[Bug] Too many vertices for one time post in SparkLoader

[simon824]

Bug Type (问题类型)

gremlin (结果不合预期)

Before submit

• I had searched in the issues and found no similar issues.

Environment (环境信息)

• Server Version: v0.12.x
• Loader Version: v0.12.x
• Data Size: xx vertices, xx edges

Expected & Actual behavior (期望与实际表现)

The option batch.max_vertices_per_batch default value is 500, if spark/flink default value of batch_size is bigger than 500 ,will cause the below exception.

class java.lang.IllegalArgumentException: Too many vertices for one time post, the maximum number is '500'
  at com.baidu.hugegraph.exception.ServerException.fromResponse(ServerException.java:47)
  at com.baidu.hugegraph.client.RestClient.checkStatus(RestClient.java:93)
  at com.baidu.hugegraph.rest.AbstractRestClient.post(AbstractRestClient.java:231)
  at com.baidu.hugegraph.rest.AbstractRestClient.post(AbstractRestClient.java:211)
  at com.baidu.hugegraph.api.graph.VertexAPI.create(VertexAPI.java:58)
  at com.baidu.hugegraph.driver.GraphManager.addVertices(GraphManager.java:96)
  at com.baidu.hugegraph.loader.spark.HugeGraphSparkLoader.flush(HugeGraphSparkLoader.java:253)
  at com.baidu.hugegraph.loader.spark.HugeGraphSparkLoader.loadRow(HugeGraphSparkLoader.java:150)
  at com.baidu.hugegraph.loader.spark.HugeGraphSparkLoader.lambda$null$0(HugeGraphSparkLoader.java:111)

Vertex/Edge example (问题点 / 边数据举例)

No response

Schema [VertexLabel, EdgeLabel, IndexLabel] (元数据结构)

No response