commit | 3eaf33a6a9b4673027965be213bc0f54efb23d46 | [log] [tgz] |
---|---|---|
author | Indhumathi27 <indhumathim27@gmail.com> | Tue Feb 11 18:20:38 2020 +0530 |
committer | Jacky Li <jacky.likun@qq.com> | Mon Mar 16 17:43:12 2020 +0800 |
tree | 6f68e3eade3d9127de8facc3277256fb9a738a6c | |
parent | a5ebd5f35832fc245a85d1fb1938dc0b7a7ef80b [diff] |
[CARBONDATA-3665] Support TimeBased Cache expiration using ExpiringMap Why is this PR needed? Currently, in Carbon, we follow LRU cache based mechanism. An least-recently used entry will be removed from the cache when it is full. There is no time-based cache expiration supported in carbon. In cloud, all vm's may not have enough memory to cache everything we could cache. In that case, we can clear cache after a specified duration. This can be achieved by using cache libraries available. One of the caching library is ExpringMap, which provides flexible and powerful caching features. Please refer ExpiringMap for more info. What changes were proposed in this PR? 1. Replaced LinkedHashMap with ExpringMap 2. Added a table property to allow user to specify cache expiration duration in minutes, to clear cache entries for that table. Newly added carbon table property: index_cache_expiration_seconds which takes long value. For example: index_cache_expiration_seconds="300" -> After 5 minutes, cache will be cleared. Does this PR introduce any user interface change? Yes. (table property is added) Is any new testcase added? Yes This closes #3653
Apache CarbonData is an indexed columnar data store solution for fast analytics on big data platform, e.g.Apache Hadoop, Apache Spark, etc.
You can find the latest CarbonData document and learn more at: http://carbondata.apache.org
CarbonData file format is a columnar store in HDFS, it has many features that a modern columnar format has, such as splittable, compression schema ,complex data type etc, and CarbonData has following unique features:
CarbonData is built using Apache Maven, to build CarbonData
This is an active open source project for everyone, and we are always open to people who want to use this system or contribute to it. This guide document introduce how to contribute to CarbonData.
To get involved in CarbonData:
Apache CarbonData is an open source project of The Apache Software Foundation (ASF).