Does Metric Registrar works in Cloud Foundry without Pivotal?
I have open source Cloud Foundry and I need to get custom metrics from app. I installed Metric Registrar community plugin for CF, I registered my application with endpoint, I also defined log format. Unfortunately I see no traffic on registered endpoint.
If open source Cloud Foundry do not support Metric Registrar, is there any other way to get support for custom app metrics?
Does Metric Registrar works in Cloud Foundry without Pivotal?
The Metric Registrar is part of the VMware Tanzu Application Service product, it's not part of the Open Source Cloud Foundry project. It's a value-add feature for those using the paid product.
If open source Cloud Foundry do not support Metric Registrar, is there any other way to get support for custom app metrics?
You don't strictly need the Metric Registrar to do this. The Metric Registrar's main purpose is to take metrics from your apps and inject them into the Loggregator log/metric stream. This is convenient if you have other software that is already consuming log & metric streams from Loggregator.
You don't have to do that though, as there are other ways to export metrics from your app.
If you want them to go through Loggregator, you could export structured log messages (perhaps JSON?) via STDOUT that contains your metrics. Those will, like your other log messages, go out through Loggregator. You would then just need to have something ingesting your logs, identifying the structured messages, and parsing out your metrics. This is similar to what Metric Registrar does, you're just parsing out the structured log entries after they leave the platform.
If you have an ELK stack or similar running, you can probably make this solution work easily enough. ELK can ingest your logs & structured log metrics, then you can search/filter through the metrics and create dashboards.
Another option you could do is to run Prometheus/Grafana. You then just need to make sure your app has a Prometheus Exposition metrics endpoint (this is super easy with Java/Spring Boot & Spring Boot Actuator, but can be done in any language). Point Prometheus at your app and it will then be able to scrape metrics from your apps & you can use Grafana to view them. None of this goes through Loggregator.
If you're looking for a solution that's more automatic, you could run an APM agent (NewRelic, DataDog, AppDynamics, Dynatrace, etc..) with your apps. These will capture metrics directly from the process and export them to a SaaS platform where you can monitor/review them.
There are probably other options as well. This is just what comes to mind as I write this up.