Linux watchdog-watchdog5.8 released

Linux watchdog-watchdog5.8 released-Linux general technology-Linux programming and kernel information. The following is a detailed description. Linux comes with a watchdog implementation for monitoring system running, including a kernel watchdog module and a user space watchdog program

The kernel watchdog module communicates with the user space through the/dev/watchdog character device. Once the/dev/watchdog device is enabled for a user space program, a one-minute timer is enabled in the kernel, the user space program needs to ensure that data is written to the device within one minute, and each write operation will cause the timer to be reset. If the user space program does not perform write operations within one minute, the expiration of the timer will cause a system reboot operation.

The user space program can stop the timer in the kernel by disabling/dev/watchdog.

User space watchdog daemon:

In the user space, there is also a daemon called watchdog, which can regularly detect the system, including:

Is the process table full?
Is there enough free memory?
Are some files accessible?
Have some files changed within a given interval?
Is the average work load too high?
Has a file table overflow occurred?
Is a process still running? The process is specified by a pid file.
Do some IP addresses answer to ping?
Do network interfaces receive traffic?
Is the temperature too high? (Temperature data not always available .)
Execute a user defined command to do arbitrary tests.
If a check fails, a soft reboot may occur (simulating a shutdown command execution)

It can also trigger the running of the kernel watchdog through/dev/watchdog.

This version fixes many bugs and adds some updates. most of the changes mainly improve the availability of embedded systems. In particular, the default time interval is modified. In addition, watchdlog can avoid program suspension due to insufficient memory.

Download watchdog 5.8.

Source: oschina