Superlance

2.0.0 verified Mon Apr 27 auth: no python

Superlance is a collection of plugin/monitor scripts for the Supervisor process control system. Version 2.0.0 introduces a major restructuring: it now requires Python 3.6+ and Supervisor 4+, and all scripts are installed as console scripts (e.g., `memmon`, `httpok`). The library is actively maintained with a mature API.

pip install superlance

Common errors

error ImportError: No module named 'superlance' ↓

cause Superlance is not installed, or the environment is not activated.

fix

Run pip install superlance in the correct Python environment.

error FileNotFoundError: [Errno 2] No such file or directory: 'memmon' ↓

cause Superlance scripts are not installed as executable commands; often due to missing PATH or using old import pattern.

fix

Ensure superlance is installed in the same Python environment as supervisord. Use which memmon to locate, or run python -m superlance.memmon if using superlance <2.0.0.

error superlance.eventlistener: Error: listener configuration not found ↓

cause The supervisord.conf does not contain the required [eventlistener:...] section for the plugin.

fix

Add an eventlistener section in supervisord.conf, e.g.: [eventlistener:memmon] command=memmon events=PROCESS_STATE

Warnings

breaking Superlance 2.0.0 drops support for Python versions before 3.6 and Supervisor versions before 4. If you are on an older environment, pin to superlance==1.0.2. ↓

fix Upgrade to Python 3.6+ and Supervisor 4+. Alternatively, use `pip install superlance==1.0.2`.

breaking In Superlance 2.0.0, the old pattern of running scripts via `python -m superlance.memmon` no longer works. Use the console scripts directly (e.g., `memmon`). ↓

fix Run `memmon` instead of `python -m superlance.memmon`.

gotcha Superlance scripts read Supervisor event listener configuration from the [eventlistener:...] section in supervisord.conf. Misconfiguration of the listener (e.g., missing environment variables) causes silent failures. ↓

fix Ensure you have properly configured the [eventlistener:xxx] section in supervisord.conf and that the script path points to the correct console script.

Imports

Memmon
```
from superlance.memmon import Memmon
```
Memmon is a class that monitors memory usage of supervised processes.
HttpOk
```
from superlance.httpok import HttpOk
```
HttpOk checks HTTP endpoints and restarts processes if they are not responding.
FatalMailBatch
```
from superlance.fatalmailbatch import FatalMailBatch
```
Sends email notifications for fatal process events.

Quickstart

Verify that Superlance is installed and importable. Superlance scripts are typically run as command-line programs, not imported as libraries.

python -c "from superlance.memmon import Memmon; print('Memmon imported successfully')"