fix(system_monitor): incorrect counter increment in CPU Usage monitor

[v-nakayama7440-esol]

Signed-off-by: v-nakayama7440-esol v-nakayama7440@esol.co.jp

Description

There is a bug that the cpu_monitor does not generate a warning or error unless the CPU usage becomes more than the counter threshold.
The default parameters for monitoring CPU usage are as follows, and cpu_monitor is supposed to generate a warning after the CPU usage becomes 96% or more and it appears 2 consecutive times (monitor interval is about 1sec). As regards to error, cpu_monitor shall generate an error after the usage becomes 100% and it appears 2 consecutive times.

    usage_warn: 0.96
    usage_error: 1.00
    usage_warn_count: 2
    usage_error_count: 2

However, the current implementation of cpu_monitor generates a warning/error after the appearance of 3 times, it's counting one extra. This has been introduced from this fix #557.

Changed parameters as follows to make testing easy.

    usage_error: 0.90
    usage_error_count: 2

And Observed an error was generated after count of 3. (This is a dump of CPU Usage)

1662360194,170445574,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,16.34%,...
1662360195,526444173,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,100.00%,...
1662360196,862445342,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,99.94%,...
1662360198,246452080,...,b'\x02',cpu_monitor: CPU Usage,very high load,se-osaka-dev32,CPU all: status,very high load,CPU all: total,99.94%,...

This PR is to fix counting one extra.

Related links

#557

Tests performed

1. Change usage_warn and usage_error in cpu_monitor.param.yaml to make testing easy.

       usage_warn: 0.40
       usage_error: 0.90
       usage_warn_count: 2
       usage_error_count: 2

2. Simulate CPU high load by using stress command.

3. Verify cpu_monitor generates an error after count of 2. b'\x02' indicates an error.

   1662358072,778439042,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,39.30%,...
   1662358074,154435411,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,100.00%,...
   1662358075,486447870,...,b'\x02',cpu_monitor: CPU Usage,very high load,se-osaka-dev32,CPU all: status,very high load,CPU all: total,100.00%,...

4. Also verify cpu_monitor generates an warning after count of 2. b'\x01' indicates a warning.

   1662357625,186469428,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,32.37%,...
   1662357626,514459628,...,b'\x00',cpu_monitor: CPU Usage,OK,se-osaka-dev32,CPU all: status,OK,CPU all: total,54.64%,...
   1662357627,850450383,...,b'\x01',cpu_monitor: CPU Usage,high load,se-osaka-dev32,CPU all: status,high load,CPU all: total,53.82%,...

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[ito-san]

@v-nakayama7440-esol Please allow me to change the contents above because it is difficult to understand.

[codecov]

Codecov Report

Merging #1783 (0594199) into main (8c198af) will decrease coverage by 0.38%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main    #1783      +/-   ##
==========================================
- Coverage   10.74%   10.36%   -0.39%     
==========================================
  Files        1148     1212      +64     
  Lines       84761    87628    +2867     
  Branches    20451    20282     -169     
==========================================
- Hits         9106     9080      -26     
- Misses      66301    69067    +2766     
- Partials     9354     9481     +127     

Flag	Coverage Δ		*Carryforward flag
differential	0.00% <0.00%> (?)
total	10.37% <0.00%> (-0.36%)	⬇️	Carriedforward from 30560e6

*This pull request uses carry forward flags. Click here to find out more.

Impacted Files	Coverage Δ
...n_capture_rviz_plugin/src/screen_capture_panel.cpp	0.00% <0.00%> (ø)
...lanner/scene_module/avoidance/avoidance_module.hpp	0.00% <0.00%> (ø)
...er/scene_module/lane_change/lane_change_module.hpp	0.00% <0.00%> (ø)
...lanner/scene_module/pull_over/pull_over_module.hpp	0.00% <ø> (ø)
...th_planner/scene_module/scene_module_interface.hpp	0.00% <ø> (ø)
...er/src/scene_module/avoidance/avoidance_module.cpp	0.00% <0.00%> (ø)
...rc/scene_module/lane_change/lane_change_module.cpp	0.00% <0.00%> (ø)
...nner/src/scene_module/pull_out/pull_out_module.cpp	0.00% <0.00%> (ø)
...er/src/scene_module/pull_over/pull_over_module.cpp	0.00% <0.00%> (ø)
...er/include/scene_module/scene_module_interface.hpp	0.00% <0.00%> (ø)
... and 208 more

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[ito-san]

@v-nakayama7440-esol Please allow me to change the contents above because it is difficult to understand.

Thank you for the PR. Completed to fix the contents above.

[ito-san]

• Parameters

    usage_warn: 0.40
    usage_error: 0.90
    usage_warn_count: 2
    usage_error_count: 2

• Verified a warning was generated after count of 2.

  stress-ng -k -c 12 -l 40

  ros2 topic echo /diagnostics | grep -e "cpu_monitor: CPU Usage" -B 1 -e "cpu_monitor: CPU Usage" -A 7
  

• Verified an error was generated after count of 2.

  stress-ng -k -c 12 -l 90

  ros2 topic echo /diagnostics | grep -e "cpu_monitor: CPU Usage" -B 1 -e "cpu_monitor: CPU Usage" -A 7
  

[ito-san]

LGTM

[andoh104]

@ito-san @v-nakayama7440-esol
This code something strange.

    if (usage_error_check_cnt_[idx] < usage_error_count_) {
      usage_error_check_cnt_[idx]++;
    }
    if (usage_error_check_cnt_[idx] >= usage_error_count_) {
      level = DiagStatus::ERROR;
    }

Same logic

    if (++usage_error_check_cnt_[idx] >= usage_error_count_) {
      level = DiagStatus::ERROR;
      usage_error_check_cnt_[idx] = usage_error_count;  // <-- do you need this code?
    }

[ito-san]

@andoh104
Thank you for pointing out. It seems to be good to fix but I think you're missing suffix underscore(_) to usage_error_count.

usage_error_check_cnt_[idx] = usage_error_count; // <-- do you need this code?

usage_error_check_cnt_[idx] = usage_error_count_; is needed.
Because without this logic, it counts forever and ever, and eventually it may cause an overflow and exit error condition.
@v-nakayama7440-esol
Could you please consider to fix this?

[ito-san]

@v-nakayama7440-esol

Could you please consider to fix this?

Sorry, I withdraw my request after discussing internally in TIER IV. Please leave it there!