java.lang.UnsatisfiedLinkError: Can't load library: /tmp/libh3-java6591047064313530667.so

[ytdxwhy]

Hi,
I have a flink job, H3Core.newInstance() is initialized in the open method , when restore from flink state , it throws an exception like this

java.lang.UnsatisfiedLinkError: Can't load library: /tmp/libh3-java6591047064313530667.so

at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1820)

at java.lang.Runtime.load0(Runtime.java:810)

at java.lang.System.load(System.java:1086)

at com.uber.h3core.H3CoreLoader.loadNatives(H3CoreLoader.java:125)

at com.uber.h3core.H3CoreLoader.loadNatives(H3CoreLoader.java:89)

at com.uber.h3core.H3Core.newInstance(H3Core.java:73)

at com.sankuai.meituan.banma.rtdw.flink.business.function.BusinessWorkStatusH3ClearRiderRichSinkFunction.open(BusinessWorkStatusH3ClearRiderRichSinkFunction.java:60)

at org.apache.flink.api.common.functions.util.FunctionUtils.openFunction(FunctionUtils.java:34)

at org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.open(AbstractUdfStreamOperator.java:102)

at org.apache.flink.streaming.api.operators.StreamSink.open(StreamSink.java:46)

at org.apache.flink.streaming.runtime.tasks.OperatorChain.initializeStateAndOpenOperators(OperatorChain.java:466)

at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$beforeInvoke$2(StreamTask.java:547)

at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$1.runThrowing(StreamTaskActionExecutor.java:50)

at org.apache.flink.streaming.runtime.tasks.StreamTask.beforeInvoke(StreamTask.java:537)

at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:577)

at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:767)

at org.apache.flink.runtime.taskmanager.Task.run(Task.java:578)

at java.lang.Thread.run(Thread.java:748)

[TRReeve]

I had a similar problem using the H3 library in a docker container.

java.lang.UnsatisfiedLinkError: /tmp/libh3-java2646520615962866068.so: /lib64/libm.so.6: version `GLIBC_2.29' not found (required by /tmp/libh3-java2646520615962866068.so)
at java.base/jdk.internal.loader.NativeLibraries.load(Native Method)
at java.base/jdk.internal.loader.NativeLibraries$NativeLibraryImpl.open(NativeLibraries.java:388)
at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:232)
at java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:174)
at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2389)
at java.base/java.lang.Runtime.load0(Runtime.java:755)
at java.base/java.lang.System.load(System.java:1953)
at com.uber.h3core.H3CoreLoader.loadNatives(H3CoreLoader.java:129)
at com.uber.h3core.H3CoreLoader.loadNatives(H3CoreLoader.java:96)
at com.uber.h3core.H3Core.newInstance(H3Core.java:79)

[isaacbrodsky]

@TRReeve Which version are you using? If you're on 3.x, could you try with the latest 4.0.0-rc4 prerelease version as the GLIBC requirement should be lower? I believe this is a different issue than @ytdxwhy's.

@ytdxwhy Unfortunately it's a little tough to tell from that error what went wrong. My main suspect would be that the shared object file couldn't be written to the temp directory for some reason, or that the file was deleted between being written and being loaded by H3-Java. Is it possible that the application environment is different when resuming than the environment used when starting your application?

[dyrpsf]

Hi @ytdxwhy and @TRReeve,

I looked into the UnsatisfiedLinkError you were both encountering in Flink and Docker environments. Because distributed workers and containers can aggressively clean up or isolate the default /tmp directory, H3CoreLoader loses track of the extracted native library when the state is restored.

To fix this, I've added an escape hatch: you can now specify a custom, stable extraction directory using the Java system property h3.native.dir (e.g., -Dh3.native.dir=/your/custom/path). If the property isn't provided, it will safely fall back to the default OS temp directory behavior.

I have opened PR #209 with these changes. Let me know if this setup works for your infrastructure!