使用JanusGraph的ReferenceEdge序列化错误

Question

在Java应用程序中使用Gremlin从远程JanusGraph服务器检索边缘列表时，我遇到了序列化错误（以下是错误消息和配置）。

这是引发错误的遍历：

List<Edge> eList = g.E().toList();

试图只获得一个边缘也会引发错误：

Edge edge= g.E().next();

然而，当检索顶点或顶点列表时，它可以完美地工作：

List<Vertex> vList = g.V().toList();

这是我的remote-objects.yaml文件:

hosts: [localhost]
port: 8182
serializer: { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV3d0,
              config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}

这是获得远程遍历的代码:

PropertiesConfiguration conf = new PropertiesConfiguration(remote-objects.yaml);
cluster = Cluster.open(conf.getString("gremlin.remote.driver.clusterFile"));
client = cluster.connect();
g = AnonymousTraversalSource.traversal().withRemote(propFileName);

这是我的服务器配置中的序列化程序：

serializers:
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV3d0, config: { ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV3d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV3d0, config: { serializeResultToString: true }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0, config: { ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV3d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  # Older serialization versions for backwards compatibility:
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0, config: { ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV1d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoLiteMessageSerializerV1d0, config: {ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV1d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0, config: { serializeResultToString: true }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV2d0, config: { ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV2d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV1d0, config: { ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV1d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistryV1d0] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0, config: { ioRegistries: [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV1d0, org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistryV1d0] }}

这是错误消息：

java.util.concurrent.CompletionException: io.netty.handler.codec.DecoderException: org.apache.tinkerpop.gremlin.driver.ser.SerializationException: org.apache.tinkerpop.shaded.kryo.KryoException: java.lang.NegativeArraySizeException
Serialization trace:
id (org.apache.tinkerpop.gremlin.structure.util.reference.ReferenceEdge)
    at java.util.concurrent.CompletableFuture.reportJoin(CompletableFuture.java:375)
CompletableFuture.java:375
    at java.util.concurrent.CompletableFuture.join(CompletableFuture.java:1934)
CompletableFuture.java:1934
    at org.apache.tinkerpop.gremlin.driver.ResultSet.one(ResultSet.java:119)
ResultSet.java:119
    at org.apache.tinkerpop.gremlin.driver.ResultSet$1.hasNext(ResultSet.java:171)
ResultSet.java:171
    at org.apache.tinkerpop.gremlin.driver.ResultSet$1.next(ResultSet.java:178)
ResultSet.java:178
    at org.apache.tinkerpop.gremlin.driver.ResultSet$1.next(ResultSet.java:165)
ResultSet.java:165
    at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteTraversal$TraverserIterator.next(DriverRemoteTraversal.java:140)
DriverRemoteTraversal.java:140
    at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteTraversal$TraverserIterator.next(DriverRemoteTraversal.java:125)
DriverRemoteTraversal.java:125
    at org.apache.tinkerpop.gremlin.driver.remote.DriverRemoteTraversal.nextTraverser(DriverRemoteTraversal.java:106)
DriverRemoteTraversal.java:106
    at org.apache.tinkerpop.gremlin.process.remote.traversal.step.map.RemoteStep.processNextStart(RemoteStep.java:80)
RemoteStep.java:80
    at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.next(AbstractStep.java:128)
AbstractStep.java:128
    at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.next(AbstractStep.java:38)
AbstractStep.java:38
    at org.apache.tinkerpop.gremlin.process.traversal.Traversal.fill(Traversal.java:179)
Traversal.java:179
    at org.apache.tinkerpop.gremlin.process.traversal.Traversal.toList(Traversal.java:117)
Traversal.java:117
    at com.ibm.graph.App.main(App.java:25)
App.java:25
Caused by: io.netty.handler.codec.DecoderException: org.apache.tinkerpop.gremlin.driver.ser.SerializationException: org.apache.tinkerpop.shaded.kryo.KryoException: java.lang.NegativeArraySizeException

Answer 1

我相信您的问题在于驱动程序和服务器之间的序列化程序配置不匹配。对于驱动程序，您可以执行以下操作：

serializer: { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV3d0,
              config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}

但对于您拥有的服务器：

- { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV3d0, 
    config: { ioRegistries [org.apache.tinkerpop.gremlin.tinkergraph.structure.TinkerIoRegistryV3d0, 
                            org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}

您在驱动程序端省略了< code > tinkerioregistryv 3d 0 。使用< code>ioRegistries时，注册表的添加顺序很重要。因此，如果您首先在服务器上添加了< code > JanusGraphIoRegistry ,然后在驱动程序上不小心省略了< code > tinkerioregistryv 3d 0 ,那么您可能已经很幸运了，因为序列化程序注册标识符将与JansuGraph对齐。

无论如何，将< code > tinkerioregistryv 3d 0 添加到驱动程序配置中，或者将其从服务器配置中删除，一切都应该正常。顺便提一下，如果通过网络序列化TinkerGraph实例(例如，使用< code>subgraph()步骤)，通常只需要< code > tinkerioregistryv 3d 0 。