我正试图在Spark中创建一个数据帧，该数据帧将包含Apache Druid中表中的所有记录，我正在使用JDBC来完成这项工作。Druid似乎在使用Calcite Avatica JDBC驱动程序(这里提到(。
df = spark.read.format('jdbc').option('url', 'jdbc:avatica:remote:url=http://172.31.5.20:8082/druid/v2/sql/avatica/').option('driver', 'org.apache.calcite.avatica.remote.Driver').option('dbtable', 'mytable').load()
但我得到以下错误
Py4JJavaError: An error occurred while calling o456.load.
: java.sql.SQLException: While closing connection
at org.apache.calcite.avatica.Helper.createException(Helper.java:39)
at org.apache.calcite.avatica.AvaticaConnection.close(AvaticaConnection.java:156)
at org.apache.spark.sql.execution.datasources.jdbc.JDBCRDD$.resolveTable(JDBCRDD.scala:70)
at org.apache.spark.sql.execution.datasources.jdbc.JDBCRelation.<init>(JDBCRelation.scala:115)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcRelationProvider.createRelation(JdbcRelationProvider.scala:52)
at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:341)
at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:239)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:227)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:164)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:282)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "rpcMetadata" (class org.apache.calcite.avatica.remote.Service$CloseConnectionResponse), not marked as ignorable (0 known properties: ])
at [Source: (String)"{"response":"closeConnection","rpcMetadata":{"response":"rpcMetadata","serverAddress":"ip-172-31-5-234.ap-southeast-1.compute.internal:8082"}}
"; line: 1, column: 46] (through reference chain: org.apache.calcite.avatica.remote.Service$CloseConnectionResponse["rpcMetadata"])
at org.apache.calcite.avatica.remote.JsonService.handle(JsonService.java:142)
at org.apache.calcite.avatica.remote.JsonService.apply(JsonService.java:229)
at org.apache.calcite.avatica.remote.RemoteMeta.closeConnection(RemoteMeta.java:78)
at org.apache.calcite.avatica.AvaticaConnection.close(AvaticaConnection.java:153)
... 18 more
Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "rpcMetadata" (class org.apache.calcite.avatica.remote.Service$CloseConnectionResponse), not marked as ignorable (0 known properties: ])
at [Source: (String)"{"response":"closeConnection","rpcMetadata":{"response":"rpcMetadata","serverAddress":"ip-172-31-5-234.ap-southeast-1.compute.internal:8082"}}
"; line: 1, column: 46] (through reference chain: org.apache.calcite.avatica.remote.Service$CloseConnectionResponse["rpcMetadata"])
at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:61)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:823)
at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1153)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1589)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownVanilla(BeanDeserializerBase.java:1567)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:294)
at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:189)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedForId(AsPropertyTypeDeserializer.java:130)
at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:97)
at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeWithType(BeanDeserializerBase.java:1178)
at com.fasterxml.jackson.databind.deser.impl.TypeWrappedDeserializer.deserialize(TypeWrappedDeserializer.java:68)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4014)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3005)
at org.apache.calcite.avatica.remote.JsonService.decode(JsonService.java:131)
at org.apache.calcite.avatica.remote.JsonService.apply(JsonService.java:227)
... 20 more
有人知道这可能是什么原因吗？我该如何解决？这似乎是Avatica驱动程序的一个问题，它得到了一个带有不可识别字段的json对象
我正在使用驱动程序org.apache.calcite.avatica:avatica-core:1.17.0，并已将jar文件添加到我的spark.jars属性中。我正在使用Druid 0.19.0和Spark2。
编辑：我检查了Avatica JDBC框架的源代码，注释为@JsonCreator的构造函数需要在被反序列化的json对象中有一个名为rpcMetadata的属性。源代码在这里。
使用下面的库&再试一次。
"org.apache.calcite.avatica" % "avatica" % "1.8.0"