S06Spring request to databaseimplemented
JVM scope, capacity, invariant, and wait-for cycle
Connect one-JVM JMM repairs to the database ownership boundary, then separate Hikari pressure, lost-update correctness, and PostgreSQL deadlock mechanics.
REAL_JAVA_21_WORKERSJMM_CONTRACTREAL_HIKARI_POSTGRESQLREAL_TRANSACTION_INTERLEAVINGNOT_OBSERVEDabout 120 min
Outcomes
- • Distinguish volatile visibility from compound atomicity and name the one-JVM owner limit.
- • Classify queueing versus acquisition timeout.
- • Repair a stale overwrite with a DB-owned concurrency mechanism.
- • Recognize a 40P01 victim and survivor without conflating it with pool exhaustion.
Recommended context
- • s05-persistence
- • j08-threads-jmm
Endpoint family / fixed variants
- • /api/labs/concurrency-scope
- • /api/labs/pool-exhaustion
- • /api/labs/lost-update
- • /api/labs/deadlock
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