[Java] Can't initialize RootAllocator when Unsafe isn't present even when using the NettyAllocator
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- Java
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Description
### Describe the bug, including details regarding any error messages, version, and platform.
In an Alpine docker container, the JVM doesn't have the Unsafe jars (for version 17 of openjdk). Even though we set the properties to use the Netty allocator instead, Arrow tries to load the Unsafe jars anyway, doesn't catch the exception and throws it to the caller of new RootAllocator().
The problem is this line of code:
at org.apache.arrow.memory.NettyAllocationManager.(NettyAllocationManager.java:51)
` private static final PooledByteBufAllocatorL INNER_ALLOCATOR = new PooledByteBufAllocatorL();`
It is only used a couple of times and only for default initialization. Perhaps just hard-code those defaults instead or just pull them from the same properties Netty does. You have to be really careful with static variables and if they throw exceptions, they probably aren't suitable for being in a static variable.
Here is the exception and relevant output:
Exception:
```
java.lang.UnsupportedOperationException: sun.misc.Unsafe unavailable
at io.netty.util.internal.CleanerJava9.(CleanerJava9.java:68)
at io.netty.util.internal.PlatformDependent.(PlatformDependent.java:191)
at io.netty.buffer.PooledByteBufAllocator.(PooledByteBufAllocator.java:116)
at io.netty.buffer.PooledByteBufAllocatorL.(PooledByteBufAllocatorL.java:49)
at org.apache.arrow.memory.NettyAllocationManager.(NettyAllocationManager.java:51)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:375)
at org.apache.arrow.memory.DefaultAllocationManagerOption.getFactory(DefaultAllocationManagerOption.java:108)
at org.apache.arrow.memory.DefaultAllocationManagerOption.getNettyFactory(DefaultAllocationManagerOption.java:127)
at org.apache.arrow.memory.DefaultAllocationManagerOption.getDefaultAllocationManagerFactory(DefaultAllocationManagerOption.java:91)
at org.apache.arrow.memory.BaseAllocator$Config.getAllocationManagerFactory(BaseAllocator.java:773)
at org.apache.arrow.memory.ImmutableConfig.access$801(ImmutableConfig.java:24)
at org.apache.arrow.memory.ImmutableConfig$InitShim.getAllocationManagerFactory(ImmutableConfig.java:83)
at org.apache.arrow.memory.ImmutableConfig.(ImmutableConfig.java:47)
at org.apache.arrow.memory.ImmutableConfig.(ImmutableConfig.java:24)
at org.apache.arrow.memory.ImmutableConfig$Builder.build(ImmutableConfig.java:485)
at org.apache.arrow.memory.BaseAllocator.(BaseAllocator.java:62)
at schema:public//org.seme.hadoop.ArrowFileWriterUDF.writeArrowFile(ArrowFileWriterUDF.java:131)
at org.postgresql.pljava.internal@1.6.5/org.postgresql.pljava.internal.EntryPoints.lambda$invocable$0(EntryPoints.java:130)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at org.postgresql.pljava.internal@1.6.5/org.postgresql.pljava.internal.EntryPoints.doPrivilegedAndUnwrap(EntryPoints.java:312)
at org.postgresql.pljava.internal@1.6.5/org.postgresql.pljava.internal.EntryPoints.invoke(EntryPoints.java:158)
```
Debug output:
```
18:37:28.295 [main] DEBUG io.netty.util.ResourceLeakDetector -- -Dio.netty.leakDetection.level: simple
18:37:28.295 [main] DEBUG io.netty.util.ResourceLeakDetector -- -Dio.netty.leakDetection.targetRecords: 4
18:37:28.305 [main] DEBUG io.netty.util.internal.PlatformDependent0 -- -Dio.netty.noUnsafe: true
18:37:28.305 [main] DEBUG io.netty.util.internal.PlatformDependent0 -- sun.misc.Unsafe: unavailable (io.netty.noUnsafe)
18:37:28.305 [main] DEBUG io.netty.util.internal.PlatformDependent0 -- Java version: 17
18:37:28.306 [main] DEBUG io.netty.util.internal.PlatformDependent0 -- java.nio.DirectByteBuffer.(long, {int,long}): unavailable
18:37:28.307 [main] DEBUG io.netty.util.internal.PlatformDependent -- maxDirectMemory: 16802381824 bytes (maybe)
18:37:28.307 [main] DEBUG io.netty.util.internal.PlatformDependent -- -Dio.netty.tmpdir: /tmp (java.io.tmpdir)
18:37:28.307 [main] DEBUG io.netty.util.internal.PlatformDependent -- -Dio.netty.bitMode: 64 (sun.arch.data.model)
18:37:28.307 [main] DEBUG io.netty.util.internal.PlatformDependent -- -Dio.netty.maxDirectMemory: -1 bytes
18:37:28.307 [main] DEBUG io.netty.util.internal.PlatformDependent -- -Dio.netty.uninitializedArrayAllocationThreshold: -1
18:37:28.309 [main] DEBUG io.netty.util.internal.PlatformDependent -- -Dio.netty.noPreferDirect: true
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.numHeapArenas: 16
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.numDirectArenas: 16
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.pageSize: 8192
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.maxOrder: 9
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.chunkSize: 4194304
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.smallCacheSize: 256
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.normalCacheSize: 64
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.maxCachedBufferCapacity: 32768
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.cacheTrimInterval: 8192
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.cacheTrimIntervalMillis: 0
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.useCacheForAllThreads: false
18:37:28.310 [main] DEBUG io.netty.buffer.PooledByteBufAllocator -- -Dio.netty.allocator.maxCachedByteBuffersPerChunk: 1023
18:37:28.313 [main] DEBUG io.netty.util.internal.InternalThreadLocalMap -- -Dio.netty.threadLocalMap.stringBuilder.initialSize: 1024
18:37:28.313 [main] DEBUG io.netty.util.internal.InternalThreadLocalMap -- -Dio.netty.threadLocalMap.stringBuilder.maxSize: 4096
18:37:28.320 [main] DEBUG io.netty.buffer.AbstractByteBuf -- -Dio.netty.buffer.checkAccessible: true
18:37:28.320 [main] DEBUG io.netty.buffer.AbstractByteBuf -- -Dio.netty.buffer.checkBounds: true
18:37:28.321 [main] DEBUG io.netty.util.ResourceLeakDetectorFactory -- Loaded default ResourceLeakDetector: io.netty.util.ResourceLeakDetector@7cc5bdbd
18:37:28.400 [shutdown-hook-0] DEBUG org.apache.hadoop.hdfs.DataStreamer -- block==null waiting for ack for: -1
```
### Component(s)
Java
Contributor guide
Research direction
Start with NettyAllocationManager.java at the PooledByteBufAllocatorL static initialization, then trace DefaultAllocationManagerOption.java and the new RootAllocator() entry point. Reproduce the failure with Java 17 in an Alpine container and verify that selecting the Netty allocator no longer fails when Unsafe is unavailable.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100