I'm relatively new to monitoring logs and metrics, and I've come across Grafana Alloy (they refer to it as Alloy) being used in one of our K8s clusters. I'm curious about what Alloy actually is and how it differs from just installing Grafana on the cluster itself.
While reviewing the Grafana Alloy documentation, particularly the "Collect and forward data" section, I noticed it mentions the ability to:
- Collect Kubernetes logs
- Collect Prometheus metrics
- Collect OpenTelemetry data
I understand the parts about collecting logs through Loki and metrics via Prometheus, but I'm not sure how OpenTelemetry fits in. It seems like Alloy can gather logs, metrics, and traces. If we use Alloy, do we still need to collect logs with Loki and metrics with Prometheus separately?
I'm digging deep but thought I'd reach out to the community for a bit of guidance. Thanks a lot!
4 Answers
Many users aren't fans of OpenTelemetry for collecting logs and metrics, mainly because it can get pretty chaotic. However, it does have solid support for tracing. Most people seem to prefer using Prometheus and Loki for their standard data collection, with traces often going into Tempo through OpenTelemetry.
Alloy is essentially an observability agent. It's mainly useful if you're opting for Grafana's SaaS storage service. If you're planning to manage your own local storage setups—for metrics with Prometheus and logs with Loki—then you probably don’t need Alloy. Prometheus can collect metrics while Loki functions just for storage, so there's no real need for Alloy if you're sticking to those tools.
Alloy functions as a data scraper that collects logs, metrics, and traces. Think of Loki and Prometheus as the storage systems for logs and metrics, respectively, while Grafana serves as the visualizer for all the data you gather. The flow looks like this: Alloy collects data and sends it to Loki and Prometheus, while Grafana presents it all visually. It's a neat setup!
To clarify with simpler terms:
- Prometheus handles metrics,
- Loki manages logs,
- Alloy is the data collector that gathers everything,
- Then Grafana displays it for users. It's kind of a pipeline of data!
Since you're just starting out, I would suggest reaching out to your team instead of just relying on online forums. It's a great way to learn, and it shows you're eager to understand the tools you're working with. They'll be able to provide insights specific to your environment and the decisions made regarding the tools used.
We actually implement Alloy with Mimir for self-hosting, as using Grafana Cloud for our 40+ million metric series would be financially overwhelming.