This article records and analyzes how upgrading an application to JDK 11 changed the Direct Memory management strategy, causing a sharp increase in memory‑utilization alerts, and demonstrates step‑by‑step troubleshooting, code inspection, and JVM parameter tuning to restore normal memory usage.
This comprehensive guide walks you through systematic JVM memory issue diagnosis, covering initial data collection, analysis of heap, metaspace, direct memory, stack problems, and practical command‑line tools, while offering actionable tips and real‑world examples for effective troubleshooting.
The article explains AutoMQ's memory‑cache architecture, compares LogCache and BlockCache designs, analyzes Netty's internal and external memory fragmentation caused by the Buddy and PageRun/PoolSubpage allocators, and presents mitigation techniques such as ByteBufSeqAlloc to reduce OOM risks.
This article explains the common Java OutOfMemoryError types—including heap space, GC overhead limit exceeded, Metaspace, CodeCache, Direct Memory, and Linux OOM Killer—detailing their causes, symptoms, and step‑by‑step troubleshooting techniques for backend developers.
This article investigates the severe memory growth and latency spikes observed when synchronizing data across data centers in a Netty‑driven online computation service, analyzes the impact of JDK 17 ZGC and direct‑buffer allocation, and presents the debugging steps, source‑code insights, and configuration changes that ultimately resolved the issue.
This article examines the various causes of Java OutOfMemoryError, demonstrating heap overflow, stack overflow, metaspace exhaustion, and direct memory exhaustion through practical code examples, and explains how to diagnose and differentiate memory leaks from genuine memory overuse using JVM tools.
This article explains the various types of Java OutOfMemoryError, shows how to trigger each one on HotSpot JVM, provides diagnostic steps and relevant JVM flags, and offers practical code examples for heap, stack, metaspace, and direct memory overflow scenarios.
