问题描述
cacheloader:用例
cacheloader : Use case
使用GemFire的主要用例之一是，它将GemFire用作快速运行的缓存，该缓存可保存最新数据(例如最近1个月的数据)，而所有剩余数据都位于后端数据库中.我的意思是1个月前的Gemfire数据在1个月后溢出到数据库中.但是，当用户寻找超过1个月的数据时，我们需要进入数据库并获取数据.缓存加载器适用于在缓存未命中并从数据库获取数据时执行此操作.关于缓存加载器，只有当我们对某个键执行Get操作并且该键丢失时，才会触发我认为缓存未命中.
One of main use case where GemFire is used is, where it is used as a fast running cache which holds most recent data (example last 1 month) and all remaining data sits in back-end database. I mean Gemfire data which is 1 month old is overflowed to database after 1 month.However when user is looking for data which was beyond 1 month, we need to go to the database and get the data.Cache loader is suitable for doing this operation on cache misses and gets data from the database. Regarding cache loader I beleive cache misses is triggered only when we do a Get operation on a key and if the key is missing.
我不明白的是，当数据溢出到后端时，我相信Gemfire中没有引用.另外，用户可能不知道Key-要对Key进行get操作，他可能需要在除key之外的其他某些字段上执行OQL查询.当我不知道键时如何触发缓存未命中?
What I do not understand is when the data gets overflowed to back-end, I beleieve no reference exist in Gemfire. Also a user may not know the Key - to do a get operation on Key, he might need to execute a OQL query on some other fields other than key.How will cache miss be triggered when I don't know the key?
那Cache loader如何适合整个解决方案?
Then how does Cache loader fits into the overall solution?
推荐答案
Geode在查询操作期间不会调用CacheLoader.
Geode will not invoke a CacheLoader during a Query operation.
从 Geode文档:
(强调是我自己的)
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