Latest stories from ShopperCove

What Is Nagle's Algorithm? TCP_NODELAY vs Nagle Tested

Hands-on TCP_NODELAY vs Nagle: 1-byte reuse 124k vs 73k RPS; 32×16B writes favor Nagle (~1.7× fewer OutSegs). Delayed-ACK mean trap on localhost.

ulimit Soft vs Hard File Descriptors: EMFILE Lab with Real Numbers

Hands-on RLIMIT_NOFILE lab: soft=64 → EMFILE after 58 held accepts; soft=512 takes 200/200. Soft raises without root; hard does not. Real numbers.

SO_REUSEPORT vs Single Listen: Independent Queues and ListenOverflows

Hands-on SO_REUSEPORT lab: ss shows 4 listen queues; backlog=8 flood 72% vs 62% OK; ~41% fewer ListenOverflows. Real localhost numbers, no Docker.

TCP Listen Backlog Lab: somaxconn, ListenOverflows, and Silent Drops

Hands-on TCP backlog lab: backlog=1 + slow accept → 34/200 OK, ListenOverflows +357; backlog=128 stays 200/200. Real ss + netstat numbers.

Unix Domain Socket vs TCP Localhost: Latency and Throughput Lab

Hands-on UDS vs TCP loopback echo: connect-per ~3× RPS (49k vs 16k); reuse ~1.3×. Real Python numbers, no Docker.

HTTP Keep-Alive vs Connection: close: Localhost Numbers and a Simulated-RTT Trap

Clozure AI Business OS Review: Pricing, Claims, and Fit

Nginx limit_req Rate-Limit Lab: Burst, nodelay, and the return Pitfall

Hands-on nginx 1.26 limit_req on localhost: 5r/s burst=10 nodelay yields 11/200 OK then 429s; return bypasses limiting; paced 5r/s stays green. Real numbers, no Docker.

Lily in CI: Trying Fuzz-Based Backdoor Detection on a Real Repo

Hands-on Lily (ASE 2026) on an owned C toy: rosa/lily 0.6.0 pin, directed catch of a localhost-bind trigger, clean refactor with zero flags, discovery miss, and CI cost math.

SBOM Signing in CI: How to Sign and Attest With Cosign

One CI shape: build an image by digest, Syft SBOM, Cosign sign + SBOM attest, verify success, and prove wrong-key/unsigned failure — the operational follow-on to after-xz.