RSS Contracts: Stop OOMKilled Java Pods in Kubernetes by Testing RSS as an API
Use cgroup RSS budgets, CI sampling, and runtime headroom to catch JVM memory regressions before they hit production.
#java
13 posts
Kubernetes CPU Throttling Autopsy: Why p99 Latency Explodes at 40% CPU Usage
CPU looks OK but tail latency is catastrophic. I'll show how to correlate CFS throttling with latency spikes and why removing CPU limits can paradoxically help.
Circuit Breaker vs Rate Limiter vs Bulkhead: When to Use Which Pattern
Three resilience patterns that are often confused. I'll show exactly when each prevents cascading failures and when it makes things worse with real metrics.
When Prepared Statements Make PostgreSQL 10× Slower: Generic Plan Trap
Same query, same params, but prod is slow and staging works fine. I'll show how to reproduce the generic plan problem with pgBouncer, Java/Go and how to fix it.
Java Virtual Threads vs Reactive: When to Drop WebFlux for Project Loom
Virtual Threads in Java 21 promise simpler code than Reactive. I benchmark both under 10k concurrent connections and show where each wins.
JVM Native Memory in Kubernetes: Why Your Pod Gets OOMKilled with 50% Heap
Heap is 50% full but pod gets OOMKilled. I'll show how to track native memory (Metaspace, threads, NIO) and prevent container memory issues.
HTTP Keep-Alive Connection Reset: Why Your Requests Fail with 'Connection Reset by Peer'
Sporadic 'connection reset by peer' errors in production. I'll show how keep-alive timeout mismatches between client and server cause this and how to fix it.
Redlock vs PostgreSQL Advisory Locks: When You Don't Need Redis for Distributed Locking
Adding Redis just for distributed locks? PostgreSQL advisory locks might be enough. I compare both with failure scenarios and performance benchmarks.
Architectural Linting: Automated Protection Against Spaghetti Code
How to enforce architectural rules in CI/CD. Dependency Cruiser for JS/TS, ArchUnit for Java, and practical configuration examples.
Adaptive Concurrency Limits: Stop Guessing Thread Pool Sizes
Thread pool 200 because that's what Stack Overflow says? Netflix's algorithm adjusts concurrency automatically based on latency. I show how it works with benchmarks.
Java Profiling in Hardened Kubernetes: When Security Blocks Your Debugger
Can't attach profiler to production JVM. seccomp blocks perf_event_open, container drops CAP_SYS_PTRACE, and PodSecurityPolicy prevents privileged mode. Here's how to profile anyway.
Java OOMKilled With Stable Heap: Native Memory, Direct Buffers, and glibc Arenas
Heap metrics look fine, GC is happy, but the container keeps dying. The culprit: native memory from direct buffers, JNI, and glibc memory allocator fragmentation.
JVM Metaspace OOM in Kubernetes: Why MaxMetaspaceSize Alone Won't Save You
Pod OOMKilled despite MaxMetaspaceSize set. The cause: Metaspace grows outside heap, container memory limit doesn't account for it, and class unloading isn't happening.