Brief-Wishbone9091
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Does it mean the server is down? For what reasons? Is there a way to know?
What does too many sleeping processes mean in linux top command?
- Thread starter Brief-Wishbone9091
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In relation to sleeping processes, it depends on what sort of sleep is being referred to. To find out the nature of the sleeping process, run ps:
The S in the STAT column shows the processes that are sleeping, but interruptible. The main one of these is init, PID 1, which simply waits for a signal to reawaken after sleeping, that signal often being "poweroff" or the like. All the processes marked with the S are idle awaiting a signal to restart in the same way. These are all interruptible processes. They are usually normal.
The other sleeping process would be noted in the same STAT column with a D, which is an uninterruptible process. There aren't any in this output above from this machine because everything is in order. The D indicates that something has gone amiss, often a kernel system call, and they can't be interrupted to restart from idle, nor be interrupted to be killed. Usually the only way to void them is to reboot the machine.
If a process is marked D as uninterruptible, but by chance oscillates from that state to interruptible and back again, there's a neat little one liner "while loop" bash command that one can set running to try and manage that mentioned here at the end of this response:
stackoverflow.com
Code:
[flip@flop ~]$ ps aux | less
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.1 21140 12468 ? Ss 05:21 0:02 /sbin/init
root 2 0.0 0.0 0 0 ? S 05:21 0:00 [kthreadd]
root 3 0.0 0.0 0 0 ? I< 05:21 0:00 [rcu_gp]
root 4 0.0 0.0 0 0 ? I< 05:21 0:00 [rcu_par_gp]
root 5 0.0 0.0 0 0 ? I< 05:21 0:00 [slub_flushwq]
root 6 0.0 0.0 0 0 ? I< 05:21 0:00 [netns]
root 11 0.0 0.0 0 0 ? I< 05:21 0:00 [mm_percpu_wq]
root 12 0.0 0.0 0 0 ? I 05:21 0:00 [rcu_tasks_kthread]
root 13 0.0 0.0 0 0 ? I 05:21 0:00 [rcu_tasks_rude_kthread]
root 14 0.0 0.0 0 0 ? I 05:21 0:00 [rcu_tasks_trace_kthread]
root 15 0.0 0.0 0 0 ? S 05:21 0:00 [ksoftirqd/0]
root 16 0.0 0.0 0 0 ? I 05:21 0:00 [rcu_preempt]
root 17 0.0 0.0 0 0 ? S 05:21 0:00 [migration/0]
root 18 0.0 0.0 0 0 ? S 05:21 0:00 [idle_inject/0]
root 19 0.0 0.0 0 0 ? S 05:21 0:00 [cpuhp/0]
root 20 0.0 0.0 0 0 ? S 05:21 0:00 [cpuhp/1]
root 21 0.0 0.0 0 0 ? S 05:21 0:00 [idle_inject/1]
root 22 0.0 0.0 0 0 ? S 05:21 0:00 [migration/1]
root 23 0.0 0.0 0 0 ? S 05:21 0:00 [ksoftirqd/1]
<snip>The S in the STAT column shows the processes that are sleeping, but interruptible. The main one of these is init, PID 1, which simply waits for a signal to reawaken after sleeping, that signal often being "poweroff" or the like. All the processes marked with the S are idle awaiting a signal to restart in the same way. These are all interruptible processes. They are usually normal.
The other sleeping process would be noted in the same STAT column with a D, which is an uninterruptible process. There aren't any in this output above from this machine because everything is in order. The D indicates that something has gone amiss, often a kernel system call, and they can't be interrupted to restart from idle, nor be interrupted to be killed. Usually the only way to void them is to reboot the machine.
If a process is marked D as uninterruptible, but by chance oscillates from that state to interruptible and back again, there's a neat little one liner "while loop" bash command that one can set running to try and manage that mentioned here at the end of this response:
Process is in interruptible sleep - how to find out what it is waiting for
I have an daemon running on Debain on Arm. Sometimes this daemon hangs/is not responding anymore. When looking at the process with "ps ax" the stat column is "Dl" which means "uninterruptible sleep (
stackoverflow.com
