LSFJRTests < Sandbox

Test with srmcp of 196 MB file: for ifconfig got size of 204.9... OK

Using standard PAT:

| | *dcap-read* | *dcap-readv* | *tstoragefile-read* | *tstoragefile-read-actual* | *tstoragefile-read-cache* | *tstoragefile-readv-actual* | *from IFCONFIG*|
| *std, 1 file* |  36.32|  /|  36.32|  36.32|  /|  /|  245.23|
| *cache=20MB, 1 file* |  2.3|  217.735|  36.32|  2.3|  33.99|  217.735|  285.56|
| *patched4, cache=20MB, 1 file* |  98.6723|  /|  36.327|  98.6723|  31.0044|  /|  145|
| *cache=20MB, 10k events* |  69.1704|  9032.86|  1384|  69.1704|  1314.83|  9032.86|  11451.0|
| *patched4, cache=20MB, 10k events* |  3857.27|  /|  1384|  3857.27|  1183.52|  /|  5540.3|

   * PAT_WN08_PSI_network_1file_1_commented.png: "srmcp" is the copy to local area of a file from the SE (196 MB), can be used as reference<br />
     <img src="%ATTACHURLPATH%/PAT_WN08_PSI_network_1file_1_commented.png" alt="PAT_WN08_PSI_network_1file_1_commented.png" width='897' height='679' />


   * PAT_WN08_PSI_network_10kevts_CACHE20_patch4_commented.png: <br />
     <img src="%ATTACHURLPATH%/PAT_WN08_PSI_network_10kevts_CACHE20_patch4_commented.png" alt="PAT_WN08_PSI_network_10kevts_CACHE20_patch4_commented.png" width='897' height='679' />


seems that using rh auto-detect for dcache selects the buffering:

http://cmslxr.fnal.gov/lxr/source/Utilities/DCacheAdaptor/plugins/DCacheStorageMaker.cc#038

http://cmslxr.fnal.gov/lxr/source/Utilities/DCacheAdaptor/src/DCacheFile.cc#132

<verbatim>
126   // Turn off read-ahead, or adjust read-ahead size depending on
127   // whether buffering has been requested.  This is a very tricky
128   // balance here.  Without read-ahead data processing appears to
129   // become exceedingly slow, and with default (1MB) read-ahead
130   // it appears to saturate disk servers and network.  Try tread
131   // reasonable middle ground here.
132   if (flags & IOFlags::OpenUnbuffered)
133     dc_noBuffering(m_fd);
134   else
135     dc_setBufferSize(m_fd, 64000);
136 
</verbatim>


-- Main.LeonardoSala - 22-Jan-2010

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who	Comment
png	PAT_WN08_PSI_network_10kevts_CACHE20_patch4_commented.png	r1	manage	39.5 K	2010-01-25 - 00:43	UnknownUser
png	PAT_WN08_PSI_network_1file_1_commented.png	r1	manage	61.0 K	2010-01-22 - 17:00	UnknownUser

Topic revision: r5 - 2010-01-25 - unknown

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