NewAutomationWorld

netstat (network statistics) - Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships Type the following command: $netstat Listening on all ports      $netstat -a OPTIONS -l, --listening         Show only listening sockets.  (These are omitted by default.)      $netstat -i

tcpdump - dump traffic on a network. Tcpdump  prints  out a description of the contents of packets on a network interface that match the boolean expression. Type the following command: $tcpdump You need to interrupt the command else it would keep scrolling http://unix.stackexchange.com/questions/82919/what-does-the-eth0-interface-name-mean-in-linux OPTIONS -i interface --interface=interface Listen on interface.  If unspecified, tcpdump searches the system interface list for the lowest numbered,  configured  up  interface (excluding loopback), which may turn out to be, for example, ``eth0''.      $tcpdump -i eth0 -c count                Exit after receiving count packets. $tcpdump -c 30 -i eth0 -D --list-interfaces, prints  the list of the network interfaces available on the system and on which tcpdump can capture packets.  For ea...

iostat - Report Central Processing Unit (CPU) statistics and input/output statistics for devices and partitions. It is used for monitoring system input/output device loading by observing the time the devices are active in relation to their average transfer rates.The iostat command generates reports that can be used to change system configuration to better balance the input/output load between physical disks. The first report generated by the iostat command provides statistics concerning the time since the system was booted, unless the -y  option is used (in this case, this first report is omitted).  Each subsequent report covers the time since the previous report. Type the following command: $iostat REPORTS The iostat command generates two types of reports, the CPU Utilization report and the Device Utilization report. CPU Utilization Report - The first report generated by the iostat command is the CPU Utilization Report. For multiprocessor systems, the CPU valu...

Free command is frontend to /proc/meminfo file. It provide more human readable output to show you the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel: $ free -m vmstat command =========================================== The vmstat, sar and iostat commands are the collection of package included in sysstat – the system monitoring tools. vmstat - Report virtual memory statistics. It reports information about processes, memory, paging, block IO, traps, disks and cpu activity. The  first report produced gives averages since the last reboot.  Additional reports give information on a sampling period of length delay. Type the following command: $vmstat FIELD DESCRIPTION FOR VM MODE   Procs         r: The number of runnable processes (running or waiting for run time).         b: The number of processes in uninterruptible sleep. ...

Top command and options What server side statistics should be gathered during performance testing. We have not yet looked in to specific statistics which we should gather for server side monitoring. In this post we would have a look at useful Linux commands which can be used to gather several important performance statistics. We would use these commands in future performance testing tutorials to gather server side performance statistics. Most of the description of these commands is from command manual. So lets begin -   The top program provides a dynamic real-time view of a running system.  It can display system summary information as well as a list of processes or threads currently being managed by the Linux kernel. Type the following command: $ top The top command used to display all the running and active real-time processes in ordered list and updates it regularly. Press ‘c‘ option in running top command, it will display absolute path of running proces...

Factors To Be Considered for Performance Have performance test workflow(s) been identified? Has sanity functional tests been successful. You would not want to carry out performance tests on an application which is functionally broken. What does the target system (hardware) look like (specify all server and network appliance configurations)?. Monitor load average, cpu, memory etc on all servers. These can be easily monitored using  top  command on unix system. Don’t  forget to monitor health of test agents.  load average, cpu utilization, IO, Memory usage are the least you should monitor on test agent. Many a times you would encounter that you hit system limit on load test agent which degrades test results. Is test environment same as live environment else test results would have to be extrapolated Has  bench marking  been done ? (The objective of Benchmark tests is to determine end-to-end timing of various critical...