Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Ktor no netty_transport_native_epoll_x86_64 in java.library.path #1670

Open
softshipper opened this issue Feb 24, 2020 · 4 comments
Open

Ktor no netty_transport_native_epoll_x86_64 in java.library.path #1670

softshipper opened this issue Feb 24, 2020 · 4 comments
Labels
bug Server

Comments

@softshipper
Copy link

Hi all

During starting Ktor application, I've got the following logs:

java.lang.UnsatisfiedLinkError: no netty_transport_native_epoll_x86_64 in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1871)
    at java.lang.Runtime.loadLibrary0(Runtime.java:872)
    at java.lang.System.loadLibrary(System.java:1124)
    at io.netty.util.internal.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:38)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at io.netty.util.internal.NativeLibraryLoader$1.run(NativeLibraryLoader.java:369)
    at java.security.AccessController.doPrivileged(Native Method)
    at io.netty.util.internal.NativeLibraryLoader.loadLibraryByHelper(NativeLibraryLoader.java:361)
    at io.netty.util.internal.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:339)
    at io.netty.util.internal.NativeLibraryLoader.load(NativeLibraryLoader.java:136)
    at io.netty.channel.epoll.Native.loadNativeLibrary(Native.java:231)
    at io.netty.channel.epoll.Native.<clinit>(Native.java:58)
    at io.netty.channel.epoll.Epoll.<clinit>(Epoll.java:39)
    at io.ktor.server.netty.EventLoopGroupProxy$Companion.create(NettyApplicationEngine.kt:189)
    at io.ktor.server.netty.NettyApplicationEngine.<init>(NettyApplicationEngine.kt:74)
    at io.ktor.server.netty.EngineMain.main(EngineMain.kt:22)
22:56:07.760 [main] DEBUG io.netty.util.internal.NativeLibraryLoader - netty_transport_native_epoll_x86_64 cannot be loaded from java.library.path, now trying export to -Dio.netty.native.workdir: /tmp
java.lang.UnsatisfiedLinkError: no netty_transport_native_epoll_x86_64 in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1871)
    at java.lang.Runtime.loadLibrary0(Runtime.java:872)
    at java.lang.System.loadLibrary(System.java:1124)
    at io.netty.util.internal.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:38)
    at io.netty.util.internal.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:349)
    at io.netty.util.internal.NativeLibraryLoader.load(NativeLibraryLoader.java:136)
    at io.netty.channel.epoll.Native.loadNativeLibrary(Native.java:231)
    at io.netty.channel.epoll.Native.<clinit>(Native.java:58)
    at io.netty.channel.epoll.Epoll.<clinit>(Epoll.java:39)
    at io.ktor.server.netty.EventLoopGroupProxy$Companion.create(NettyApplicationEngine.kt:189)
    at io.ktor.server.netty.NettyApplicationEngine.<init>(NettyApplicationEngine.kt:74)
    at io.ktor.server.netty.EngineMain.main(EngineMain.kt:22)
    Suppressed: java.lang.UnsatisfiedLinkError: no netty_transport_native_epoll_x86_64 in java.library.path
        at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1871)
        at java.lang.Runtime.loadLibrary0(Runtime.java:872)
        at java.lang.System.loadLibrary(System.java:1124)
        at io.netty.util.internal.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:38)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at io.netty.util.internal.NativeLibraryLoader$1.run(NativeLibraryLoader.java:369)
        at java.security.AccessController.doPrivileged(Native Method)
        at io.netty.util.internal.NativeLibraryLoader.loadLibraryByHelper(NativeLibraryLoader.java:361)
        at io.netty.util.internal.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:339)
        ... 7 common frames omitted
22:56:07.761 [main] DEBUG io.netty.util.internal.NativeLibraryLoader - Unable to load the library 'netty_transport_native_epoll', trying other loading mechanism.
java.lang.UnsatisfiedLinkError: no netty_transport_native_epoll in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1871)
    at java.lang.Runtime.loadLibrary0(Runtime.java:872)
    at java.lang.System.loadLibrary(System.java:1124)
    at io.netty.util.internal.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:38)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at io.netty.util.internal.NativeLibraryLoader$1.run(NativeLibraryLoader.java:369)
    at java.security.AccessController.doPrivileged(Native Method)
    at io.netty.util.internal.NativeLibraryLoader.loadLibraryByHelper(NativeLibraryLoader.java:361)
    at io.netty.util.internal.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:339)
    at io.netty.util.internal.NativeLibraryLoader.load(NativeLibraryLoader.java:136)
    at io.netty.channel.epoll.Native.loadNativeLibrary(Native.java:234)
    at io.netty.channel.epoll.Native.<clinit>(Native.java:58)
    at io.netty.channel.epoll.Epoll.<clinit>(Epoll.java:39)
    at io.ktor.server.netty.EventLoopGroupProxy$Companion.create(NettyApplicationEngine.kt:189)
    at io.ktor.server.netty.NettyApplicationEngine.<init>(NettyApplicationEngine.kt:74)
    at io.ktor.server.netty.EngineMain.main(EngineMain.kt:22)
22:56:07.761 [main] DEBUG io.netty.util.internal.NativeLibraryLoader - netty_transport_native_epoll cannot be loaded from java.library.path, now trying export to -Dio.netty.native.workdir: /tmp
java.lang.UnsatisfiedLinkError: no netty_transport_native_epoll in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1871)
    at java.lang.Runtime.loadLibrary0(Runtime.java:872)
    at java.lang.System.loadLibrary(System.java:1124)
    at io.netty.util.internal.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:38)
    at io.netty.util.internal.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:349)
    at io.netty.util.internal.NativeLibraryLoader.load(NativeLibraryLoader.java:136)
    at io.netty.channel.epoll.Native.loadNativeLibrary(Native.java:234)
    at io.netty.channel.epoll.Native.<clinit>(Native.java:58)
    at io.netty.channel.epoll.Epoll.<clinit>(Epoll.java:39)
    at io.ktor.server.netty.EventLoopGroupProxy$Companion.create(NettyApplicationEngine.kt:189)
    at io.ktor.server.netty.NettyApplicationEngine.<init>(NettyApplicationEngine.kt:74)
    at io.ktor.server.netty.EngineMain.main(EngineMain.kt:22)
    Suppressed: java.lang.UnsatisfiedLinkError: no netty_transport_native_epoll in java.library.path
        at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1871)
        at java.lang.Runtime.loadLibrary0(Runtime.java:872)
        at java.lang.System.loadLibrary(System.java:1124)
        at io.netty.util.internal.NativeLibraryUtil.loadLibrary(NativeLibraryUtil.java:38)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at io.netty.util.internal.NativeLibraryLoader$1.run(NativeLibraryLoader.java:369)
        at java.security.AccessController.doPrivileged(Native Method)
        at io.netty.util.internal.NativeLibraryLoader.loadLibraryByHelper(NativeLibraryLoader.java:361)
        at io.netty.util.internal.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:339)
        ... 7 common frames omitted

