liran-funaro commented on issue #9967: URL: https://github.com/apache/druid/issues/9967#issuecomment-953824508
@Mrxiashu In Oak, `maxRowsInMemory` and `maxBytesInMemory` behaves the same as the OnheapIncrementalIndex. Are the offheap usage for Oak and Onheap the same? That doesn't seem right. Did you monitor the overall machine memory usage? The main benefit of Oak is its low memory and CPU footprint. * `oakMaxMemoryCapacity` is an internal configuration that preallocates the array for the offheap buffers, but it doesn't preallocate the buffers. It is safe set it to an arbitrary larger number. * `oakBlockSize` is the size of the allocation block. If you witness an excessive memory usage, you can lower the size of the blocks. This will reduce the memory overhead but migth impact performance. The default it 8MB since the main benefit from OakIncrementalIndex is the reduced memory footprint. * `oakChunkMaxItems` this is an internal configuration. Oak map is build of two layers. The first layer is an ordered map of chunks where each chunk is an ordered array of key/value pairs. Larger chunks will yield smaller tree in the first layer and less on-heap objects. The impact of larger chunks is yet to be determined. I would suggest to set it to the default value. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
