Why Replace Datadog or New Relic with SigNoz?
SaaS observability tools follow a punishing pricing model: free for a handful of hosts, then costs spiral with every new service. For a web agency managing ten client projects or an independent developer scaling a SaaS product, the monthly bill can easily exceed $200–500 with no proportional value gain.
SigNoz changes the equation. It is an open-source observability platform (Apache 2.0 license) powered by ClickHouse for high-performance trace and metric storage, and the OpenTelemetry protocol for instrumentation. Your data stays on your infrastructure, you control retention, and you only pay for the VPS running the stack.
What SigNoz Gives You
- Distributed traces: visualize the full path of an HTTP request across your microservices, with spans, durations, and errors at every hop.
- Prometheus-compatible metrics: import existing dashboards or build new ones directly in the SigNoz UI.
- Centralized logs: collect and correlate structured logs from all your applications in a unified interface.
- Configurable alerts: set thresholds on any metric and receive notifications via Slack, PagerDuty, or webhooks.
- Customizable dashboards: build business or technical views in a few clicks — no LoQL or PromQL required.
- Modern UI: responsive React interface accessible on port 8080 of your VPS, with no proprietary client-side agent.
Prerequisites Before You Start
SigNoz relies on ClickHouse, a columnar database engine that is memory-hungry. The recommended minimum is 4 GB of RAM — below that, ClickHouse gets killed by the kernel's OOM killer before the UI even loads. For production use with multiple instrumented applications, target 8 GB.
Full prerequisites:
- A VPS running Ubuntu 22.04 or Debian 12.
- Docker Engine ≥ 24 and Docker Compose V2 installed.
- Port 8080 open in your firewall (SigNoz UI).
- Ports 4317 (OTLP/gRPC) and 4318 (OTLP/HTTP) open to receive traces from your apps.
- Root or sudo access on the VPS.
- At least 20 GB of free disk space for ClickHouse and its data files.
Installing SigNoz via Foundry CLI
Step 1 — Install Docker on Your VPS
curl -fsSL https://get.docker.com | sh
systemctl enable --now docker
docker compose versionStep 2 — Install Foundry CLI (foundryctl)
Since v0.112.0, SigNoz uses the Foundry CLI as its official deployment method.
curl -L https://get.foundry.so/foundryctl/latest | bash
export PATH="$HOME/.foundry/bin:$PATH"
foundryctl --versionStep 3 — Create the casting.yaml File
mkdir -p /opt/signoz && cd /opt/signoz
cat > casting.yaml << 'EOF'
apiVersion: foundry.so/v1
kind: Casting
metadata:
name: signoz
spec:
release: stable
components:
- name: signoz
enabled: true
- name: clickhouse
enabled: true
EOFStep 4 — Run the Deployment
foundryctl cast -f casting.yamlFoundry CLI pulls the Docker images, sets up persistent volumes, and starts the containers in the correct order. Full startup takes about 2–3 minutes.
Step 5 — Verify SigNoz Is Running
docker compose -f /opt/signoz/docker-compose.yaml psThen open your browser at http://<VPS_IP>:8080. The SigNoz interface appears. Create your admin account on first login. Note: the old port 3301 mentioned in older tutorials is obsolete — the current UI port is 8080.
Step 6 — Secure Access with a Reverse Proxy
Never expose port 8080 directly in production. Use Nginx as a reverse proxy with TLS:
server {
listen 443 ssl;
server_name signoz.yourdomain.com;
ssl_certificate /etc/letsencrypt/live/signoz.yourdomain.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/signoz.yourdomain.com/privkey.pem;
location / {
proxy_pass http://127.0.0.1:8080;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
}
}Block port 8080 from outside: ufw deny 8080.
Instrument Your Application with the OpenTelemetry SDK
SigNoz receives traces via the OTLP protocol. Node.js:
npm install @opentelemetry/sdk-node @opentelemetry/auto-instrumentations-nodeOTEL_EXPORTER_OTLP_ENDPOINT="http://<VPS_IP>:4318" \
OTEL_SERVICE_NAME="my-api" \
node -r ./tracing.js app.jsPython:
pip install opentelemetry-distro opentelemetry-exporter-otlp
opentelemetry-bootstrap -a install
OTEL_EXPORTER_OTLP_ENDPOINT="http://<VPS_IP>:4318" \
OTEL_SERVICE_NAME="my-python-service" \
opentelemetry-instrument uvicorn main:appCreate Dashboards and Alerts
Once your applications are instrumented, SigNoz automatically populates the Services view with P50/P99 latency, error rate, and throughput for each service.
Create a custom dashboard: go to Dashboards → New Dashboard, add a Time Series panel, select a Prometheus metric, and apply filters by service or environment.
Configure a latency P99 alert: go to Alerts → New Alert Rule, choose Metric Based Alert, enter your condition (e.g., p99(signoz_latency_bucket{service_name="my-api"}) > 500), and configure a Slack or webhook notification channel.
Watch Out for ClickHouse OOM Kills
ClickHouse is the most memory-intensive component in the SigNoz stack. On a VPS with less than 4 GB of available RAM, the Linux kernel may kill the ClickHouse process with exit code 137.
Diagnose it:
dmesg | grep -i oomYou will see a line like Out of memory: Killed process XXXX (clickhouse-serv).
Fixes: upgrade your VPS RAM (recommended), or cap ClickHouse memory by adding max_memory_usage=2000000000 to /etc/clickhouse-server/users.xml.
SigNoz vs Datadog vs Grafana Cloud
| Criteria | SigNoz (self-hosted) | Datadog | Grafana Cloud |
|---|---|---|---|
| Monthly cost (5 services) | VPS cost only (~$10-20) | ~$75-150 + custom metrics | Free up to 10k series, then ~$8/1k |
| Distributed traces | Yes (native OpenTelemetry) | Yes (proprietary agent) | Yes (Tempo, via OTLP) |
| Data sovereignty | Full — data on your VPS | Data at Datadog (US/EU) | Data at Grafana Labs |
| Operational complexity | Medium (Docker, 1 VPS) | None (SaaS) | Low (SaaS) |
| Metrics | Yes (Prometheus-compatible) | Yes (proprietary + Prometheus) | Yes (Mimir, Prometheus-compatible) |
| Logs | Yes (built-in) | Yes (additional cost) | Yes (Loki, additional cost) |
| Updates | Manual (foundryctl) | Automatic | Automatic |
| Support | Community + paid plan | Paid (included) | Community + paid plan |
Troubleshooting Common Issues
UI does not load on port 8080: check that the signoz-frontend container is running and that your firewall allows the port.
Traces do not appear: verify that port 4318 (OTLP/HTTP) is reachable from your application: curl -v http://<VPS_IP>:4318. A 405 Method Not Allowed response confirms the collector is listening.
ClickHouse container keeps restarting: almost certainly an OOM kill. Confirm with dmesg | grep -i oom.
Plan Your ClickHouse Data Retention
By default, SigNoz retains traces for 3 days and metrics for 30 days. Adjust retention in the SigNoz UI under Settings → Retention Period. For an agency managing multiple client projects, 7 days of traces and 90 days of metrics strikes a good balance between visibility and disk usage.
