perf: further reduce RSS for .NET (AOT) and Java (Native) - #5
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Target: bring both implementations under 16 MB RSS (previously 17.1 MB and 17.9 MB respectively). Stays at flag/config level — no API swap. Java Native (memory.yml, ci.yml): - Lower heap: MaxHeapSize 16m → 8m, MinHeapSize 1m → 512k - Add MaxNewSize=2m to bound young generation under serial GC - Explicitly disable monitoring (--enable-monitoring=) - Drop deadlock watchdog thread (-H:DeadlockWatchdogInterval=0) .NET AOT (dotnet.csproj): - More trimming knobs: DebuggerSupport, StackTraceSupport, UseSystemResourceKeys, MetadataUpdaterSupport, EnableUnsafeBinaryFormatterSerialization, EnableUnsafeUTF7Encoding, IlcGenerateStackTraceData, IlcDisableReflection .NET runtime config: - Disable concurrent GC to drop background GC thread - Lower HeapHardLimit 20 MB → 12 MB - Return decommitted VM to OS (RetainVM=false) Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
GraalVM 25.0.2 rejects an empty value for --enable-monitoring; the flag is an opt-in list (heapdump/jfr/jvmstat/...) with no "explicit none" form, since none is already the default. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
…cbc06 # Conflicts: # .github/workflows/memory.yml
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Summary
Aim: bring .NET (AOT) and Java (Native) RSS under 16 MB. Current baseline from the
Memoryworkflow:This PR stays at the flag/config level — no HTTP API swap. If either implementation is still >16 MB after CI runs, a Phase 2 swap to
System.Net.HttpListener/ rawServerSocketis the planned fallback.Changes
Java Native (
.github/workflows/memory.yml,.github/workflows/ci.yml)MaxHeapSize 16m → 8m,MinHeapSize 1m → 512k, newMaxNewSize=2m. With--gc=serial, the GC sizes its committed regions against the max — lowering the cap is the single biggest expected win.--enable-monitoring=— explicit empty value to assert nothing (JFR, jvmstat, heap-dump, etc.) is enabled.-H:DeadlockWatchdogInterval=0— drops the watchdog thread..NET AOT (
dotnet/dotnet.csproj)Eight new trimming/feature-switch properties:
DebuggerSupport=false,MetadataUpdaterSupport=false— drop debugger and hot-reload metadata.StackTraceSupport=false+IlcGenerateStackTraceData=false— strip stack-trace string tables.UseSystemResourceKeys=true— replace localized exception messages with their resource keys.EnableUnsafeBinaryFormatterSerialization=false,EnableUnsafeUTF7Encoding=false— drop unused encoders.IlcDisableReflection=true— most aggressive;WebApplication.CreateSlimBuilder()is the slim path so this should be safe, but it's the easiest to revert in isolation if the publish breaks..NET runtime config (
dotnet/runtimeconfig.template.json)System.GC.Concurrent: true → false— drops the background GC thread (each thread reserves ~1 MB of stack visible in RSS); this is the biggest expected .NET win.System.GC.HeapHardLimit: 20 MB → 12 MB.System.GC.RetainVM: false— return decommitted segments to the OS sooner.Test plan
CIworkflow'sBuild native imagestep still succeeds (no broken flags).CIworkflow'sVerify HTTP 200step still passes (server starts and responds).Memoryworkflow report shows.NET (AOT)< 16384 KB.Memoryworkflow report showsJava (Native)< 16384 KB.MaxHeapSizeto4m; for .NET try removingIlcDisableReflectionfirst (if publish failed) or lowerHeapHardLimitto 10 MB.🤖 Generated with Claude Code