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
Related
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).
my group and I are running a server that is based upon Django and uses mod_wsgi to run an Apache server. We will not be working on this project after it is over, so I am attempting to set up cronjob similar functionality to check if the apache server has shut down(system restart or power failure), and if it has, will restart the server for me. I've found documentation on how to check if an apache server is down and restart the server if it is, but our server uses https and thus our start command is pretty verbose.
Can I simply use the functionality provided in these examples:
https://askubuntu.com/questions/277389/cron-job-to-restart-apache
https://www.digitalocean.com/community/tutorials/how-to-use-a-simple-bash-script-to-restart-server-programs
Or do I need a much more complicated process to make this happen?
The command we use to initially start the server is
python manage.py runmodwsgi --host 0.0.0.0 --port 8001 --https-port 8000 --ssl-certificate (certificate Location) --server-name (Domain Name)
I'm pretty new to Linux and using both Mod-wsgi as well as Apache so any help is greatly appreciated.
I suppose it is not good way to resolve this problem.
I recommend you use monit (https://mmonit.com/). It is cool program for checking services.
apt-get install monit
Apache restart configuration directives:
check process httpd with pidfile /var/run/httpd.pid
group apache
start program = "/etc/init.d/httpd start"
stop program = "/etc/init.d/httpd stop"
if failed host 127.0.0.1 port 80
protocol http then restart
if 5 restarts within 5 cycles then timeout
You are better off using the --setup-only option to mod_wsgi-express or the Django integration for it, to generate the configuration but not run it. Then as others have mentioned, integrate it into the system service manager.
The two commands for starting and stopping the Apache/mod_wsgi instance would be apachectl start and apachectl stop, where apachectl is that which was generated when running with the additional --setup-only option.
When running it as a system service, also make sure you use the --server-root option to specify a more persistent location for the generated configuration. Do not use the default under /tmp if running for anything but temporary development sessions as some Linux systems will remove files under /tmp causing things to start failing after a while.
Also, since under a service manager it would generally be starting as root, particularly if listening on port 80 is a requirement, ensure you use the --user and --group options to specify what user/group your Python web application should run as.
Read:
https://pypi.python.org/pypi/mod_wsgi
for more details of the --setup-only option and start-server commands for generating the configuration. Because you are using the Django integration, you will need to use the --setup-only option.
For more informed helped, bring your issue to the mod_wsgi mailing list. The mod_wsgi-express way of running Apache/mod_wsgi is new enough that unlikely that anyone here is really going to know much about it.
There is no need to do this at all. There is no reason to start up Apache manually; once it's installed as a system service, Ubuntu will start it up automatically on restart or crash.
You should reflect on why you feel the need to do this for Apache specifically, and not any of the other system services you depend on, such as the database.
We would like to monitor our CouchDB installation using the default pid file method with MONIT, however although couchdb is working fine there is no pid file generated under /var/run/couchdb, there is only a couch.uri file.
Permissions on /var/run/couchdb are good (couch:couch) and service couchdb stop and start work fine, although for MONIT to stop/start we would need the /etc/init.d/couchdb start/stop option (which again isn't present).
For info we just installed using apt-get install couchdb on Ubuntu 14.04.
Any advice appreciated.
Best regards
RichBos
I have done this with an older version (1.3) of CouchDB installed from source. Please check if this is working for you:
check process couchdb with pidfile
/usr/local/var/run/couchdb/couchdb.pid
group database
start program = "/etc/init.d/couchdb start -u couchdb"
stop program = "/etc/init.d/couchdb stop -u couchdb"
if failed host 127.0.0.1 port 5984 then restart
if cpu is greater than 40% for 2 cycles then alert
if cpu > 60% for 5 cycles then restart
if 10 restarts within 10 cycles then timeout
If you have installed it via a package manager, you will most likely find the pid in /var/run/couchdb/couchdb.pid
The place of the pid file did not change since 1.3. So chances are good, that it's working for you.
I want to run Derby in network mode on my virtual private server. I can connect to my server by ssh, execute
java -jar derbyrun.jar server start -noSecurityManager
and the network server starts succesfully as expected. However when I close the ssh connection that inevitably also shuts down Derby. Is there a way to start Derby without leaving the command prompt stuck, so that I can disconnect from my server and leave it running?
Perhaps
nohup java -jar derbyrun.jar server start -noSecurityManager &
would work?
I was configuring Jenkins last night to run some reporting plugins (codestyle, findbugs, cobertura). When I ran my build job it got hung up somewhere in codestyle, and the server ui became unresponsive.
Today I logged in to the server and the Jenkins log is reporting errors that look like the server ran out of memory, but more than that, I cannot seem to stop or restart the server. I have limited experience with services in linux.
Jenkins was installed on Ubuntu with atp. I have tried $ sudo /etc/init.d/jenkins restart but it reports
* Starting Jenkins Continuous Integration Server jenkins
The selected http port (8080) seems to be in use by another program
Please select another port to use for jenkins
When I try to run service jenkins status to get a pid to kill i get
2 instances of jenkins are running at the moment
but the pidfile /var/run/jenkins/jenkins.pid is missing
Running netstat and ps has identified the port being held by a jenkins instance.
How can I recover from this?
Mostly I was concerned about abruptly killing the Jenkins server while it has gone rogue. Something this tied into process with server connections and plugins makes me wary of taking a shotgun to the process.
That's exactly what I did. server jenkins status didn't work, so I got the process id from netstat -tulpn. kill -15 didn't work so I did kill -9, waited a respectful grieving period, then restarted the Jenkins service.
I will next be investigating the root problem of running out of memory in my Jenkins installation so hopefully this doesn't happen again while I am firewalled away from my server.
Where is your server hosted?
I had the same issue with AWS EC2 server.
Command lines did not work to reboot the server.
However, on AWS admin console, I did: EC2 -> restart and it works like a charm.
This may not be a solution but a workaround.
I was able to do
sudo ps aux | grep jenkins
To find a list of jenkins processes. Then I ran
sudo kill <pid>
And then finally
sudo service jenkins restart