About connections:

Number of connections is not number of users. Each user browser can open multiple connections at the same time. On the opposite, while more rare, multiple users using the same proxy could appear only through one connection.

In some high connection high load servers, this log would be helpful to monitor and tune the server with number of connections on it.

We can simply sort out the total number of connections in a port by using the command netstat.

There isn’t any log entries with total number of connections. But, we will get the history of resource usage information by installing sar (Systat) on the server.

Then, we can create a cronjob to monitor the server connections. In this post I am explaining the method to create a log for total number of connection to server. Before creating a script and setting cron, you must have the idea to use the command “netstat” to list total number of connections in server.

By considering the service Apache, we can sort it by using the port 80.

netstat -ntlp|grep :80|wc -l

Example:

netstat -ntlp|grep :80|wc -l
110

If you want to monitor the total connection to your Apache service at times, create a cronjob to save this to a file as a log. Here I am using the command “date” to get the time details when the “netstat” taking the connection log. Please do follow these steps to create a log with connection details.

Step 1 : Create a file to get the log.

touch connection.txt

Step 2 : Create a script for the same.

2.1 –> Use the command ‘date’ for time details.
2.2 –> Use ‘echo’ to print your instructions.
2.3 –> Use ‘netstat’ for connection details.

Simply;

echo "Time"
date
echo "Total no: of connection in port 80"
netstat -ntlp|grep :80|wc -l
echo ""

Step 3 : Change the file permission as executable.

chmod 755 connections.log

Step 4 : Test the script from the location.

./connection.txt
Time
Wed Jun 20 10:42:02 MSD 2018
Total no: of connection in port 80
1

Step 5 : Create a file to log the connection information.

touch connections.log

Step 6 : Create a cronjob to execute this periodically.

crontab -e

*/30 * * * * /root/connection.txt >> connections.log

DONE!!

This will save the total number of connections to the file connections.log.

If you like the above post click here to know the process how to monitor the centos Apache serve using cacti.