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temBoard performances

temBoard UI has a built-in, logfmt based, performances tracing. You enable performance tracing, execute temBoard UI and analyze the logs afterward using a development grafana setup.

Enabling performance tracing

Define the PERF environment variable in temBoard UI execution environment. With systemd, create a directory /etc/systemd/system/temboard.service.d/ and put the following content in the enable-perf-tracing.conf drop-in file:


Ensure logging level is set to DEBUG in /etc/temboard/temboard.conf:

method = stderr
level = DEBUG

Reload systemd with systemctl daemon-reload. Restart temBoard with systemctl restart temboard.

You will see the following perf messages in temBoard logs.

2022-01-27 12:35:36,257 [2673406] [taskmanager     ] DEBUG: Activate worker purge_data_worker
2022-01-27 12:35:36,260 [2673427] [services        ]  INFO: Starting worker pool.
2022-01-27 12:35:36,261 [2673406] [services        ]  INFO: Starting web.
2022-01-27 12:35:36,262 [2673427] [perf            ] DEBUG: Scheduling perf counters each 15 seconds.
2022-01-27 12:35:36,262 [2673428] [services        ]  INFO: Starting scheduler.
2022-01-27 12:35:36,262 [2673406] [perf            ] DEBUG: Scheduling perf counters each 15 seconds.
2022-01-27 12:35:36,263 [2673427] [perf            ] DEBUG: io_rchar=0 io_wchar=184 pid=2673427 service=worker-pool stime=0.0 utime=0.0 vsize=116420608
2022-01-27 12:35:36,263 [2673406] [perf            ] DEBUG: io_rchar=9610041 io_wchar=108165 pid=2673406 service=web stime=0.05 utime=0.66 vsize=116420608
2022-01-27 12:35:36,263 [2673427] [services        ] DEBUG: Entering worker pool loop.
2022-01-27 12:35:36,263 [2673428] [perf            ] DEBUG: Scheduling perf counters each 15 seconds.
2022-01-27 12:35:36,263 [2673428] [perf            ] DEBUG: io_rchar=0 io_wchar=182 pid=2673428 service=scheduler stime=0.0 utime=0.0 vsize=116420608
2022-01-27 12:35:36,264 [2673428] [taskmanager     ] DEBUG: Update Task aggregate_data with options={}

To export logs from journald, use the following command:

# journalctl -u temboard --utc --output=short-iso --since '-30 minutes'

Adapt --since argument to your needs.

Visualize with Grafana

To visualize temBoard’s performances traces, the development environment of temBoard ships et Grafana setup with Prometheus and Loki. See Contributing to setup a development environment. dev/bin/ Python script backfills Prometheus and Loki from temBoard traces file.

$ docker compose up -d
$ ./dev/bin/ my-temboard.log
I: Analyzing systemd.log.
I: Read timezone from /etc: Europe/Paris.
D: HTTP Request: POST "HTTP/1.1 204 No Content"
I: Parsed messages from 2022-01-27 15:09:54+01:00 to 2022-01-27 18:03:15+01:00.
I: Log time span is 2:53:21.
I: Exported 1209 points in OpenMetrics format.
I: Inserted 18742 log messages in Loki.
I: Backfilling Prometheus from OpenMetrics.
01FTE7W2G0CGHM0GZQFYP2KD0Z  1643294766000  1643299198001  1h13m52.001s  1643         1086         1086         117422
01FTE7W2J70EJATMMGAXHHDP09  1643299209000  1643302995001  1h3m6.001s   4484         3476         3476         372009
I: View graph and messages at:

Follow the final link to see the dashboard narrowed to the date interval corresponding to log messages dates and filtered to the named log file.

Please take advise:

  • Avoid reusing the same file name for multiple temBoard logs.
  • Avoid reimporting a log file.
  • Avoid importing file newer than 3 hours. Loki and Prometheus backfilling is not very consistent with hot data.
  • Grafana may need a few minutes to show you labels and points right after imports. Be patient.

If you need to restart from scratch, just trash the compose setup and restart.

$ docker compose down -v
Stopping perfui_prometheus_1 ... done
Stopping perfui_loki_1       ... done
Stopping perfui_grafana_1    ... done
Removing perfui_prometheus_1 ... done
Removing perfui_loki_1       ... done
Removing perfui_grafana_1    ... done
Removing network perfui_default
Removing volume perfui_grafana-data
$ make develop

Last update: 2024-03-04