Monitoring & Reliability Glossary

A DNS record that maps a hostname to an IPv4 address (e.g. `foursight.cloud → 76.76.21.21`).

Maps a hostname to an IPv6 address. Functionally the IPv6 equivalent of an A record.

The yearly value of a single customer contract, normalized to one year. Used to size and segment enterprise sales pipelines.

A class of ciphers that encrypt data and authenticate it in a single operation. AES-GCM and ChaCha20-Poly1305 are the standard AEAD ciphers in TLS 1.2 and the only ones allowed in TLS 1.3.

Desensitization caused by too many low-quality alerts. Leads to slower response times, missed real incidents, and on-call burnout.

A managed service (most commonly AWS API Gateway) that fronts your backend with routing, rate-limiting, auth, throttling, and request transformation.

Annualised subscription revenue, i.e. MRR × 12. Standard top-line metric for SaaS valuation and growth tracking.

Availability measures whether a service responds (uptime %). Reliability measures whether it responds correctly and within acceptable latency. A service can be available but unreliable if responses are slow or wrong.

Amazon's serverless function-as-a-service product — runs your code in response to events without you managing servers. Has measurable cold-start latency the first time a function runs after idle.