Intermittent "Invalid Metric Type" Error in Mixpanel Integration with Spring Boot

Question

I'm encountering an intermittent "invalid metric type" error in my Spring Boot application when integrating with Mixpanel. The error appears in my logs as follows:

time="2024-11-03T23:00:58.328155210Z" level=error msg="invalid metric type for 0263554c5365dd6303716d90826da57990b4dcc0f37dbc8a7263402ced2ac063" error="<nil>"

The error does not happen consistently, only sometimes. Here are a few details about my setup:

• Environment: Spring Boot application with a MixPanelService to handle tracking.

• Concurrency: Each time a tracking event is triggered, a new instance of MixPanelService is created.

• Tracking Module Setup:

public enum TrackingModuleEnum {
    MIXPANEL(MixPanelService.class);
    private final Class moduleClass;
    
    private TrackingModuleEnum(Class moduleClass) {
        this.moduleClass = moduleClass;
    }

    public ITrackingModule getModuleService(String moduleInfo) {
        try {
            ITrackingModule module = (ITrackingModule) this.moduleClass.newInstance();
            module.initialize(moduleInfo);
            return module;
        } catch (InstantiationException | IllegalAccessException e) {
            log.error(e.getMessage());
        }
        return null;
    }
}

MixPanelService: Handles methods like trackDailyEvent and trackWeeklyEvents, which are called frequently.

Troubleshooting Steps Taken:

• Concurrency Check: I've considered that this could be a concurrency issue, even though each event creates a new MixPanelService instance. Adding synchronized to methods like trackDailyEvent didn’t fully resolve the issue.
• Data Validation: Ensured that the data payload aligns with Mixpanel’s expected schema.
• Rate Limiting: The issue persists even under moderate load, so it seems unrelated to Mixpanel's rate limits.

Questions:

• Has anyone encountered this specific "invalid metric type" error with Mixpanel before? Could it be originating from a middleware or logging layer rather than Mixpanel itself?
• Is there a known issue with Mixpanel’s Java SDK or Spring Boot that could be causing this error?
• Are there any recommended concurrency testing libraries or approaches to further diagnose if concurrency is causing this intermittent issue?

Any guidance or suggestions on additional troubleshooting steps would be greatly appreciated! Thanks!