0 views collected around this technical thread.
java.lang.OutOfMemoryError: Metaspace occurs when the JVM's native Metaspace exceeds its configured limit, often due to excessive dynamic class generation, large numbers of loaded classes or classloader leaks, and can be mitigated by increasing Metaspace size, fixing memory leaks, and optimizing class loading.
After upgrading core services to JDK 11, the team encountered a Metaspace rise and off‑heap memory growth caused by class‑loading changes and Netty’s disabled native buffers, which were resolved by expanding Metaspace to 768 MB and adding JVM options to enable Netty reflection and open required modules, restoring 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.
This article explains the JVM memory architecture—including heap, stack, native stack, method area, and program counter—detailing heap generations, object allocation strategies, object layout, reference types, and the complete lifecycle of Java objects from creation to garbage collection.
This article explains the various Java OutOfMemoryError types—including Java heap space, GC overhead limit exceeded, Metaspace, CodeCache, Direct Memory, and Linux OOM Killer—describes their causes, typical symptoms, and provides step‑by‑step troubleshooting and mitigation strategies for developers.
This article documents a step‑by‑step investigation of a high TP99 caused by frequent Full GC in a Java service, describing the diagnostic mindset, tools used, GC trigger conditions, object promotion mechanisms, the impact of AdaptiveSizePolicy and Metaspace, and the concrete configuration and code changes that eliminated the issue.
This article documents a month‑long JVM garbage‑collection tuning process that reduced daily FullGC occurrences from over 40 to less than one per ten days by adjusting heap parameters, fixing memory leaks, and tuning Metaspace, while providing detailed analysis, code snippets, and performance graphs.
This article walks through a real‑world investigation of a Metaspace Out‑Of‑Memory error in a Java service, detailing how JVM monitoring tools, class‑loader behavior, and hot‑deployment agents contributed to the issue and presenting practical fixes and preventive measures.
This article provides a comprehensive overview of the Java Virtual Machine memory architecture, covering heap layout, object allocation, Metaspace, stack frames, native method stacks, program counters, direct memory, and code cache, complete with configuration tips and practical code examples.
This article explains the JVM memory layout, covering the heap (young and old generations), Metaspace, virtual machine stacks, native method stacks, and the program‑counter register, while describing their roles, configuration parameters and how they interact during garbage collection and method execution.
This article explains the JVM memory architecture, covering the heap (young and old generations, Eden and Survivor spaces), Metaspace, virtual machine stacks, native method stacks, and the program counter register, while also illustrating key JVM parameters and bytecode execution with examples.
A production incident on an elastic‑cloud deployment revealed that setting the JVM Metaspace limit to 64 MiB, while the application required around 76 MiB, triggered continuous Full GC, causing stop‑the‑world pauses, full‑line time‑outs, and a costly rollback.
The article recounts a staged rollout of the Maybach service on elastic cloud, details the timeline of successful and failing deployments, analyzes JVM metrics revealing excessive Metaspace usage that triggered continuous full garbage collections, and explains how this caused system‑wide timeouts and a half‑hour outage.
This article provides a comprehensive overview of the Java Virtual Machine memory layout, explaining each region such as the heap, metaspace, stack, program counter, direct memory and code cache, along with allocation strategies, tuning parameters, and practical OOM demonstrations.
This article explains the causes of various Java OutOfMemoryError scenarios—including heap, stack, metaspace, and direct memory overflow—provides diagnostic tools, shows reproducible code examples, and offers practical solutions such as adjusting JVM parameters and optimizing code to prevent memory exhaustion.
Tracing a large method with Arthas caused a Metaspace OOM because constant‑pool rewrites inflated the Non‑Class space, each rewrite copying a massive StackMapTable, but preserving the original constant‑pool layout in Arthas stops the growth, and exposing off‑heap metrics aids production monitoring.
This article provides a comprehensive overview of the Java Virtual Machine memory layout, explaining the roles and allocation strategies of the heap, metaspace, stack frames, program counter, direct memory, and code cache, and includes practical code examples for heap tuning and OOM demonstration.
This article explains when and how Java classes are loaded, details the JVM's ClassLoader implementation—including the native defineClass1 method, InstanceKlass creation, SystemDictionary registration, and parallel loading locks—then demonstrates breaking the parent‑delegation model with a custom ClassLoader and discusses practical usage scenarios.
This article explains the distinction between Java memory regions and the Java Memory Model, describes each JVM runtime data area—including the program counter, stacks, heap, metaspace, and direct memory—and outlines how the model governs visibility, ordering, and synchronization in concurrent programs.
This article provides a comprehensive overview of the Java Virtual Machine memory layout, covering heap regions, Metaspace, stack frames, native method stack, program counter, direct memory, and code cache, along with configuration tips, diagnostic commands, and illustrative code examples to help readers understand memory allocation and garbage collection.