1. Introduction: Two collection philosophies
Although they both operate in the field of telemetry data collection and routing, Grafana Alloy and Dynatrace ActiveGate address very different use cases and philosophies.
The context
Grafana Alloy is an agnostic open-source collector based on the OpenTelemetry Collector. Its purpose is to ingest, transform, and route any data to any backend.
Dynatrace ActiveGate, on the other hand, is a central component of the proprietary Dynatrace ecosystem. It acts primarily as a secure gateway (proxy) between local agents (OneAgents) and the Dynatrace cluster, while executing remote collection tasks (API, cloud).
2. Why integrate a Proxy/Gateway in your architecture?
Before comparing the tools, it is essential to understand the value of an intermediate gateway in a cloud-native observability strategy.
Security and traffic management
In complex environments, allowing each agent (server, Kubernetes pod) to communicate directly with a remote backend (SaaS or central cluster) poses security problems. A gateway acts as a single point of egress, drastically limiting firewall openings and masking the internal network topology.
Filtering and cost optimization
Gateways allow aggregating, compressing, and filtering data (logs, traces, metrics) before transmission. This reduces bandwidth consumption and removes noise to control ingestion costs on the backend side.
Transformation and Data Masking
An observability proxy is the ideal point to apply global rules: mask sensitive data (PII, tokens, credit card numbers) contained in logs or traces before they leave the secure perimeter.
3. Grafana Alloy: The engineer's tool
Alloy is designed to offer total and granular control over telemetry pipelines through configuration as code.
Its strengths
- Agnostic (Vendor-neutral): Alloy can scrape Prometheus, receive Filebeat logs, and export everything to Datadog, Elastic, Dynatrace, or Grafana Mimir. You are not locked into an ecosystem.
- Programmable configuration: Thanks to the River language, you build complex pipelines (filtering, sensitive data masking, conditional routing) declaratively.
- Native clustering: Alloy handles load balancing itself to autonomously scrape thousands of Kubernetes pods or servers.
- Proxy/Gateway functionality: Just like ActiveGate, Alloy can be deployed as a centralized gateway to receive data from multiple local agents, process it (filtering, batching, compression), and send it to a remote backend via a single egress point.
- Agentless remote collection: Like ActiveGate, Alloy has built-in components to directly query Cloud APIs (AWS CloudWatch, Azure Monitor, GCP) or systems like vCenter to retrieve metrics and logs autonomously, without requiring a local agent.
Its weaknesses
- Learning curve: You have to code and maintain the pipelines. This requires DevOps/SRE skills to configure the collection correctly.
- No auto-instrumentation: Alloy is a collector, not an instrumentation agent. It will not automatically inject code into your Java or Node.js applications (unlike the Dynatrace OneAgent).
- Synthetic tests: Alloy integrates the
blackbox_exportermodule for simple tests (ping, HTTP requests), but requires an external tool (like Grafana k6) to execute complex scenarios, whereas ActiveGate is autonomous.
4. Dynatrace ActiveGate: The enterprise gateway
ActiveGate is not an agent itself; it is the local orchestrator of Dynatrace for a specific datacenter or cloud.
Its strengths
- Zero local configuration: Once installed, ActiveGate is 100% managed and updated from the Dynatrace web interface (SaaS). There are almost no configuration files to maintain on the server.
- Optimized network security: It serves as a single egress point. Thousands of OneAgents can send their data to the ActiveGate, which compresses, encrypts, and transmits the traffic to Dynatrace via a single outbound port opened on the firewall (443).
- Backend proxy: Unlike Alloy, which only routes telemetry data, ActiveGate can act as a proxy (reverse proxy) to directly access the web interface or API of your Dynatrace cluster.
- Remote execution (Extensions & Synthetics): ActiveGate queries Cloud APIs (AWS, Azure, VMware vCenter) to collect metrics agentlessly. It also executes synthetic tests (Private Synthetic Locations) completely autonomously from your internal network.
- Native OTLP support: ActiveGate now serves as an entry point to directly ingest OpenTelemetry (OTLP) traces to send them to Dynatrace.
Its weaknesses
- Absolute Vendor Lock-in: ActiveGate is only used to communicate with the Dynatrace ecosystem. It cannot export data to Grafana or Elastic.
- Black box: The code is proprietary. If there is unexpected behavior during ingestion, debugging relies entirely on the vendor's support.
5. Technical comparison
Summary table of fundamental differences.
Head-to-head
| Criterion | Grafana Alloy | Dynatrace ActiveGate |
|---|---|---|
| Project nature | Open Source (Apache 2.0 / GNU) | Proprietary / Commercial |
| Main use case | Universal collection pipeline, Gateway | OneAgent traffic proxy, API Polling, Synthetic Tests |
| Configuration mode | Code files (River language) | Centralized via Dynatrace UI (SaaS) |
| Proxy for Backend (UI/API) | No | Yes |
| Synthetic Tests | blackbox_exporter (integrated) or k6 (external) | Autonomous and native execution |
| Supported destinations | All (Agnostic via OTLP/Prometheus) | Dynatrace Cluster / SaaS only |
| Instruments applications? | No (Collector only) | No (Works alongside OneAgent) |
| OpenTelemetry Support (OTLP) | Excellent (Integrates OTel Collector) | Yes (Serves as OTLP Ingest Endpoint) |
6. Conclusion: Which to choose?
These two tools are generally not in direct competition, as their adoption depends on your overall choice of monitoring tool.
When to use Dynatrace ActiveGate?
If your company has chosen (and paid the license for) Dynatrace, deploying ActiveGates is unavoidable. It is essential to secure your OneAgent traffic, save bandwidth through compression, and query your Cloud environments (AWS/Azure) without deploying additional agents.
When to use Grafana Alloy?
Choose Grafana Alloy if you are building a custom observability architecture, open-source or based on the LGTM stack (Loki, Grafana, Tempo, Mimir). It is perfect if you need to heavily transform your data before storing it, or if you want to retain control over your pipelines while keeping the freedom to switch observability backends in the future.
NOTE: It is technically possible to use both! For example, Grafana Alloy can collect specific Prometheus metrics in a Kubernetes cluster and send them in OTLP format to a Dynatrace ActiveGate, which will handle routing them securely to the SaaS.
7. Go further
Train yourself in observability standards.
Our recommended courses
To master these architectural concepts, discover our courses: