Simple plugin for .NET Core and .NET Framework applications to export Hangfire stats to Prometheus.
The plugin uses the Hangfire JobStorage class to export metric "hangfire_job_count" using "state" label to indicate jobs in various states. The metrics are updated before every scrape. The states exported are:
- Failed
- Enqueued
- Scheduled
- Processing
- Succeeded
- Retry
Hangfire.Prometheus plugin is initialized in Configure() using UseHangfirePrometheusExporter() method. Hangfire job storage must already be initialized. If the job storage is not initialized, the exporter will not be initialized as well, and will report no error.
public void ConfigureServices(IServiceCollection services)
{
services.AddHangfire(...);
}
public void Configure(IApplicationBuilder app)
{
app.UsePrometheusHangfireExporter();
app.UseMetricServer();
app.UseHangfireDashboard();
app.UseHangfireServer();
}
The following settings are available for this plugin using Hangfire.Prometheus.HangfirePrometheusSettings class:
| Setting Name | Type | Default Setting | Description |
|---|---|---|---|
| CollectorRegistry | Prometheus.CollectorRegistry | Metrics.DefaultRegistry | Prometheus CollectorRegistry to use. |
| FailScrapeOnException | Boolean | true | Controls whether to fail the scrape if there is an exception during Hangifre statistics collection. |
An instance of HangfirePrometheusSettings class can be passed to UsePrometheusHangfireExporter() to use settings other than defaults:
public void Configure(IApplicationBuilder app)
{
CollectionRegistry myRegistry = Metrics.NewCustomRegistry();
app.UsePrometheusHangfireExporter(new HangfirePrometheusSettings { CollectorRegistry = myRegistry });
app.UseMetricServer(...);
}
Simultaneous scrapes proceed at the same time. Care should be taken when setting the scrape interval period to minimize simultaneous scrapes.
This plugin uses Hangfire job storage to retrieve job statistics. If multiple Hangfire servers are using the same job storage only a single instance should be exporting Hangfire metrics or only a single instance must be scraped.