Xelvaris
Practical engineering writing for people who keep systems alive.
Practical Notes on Postgres Connection Pooling
June 6, 2026
Each incoming PostgreSQL connection instantiates an isolated operating system process with dedicated memory overhead, necessitating a dedicated pooling proxy in growing deployments. Classic session pooling acts transparently, whereas high-throughput transaction pooling frequently disrupts stateful features such as advisory locking, pub-sub listeners, and session-scoped variables.
Connection pool instability frequently originates from careless application lifecycle management: unclosed checkouts accumulating over time, open cursors lingering during external API calls, or schema alter scripts monopolizing pooled sockets. Transaction mode exposes these architectural flaws aggressively, failing unhygienic workflows on the spot.
Zero-Downtime Deployments Without the Drama
August 28, 2026
Popular engineering lore depicts seamless releases through elaborate blue-green switches and instantaneous traffic flips. Production reality centers on disciplined fundamentals: synthetic probes verifying realistic workloads, graceful connection draining on retiring nodes, and database schema mutati…
Structuring DNS for Reliability
September 26, 2026
Nameserver outages are devastating because they paralyze systems globally: infrastructure monitors report operational green across every host while end users cannot locate your endpoints. Mitigating this catastrophic blind spot requires standard multi-provider redundancy backed by distinct network b…
The Hidden Cost of Chatty Microservices
August 22, 2026
Decomposing monolithic applications substitutes in-memory execution paths with network boundaries, creating massive fan-out overhead. Where an operation once invoked three internal functions, it now executes three network dispatches across distinct services, multiplying timeout policies and failure …
What Good Observability Actually Looks Like
June 21, 2026
Dashboards multiply like rabbits and answer questions nobody asked this month. Good observability starts from the opposite direction: the alert fired, a human is awake, and the tooling should answer 'what changed' within a minute.…
More reading
- Email Deliverability: Authentication Beyond SPF — Email, August 18, 2026
- Managing Secrets Without Losing Sleep — Security, September 4, 2026
- Reading Latency Percentiles Without Fooling Yourself — Operations, June 30, 2026
About us
We cover the unglamorous middle of software: queues that back up, caches that lie, and DNS at 3 a.m. Everything is written from real operational experience.