The Webalert Blog
Expert insights on website monitoring, uptime optimization, SSL management, and building trust with status pages.
RSS Feed
Apdex Score Explained: Formula, T Threshold, Pitfalls
Calculate Apdex from satisfied and tolerating requests, choose a meaningful T threshold, interpret scores, and avoid the aggregation traps that hide slow users.
May 29, 2026
9 min read
HTTP/3 & QUIC Monitoring: What Changes and What to Watch
How HTTP/3 and QUIC change monitoring: UDP 443, 0-RTT, connection migration, fallback to HTTP/2, and the new failure modes and metrics you must watch.
May 29, 2026
9 min read
P50 vs P95 vs P99 Latency Explained (With Practical Formulas & Tail Latency Examples)
Understand P50 (median), P95, and P99 tail latency. Learn why average latency is misleading, how percentiles are calculated, and how to set accurate SLO alerts.
May 29, 2026
10 min read
Active Record Performance Monitoring: N+1, SQL, and Pools
Monitor Active Record query count, N+1 lazy loads, slow SQL, object instantiation, and connection pool waits using Rails instrumentation and database evidence.
May 28, 2026
14 min read
AI Crawler Monitoring: Verify Bots, Purpose & Access
Monitor AI crawlers by documented purpose, robots.txt policy, user agent, and official IP data—without confusing training, search indexing, and user fetches.
May 28, 2026
14 min read
Real User Monitoring (RUM): How It Works and When to Use It
Learn how browser RUM captures Core Web Vitals, errors and real-user context, how to sample and protect privacy, and when synthetic checks are still required.
May 28, 2026
13 min read
5xx Server Errors: 500, 502, 503, 504 Explained
Understand 500, 502, 503 and 504 server errors, diagnose application, proxy and upstream causes, and monitor status, body and error-rate patterns.
May 27, 2026
17 min read
Is My Website Down? A 60-Second Outside Check
Run a 60-second outside check to separate a real, regional, or local website outage using another network, DNS, HTTP headers, and external probes.
May 27, 2026
11 min read
Uptime Percentage Calculator: Allowed Downtime by SLA
Convert 99% through 99.999% uptime into allowed downtime per day, week, 30-day month, quarter, and year, with formulas for any custom target.
May 27, 2026
11 min read
Cron Dead-Man Switch Monitoring: Detect Missed Scheduled Jobs
Detect cron jobs that never run with schedule-aware heartbeats, last-success timestamps, grace periods, idempotent retries, and clear missed-job alerts.
May 26, 2026
11 min read
Incoming Webhook Monitoring: Retries and Security
Monitor incoming webhook receipt, signature verification, queue age, processing outcomes, duplicates and provider retries without exposing secrets.
May 26, 2026
12 min read
Response Body Validation: Detect False 200 OK
Validate required HTML, JSON fields, schemas and negative error markers so status-only monitors catch false-green pages, APIs and login redirects.
May 26, 2026
13 min read