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.
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.
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.
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
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.
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.
At least in Cassandra 3.0 start_rpc is set to true by default. https://docs.datastax.com/en/cassandra/3.0/cassandra/configuration/configCassandra_yaml.html
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 :)
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...
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?
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
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"
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
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
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.logfile 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)...
来源：https://stackoverflow.com/questions/29121904/cassandra-cqlsh-connection-refused