Runtime agent attach on Windows is very slow when debugging

[Trass3r]

opentelemetry-java-contrib/runtime-attach/runtime-attach-core/src/main/java/io/opentelemetry/contrib/attach/core/AgentFileProvider.java

Line 57 in 4eb0473

Files.copy(jarAsInputStream, agentJarPath);

This line takes forever in my SpringBootApplication when in debug mode, it's fine when running normally.
GraalVM 17.0.12

https://github.com/microsoft/ApplicationInsights-Java/blob/aee3513604c5b56a23acdceabf97aa0f31064dd2/agent/runtime-attach/src/main/java/com/microsoft/applicationinsights/attach/ApplicationInsights.java#L63

Has anyone else experienced this?

[Trass3r]

        at jdk.internal.misc.Unsafe.toUnsignedInt([email protected]/Unsafe.java:3799)
        at jdk.internal.misc.Unsafe.makeInt([email protected]/Unsafe.java:3749)
        at jdk.internal.misc.Unsafe.getIntUnaligned([email protected]/Unsafe.java:3557)
        at jdk.internal.misc.Unsafe.getIntUnaligned([email protected]/Unsafe.java:3565)
        at java.lang.invoke.VarHandleByteArrayAsInts$ArrayHandle.get([email protected]/VarHandleByteArrayAsInts.java:118)
        at java.lang.invoke.VarHandleGuards.guard_LI_I([email protected]/VarHandleGuards.java:163)     <-- hotspot
        at sun.security.provider.ByteArrayAccess.b2iBig64([email protected]/ByteArrayAccess.java:114)
        at sun.security.provider.SHA2.implCompress0([email protected]/SHA2.java:146)
        at sun.security.provider.SHA2.implCompress([email protected]/SHA2.java:122)
        at sun.security.provider.DigestBase.implCompressMultiBlock0([email protected]/DigestBase.java:150)
        at sun.security.provider.DigestBase.implCompressMultiBlock([email protected]/DigestBase.java:144)
        at sun.security.provider.DigestBase.engineUpdate([email protected]/DigestBase.java:131)
        at java.security.MessageDigest$Delegate.engineUpdate([email protected]/MessageDigest.java:658)
        at java.security.MessageDigest.update([email protected]/MessageDigest.java:349)
        at sun.security.util.ManifestEntryVerifier.update([email protected]/ManifestEntryVerifier.java:175)
        at java.util.jar.JarVerifier.update([email protected]/JarVerifier.java:236)
        at java.util.jar.JarVerifier$VerifierStream.read([email protected]/JarVerifier.java:483)
        at java.io.FilterInputStream.read([email protected]/FilterInputStream.java:132)
        at java.io.InputStream.transferTo([email protected]/Unknown Source)
        at java.nio.file.Files.copy([email protected]/Unknown Source)
        at io.opentelemetry.contrib.attach.core.AgentFileProvider.createTempAgentJarFileIn(Unknown Source)
        at io.opentelemetry.contrib.attach.core.AgentFileProvider.getAgentFile(Unknown Source)
        at io.opentelemetry.contrib.attach.core.CoreRuntimeAttach.attachJavaagentToCurrentJvm(Unknown Source)
        at com.microsoft.applicationinsights.attach.ApplicationInsights.attach(Unknown Source)

[trask]

hi @Trass3r!

sun.security.util.ManifestEntryVerifier
...
com.microsoft.applicationinsights.attach.ApplicationInsights

it looks like you're using the applicationinsights-runtime-attach jar, which is signed per Microsoft policy

unfortunately, jar file signature verification is very slow when the JIT compiler is not enabled, which may be what's happening when you're running under the debugger

cc @jeanbisutti @karianna

[laurit]

If things are really slow only when debugger is attached then try deleting all method breakpoints you have, line breakpoints are fine.