I am trying to connect to a remote cassandra database using dbeaver.
I installed cassandra over an ubuntu machine from digital ocean, and I am running the dbeaver from my local machine.
When I leave the default /etc/cassandra/cassandra.yaml file, and then run the netstat -ntlp | grep 9420 I find that the connection is on and waiting for connection but once I update both the listen_address and the rpc_address to the public IP address of the remote machine, I found that I am no longer able to connect even locally to the database, using cqlsh cli.
What are the steps I should do to connect to a remote cassandra database, I read a lot of articles, but obviously there is something missing I can't understand
I currently have 3 machines, all bootcamped macs running Ubuntu, and am trying to set them up as a Hadoop cluster using CDH 5. While using the installer wizard, when it 'inspects the hosts for correctness I get the errors shown below.
The inspector fails on all hosts and it says
IOException thrown while collecting data from host: Connection refused
While setting up the machines the only thing I did before running the cloudera manager installer was enable ssh.
In the hosts file all have localhost and my user on 127.0.0.1
Any ideas on why the connection was refused orhat I could do to fix it?
I would recommend assigning static IP addressees to all 3 machines. After that, make sure your /etc/hosts file does not map your hostname to 127.0.1.1 as Ubuntu often does by default (just localhost should be bound to 127.0.1.1). Finally, verify that you can ping all the machines from each other.
I've just started working with Cassandra (datastax), version 2.1.3 and cqlsh version 5.0.1.
Cassandra starts up fine and the cluster is operational instantly.
Cqlsh is not working (on any of the nodes) and emits the following error:
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")})
I have tried starting cqlsh up with the hosts own ip, other hosts ip, different ports yet the result remains the same - always connection refused.
You need to edit cassandra.yaml on the node you are trying to connect to and set the node ip address for rpc_address and listen_address and restart Cassandra.
rpc_address is the address on which Cassandra listens to the client calls.
listen_address is the address on which Cassandra listens to the other Cassandra nodes.
Try to change the rpc_address to point to the node's IP instead of 0.0.0.0 and specify the IP while connecting to the cqlsh, as if the IP is 10.0.1.34 and the rpc_port left to the default value 9160 then the following should work:
cqlsh 10.0.1.34 9160
Or:
cqlsh 10.0.1.34
Also make sure that start_rpc is set to true in /etc/cassandra/cassandra.yaml configuration file.
If you check the system.log file for cassandra in /var/log/cassandra, you will see that this problem occurs because the rpc server has not started.
By default, the start_rpc is set to false in the cassandra.yaml file. Set it to start_rpc: true and then try again.
From Cassandra 3.0 onwards, start_rpc is set to true by default. https://docs.datastax.com/en/cassandra/3.0/cassandra/configuration/configCassandra_yaml.html
This is because of some pre-configurations in the cassandra. And to fix this, there are following commented lines in the cassandra-env.sh file:
#add this if you’re having trouble connecting:
#JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname=<public name>
where you have to start fixing the error.
Open the terminal and start fixing using the following easy steps:
Step-1
use
sudo nano /etc/cassandra/cassandra-env.sh
this command and search for JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname= uncomment the line by simply removing # attached in the start of the line.
NOTE: If you have never opened this file to fix this error then you will find JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname=<public name>
Step-2
Now replace <public name> with 127.0.0.1 or the server IP.
Step-3 Save the file and restart the cassandra using systemctl restart cassandra.service (if you haven't the server is alredy running). OR start the cassandra using systemctl start cassandra.service (if the server is not running).
Step-4 Check the status either by using sudo service cassandra status or systemctl status cassandra.service.
Note: Once check the system monitor whether cassandra is running there or not.
Try cqlsh now. It'll work.
Note: nano is editor you can use other editors you are comfortable with.
Look for native_transport_port in /etc/cassandra/cassandra.yaml
The default is 9842.
native_transport_port: 9842
For connecting to localhost with cqlsh, this port worked for me.
cqlsh 127.0.0.1 9842
It is a good idea to check the cassandra log if even the server is running. I was getting exactly the same message and unable to do anything with that and then I found out that there are errors in the log and the system is actually not working.
Silly, I know, but could happen...
