我正在使用 Druid 0.9.1.1 并尝试将每天数据源的所有段合并到一个段中。而合并任务启动失败并出现错误:
{"error":"Instantiation of [simple type, class io.druid.timeline.DataSegment] value failed: null (through reference chain: java.util.ArrayList[0])"}
我从段元数据查询中获得了段详细信息。driud 文档没有帮助,因为仅指定了整体查询的原始结构,但没有指定所需的段详细结构(以下是 druid 文档的建议)。
{
"type": "merge",
"id": <task_id>,
"dataSource": <task_datasource>,
"aggregations": <list of aggregators>,
"segments": <JSON list of DataSegment objects to merge>
}
示例查询:
{
"type": "merge",
"id": "envoy_merge_task",
"dataSource": "dcap.envoy.diskmounts.kafka",
"segments": [{"id":"dcap.sermon.threshold.kafka_2017-05-22T00:00:00.000Z_2017-05-23T00:00:00.000Z_2017-05-22T07:00:02.951Z","intervals":["2017-05-22T00:00:00.000Z/2017-05-23T00:00:00.000Z"],"columns":{},"size":5460959,"numRows":41577,"aggregators":null,"queryGranularity":null},{"id":"dcap.sermon.threshold.kafka_2017-05-22T00:00:00.000Z_2017-05-23T00:00:00.000Z_2017-05-22T07:00:02.951Z_1","intervals":["2017-05-22T00:00:00.000Z/2017-05-23T00:00:00.000Z"],"columns":{},"size":5448881,"numRows":41577,"aggregators":null,"queryGranularity":null},{"id":"dcap.sermon.threshold.kafka_2017-05-22T00:00:00.000Z_2017-05-23T00:00:00.000Z_2017-05-22T07:00:02.951Z_2","intervals":["2017-05-22T00:00:00.000Z/2017-05-23T00:00:00.000Z"],"columns":{},"size":5454452,"numRows":41571,"aggregators":null,"queryGranularity":null},{"id":"dcap.sermon.threshold.kafka_2017-05-22T00:00:00.000Z_2017-05-23T00:00:00.000Z_2017-05-22T07:00:02.951Z_3","intervals":["2017-05-22T00:00:00.000Z/2017-05-23T00:00:00.000Z"],"columns":{},"size":5456267,"numRows":41569,"aggregators":null,"queryGranularity":null}] }
我为“segments”键尝试了不同形式的结构,导致相同的错误。
例子 :
"segments": [{"id":"dcap.envoy.diskmounts.kafka_2017-05-21T06:00:00.000Z_2017-05-21T07:00:00.000Z_2017-05-21T06:02:43.482Z"},{"id":"dcap.envoy.diskmounts.kafka_2017-05-21T06:00:00.000Z_2017-05-21T07:00:00.000Z_2017-05-21T06:02:43.482Z_1"},{"id":"dcap.envoy.diskmounts.kafka_2017-05-21T06:00:00.000Z_2017-05-21T07:00:00.000Z_2017-05-21T06:02:43.482Z_2"},{"id":"dcap.envoy.diskmounts.kafka_2017-05-21T06:00:00.000Z_2017-05-21T07:00:00.000Z_2017-05-21T06:02:43.482Z_3"}]
段合并任务的正确结构是什么。