I don’t understand what does mean drop/load segments. It is about rule for coordinator.
We update rules and we expect that historical drop/load segments for given interval.
Drop - is it permanent drop from cluster ? I mean that given segments disappear forever.
Dropping a segment is actually telling the historical to stop serving it.
But the actual data about the segment still at the deep storage for instance HDFS.
Drop from memory ?
yes drop it from the historical cache memory mapped file cache
Load - load from where ? I think that from deepStorage to memory. Am I wrong ?
Load will be from deep storage like HDFS or S3.
Keep in mind that druid historical need to load the data from the deep store to their memory in order to serve data.