Is there a way to display individual applications that are running and the percentage of resources they are taking up?
You can start by try to used the "process status" command: ps
Doing a man ps might help. Typical command line flags are:
ps -ef
ps -aux
Take note that it depends on your system used.
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There are free tools available to monitor and manage performance on UNIX systems. UNIX has following major resource types that need to be monitored and tuned:
- CPU
- Memory
- Disk space
- Communications lines
- I/O Time
- Network Time
- Applications programs
Performance Components
The following are the major component where total system time goes:
User state CPU
The actual amount of time the CPU spends running the users program in the user state. It includes time spent executing library calls, but does not include time spent in the kernel on its behalf.
System state CPU
This is the amount of time the CPU spends in the system state on behalf of this program. All I/O routines require kernel services. The programmer can affect this value by the use of blocking for I/O transfers.
I/O Time and Network Time
These are the amount of time spent moving data and servicing I/O requests
Virtual Memory Performance
This includes context switching and swapping.
Application Program
Time spent running other programs - when the system is not servicing this application because another application currently has the CPU.
Performance Tools
In your Unix system, it provides the following important tools to measure and fine tune Unix system performance:
Command: nice/renice
Run a program with modified scheduling priority
Command: netstat
Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships
Command: time
Time a simple command or give resource usage
Command: uptime
System Load Average
Command: ps
Report a snapshot of the current processes.
Command: vmstat
Report virtual memory statistics
Command: gprof
Display call graph profile data
Command: prof
Process Profiling
Command: top
Display system tasks
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top - 'top' is the linux command used to view the server's current utilization statistics (cpu and memory usage), breaking down each process and its utilization state.
To view the server's local resource utilization stats:
top
Sample output from command:
top - 07:00:06 up 16:48, 1 user, load average: 0.00, 0.00, 0.00
Tasks: 38 total, 1 running, 37 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0% user, 0.3% system, 0.0% nice, 99.7% idle
Mem: 255972k total, 222280k used, 33692k free, 18328k buffers
Swap: 1052248k total, 0k used, 1052248k free, 99960k
cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ Command
6505 bobby 15 0 968 968 796 R 0.3 0.4 0:00.04 top
1 root 15 0 480 480 428 S 0.0 0.2 0:04.03 init
2 root 16 0 0 0 0 S 0.0 0.0 0:00.00 keventd
3 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd_CPU0
4 root 25 0 0 0 0 S 0.0 0.0 0:00.00 kswapd
5 root 25 0 0 0 0 S 0.0 0.0 0:00.00 bdflush
6 root 15 0 0 0 0 S 0.0 0.0 0:00.00 kupdated
103 root 25 0 0 0 0 S 0.0 0.0 0:00.00 khubd
1340 root 17 0 856 856 600 S 0.0 0.3 0:00.01 devfsd
3606 root 25 0 0 0 0 S 0.0 0.0 0:00.00 kjournald
4077 root 24 0 1420 1420 988 S 0.0 0.6 0:00.10 mysqld_safe
4160 root 16 0 716 716 548 S 0.0 0.3 0:00.09 syslog-ng
4190 mysql 16 0 5668 5668 2672 S 0.0 2.2 0:00.27 mysqld
4195 root 17 0 1376 1376 1252 S 0.0 0.5 0:00.86 sshd
4201 mysql 15 0 5668 5668 2672 S 0.0 2.2 0:00.06 mysqld
4202 mysql 16 0 5668 5668 2672 S 0.0 2.2 0:00.04 mysqld
4203 mysql 16 0 5668 5668 2672 S 0.0 2.2 0:00.00 mysqld
The processes are sorted, by default, from top down, with the top process utilizing the most CPU cycles.
This can be further sorted by M and P (for Memory and Processor usage, respectively).
You'll also want to take note of how much total memory is available on your system, and how much is currently being used. If all of your physical memory is being used, the system will begin to dip into swap space on the HDD, and this can cause iowait (disk access) to rise, further increasing the load on the system.
mysql and apache (httpd) are common culprits of load, and if either are responsible, you will need to make sure that they are optimized for both your traffic expectations and available system resources.
Once you are finished using the 'top' command, you can exit by simply hitting q (quit).
