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Are you reading a tree via ttreecache? Lukasz On Thu, Jan 27, 2011 at 5:04 PM, Brian Bockelman <[log in to unmask]> wrote: > Hi Lukasz, > > Here's a bit higher of a level of debug: > > 110127 16:57:13 001 Xrd: Read: Read(offs=2664306755, len=104) > 110127 16:57:13 001 Xrd: Read: Cache response: got 104@2664306859 bytes. Holes= 0 Outstanding= 0 > 110127 16:57:13 001 Xrd: Read: Found data in cache. len=104 offset=2664306755 > 110127 16:57:13 001 Xrd: Read: Read(offs=2664371953, len=1149) > 110127 16:57:13 001 Xrd: Read: Cache response: got 0@2664371953 bytes. Holes= 1 Outstanding= 0 > 110127 16:57:13 001 Xrd: Read: Hole in the cache: offs=2664371953, len=1149 > 110127 16:57:13 001 Xrd: Read_Async: Requesting to read 16384 bytes of data at offset 2664366080 > 110127 16:57:13 001 Xrd: Read_Async: Requesting pathid 0 > 110127 16:57:13 001 Xrd: Read: Waiting 1outstanding blocks. > 110127 16:57:13 16248 Xrd: ProcessUnsolicitedMsg: Incoming unsolicited response from streamid 3 > 110127 16:57:13 16248 Xrd: ProcessUnsolicitedMsg: Processing async response from streamid 3 father=2 > 110127 16:57:13 16248 Xrd: ProcessUnsolicitedMsg: Putting kXR_read data into cache. Offset=2664366080 len 16384 > > This is the URL used: > > root://xrootd.unl.edu//store/data/Run2010B/BTau/AOD/Dec4ReReco_v1/0007/B26C2B64-E101-E011-9C89-002481E14F38.root?readaheadsz=32768&cachesz=3276800&readaheadstrategy=1&readtrimblksz=16384 > > So, it seems readtrimblksz works and cachesz/readaheadsz doesn't. > > Brian > > On Jan 27, 2011, at 10:46 AM, Lukasz Janyst wrote: > >> Hi Brian, >> >> it looks like there are two possibilities: >> >> * if you're not using a ttreecache: you have disabled the readahead by >> configuring an unknown readahead strategy in the environment >> * if you're reading from a ttree through a ttreecache: the readahead is disabled >> >> Cheers, >> Lukasz >> >> On Thu, Jan 27, 2011 at 4:20 PM, Brian Bockelman <[log in to unmask]> wrote: >>> Hi, >>> >>> I'm opening a file with the following opaque data: >>> >>> root://xrootd.unl.edu:1094//store/data/Run2010B/BTau/AOD/Dec4ReReco_v1/0007/B26C2B64-E101-E011-9C89-002481E14F38.root?readaheadsz=32768&cachesz=327680 >>> >>> I.e., I would expect the minimal read size is 32KB. However, I see the following read pattern: >>> >>> 110127 16:11:34 001 Xrd: Read: Hole in the cache: offs=2673920000, len=55 >>> 110127 16:11:34 001 Xrd: Read: Hole in the cache: offs=2673920512, len=145 >>> 110127 16:11:34 001 Xrd: Read: Hole in the cache: offs=2673921024, len=70 >>> 110127 16:11:34 001 Xrd: Read: Hole in the cache: offs=2673921536, len=154 >>> 110127 16:11:34 001 Xrd: Read: Hole in the cache: offs=2673922048, len=24 >>> 110127 16:11:35 001 Xrd: Read: Hole in the cache: offs=2673922560, len=162 >>> >>> I would have expected all these reads to be handled by the cache. This is with ROOT 5.27.06b. >>> >>> Brian >>> >>> > >