sonic-buildimage/files/image_config/monit/restart_service
yozhao101 3af05fdffe [Monit] Restart telemetry container if memory usage is beyond the threshold (#7645)
Signed-off-by: Yong Zhao yozhao@microsoft.com

Why I did it
This PR aims to monitor the memory usage of streaming telemetry container and restart streaming telemetry container if memory usage is larger than the pre-defined threshold.

How I did it
I borrowed the system tool Monit to run a script memory_checker which will periodically check the memory usage of streaming telemetry container. If the memory usage of telemetry container is larger than the pre-defined threshold for 10 times during 20 cycles, then an alerting message will be written into syslog and at the same time Monit will run the script restart_service to restart the streaming telemetry container.

How to verify it
I verified this implementation on device str-7260cx3-acs-1.
2021-05-31 04:38:18 +00:00

106 lines
3.4 KiB
Python
Executable File

#!/usr/bin/env python3
"""
restart_service
This script is part of the feature which will restart the container if memory
usage of it is larger than the threshold value.
This script is intended to be run by Monit and is used to restart the specified
container if the memory usage of it is larger than the threshold value for X
times within Y cycles/minutes.
The following is an example in Monit configuration file to show how Monit will run
this script:
check program container_memory_<container_name> with path "/usr/bin/memory_checker <container_name> <threshold_value>"
if status == 3 for X times within Y cycles exec "/usr/bin/restart_service <container_name>"
"""
import argparse
import sys
import syslog
import subprocess
def get_command_result(command):
"""Executes command and return the exit code, stdout and stderr.
Args:
command: A string contains the command to be executed.
Returns:
An integer contains the exit code.
A string contains the output of stdout.
A string contains the output of stderr.
"""
command_stdout = ""
command_stderr = ""
try:
proc_instance = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
shell=True, universal_newlines=True)
command_stdout, command_stderr = proc_instance.communicate()
if proc_instance.returncode != 0:
return 1, command_stdout.strip(), command_stderr.strip()
except (OSError, ValueError) as err:
return 2, command_stdout.strip(), err
return 0, command_stdout.strip(), command_stderr.strip()
def reset_failed_flag(service_name):
"""Reset the failed status of a service.
Args:
service_name: Name of the service.
Returns:
None
"""
reset_failed_command = "sudo systemctl reset-failed {}.service".format(service_name)
syslog.syslog(syslog.LOG_INFO, "Resetting failed status of service '{}' ..."
.format(service_name))
exit_code, command_stdout, command_stderr = get_command_result(reset_failed_command)
if exit_code == 0:
syslog.syslog(syslog.LOG_INFO, "Succeeded to reset failed status of service '{}.service'."
.format(service_name))
else:
syslog.syslog(syslog.LOG_ERR, "Failed to reset failed status of service '{}'. Error: {}"
.format(service_name, command_stderr))
def restart_service(service_name):
"""Reset the failed status of a service and then restart it.
Args:
service_name: Name of specified service.
Returns:
None.
"""
restart_command = "sudo systemctl restart {}.service".format(service_name)
reset_failed_flag(service_name)
syslog.syslog(syslog.LOG_INFO, "Restarting service '{}' ...".format(service_name))
exit_code, command_stdout, command_stderr = get_command_result(restart_command)
if exit_code != 0:
syslog.syslog(syslog.LOG_ERR, "Failed to restart the service '{}'. Error: {}"
.format(service_name, command_stderr))
def main():
parser = argparse.ArgumentParser(description="Restart a specific service",
usage="/usr/bin/restart_service <service_name>")
parser.add_argument("service_name", help="service name")
args = parser.parse_args()
restart_service(args.service_name)
if __name__ == "__main__":
main()