A slow page is rarely one slow thing. It is a sum of intervals: time queued in the accept backlog, time waiting for a free PHP-FPM worker, time spent in…
Read Morejemalloc Arena and Decay Tuning for Redis and nginx on Memory-Constrained Instances
Long-running daemons on small instances accumulate memory that the allocator never returns to the kernel. The process RSS climbs for days while the application’s own live heap stays flat, and…
Read Morenftables Set Performance: Hash Sizing, Timeouts and the Cost of Linear Rules
nftables sets are the single biggest performance lever most firewall configurations never touch. A ruleset with 400 individual ip saddr matches evaluates linearly; the same 400 addresses placed in a…
Read MoreMTU and PMTUD Black Holes: Diagnosing the Stalls That Look Like TLS Failures
Most TLS failures that are not certificate errors are MTU problems wearing a disguise. The TCP handshake completes, the certificate verifies, the first small HTTP response arrives — and then…
Read MoreTLS 1.3 Post-Quantum Hybrid Key Exchange on a VPS: Measuring the CPU and Handshake Cost
OpenSSL 3.5 and BoringSSL now ship the X25519MLKEM768 hybrid group enabled by default, and browsers have started negotiating it. On a VPS, that changes the arithmetic of a TLS handshake:…
Read MoreNVMe Wearout Telemetry on a VPS: Reading SMART Attributes to Predict SSD Failure
An NVMe drive fails in a predictable sequence: endurance is consumed, spare blocks are reallocated, the media error rate climbs, and only then does write latency spike and the device…
Read MoreLowering DNS TTL Before a VPS Cutover: A Measured Rollback-Safe Procedure
A cutover fails in the rollback, not in the switch. The switch is one edit to an A record; the rollback is where you discover a resolver on the other…
Read MoreHugepages and io_uring on a VPS: Measuring Real Throughput Gains
Two kernel features get recommended together in almost every high-throughput tuning guide: transparent hugepages for the page tables, and io_uring for the syscall path. They solve different problems — one…
Read MoreWireGuard Performance Tuning on a VPS: MTU, Multicore and Throughput Measurement
WireGuard is fast by default, but “fast by default” is not the same as “fast on your VPS”. A single-threaded tunnel on a small instance can saturate at a few…
Read Moredm-crypt and LUKS Encryption Overhead on a VPS: Measuring the Real Cost of AES-NI
Encrypting a VPS disk used to mean paying a heavy performance tax. With AES-NI hardware acceleration present, that tax is often under five percent for throughput and near zero for…
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