On Thu, Oct 24, 2013 at 6:38 AM, Jukka Zitting <[email protected]> wrote: > Hi, > > On Thu, Oct 24, 2013 at 2:48 AM, Tobias Bocanegra <[email protected]> wrote: >> [Inline image 1] > > The image didn't survive it's trip to the mailing list. Can you post a > link to it? the relevant information was:
java.util.UUID, 353'574 Objects (41%), 22'628'736 shallow size > >> I thought that Oak does not use UUIDs so much anymore - why do I have 20mb >> of them? they are all allocated via the SegmentMK. > > The SegmentMK uses UUIDs to identify segments. > > Currently multiple copies of each UUID are kept in memory, one for the > segment itself and another for each other segment that contains a > reference to it. Avoiding those duplicates should bring the memory > requirement down by an order of magnitude. > > Another reason for the high memory use is that currently the TarMK > (not the MongoDB backend of SegmentMK) keeps all Segment UUIDs in > memory all the time to avoid having to scan through the tar files when > looking up a segment. A segment index at the end of each tar file > should take care of that. > > BR, > > Jukka Zitting -- toby
