无法获取图形的管理实例

Question

我从 gremlin 控制台连接到 gremlin 服务器：

:remote connect tinkerpop.server config/connect_config.yaml

我可以执行如下查询：

:> graph.getGraphName()
:> g.V().count().next()
:> g.V().drop().iterate()
:> g.V().values('LOL')

和许多其他人。 g - GraphTraversalSource，图 - StandardJanusGraph。我需要配置图表模式：

:> mg = graph.openManagenet()

但是当我尝试执行此查询时，出现异常：

gremlin> :> mngmt = graph.openManagement()
Server could not serialize the result requested. Server error - Error during serialization: Class is not registered: org.janusgraph.graphdb.database.management.ManagementSystem
Note: To register this class use: kryo.register(org.janusgraph.graphdb.database.management.ManagementSystem.class);. Note that the class must be serializable by the client and server for proper operation.
Type ':help' or ':h' for help.
Display stack trace? [yN]y
org.apache.tinkerpop.gremlin.groovy.plugin.RemoteException: Server could not serialize the result requested. Server error - Error during serialization: Class is not registered: org.janusgraph.graphdb.database.management.ManagementSystem
Note: To register this class use: kryo.register(org.janusgraph.graphdb.database.management.ManagementSystem.class);. Note that the class must be serializable by the client and server for proper operation.
    at org.apache.tinkerpop.gremlin.console.groovy.plugin.DriverRemoteAcceptor.submit(DriverRemoteAcceptor.java:186)
    at org.apache.tinkerpop.gremlin.console.commands.SubmitCommand.execute(SubmitCommand.groovy:41)
    at org.codehaus.groovy.tools.shell.Shell.execute(Shell.groovy:104)
    at org.codehaus.groovy.tools.shell.Groovysh.super$execute(Groovysh.groovy)
    at sun.reflect.GeneratedMethodAccessor15.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1225)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:145)
    at org.codehaus.groovy.tools.shell.Groovysh.executeCommand(Groovysh.groovy:273)
    at org.codehaus.groovy.tools.shell.Groovysh.execute(Groovysh.groovy:164)
    at org.apache.tinkerpop.gremlin.console.GremlinGroovysh.super$execute(GremlinGroovysh.groovy)
    at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1225)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:145)
    at org.apache.tinkerpop.gremlin.console.GremlinGroovysh.execute(GremlinGroovysh.groovy:72)
    at org.codehaus.groovy.tools.shell.Shell.leftShift(Shell.groovy:122)
    at org.codehaus.groovy.tools.shell.ShellRunner.work(ShellRunner.groovy:95)
    at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$work(InteractiveShellRunner.groovy)
    at sun.reflect.GeneratedMethodAccessor35.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1225)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:145)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:165)
    at org.codehaus.groovy.tools.shell.InteractiveShellRunner.work(InteractiveShellRunner.groovy:130)
    at org.codehaus.groovy.tools.shell.ShellRunner.run(ShellRunner.groovy:59)
    at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$run(InteractiveShellRunner.groovy)
    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 org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1225)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:145)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:165)
    at org.codehaus.groovy.tools.shell.InteractiveShellRunner.run(InteractiveShellRunner.groovy:89)
    at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:236)
    at org.apache.tinkerpop.gremlin.console.Console.<init>(Console.groovy:169)
    at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:236)
    at org.apache.tinkerpop.gremlin.console.Console.main(Console.groovy:481)

有人能告诉我我必须做什么才能解决这个问题吗？

Answer 1

我不确定 ManagementSystem 是否可序列化，所以这就是您收到该错误的原因。至少有两种方法可以解决这个问题。首先，您没有 post 您的 config/connect_config.yaml 中的内容，但我认为它没有为序列化程序使用这种配置选项：

hosts: [localhost]
port: 8182
serializer: { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV3d0, config: { serializeResultToString: true }}

通过使用 serializeResultToString 选项（并假设在 Gremlin Server 的配置中配置了序列化程序），您告诉 Gremlin Server 获取您获得的任何结果并在它被调用之前调用 toString() return编辑。这样，您就永远不会出现序列化错误。

但是，缺点是您只能返回 String 值。一般来说，我认为这对于大多数 Gremlin 控制台交互来说是可以的（尤其是管理性交互，例如您尝试使用 ManagementSystem API 执行的交互）。因此，如果您想继续使用当前配置它试图序列化实际的 "objects" 你只需要确保你的脚本只有 return 可序列化的数据，而不是：

:> mg = graph.openManagement()

做

:> mg = graph.openManagement();[]

这不是 return mg，而是一个空列表。

无法获取图形的管理实例

Can't get management instance of graph

gremlin

gremlin-server