I'm trying to experiment with Cassandra on my system with the below configuration:
OS: Ubuntu 16.04 LTS
Kernel: 4.10.1
Cassandra source GitHub link: https://github.com/apache/cassandra
Setup process on IntelliJ link: https://wiki.apache.org/cassandra/RunningCassandraInIDEA
I open a terminal and run the below commands from the root directory of Cassandra source code without any failure:
bin/cassandra -f (it starts Cassandra successfully)
bin/nodetool status (Get information about the node e.g. datacenter, status etc.)
bin/cqlsh (opens the interface for running the queries)
However, when I follow the setup process for IntelliJ, I'm able to start the server from IntelliJ by hitting "Run" but "nodetool status" command always returns the below error:
Failed to connect to '127.0.0.1:7199' - ConnectException: 'Connection refused (Connection refused).
Interestingly, when i run "bin/cqlsh" command, it connects successfully, which means the node is running just fine.
Any idea what might be causing "nodetool status" to return "connection refused"?
I also tried turning the firewall off but didn't help.
Fixed the issue by adding some more VM arguments as below:
Add the following VM arguments if you want to use nodetool
-Djava.rmi.server.hostname=$JMX_HOST (I entered 127.0.0.1)
-Dcom.sun.management.jmxremote.port=$JMX_PORT (I entered 7199)
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false
Here is the link for reference: https://wiki.apache.org/cassandra/RunningCassandraInEclipse
These VM arguments are not provided in the wiki page for Cassandra setup with IntelliJ: https://wiki.apache.org/cassandra/RunningCassandraInIDEA (posted in my question as well).
Mongo shell not connecting
I have dedicated centos server
I installed mongodb as a service in my server from here
I even restarted server after installing mongodb
When i tries to run mongo shell it always saying
Error: couldn't connect to server 127.0.0.1:27017 (127.0.0.1), connection attempt failed at src/mongo/shell/mongo.js:146
I tried to remove that mongod.lock but no joy
I dont understand why this happens, because when mongod starts as a service it creates a log in system and telling that it has opened the door to listen incoming connection on port 27017. But it is throwing error while i connecting to mongo shell.
Please see this steps i have used --> click here
Well i wants to use this mongo service first of all at local based with only 127.0.0.1 access. I can change that in mongod.conf file afterward.
Be sure with iptables, Firwalll causing this kind of issue on live server.
So please do this if you facing this kind of same issue,
Do iptables off for a moment
# /etc/init.d/iptables stop
# sudo service mongod start
# mongo
Here what i wanted to see finally,
MongoDB shell version: 2.6.7
connecting to: test
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
http://docs.mongodb.org/
Questions? Try the support group
http://groups.google.com/group/mongodb-user
show dbs
admin (empty)
local 0.078GB
Thanks guys who considered my question and looking in it.
Thanks a lot.
I installed Cassandra on OSX.
When trying to run cqlsh from /bin/, I get the following error:
> Connection error: ('Unable to connect to any servers', {'127.0.0.1':
> ConnectionShutdown('Connection <AsyncoreConnection(4522252560)
> 127.0.0.1:9160 (closed)> is already closed',)})
I had difficulty installing Cassandra, and had used brew install cassandra, installed DSE from datastax, and downloaded a binary from Apache.
I think the issue was the result of having a previous installation that wasn't properly uninstalled. My user .cassandra directory had some default configs, that must have been for a different version, and prevented cqlsh from starting.
rm -Rf ~/.cassandra
After that, I could run cqlsh properly.
$ bin/cqlsh
Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 2.1.2 | CQL spec 3.2.0 | Native protocol v3]
Use HELP for help.
cqlsh>
Running cassandra helped me to troubleshot the problem:
> cassandra
Cassandra 3.0 and later require Java 8u40 or later.
and:
> java -version
java version "1.7.0_95"
OpenJDK Runtime Environment (IcedTea 2.6.4) (7u95-2.6.4-3)
OpenJDK 64-Bit Server VM (build 24.95-b01, mixed mode)
After installing Java 8 it worked.
Cassandra-2.1 uses 9042 as cqlsh port.Connect on this it is default port.If you want to connect on 9160 port then change it by setting environment variable CQLSH_PORT and CQLSH_HOST but for setting this you have to change rpc_port from default 9160 to any other port.
Well, I faced same issue and this is what i did on Mac.
$cd /usr/local/Cellar/cassandra/3.10_1/bin/
Or wherever your cassandra is installed.
$cassandra
this initializes all configuration in your local system to start cassandra.
$./cqlsh
This lets you enter cql query mode.
I resolved this in DSE-5.0 by editing below file:
vi ~/.cassandra/cqlshrc
And editing below configs to current IP address (192.168.1.6) of the machine I am running. In my case it's my MacBook.
[connection]
hostname = 192.168.1.6
port = 9042
; factory = cqlshlib.kerberos_ssl.kerberos_ssl_transport_factory
; [kerberos]
; hostname = 192.168.1.6
; service = cassandra
; optional
; principal = bill/cassandra-admin#foo.example.com
I hope it will help someone.
Thanks,
Chandan
I faced this issue when I was trying to connect to Cassandra 2.0.1 version using cqlsh 5.0.1
[cqlsh 4.1.1 | Cassandra 2.0.11.83 | CQL spec 3.1.1 | ]
[cqlsh 5.0.1 | Cassandra 2.1.2 | CQL spec 3.2.0 ]
This is just one of the reasons for the error "Connection error: ('Unable to connect to any servers',".
When I used the cqlsh client compatible with Cassandra 2.0.1, I was able to connect to the cluster.
