update exchange kafka (#2167)

docs-2.0/nebula-exchange/use-exchange/ex-ug-import-from-kafka.md

@@ -98,6 +98,10 @@ For more information, see [Quick start workflow](../../2.quick-start/1.quick-sta
 
 After Exchange is compiled, copy the conf file `target/classes/application.conf` to set Kafka data source configuration. In this example, the copied file is called `kafka_application.conf`. For details on each configuration item, see [Parameters in the configuration file](../parameter-reference/ex-ug-parameter.md).
 
+!!! note
+
+    When importing Kafka data, a configuration file can only handle one tag or edge type. If there are multiple tag or edge types, you need to create multiple configuration files.
+
 ```conf
 {
   # Spark configuration
@@ -195,124 +199,73 @@ After Exchange is compiled, copy the conf file `target/classes/application.conf`
       # Flow control, with a rate limit on the maximum offset processed per trigger interval, may not be configured.
       # maxOffsetsPerTrigger:10000
     }
-    # Set the information about the Tag Team.
-    {
-      name: team
-      type: {
-        source: kafka
-        sink: client
-      }
-      service: "127.0.0.1:9092"
-      topic: "topic_name2"
-      fields: [key]
-      nebula.fields: [name]
-      vertex:{
-          field:key
-      }
-      batch: 10
-      partition: 10
-      interval.seconds: 10
-      startingOffsets: latest
-      # maxOffsetsPerTrigger:10000
-    }
-
   ]
 
   # Processing edges
-  edges: [
-    # Set the information about the Edge Type follow.
-    {
-      # The corresponding Edge Type name in NebulaGraph.
-      name: follow
-
-      type: {
-        # Specify the data source file format to Kafka.
-        source: kafka
-
-        # Specify how to import the Edge type data into NebulaGraph.
-        # Specify how to import the data into NebulaGraph. Only client is supported.
-        sink: client
-      }
-
-      # Kafka server address.
-      service: "127.0.0.1:9092"
-      # Message category.
-      topic: "topic_name3"
-
-      # Kafka data has a fixed domain name: key, value, topic, partition, offset, timestamp, timestampType.
-      # If multiple fields need to be specified after Spark reads as DataFrame, separate them with commas.
-      # Specify the field name in fields. For example, use key for degree in Nebula, as shown in the following.
-      fields: [key]
-      nebula.fields: [degree]
-
-      # In source, use a column in the topic as the source of the edge's source vertex.
-      # In target, use a column in the topic as the source of the edge's destination vertex.
-      source:{
-          field:timestamp
-      # udf:{
-      #            separator:"_"
-      #            oldColNames:[field-0,field-1,field-2]
-      #            newColName:new-field
-      #        }
-      }
-
-
-      target:{
-          field:offset
-      # udf:{
-      #            separator:"_"
-      #            oldColNames:[field-0,field-1,field-2]
-      #            newColName:new-field
-      #        }
-      }
-
-      # (Optional) Specify a column as the source of the rank.
-      #ranking: rank
-
-      # The number of data written to NebulaGraph in a single batch.
-      batch: 10
-
-      # The number of Spark partitions.
-      partition: 10
-
-      # The interval for message reading. Unit: second.
-      interval.seconds: 10
-      # The consumer offsets. The default value is latest. Optional value are latest and earliest.
-      startingOffsets: latest
-      # Flow control, with a rate limit on the maximum offset processed per trigger interval, may not be configured.
-      # maxOffsetsPerTrigger:10000
-    }
-
-    # Set the information about the Edge Type serve.
-    {
-      name: serve
-      type: {
-        source: kafka
-        sink: client
-      }
-      service: "127.0.0.1:9092"
-      topic: "topic_name4"
-
-      fields: [timestamp,offset]
-      nebula.fields: [start_year,end_year]
-      source:{
-          field:key
-      }
-
-      target:{
-          field:value
-      }
-
-      # (Optional) Specify a column as the source of the rank.
-      #ranking: rank
-
-      batch: 10
-      partition: 10
-      interval.seconds: 10
-      startingOffsets: latest
-      # maxOffsetsPerTrigger:10000
-    }
-  ]
+  #edges: [
+  #  # Set the information about the Edge Type follow.
+  #  {
+  #    # The corresponding Edge Type name in NebulaGraph.
+  #    name: follow
+
+  #    type: {
+  #      # Specify the data source file format to Kafka.
+  #      source: kafka
+
+  #      # Specify how to import the Edge type data into NebulaGraph.
+  #      # Specify how to import the data into NebulaGraph. Only client is supported.
+  #      sink: client
+  #    }
+
+  #    # Kafka server address.
+  #    service: "127.0.0.1:9092"
+  #    # Message category.
+  #    topic: "topic_name3"
+
+  #    # Kafka data has a fixed domain name: key, value, topic, partition, offset, timestamp, timestampType.
+  #    # If multiple fields need to be specified after Spark reads as DataFrame, separate them with commas.
+  #    # Specify the field name in fields. For example, use key for degree in Nebula, as shown in the following.
+  #    fields: [key]
+  #    nebula.fields: [degree]
+
+  #    # In source, use a column in the topic as the source of the edge's source vertex.
+  #    # In target, use a column in the topic as the source of the edge's destination vertex.
+  #    source:{
+  #        field:timestamp
+  #    # udf:{
+  #    #            separator:"_"
+  #    #            oldColNames:[field-0,field-1,field-2]
+  #    #            newColName:new-field
+  #    #        }
+  #    }
+
+
+  #    target:{
+  #        field:offset
+  #    # udf:{
+  #    #            separator:"_"
+  #    #            oldColNames:[field-0,field-1,field-2]
+  #    #            newColName:new-field
+  #    #        }
+  #    }
+
+  #    # (Optional) Specify a column as the source of the rank.
+  #    #ranking: rank
+
+  #    # The number of data written to NebulaGraph in a single batch.
+  #    batch: 10
+
+  #    # The number of Spark partitions.
+  #    partition: 10
+
+  #    # The interval for message reading. Unit: second.
+  #    interval.seconds: 10
+  #    # The consumer offsets. The default value is latest. Optional value are latest and earliest.
+  #    startingOffsets: latest
+  #    # Flow control, with a rate limit on the maximum offset processed per trigger interval, may not be configured.
+  #    # maxOffsetsPerTrigger:10000
+  #  }
+  #]
 }
 ```