我们正在尝试使用 PredictionIO (ver. 0.9.5) + Universal Recommender (v. 0.2.3) 为我们服务的用户构建个人推荐。EventServer 正在收集有关用户对 MySQL 数据库中项目评分的事件，Recommender 的 retrain 由调度程序运行，并将个人推荐存储到 ElasticSearch。在开始和后来的一些训练中，推荐者的响应看起来不错，有很多项目，但过了一段时间，推荐的数量开始下降。我们查看了 ElasticSearch 中的数据：item 存在，但是它们的属性被删除了。我们想知道为什么会发生这种情况？
附件中的 engine.json 示例：engine.json
提前致谢！
The item will not be written to Elasticsearch if there are no events for it in the EventServer. Are you erasing data in the EventServer between training times? Or starting from all new data, dropping the old?
If you once had events, an item will be written to Elasaticsearch, but if later there are no events it will disappear because the Elasticsearch index is replaced on every train. The EventServer is meant to accumulate data over time, not to be erased before every train.
BTW you should upgrade to the new PredictionIO v0.9.6 and Universal Recommender v0.3.0. These must be upgraded together and taken from these repositories.
https://github.com/actionml/PredictionIO
https://github.com/actionml/template-scala-parallel-universal-recommendation