Hope this helps to find the root cause.
I got the same error after moving from Java 8 to Java 11. From https://github.com/nosan/embedded-cassandra/issues/21, Apache Cassandra does not yet have support for java 11.
Reverting to the system's current java version to Java 8 solved the problem.
Just add/modify the following into the cassandra.yaml:
rpc_address: 127.0.0.1
seeds: "127.0.0.1"
listen_address: 127.0.0.1
Note that, the values in all these fields must be same.
That means, if you are pointing to a static IP, then the same IP should be used. And if you are just pointing the localhost, then localhost must be used in all fields.
I got myself into a mess so here was my scenario if anyone else runs into it:
I followed this tutorial
http://www.datastax.com/2012/01/working-with-apache-cassandra-on-mac-os-x
(which is somewhat outdated).
I got everything installed and working - all good. Then I decided to download Datastax Enterprise tools to try them out
Ran into errors during the install but the install went through. Again following the tutorial above, tried running the ./datastax-agent program and it failed. Decided to just bag it so ran their uninstaller in their installation folder.
Tried to go back to original cassandra folder (what I had working in step 2) and run "sudo ./cassandra" then I started getting JMX error (message "Unable to bind JMX, is Cassandra already running?") which led me to this link about changing the port which i did (not really fixing the issue but working around it) run two cassandra versions in the same machine.
Got the server service running underneath a new port but when trying to connect with the client "sudo ./cqlsh" would not work (would get "Error=none" or destination not found).
Did the remove step #Peter mentioned above and tried again and still did not work.
Decided to go back and see what was holding onto the original port cassandra was using which I changed in step 4 Who is listening on a given TCP port on Mac OS X?
Determined that JAVA.app was hanging onto it so killed it within Activity Monitor.
Reran the remove command #Peter mentioned above again and decided to download the stable release (v2.0.13) instead of the dev release and walk through the tutorial from step 1 again.
Exited and re-opened terminal. Ran "sudo ./cassandra" - worked perfect running under standard ports. Open another terminal window and ran "sudo ./cqlsh" and this also worked correctly.
I believe between Java hanging onto the default port 9042 (maybe from the DataStax install errors), version/host/port settings within ~/.cassandra/cqlshrc and using the dev version of cassandra these were all causing me fits.
I was having trouble connecting Cassandra from the terminal
[
and then I tried to connect using /usr/local/Cellar/
[
and then invoke cassandra. Then opened a new terminal and typed cqlsh the Cassandra started.
Hope this may also applicable one to resolve Cassandra issue.
install java jdk and Set JAVA_HOME in Environment Variables or set JAVA_HOME = java path in command prompt.
after
run cassandra.bat
it will show the logs if you get any error
You need to start Cassandra form the install_location's bin directory.
For example, this command will start Cassandra in the foreground:
$ ./cassandra -f
Then open another terminal tab (command + t) and run cqlsh
$ ./cqlsh
Ensure that DEFAULT_HOST = '127.0.0.1' in script cqlsh.py is pointing to the node IP where you have done your cassandra installation.
In my case I had installed cassandra on 10.160.1.5, edited above file and it started working.
Running cqlsh gets this error for me but running bin/cqlsh from the cassandra directory works.
I faced the same issue. I ran cassandra.bat --> This appears to have started the server. Then I opened a new command prompt (run as an administrator), changed directory to the cassandra/bin location. When I ran the command cqlsh, voila it worked!
I solve this issue by just simply restarting cassandra sudo systemctl restart cassandra
In case of MacOSX, it worked to just run
cassandra
rather than running it through brew services start cassandra.
I was having the same problem with Cassandra configured with SSL.
cqlsh --ssl
Solves connects correctly.
I downloaded postgresql-9.1.
but when I execute the command in terminal:
$ createdb mydb
I get the following message:
createdb: could not connect to database postgres: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
please tell me how to sort this problem.I have even tried to uninstall and then reinstall it. I am trying to run this on linux mint 15 (cinnamon).
Use ps to see if the postgresql process is actually running. If not, start it (service postgresql start). Normally should start up itself on boot after installation but who knows. Also, some error may prevent it from starting on boot.
If postgresql is running, then you may need to edit pg_hba.conf in the data directory. Again, normally the database should listen for local connections by default but who knows.
I installed single node cluster in my local dev box which is running Windows 7 and it was working fine. Due to some reason, I need to restart my desktop and then after that whenever I am doing like this on the command prompt, it always gives me the below exception-
S:\Apache Cassandra\apache-cassandra-1.2.3\bin>cassandra -f
Starting Cassandra Server
Error: Exception thrown by the agent : java.rmi.server.ExportException: Port already in use: 7199; nested exception is:
java.net.BindException: Address already in use: JVM_Bind
Meaning port being used somewhere. I have made some changes in cassandra.yaml file so I need to shutdown the Cassandra server and then restart it again.
Can anybody help me with this?
Thanks for the help.
in windows7, with apache cassandra, a pid.txt file gets created at the root folder of cassandra. Give following instruction to stop the server:
d:/cassandra/bin> stop-server -p ../pid.txt -f
Running -f starts the server as a service, you can stop it through the task manager.
It sounds like your Cassandra server starts on it's own as a service in the background when your machine boots. You can configure windows startup services. To run cassandra in the foreground on windows simply use:
> cassandra.bat
If your are using Cassandra bundled with DataStax Community Edition and running as a service on startup of your machine then you can execute following commands to start and stop Cassandra server.
Start command prompt with admin rights
run following commands
net start DataStax_Cassandra_Community_Server
net stop DataStax_Cassandra_Community_Server