Hey list,

i was just wondering if anyone else is experiencing very slow ( ~ 3.5 MB/sec ) re-fill of the row cache at start up. We operate with a large row cache ( 10-15GB currently ) and we already measure startup times in hours :-)

How is the "saved row cache file" processed? Are the cached row keys simply iterated over and their respective rows read from SSTables - possibly creating random reads with small enough sstable files, if the keys were not stored in a manner optimised for a quick re-fill ? -  or is there a smarter algorithm ( i.e. scan through one sstable at a time, filter rows that should be in row cache )  at work and this operation is purely disk i/o bound ?

( Admittedly whatever is going on is still much more preferable to starting with a cold row cache )

thanks!
Andras



Andras Szerdahelyi

Solutions Architect, IgnitionOne | 1831 Diegem E.Mommaertslaan 20A
M: +32 493 05 50 88 | Skype: sandrew84