I did some tests after 2.5 to 4.1 migration and it turned out that the whole restore process is now at least 5 times slower than it was on 2.5 server.
There is no visible difference with the small buckets with few thousands documents, but the buckets with more than 100 thousands restores much slower.
Generally a backup with ~2 million documents in few buckets was restored in 7 minutes on CB 2.5.
so I removed CB 2.5 and installed 4.1, I used the same memory size on for CB and the same bucket sizes
and restored the same backup as previously - it took 55 minutes. (almost 8 times slower)
I though it might be some kind of conversion when restore 2.5 backup on 4.1 server so after that I created a backup on this new 4.1 server and after recreating all buckets I restored it back on 4.1 server. It took 37minutes (5 times slower)
I repeated this twice plus one time different windows machines, with very similar results.
We have the same issues with our CBs on Linux. The restore time has increased significantly.
so just want to know if this is a bug or a new CB feature?