fix: unbind ShutdownStateSaver on ReActAgent.close() to prevent memory leak#2384
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fix: unbind ShutdownStateSaver on ReActAgent.close() to prevent memory leak#2384sikisama wants to merge 1 commit into
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…y leak GracefulShutdownManager.bindStateSaver() registers a ShutdownStateSaver in a static ConcurrentHashMap (stateSavers) keyed by agentId, but there is no corresponding unbind method. ReActAgent.close() was a no-op. When ephemeral/per-call ReActAgent instances are created with an AgentStateStore (e.g. via factory patterns), each constructor call registers a saver that is never removed. The stateSavers map grows unboundedly, retaining all agent instances (and their Model, HttpClient, Memory, Toolkit references) until JVM exit. In production this caused 8073+ ReActAgent instances to accumulate in stateSavers (ConcurrentHashMap capacity 16384), occupying 140MB (43% of heap). The leak also indirectly caused HttpClient thread proliferation (1600+ groups) and CLOSE-WAIT connection buildup. Fix: - Add GracefulShutdownManager.unbindStateSaver(Agent) to remove the entry - Implement ReActAgent.close() to call unbindStateSaver(this) - Users should call agent.close() (or use try-with-resources) after each per-call agent is done
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Summary
Fixes a memory leak in
GracefulShutdownManager.stateSaverswhere per-callReActAgentinstances (created withAgentStateStore) register aShutdownStateSaverin the constructor but are never unregistered.Changes
GracefulShutdownManager.java: AddunbindStateSaver(Agent)method (counterpart tobindStateSaver)ReActAgent.java: Implementclose()to callshutdownManager.unbindStateSaver(this)(was no-op)Problem
bindStateSaver()doesstateSavers.put(agentId, saver)but there was no remove/unbind path.ReActAgent.close()was a no-op. In high-throughput services creating one agent per request (as documented in the class Javadoc),stateSaversaccumulates every agent instance forever — retaining their Model, HttpClient, Memory, Toolkit, etc.Production heap dump showed 8073 ReActAgent instances retained by
stateSavers(ConcurrentHashMap capacity 16384), occupying 140MB (43% of heap), plus 1666+ HttpClient thread groups and CLOSE-WAIT connection buildup.Testing
close()is called;stateSaversstays bounded.Checklist
close()is safe to call multiple times (ConcurrentHashMap.removeis idempotent)stateSaversis only read duringperformGracefulShutdown; removing an already-closed agent's entry is correct — that agent is no longer active)stateSaverssize stays bounded after close())