If your nodes only have a single IP address, you can use it for both listen_address and rpc_address. It isn't really necessary to use broadcast_address unless you have a complicated network topology where nodes can only talk to nodes in a remote DC using public IP addresses, for example with EC2 multi-region deployments.
Your question isn't really about Cassandra but about networking. You need to talk to your network admin to configure the firewalls to only allow connections to port 9042 from the application servers. Cheers!

Cassandra 3.9, how to remote access [duplicate]

I have built Cassandra server 2.0.3, then run it. It is starting and then stopped with messages:
X:\MyProjects\cassandra\apache-cassandra-2.0.3-src\bin>cassandra.bat >log.txt
java.lang.RuntimeException: Unable to gossip with any seeds
at org.apache.cassandra.gms.Gossiper.doShadowRound(Gossiper.java:1160)
at org.apache.cassandra.service.StorageService.checkForEndpointCollision
(StorageService.java:416)
at org.apache.cassandra.service.StorageService.joinTokenRing(StorageServ
ice.java:608)
at org.apache.cassandra.service.StorageService.initServer(StorageService
.java:576)
at org.apache.cassandra.service.StorageService.initServer(StorageService
.java:475)
at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.ja
va:346)
at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon
.java:461)
at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.jav
a:504)
What I can change to run it?

I had a similar problem with my cassandra v2.0.4 cluster running a single node.
Check your cassandra.yaml and make sure that your "listen_address" and "seeds" values match, with the exception that the seeds value requires quotes around it.

You might get this problem if your private IP address is different than the public one (like on AWS). For example, the host thinks it's "172.31.0.2" when it's visible as "55.70.33.10".
The solution to this problem is:
listen_address: 172.31.0.2
broadcast_address: 55.70.33.10

in cassandra.yaml
Make sure your cluster_name entry match on all the nodes in the cluster
(you may need to delete your storage if you changed the cluster name)
Verify that all nodes can ping to each other
broadcast_rpc_address and listen_address should be set to local IP
(not localhost or 127.0.0.1)
seeds should point to the IP address of the seed(s)

If you are on AWS and use the Ec2MultiRegionSnitch you will need to set the seeds to the public IP addresses rather than the private IPs.

I had the same problem on Ubuntu 16.04. I'm not sure which of these changes made it work, where XXX.XXX.XXX.XXX is your public facing IP address, below are selections from cassandra.yaml
seed_provider:
# Addresses of hosts that are deemed contact points.
# Cassandra nodes use this list of hosts to find each other and learn
# the topology of the ring. You must change this if you are running
# multiple nodes!
- class_name: org.apache.cassandra.locator.SimpleSeedProvider
parameters:
# seeds is actually a comma-delimited list of addresses.
# Ex: "<ip1>,<ip2>,<ip3>"
- seeds: "XXX.XXX.XXX.XXX"
listen_address: XXX.XXX.XXX.XXX
broadcast_address: XXX.XXX.XXX.XXX
broadcast_rpc_address: XXX.XXX.XXX.XXX
listen_on_broadcast_address: true
start_rpc: true
rpc_address: XXX.XXX.XXX.XXX
I also needed to restart my Virtual Machine for some reason. ¯_(ツ)_/¯

For a quick single node setup on RHEL, I did the following:
Get info about your network interface setup:
# /sbin/ifconfig -a
It will list the interfaces and the ip addresses they are attached to.
Usually it will show an "Ethernet" interface and a "Local Loopback".
Get the associated ip addresses.
Then edit conf/cassandra.yaml:
rpc_address: [Local Loopback address]
broadcast_rpc_address: [Ethernet address]
listen_address: [Local Loopback address]
broadcast_address: [Ethernet address]
listen_on_broadcast_address: true
seed_provider:
- class_name: org.apache.cassandra.locator.SimpleSeedProvider
parameters:
- seeds: "[Ethernet address]"
Then also, open the correct ports on Linux firewall, being 9042, 7000 and 7001. More info about opening ports on Linux here:
http://ask.xmodulo.com/open-port-firewall-centos-rhel.html

in cassandra.yaml, I update the seed from domain name to IP address. and it works.

Happened to me because in my configuration the "intial_token" settings was specified (I think because I just copied to configuration file over from another cluster member). After clearing the data directory, commenting out the setting and restarting the node, it worked fine for me.

