Port Already In Use:
Sometimes, some process might be holding the required port during development process. This should have happened when the earlier dev web server was not shutdown properly.
Use the following command to find out which process is using the port no 3000
sudo netstat -lpn | grep 3000
and you will get output similar to the below line
tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN 10416/rails
where 10416 is the process id of the process holding the particular port no 3000.
So kill the process with id 10416 using the following command
kill 10416
But be sure that you are killing some processes which are related to your development only. I knew that the rails development server which i was using was the one which might be holding the port 3000. So, i was sure that i can kill that process.
Sometimes, some process might be holding the required port during development process. This should have happened when the earlier dev web server was not shutdown properly.
Use the following command to find out which process is using the port no 3000
sudo netstat -lpn | grep 3000
and you will get output similar to the below line
tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN 10416/rails
where 10416 is the process id of the process holding the particular port no 3000.
So kill the process with id 10416 using the following command
kill 10416
But be sure that you are killing some processes which are related to your development only. I knew that the rails development server which i was using was the one which might be holding the port 3000. So, i was sure that i can kill that process.