JVM memory and GC tuning
Free JVM module: heap, metaspace, allocation rate, and GC pauses versus connection leaks. First topics open in the browser — no sign-up.
Free Core Java module on heap, metaspace, allocation, and GC pauses. Open the first JVM topics in the browser with no account.
When a service dies with OutOfMemoryError or multi-second GC pauses, the answer is rarely “add RAM”. This module covers heap vs metaspace, allocation rate, and how to read a basic GC log — the same material as the paid JVM track.
Use it next to the HikariCP lab: pool exhaustion is not a heap problem, and treating it as one is a common on-call mistake. The module helps you tell memory pressure from connection leaks.
What you will cover
- Heap, young generation, and old generation
- Metaspace vs PermGen-era myths
- Allocation rate and GC pause symptoms
- When OOM is a leak vs a sizing issue
- First topics free; full JVM track after sign-in
Related free labs and modules
Common questions
Is there a free JVM memory and GC tutorial?
Yes. This module’s first topics on heap, metaspace, and GC are open without an account. Sign in to continue the JVM track.
Is HikariCP pool exhaustion a memory leak?
Usually no. Pool exhaustion is unclosed JDBC connections. Heap OOM is a different class of bug. This module and the HikariCP lab are meant to be contrasted.
Do I need production JVM flags to start?
No. The guest pages explain the concepts in the browser. You do not upload heap dumps to start.
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