I experienced this error today...
I could not find any reason for the error other than timing issues.
I restarted many times and after a while it sticked. It looks like they expect a bi-directional communication on the gossip channel and if it does not happen quickly enough (which looks like a very small amount of time to me) then they drop the line and generate that error.
In my case I just upgraded my software and restarted the computer. So it was clearly not a connection issue between the computers (I have firewalls and SSL, to complicate matters) and the node was connected before... So the one entry I found in that regard from datastax did not apply...
https://support.datastax.com/hc/en-us/articles/209691483-Bootstap-fails-with-Unable-to-gossip-with-any-seeds-yet-new-node-can-connect-to-seed-nodes

I got the same error. There can be more than one solution. Hope my mistake is what you have done.
I had my localhost IP pointing to some domain name (and I did that in order that my Spring boot application's server context is some domain name like www.example.com:8080 instead of localhost:8080, and I had the following entry in my hosts file on Windows system).
127.0.0.1 www.example.com
While my cassandra batch file was looking for localhost which it didn't find. So, I made another entry for localhost too in my hosts file as:
127.0.0.1 localhost
127.0.0.1 www.example.com
After adding it, I opened new command prompt, ran cassandra batch from the cassandra bin directory and it then worked.

Disable the firewall and SELINUX and try again

In our case ssl was enabled, and cassandra.yaml configuration looks fine as per above comments. Then we enabled ssl debugging by by adding below jvm paramter in cassandra-env.sh -Djavax.net.debug=ssl:handshake
After starting the node again we noticed below in cassandra log file
MessagingService-Outgoing-geo2_host/xx.xx.xx.xx, Exception while
waiting for close javax.net.ssl.SSLHandshakeException: Received fatal
alert: certificate_unknown
After further investigating the ssl debug logs we got to know that the certificate was not valid. After fixing this ssl issue node was able to join the cluster.

Thanks to elvingt
His answer just remind me , I need to verify that all node needs to be able to talk to each other.
https://support.datastax.com/hc/en-us/articles/209691483-Bootstap-fails-with-Unable-to-gossip-with-any-seeds-yet-new-node-can-connect-to-seed-nodes
Gossip communications must be bi-directional.
To verify use this commnd, and you need test from BOTH SIDE
nc -vz {your_node_ip} 7000
Then I recollect that I turned on my ubuntu firewall last night. I open it by
sudo ufw allow 7000/tcp
And it is working now

Getting error during startup/bootstrap
Unable to gossip with any seeds
indicates there is some issue with broadcast_address. broadcast_address is responsible for communication with other nodes not with clients.
This address must be set in seed node(mandatory for seed node), If you are using cloud VMs you might have different IPs(public and private) hence its recommended to use your private IPs for broadcast_address this will save your n/w cost as well.
# Address to broadcast to other Cassandra nodes
# Leaving this blank will set it to the same value as listen_address
broadcast_address: 10.11.xx.xxx
In my scenario I was using IBM and once I set broadcast_address in seed nodes issue got resolved.
Please make sure you are starting your seed node first then other node, this order is mandatory.

in cassandra.yaml
changing listen_address value from localhost to domainName solved my issue

I had same issue, I checked port, used tcpdump, netcat to test connections and finally it comes to expired SSL certificates on internode_encryption. I modified internode_encryption to make it 'none', restarted all nodes and it worked.
Before all neighbor nodes were down. And node repair command was failing with:
"Did not get positive replies from all endpoints"
P.S Dont leave internode_encryption as none for a long time, just regenerate certs and enable it back.

Cassandra - What's the relation between 'start_rpc' and 'rpc_address' in cassandra.yaml

I'm using cassandra 3.6.
The names seem to implying me that I need to enable start_rpc before set rpc_address.
I try disable start_rpc and set rpc_address to my local network address 192.168.201.144 ,my cluster is still working but I need to use CQLSH_HOST=192.168.201.144 apache-cassandra-3.6/bin/cqlsh in order to connect to cassandra.
What's the relation between them?

If you want to start rpc service, you need modify them together:
start_rpc: true
rpc_address: 192.168.XXX.XXX
Rpc_address is the listen address for client connections (Thrift RPC service and native transport).Valid values are:
unset:
Resolves the address using the hostname configuration of the node. If left unset, the hostname must resolve to the IP address of this node using /etc/hostname, /etc/hosts, or DNS.
0.0.0.0:
Listens on all configured interfaces, but you must set the broadcast_rpc_address to a value other than
0.0.0.0.
IP address
hostname

How to create a Cassandra node Cluster in Windows7 pcs?

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.

Connecting to BAM internal cassandra

Now I am trying BAM 2.3.0 and I want to know the way to connect to BAM internal Cassandra from different server. Is it possible or it is tightly coupled?

No it is not tightly coupled. Similar to making standalone Cassandra cluster you must do the configuration but since you not creating a cluster but to access from external server no need to give seed addesses. Just configure the listen and rpc address. The location of the cassandra.yaml is BAM_HOME/repository/conf/etc.
In the cassandra.yaml change listen_address and rpc_address to your IP address. If you put 127.0.0.1 the Cassandra will only listen to the connections coming from the localhost, therefore you cannot access from outside.

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