spark Could not write all entries

Caused by: org.elasticsearch.hadoop.EsHadoopException: Could not write all entries [1/1] (Maybe ES was overloaded?). Error sample (first [1] error messages):
    rejected execution of org.elasticsearch.transport.TransportService$4@7d5f91de on EsThreadPoolExecutor[bulk, queue capacity = 50, org.elasticsearch.common.util.concurrent.EsThreadPoolExecutor@3447703a[Running, pool size = 32, active threads = 32, queued tasks = 68, completed tasks = 9151096]]
Bailing out...

val masterUrl = "local"
val appName = "ttyb"
val sparkConf = new SparkConf()
  .setMaster(masterUrl)
  .setAppName(appName)
  .set("es.nodes", "172.16.14.21")
  .set("es.port", "9200")
  //Bailing out...错误
  .set("es.batch.size.entries", "1")
  //插入失败后无限重复插数据
  .set("es.batch.write.retry.count", "-1")
  //查数据等待时间
  .set("es.batch.write.retry.wait", "100")
val Spark = SparkSession.builder().config(sparkConf).getOrCreate()

org.elasticsearch.hadoop.rest.EsHadoopInvalidRequest: 
null