Had same problem recently after downgrade from Cassandra 3.0 to Cassandra 2.2 on ArchLinux.
Unlike above solutions my problem wasn't in .cassandra, but version 3.0 left its configuration in /var/lib/cassandra directory.
Following commands solved my problem:
sudo rm -R /var/lib/cassandra
sudo rm -R /var/log/cassandra
sudo rm -R /usr/share/cassandra
Then i installed cassandra and everything worked again :)
Try to change the rpc_address to point to the node's IP instead of 0.0.0.0 and specify the IP while connecting to the cqlsh, as if the IP is 10.0.2.64 and the rpc_port left to the default value 9160 then the following should work:
cqlsh 10.0.2.64 9160
OR
cqlsh 10.0.2.64
Also make sure that start_rpc is set to true in /etc/cassandra/cassandra.yaml configuration file.
The first and foremost step to diagnose is to check the Cassandra logs.
Find out the process and there will be hints in the command line parameters to tell you where the logs files are.
ps aux | grep cassandra
In my case, it was in default location /etc/cassandra/conf/cassandra.yaml (if you installed the yum package).
Make sure three things are configured and configured the same host/ip.
listen_address - you may leave it blank it will default to hostname/first IP binding with eth0 network card
rpc_address - this is optional, leave blank if you want it to be same as listen_address
seeds - this is a double quoted string of comma-separated list of IP addresses or hostnames. This was default to a hardcoded "127.0.0.1", changing it to the same as list_address and restart of Cassandra service made it work for me.
References:
https://stackoverflow.com/a/42507530/416394
https://docs.datastax.com/en/dse/5.1/dse-admin/datastax_enterprise/config/configCassandra_yaml.html#configCassandra_yaml__seed_provider
I was experiencing the same issue with Cassandra 3.11.0, anytime I changed the address of rpc or listen address cqlsh wouldn't work. I had to add the same local ip to seeds
So after much trial and error my working cassandra.yml ended up like this:
class-name: org.apache.cassandra.locator.SimpleSeedProvider
parameters:
-seeds: "192.168.0.30"
listen_adress: 192.168.0.30
rpc_address: 192.168.0.30
For me it turned out that the service wasn't running at all.
Check with
service cassandra status
If you got the same error as I got, or another type, then messing around with IP addresses won't solve your problem at all.
The error I got:
cassandra dead but pid file exists
Edit: This was the solution for my problem: https://stackoverflow.com/a/46743119/3881406
try changing the native_transport_protocol to port 9160 (if it is set to anything other than 9160; it might be pointing to 9042). Check your logs and see on which port cassandra is listening for CQL clients?
Got into this issue for [cqlsh 5.0.1 | Cassandra 3.11.4 | CQL spec 3.4.4 | Native protocol v4] had to set start_native_transport: true in cassandra.yaml file.
For verification,
try opening tailf /var/log/cassandra/system.log file in one-tab
update cassandra.yaml
restart cassandra sudo service cassandra restart
In logfile is shows.
INFO [main] 2019-03-15 19:53:06,156 Server.java:156 - Starting listening for CQL clients on /10.139.45.34:9042 (unencrypted)...
I was trying to run it on a network drive. So I increased the client_timeout in cqlsh and it worked.
Make sure that you also set "seeds" to the address which you provided at "listen_address"
Try to telnet to the given address. In my case, there was a firewall in place blocking me.
When I installed Cassandra 3.11.1, I came across this problem. I checked the /var/log/cassandra/cassandra.log and found this error
Exception encountered during startup....It is a bug and already reported. The original post link https://issues.apache.org/jira/browse/CASSANDRA-14173.
The solution is to downgrade Cassandra to 3.0
download Cassandra rpm
curl -O
https://www.apache.org/dist/cassandra/redhat/30x/cassandra-3.0.15-1.noarch.rpm
or
wget
https://www.apache.org/dist/cassandra/redhat/30x/cassandra-3.0.15-1.noarch.rpm
rpm -ivh cassandra-3.0.15-1.noarch.rpm
service cassandra start
service cassandra status # check cassandra status
cassandra (pid 2322) is running...
cqlsh # start cassandra
cqlsh --cqlversion="3.4.0"
Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.0.9 | CQL spec 3.4.0 | Native protocol v4]
try the above command. It works for me.
