使用Kafka Streams开发时，Lib上的UnsatisfiedLinkError会晃动DB dll

Question

我正在开发Windows机器上编写Kafka Streams应用程序。如果我尝试使用Kafka Streams
的leftJoin和branch功能，则在执行jar应用程序时出现以下错误：

Exception in thread "StreamThread-1" java.lang.UnsatisfiedLinkError: C:\Users\user\AppData\Local\Temp\librocksdbjni325337723194862275.dll: Can't find dependent libraries
    at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1941)
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1824)
    at java.lang.Runtime.load0(Runtime.java:809)
    at java.lang.System.load(System.java:1086)
    at org.rocksdb.NativeLibraryLoader.loadLibraryFromJar(NativeLibraryLoader.java:78)
    at org.rocksdb.NativeLibraryLoader.loadLibrary(NativeLibraryLoader.java:56)
    at org.rocksdb.RocksDB.loadLibrary(RocksDB.java:64)
    at org.rocksdb.RocksDB.<clinit>(RocksDB.java:35)
    at org.rocksdb.Options.<clinit>(Options.java:22)
    at org.apache.kafka.streams.state.internals.RocksDBStore.openDB(RocksDBStore.java:115)
    at org.apache.kafka.streams.state.internals.Segment.openDB(Segment.java:38)
    at org.apache.kafka.streams.state.internals.Segments.getOrCreateSegment(Segments.java:75)
    at org.apache.kafka.streams.state.internals.RocksDBSegmentedBytesStore.put(RocksDBSegmentedBytesStore.java:72)
    at org.apache.kafka.streams.state.internals.ChangeLoggingSegmentedBytesStore.put(ChangeLoggingSegmentedBytesStore.java:54)
    at org.apache.kafka.streams.state.internals.MeteredSegmentedBytesStore.put(MeteredSegmentedBytesStore.java:101)
    at org.apache.kafka.streams.state.internals.RocksDBWindowStore.put(RocksDBWindowStore.java:109)
    at org.apache.kafka.streams.state.internals.RocksDBWindowStore.put(RocksDBWindowStore.java:101)
    at org.apache.kafka.streams.kstream.internals.KStreamJoinWindow$KStreamJoinWindowProcessor.process(KStreamJoinWindow.java:65)
    at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:48)
    at org.apache.kafka.streams.processor.internals.StreamsMetricsImpl.measureLatencyNs(StreamsMetricsImpl.java:188)
    at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:134)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:83)
    at org.apache.kafka.streams.kstream.internals.KStreamFlatMapValues$KStreamFlatMapValuesProcessor.process(KStreamFlatMapValues.java:43)
    at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:48)
    at org.apache.kafka.streams.processor.internals.StreamsMetricsImpl.measureLatencyNs(StreamsMetricsImpl.java:188)
    at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:134)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:83)
    at org.apache.kafka.streams.kstream.internals.KStreamFilter$KStreamFilterProcessor.process(KStreamFilter.java:44)
    at org.apache.kafka.streams.processor.internals.ProcessorNode$1.run(ProcessorNode.java:48)
    at org.apache.kafka.streams.processor.internals.StreamsMetricsImpl.measureLatencyNs(StreamsMetricsImpl.java:188)
    at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:134)
    at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:83)
    at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:70)
    at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:197)
    at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:641)
    at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:368)

似乎Kafka找不到DLL，但是请稍候…我正在开发Java应用程序！

可能是什么问题呢？而且，如果我尝试像a这样的更简单的流操作，为什么不会显示此错误filter？

更新：

仅当代理中存在消息时，才会出现此问题。我正在使用Kafka Streams版本0.10.2.1。

这是引发问题的代码段

public class KafkaStreamsMainClass {

    private KafkaStreamsMainClass() {
    }

    public static void main(final String[] args) throws Exception {
        Properties streamsConfiguration = new Properties();
        streamsConfiguration.put(StreamsConfig.APPLICATION_ID_CONFIG, "kafka-streams");
        streamsConfiguration.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "kafka-server:9092");
        streamsConfiguration.put(AbstractKafkaAvroSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG, "schema-registry:8082");
        streamsConfiguration.put(StreamsConfig.COMMIT_INTERVAL_MS_CONFIG, 10 * 1000);
        streamsConfiguration.put(StreamsConfig.CACHE_MAX_BYTES_BUFFERING_CONFIG, 0);
        streamsConfiguration.put(StreamsConfig.KEY_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
        streamsConfiguration.put(StreamsConfig.VALUE_SERDE_CLASS_CONFIG, GenericAvroSerde.class);
        KStreamBuilder builder = new KStreamBuilder();
        KStream<GenericRecord, GenericRecord> sourceStream = builder.stream(SOURCE_TOPIC);

        KStream<GenericRecord, GenericRecord> finishedFiltered = sourceStream
                .filter((GenericRecord key, GenericRecord value) -> value.get("endTime") != null);

        KStream<GenericRecord, GenericRecord>[] branchedStreams = sourceStream
                .filter((GenericRecord key, GenericRecord value) -> value.get("endTime") == null)
                .branch((GenericRecord key, GenericRecord value) -> value.get("firstField") != null,
                        (GenericRecord key, GenericRecord value) -> value.get("secondField") != null);

        branchedStreams[0] = finishedFiltered.join(branchedStreams[0],
                (GenericRecord value1, GenericRecord value2) -> {
                    return value1;
                }, JoinWindows.of(TimeUnit.SECONDS.toMillis(2)));

        branchedStreams[1] = finishedFiltered.join(branchedStreams[1],
                (GenericRecord value1, GenericRecord value2) -> {
                    return value1;
                }, JoinWindows.of(TimeUnit.SECONDS.toMillis(2)));

        KafkaStreams streams = new KafkaStreams(builder, streamsConfiguration);
        streams.setUncaughtExceptionHandler((Thread thread, Throwable throwable) -> {
            throwable.printStackTrace();
        });
        streams.start();

        Runtime.getRuntime().addShutdownHook(new Thread(streams::close));
    }

}

我打开了rocksdbjni-5.0.1.jarMaven下载的档案，其中包括该librocksdbjni- win64.dll库。似乎它试图从RocksDB的外部而不是从内部检索库。

我正在Windows 7计算机上进行开发。

您是否遇到过这个问题？

Answer 1

我将kafka-streams项目更新为最新发布的版本1.0.0。

这个版本遇到了这个错误，但是在对其进行补丁并将其上传到内部Artifactory服务器上之后，我们能够在Windows和Linux上执行我们的kafka-
streams代理。下一个版本1.0.1和1.1.0将修复此错误，因此，一旦其中一个版本发布，我们将切换到它们而不是已修补的版本。

综上所述，Kafka的1.0.0版本解决了该错误。