Distributed · Real-Time · Zero Downtime

Uptime Monitoring,
Engineered for Scale.

SaaS-grade distributed architecture. Real-time WebSockets. Zero compromises.

9 nodes monitored · 17 connections · packets in flight

System Architecture

Built on patterns that survive production.

BullMQ · Redis

Decoupled Worker Nodes

Every check is a durable, queue-backed job. Workers run in isolated processes — a surge or crash never touches the API layer.

  • Horizontal scale: add workers without config changes
  • Automatic retries with exponential back-off
  • Job deduplication prevents thundering herds
  • Dead-letter queue for forensic failure analysis

Live Job Lifecycle

API Gateway

POST /monitors/:id/check

REST
BullMQ.add('ping', job)

Redis BullMQ

queue:monitors — waiting

Queue
worker.process(job)

Worker Node

HTTP ping → result emitted

BG
successtimeoutqueued
avg 42ms
pulse-worker — bash
Pulse Worker v2.4.1 initialising…
Redis BullMQ connected ● queue:monitors ready
Socket.io server listening on :3001 — 0 clients
─────────────────────────────────────────────────
›
live stream
4 events
Socket.io · WS

Real-time WebSocket Updates

Results are pushed the moment a worker emits them. No polling, no stale dashboards — subscribers receive structured events in <5ms.

  • Room-scoped broadcasts per monitor ID
  • Reconnect with buffered event replay
  • Binary-free JSON payloads stay inspector-friendly
  • Server-side presence for multi-tab deduplication
Security Layer

SSRF Network Protection

The worker enforces a strict egress allowlist before dialling any URL. Private ranges and loopback addresses are blocked at the syscall boundary — not just validated.

  • RFC-1918 + RFC-5735 ranges fully blocked
  • IPv6 link-local and ULA ranges denied
  • DNS resolution validated post-lookup (rebinding safe)
  • Audit log for every blocked attempt

SSRF Shield — Egress Filter

0 blocked
CIDR RangeStatus

10.0.0.0/8

RFC-1918 Private A

BLOCKED

172.16.0.0/12

RFC-1918 Private B

BLOCKED

192.168.0.0/16

RFC-1918 Private C

BLOCKED

127.0.0.0/8

Loopback

BLOCKED

169.254.0.0/16

Link-local / APIPA

BLOCKED

::1/128

IPv6 Loopback

BLOCKED

fc00::/7

IPv6 ULA

BLOCKED

0 private-range requests reach the network

Start monitoring in 60 seconds

Stop guessing if your app is down. Know it before your users do.

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100%Container UptimeDocker · auto-healing
<50msWS LatencyNestJS · Socket.io
DistributedWorkersRedis & BullMQ