Dear all, we are evaluating techniques for finding all keys contained in a cache. So far, we tried the most simple approaches mentioned in this mailing list like iterating over all cache entries or creating a SqlFieldsQuery asking for the _key column. While the results are correct, the performance is not satisfying if some cache content is not held in memory.
Our setup is as follows: We got a small spring boot application that is running an embedded ignite instance. We manually activated the cluster consisting of this single node. We create all caches using the partitioned mode, so we can modify indexed fields during runtime by issuing sql statements. We are aware of the fact that using partitioned mode with a single node is useless but it should not do any harm. We limit the available heap memory of the application to one gigabyte and pushed more data to the cache than the heap memory can hold. Therefore, some cache entries are written to the hard drive. In addition, we enabled persistent storage to make the cache survive restarts. What we see is that the query as well as iterating cache entries takes a long time to complete. While running the queries, we could see some decent load on the hard drive. This makes sense for iterating cache entries but not so much for the query. We expected that the query just aks the database for the content of the (indexed?) _key column, which should not require the whole entity being loaded. This request should be pretty fast even if most of the entities are not available in the heap. With less data, the requests are faster than we could explain by the smaller amount of data. Could you give us some hints about what we could have done wrong or how we could retrieve all keys used in a cache in a more efficient way? If you need more information, I am keen to provide it. Best regards Stephan -- Sent from: http://apache-ignite-users.70518.x6.nabble.com/
