Hi, 2017-03-23 16:13 GMT+01:00 Alex Parvulescu <[email protected]>: > Hi, > > To add what I have found so far. This seems related to OAK-4274, but I > think there might be a twist in there somewhere. > I'm pretty sure that this method is the one introducing the extra full > mapping of the repository: FileStoreHelper.checkFileStoreVersionOrFail [0]. > Disabling this method takes the 2x mapping away completely.
I think your analysis matches with the 2x increase in memory mappings. It might be that the memory mappings created while opening the FileStore in read-only mode are never garbage collected, even if the FileStore is correctly closed when checkFileStoreVersionOrFail() returns. To avoid this, we might want to open the FileStore in checkFileStoreVersionOrFail() with memory mapping disabled. > The reason I'm saying it is relate to OAK-4274 is because I looked at a > heap dump to verify what is keeping the references to the readonly store > and there are no live ones, the refs should be GC'ed, but for some reason > they are not. > > I'm still poking around, did not create an oak issue yet. Still pending is > to verify if this affects other areas than oak-run. > > Feedback is more than welcome! > > best, > alex > > [0] > https://github.com/apache/jackrabbit-oak/blob/1.6/oak-run/src/main/java/org/apache/jackrabbit/oak/plugins/segment/FileStoreHelper.java#L209