the build file

plugins {
    application
    kotlin("jvm") version "1.3.61"
}

group = "io.oceanstack"
version = "1.0-SNAPSHOT"

val ktor_version = "1.3.1"

repositories {
    mavenCentral()
    jcenter()
}

dependencies {
    implementation(kotlin("stdlib-jdk8"))
    compile("io.ktor:ktor-server-core:$ktor_version")
    compile("io.ktor:ktor-server-netty:$ktor_version")
    compile("ch.qos.logback:logback-classic:1.2.3")
    testCompile(group = "junit", name = "junit", version = "4.12")
}

tasks {
    compileKotlin {
        kotlinOptions.jvmTarget = "1.8"
    }
    compileTestKotlin {
        kotlinOptions.jvmTarget = "1.8"
    }
}

application {
    mainClassName = "io.ktor.server.netty.EngineMain"
}

What am I doing wrong?

The Java runtime:

java -version
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (Zulu 8.44.0.11-CA-linux64) (build 1.8.0_242-b20)
OpenJDK 64-Bit Server VM (Zulu 8.44.0.11-CA-linux64) (build 25.242-b20, mixed mode)

Thanks
@volkert-fastned
Copy link

volkert-fastned commented Feb 24, 2020 •
edited
Loading

@softshipper This issue has been raised before. I just documented a (Gradle-specific) workaround here, along with a request to have it automatically handled somehow if possible: #1672 (comment)

Note that although the workaround will allow the native transport to successfully load on startup (if available for the underlying platform), it will unfortunately not eliminate all the exceptions that Netty throws at the debug level before it ultimately succeeds in loading the native transport. The reason for this being that it tries multiple ways of locating and loading the native transport library, the first ones of which always fail (at least in the case of Ktor).

See also this answer at the Netty GitHub project: netty/netty#8263 (comment)

@e5l e5l added the Server label Feb 25, 2020
@softshipper
Copy link
Author

@volkert-fastned There is no way to prevent the error message right?

@volkert-fastned
Copy link

volkert-fastned commented Feb 26, 2020 •
edited
Loading

@softshipper As I understand it, not without increasing the logging level for the specific Netty package from DEBUG to INFO. How to do this, depends on what logging backend you're using in your project.

If you're using Log4j 2 as your logging backend, you can add a package-specific override as follows:

        <AsyncLogger name="io.netty.util.internal.NativeLibraryLoader" level="info" includeLocation="true" additivity="false">
            <AppenderRef ref="[INSERT_APPENDER_NAME_HERE]"/>
        </AsyncLogger>

Be sure to use a regular Logger here instead of an AsyncLogger, if you're not using asynchronous logging.

Of course this will also suppress the "successfully loaded" message. But if you want a confirmation in your log that the native transport has successfully been loaded and is in use, I believe you can actually query Netty programmatically for that and then log something in your code.

@oleg-larshin
Copy link

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
bug Server
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
5 participants
@cy6erGn0m @e5l @oleg-larshin @volkert-fastned @softshipper