Description

This article provides information about the different CLI knobs that can be used to restart the chassis-control.

Symptoms

Junos OS provides different knobs to restart the chassis-control, depending on the requirement. This article provides information on the behavior of each of these knobs.

Solution


The behavior of the command restart chassis-control varies, depending on whether graceful switchover is enabled or disabled.

Behavior of the different knobs when graceful switchover is enabled:

  • restart chassis-control : SIGTERM

    • The existing chassis-control process is stopped and a new one is started. SIGTERM is the polite way to kill a process; the process can catch the signal, realize that you want it to shut down, close any log files it may have open, and generally finish whatever it is doing at the time before shutting down.

    In some cases a process may even ignore SIGTERM, if it is in the middle of some task that cannot be interrupted. PFE(FPC/FEB/CFEB/DPC/MPC) will not be rebooted.

    m20-a-re0> restart chassis-control
    Chassis control process started, pid 57669

  • restart chassis-control gracefully :SIGTERM

    • The existing chassis-control process is stopped and a new one is started. SIGTERM is a polite way to kill a process; the process can catch the signal, realize that you want it to shut down, close any log files it may have open, and generally finish whatever it is doing at the time before shutting down.

    In some cases a process may even ignore SIGTERM, if it is in the middle of some task that cannot be interrupted. PFE(FPC/FEB/CFEB/DPC/MPC) will not be rebooted.

    m20-a-re0> restart chassis-control gracefully
    Chassis control process started, pid 58117

  • restart chassis-control immediately :SIGKILL

    • The existing chassis-control process is stopped and a new one is started. SIGKILL can not be ignored by a process.

    If you send SIGKILL to a process, FreeBSD will stop that process immediately. PFE(FPC/FEB/CFEB/DPC/MPC) will not be rebooted.

    m20-a-re0> restart chassis-control immediately
    m20-a-re0>

  • restart chassis-control soft :SIGHUP

    • The existing chassis-control process is not stopped. Chassisd will just read the config file and update the configurations. PFE(FPC/FEB/CFEB/DPC/MPC) will not be rebooted.

    m20-a-re0> restart chassis-control soft
    m20-a-re0>

  • restart chassisd :hard restart

    • Existing chassis-control process is stopped and a new one is started. PFE(FPC/FEB/CFEB/DPC/MPC) will be rebooted as well.

    m20-a-re0> restart chassisd
    chassisd hard restart initiated

Behavior of the different knobs when graceful switchover is disabled:

  • restart chassis-control :SIGTERM

    • The existing chassis-control process is stopped and a new one is started. SIGTERM is the polite way to kill a process; the process can catch the signal, realize that you want it to shut down, close any log files it may have open, and generally finish whatever it is doing at the time before shutting down.

    In some cases a process may even ignore SIGTERM, if it is in the middle of some task that cannot be interrupted. PFE(FPC/FEB/CFEB/DPC/MPC) will be rebooted as well.

    m320-re0> restart chassis-control
    Chassis control process started, pid 13147

  • restart chassis-control gracefully :SIGTERM

    • The existing chassis-control process is stopped and a new one is started. SIGTERM is the polite way to kill a process; the process can catch the signal, realize that you want it to shut down, close any log files it may have open, and generally finish whatever it is doing at the time before shutting down.

    In some cases a process may even ignore SIGTERM, if it is in the middle of some task that cannot be interrupted. PFE(FPC/FEB/CFEB/DPC/MPC) will be rebooted.

    m320-re0> restart chassis-control gracefully
    Chassis control process started, pid 13226

  • restart chassis-control immediately

    • The existing chassis-control process is stopped and a new one is started. SIGKILL cannot be ignored by a process.

    If you send SIGKILL to a process, FreeBSD will stop that process immediately. PFE(FPC/FEB/CFEB/DPC/MPC) will not be rebooted.

    m320-re0> restart chassis-control immediately
    m320-re0>

    Message from syslogd@m320-re0 at Nov 5 09:53:22 ...
    m320-re0 fpc0 CMLC: Going disconnected; Routing engine chassis socket closed abruptly

    Message from syslogd@m320-re0 at Nov 5 09:53:26 ...
    m320-re0 fpc6 CMLC: Going disconnected; Routing engine chassis socket closed abruptly

  • restart chassis-control soft :SIGHUP

    • The existing chassis-control process is not stopped. Chassisd will just read the config file and update the configurations. PFE(FPC/FEB/CFEB/DPC/MPC) will not be rebooted.

    m320-re0> restart chassis-control soft
    m320-re0>

  • restart chassisd :hard restart

    • The existing chassis-control process is stopped and a new one is started. PFE(FPC/FEB/CFEB/DPC/MPC) will be rebooted as well.

    m320-re0> restart chassisd
    chassisd hard restart initiated.
    m320-re0>

Summary of the differences

When Graceful Switchover is enabled:

  • restart chassis-control: PFE will not be rebooted.
  • restart chassis-control gracefully: PFE will not be rebooted.

When Graceful Switchover is not enabled:

  • restart chassis-control: PFE will be rebooted.
  • restart chassis-control gracefully: PFE will be rebooted.

With or without Graceful Switchover, these switches have the same behavior:

  • restart chassis-control immediately: PFE will not be rebooted.
  • restart chassis-control soft: PFE will not be rebooted.
  • restart chassisd : PFE will be rebooted.

Related Information