First, you need to check the port 9042 whether this open or not if open then check below things like rpc_address and listen_address. you should set the server own IP address instead 0.0.0.0 or 127.0.0.1.
If all okay then please run below command to connect cqlsh.
cqlsh IP address 9042
If you enable authentication and authorization you have to put user/pass with this command.
Check for correct IP address in the cassandra.yaml file. Majority of times the error is due to incorrect IP address of your system also the username and password too.
After doing so initiate cqlsh by the command :-
cqlsh 10.31.79.1 -u cassandra -p cassandra
check what the CASSANDRA_HOME environment variable points to. I had a old version of cassandra to which it was set. I had reset to the 3.11.6 installation that I upgraded and it started working.
Another case that wasn't mentioned for receiving the Unable to connect to any servers error is were the Client-to-Node Encryption is enabled in the client_encryption_options block in the cassandra.yaml file.
In that case you need to add the --ssl flag in order to connect:
cqlsh --ssl.
I have a cassandra node at a machine. When I access cqlsh from the same machne it works properly.
But when I tried to connect to it's cqlsh using "192.x.x.x" from another machine, I'm getting an error saying
Connection error: ('Unable to connect to any servers', {'192.x.x.x': error(111, "Tried connecting to [('192.x.x.x', 9042)]. Last error: Connection refused")})
What is the reason for this? How can I fix it?
Probably the remote Cassandra node is not bound to the external network interface but to the loopback one (this is the default configuration). You can ensure this by using "telnet thecassandrahost 9042" from the remote machine, it should not work.
In order to bind Cassandra to the external network interface you need to edit the cassandra.yaml configuration file and set the properties "listen_address" and "rpc_address" to your remote IP or "0.0.0.0" (not all versions of Cassandra support wildcard addresses).
Check also that the firewall is properly configured or disabled (sudo service iptables stop).
Set the config parameter where this file is located. Possibly /etc/cassandra/cassandra.yaml.
cassandra.yaml
listen_address: 192.x.x.x
rpc_address: 192.x.x.x
Then, restart the service.
1.Update：./conf/cassandra.yaml
rpc_address: 0.0.0.0 ("0.0.0.0" allow anywhere IP,but you can appoint an IP)
\# broadcast_rpc_address: 1.2.3.4 (Delete comment if rpc_address=0.0.0.0)
2.restart
./bin/cassandra
Case: I met a problem that I can't remote access cassandra When I using java access cassandra
I got the same issue. And I am following answer in this post. Unfortunately, I have no luck to make it work. I did some research. And it works now. Here is my change.
Environment
Ubuntu Server 16.04.3 LTS on VirtualBox,
DSE version 5.1
Install DSE
I am installing DSE follow this page
https://docs.datastax.com/en/dse/5.1/dse-dev/datastax_enterprise/install/installGUIdse.html
Go to /etc/dse/cassandra/cassandra.yaml
Change 'seeds' from 127.0.0.1 to {seriver ip} exp. mine is 172.20.10.9
listen_address
In DSE 5.1 official document says 'Never specify 0.0.0.0; it is always wrong.'
What I did is comment out 'listen_address' setting
'rpc_address' change from localhost to 0.0.0.0
'broadcast_address' change to server IP. Mine is 172.20.10.9
'broadcast_rpc_address' change to server ip
restart dse wait for couple minute,it is changing. If still not work, restart machine.
This is my log in 15 seconds.
`ubuntu08#ubuntu08:~$ nodetool status
nodetool: Failed to connect to '127.0.0.1:7199' - ConnectException: 'Connection refused (Connection refused)'.
ubuntu08#ubuntu08:~$ nodetool status
Error: The node does not have system_traces yet, probably still bootstrapping
ubuntu08#ubuntu08:~$ nodetool status
Datacenter: SearchGraphAnalytics
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns Host ID Rack
UN 10.0.0.44 278.51 KiB 32 ? 19db0016-df63-4470-9921-f3b5fe4e9341 rack1
`
I can access by run 'cqlsh 172.20.10.9' from local or another machine.
