java

2026-07-03
-Xmx Won't Save Your Native Image
JAVA_TOOL_OPTIONS is a no-op on a native binary. The 256MB OOM that docker stats couldn't see.
The Memory Benchmark · 23/41 5 min read
2026-07-03
Quarkus 12,563 vs Spring 820 (Both Numbers Are Wrong)
A Prometheus counter that resets on OOM crash-loops turned a 5x throughput advantage into a 15x deficit. The fix is six lines of awk.
The Memory Benchmark · 22/41 5 min read
2026-07-02
200 Virtual Users vs api.nasa.gov (DEMO_KEY)
A benchmark orchestrator with no mock guardrail ran 200 VUs against NASA, a small free ISS tracker, and a free weather API.
The Memory Benchmark · 20/41 4 min read
2026-07-02
The Throughput Was Always 115
28 mock APIs. Twelve benchmark scenarios. Two codebases. One number: 115 req/s.
The Memory Benchmark · 19/41 7 min read
2026-06-30
Designed a Reactive Benchmark. Imperative Won.
Built a reactive benchmark with realistic latency. The imperative rewrite survived memory pressure. Reactive didn't.
The Memory Benchmark · 18/41 5 min read
2026-06-27
265 req/s on All Three Runtimes (Until You Add a Memory Limit)
Native image, JVM, and virtual threads all hit 265 req/s. Then the memory limit dropped.
The Memory Benchmark · 17/41 6 min read
2026-06-25
ExecutorType.VIRTUAL Doesn't Exist
The Config Everyone Writes#micronaut: executors: io: type: VIRTUAL Every tutorial. Every "Micronaut + virtual threads" blog post. Every AI suggestion. This is the obvious config. One property, clean intent. It crashes at startup: No enum constant …
The Memory Benchmark · 16/41 4 min read
2026-06-22
Error Is Not Exception: Micrometer's Silent CPU Metric on Native Image
The catch block that catches nothing#This code has a bug. Not a typo, not a logic error. A type hierarchy bug. private double invoke(@Nullable Method method) { try { return method != null ? toDouble((Number) method.invoke(operatingSystemBean)) : Double.NaN; } …
The Memory Benchmark · 15/41 4 min read
2026-06-20
We Removed Reactor. Nothing Got Slower.
We took the entire reactive stack out. R2DBC, Mono, Flux, Reactor Core, loom-carrier, flatMap with its carefully-tuned concurrency arguments. Replaced it with JDBC, HikariCP, and blocking method calls. Same endpoints. Same Netty HTTP server. Same PostgreSQL. …
The Memory Benchmark · 14/41 5 min read
2026-06-19
Five Things Spring Boot 4.1 Doesn't Tell You Until It's Too Late
Spring Boot 3.5 lost OSS support on June 30, 2026. Boot 4 modularized autoconfiguration, and its silent failures cost an afternoon.
The Memory Benchmark · 13/41 5 min read