alex-plekhanov commented on code in PR #13247: URL: https://github.com/apache/ignite/pull/13247#discussion_r3527091103
########## docs/_docs/monitoring-metrics/new-metrics-system.adoc: ########## @@ -274,9 +274,10 @@ It is reused when new entries need to be added to the storage on subsequent writ The allocated size is available at the level of data storage, data region, and cache group metrics. The metric is called `TotalAllocatedSize`. -You can also get an estimate of the actual size of data by multiplying the number of link:memory-architecture#data-pages[data pages] in use by the fill factor. The fill factor is the ratio of the size of data in a page to the page size, averaged over all pages. The number of pages in use and the fill factor are available at the level of data <<Data Region Size,region metrics>>. - -For link:memory-configuration/data-regions[data region] metrics, Ignite also exposes the `SizeUsedByData` metric. It estimates how many bytes are currently occupied by data in the region, including the empty space inside non-empty pages. Use this metric when you need a more direct estimate of how much data is stored in the region, and use `TotalAllocatedSize` when you need to monitor how much space has already been allocated for that region. +For link:memory-configuration/data-regions[data region] metrics, Ignite also exposes the `SizeUsedByData` metric. +It estimates how many bytes are currently occupied by data in the region. +The metric is calculated as `(TotalAllocatedPages - EmptyDataPages) * pageSize * PagesFillFactor`, which is equivalent to `TotalUsedSize * PagesFillFactor`. `PagesFillFactor` is the average ratio of data bytes to page size in non-empty data pages. Review Comment: I think `TotalUsedSize` is not quite correct definition for "size occupied by all non empty pages" -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