This is another document for Cassandra https://docs.datastax.com/en/developer/java-driver/3.3/manual/address_resolution/
I had the same issue, I was not allowed to listen to 0.0.0.0 and Cassandra was running on a VM with Bridged network. The solution I found was to let the VM SSH to itself, port forwarding the port on the bridged network interface to localhost:
ssh -L 192.168.x.x:9042:127.0.0.1:9042 myvmuser#localhost
Since the IP of the bridged network card would change (depending on which developers machine it was run) the ssh-command had to first get the IP, this snipped worked for that:
ifconfig | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*' | grep -v '127.0.0.1'
Also, as this should happen on boot you have to create a SSH key for the vm-user and trust it via .ssh/authorized_keys.
Even after I set the RPC_ADDRESS, it didn't work for me , until I set the -e CASSANDRA_START_RPC=true option.
It was always set to false in my case. I have tried this with Ubuntu, Docker and Cassandra.
Set the following config parameter in cassandra.yaml file (For CentOS it is located in /etc/cassandra/default.conf)
rpc_address: 0.0.0.0
Verify that following values are same as below(usually they are default)
start_native_transport:true
native_transport_port:9042
Last step for CentOS , Update the firewall configuration and allow port 9042 through for incoming connections
Access the firewall from “System / Administration / Firewall” in the CentOS menu
Add the port under “Other Ports”
I edit cassandra.yaml set listen_address and roc_address as ip address resolve the problem.
OS: CentOS 6.4 (server)
I have successfully installed (yum install dsc20) the cassandra database layer in my server and can connect to it using the CQL SHel (cqlsh). But I need to run queries remotely using the DataStax's DevCenter software. So I installed it (DevCenter) in a separate workstation. (CentOS 6.4 - desktop) and tried to add a new connection in order to connect to the cassandra db.
So I gave the IP of the "CentOS 6.4 - server" (in which cassandra database is running) for the host and the port as 9160. But when testing the connection it fails.
I also tried to turn off the firewall in the server, (/etc/init.d/iptables stop). But was no luck.
I'm sure this may be due to some misconfiguration which I cannot figure out. I'll be grateful, if someone can give me a solution for this as I was researching for this and found no answers. Thank you very much in advance.
DataStax DevCenter being built on top of the DataStax Java driver has the same connectivity requirements as the driver. Namely:
start_native_transport: true
rpc_address: IP or hostname reachable from the client
Machines in the cluster accept connections on port 9042 (the native_transport_port config option)
If rpc_address is set to either a private IP or to 0.0.0.0, DevCenter will not know what node to connect to.
If your cluster has multiple nodes and these are using rpc_address: 0.0.0.0, even if you configure DevCenter with the IP(s) of a couple of nodes, it will still have issues discovering the other nodes in the cluster.
In cassandra.yaml there's a comment/warning about using rpc_address: 0.0.0.0:
Note that unlike ListenAddress above, it is allowed to specify 0.0.0.0
here if you want to listen on all interfaces, but that will break clients
that rely on node auto-discovery.
Note: it is possible that in the future DevCenter might be able to ignore/filter out nodes in the cluster configured with rpc_address: 0.0.0.0.
Try this.. It worked for me!
Run the following command on your machine where you have DevCenter installed
$> ssh -L 9042:localhost:9042 <username>#<ip-address-cassandra-db> -N
After running this command, it will prompt for password
Now in your DevCenter > Contact Hosts, provide "127.0.0.1" and test connection. Bingo, you see the magic...
In the cassandra.yaml, I set
listen_address: localhost
rpc_address: 1.2.3.4
broadcast_rpc_address: 1.2.3.4
After doing a
sudo service cassandra restart
DevCenter was able to successfully connect.
After this change, cqlsh would not start without the address:
cqlsh 1.2.3.4
You can set the environment variable $CQLSH_HOST=1.2.3.4. Then simply type cqlsh.
If there's somebody working with docker locally, it can run this command.
docker run --name cassandra -p 127.0.0.1:9042:9042 -p 127.0.0.1:9160:9160
-e CASSANDRA_LISTEN_ADDRESS=localhost
-e CASSANDRA_BROADCAST_ADDRESS=localhost
-e CASSANDRA_RPC_ADDRESS=localhost -d cassandra