[GNUnet-developers] [continued] insert - delete tests

[eric haumant]

Hello,

I've just run some tests on GNUnet 0.53 with a 100Mb file, BDB and MySQL. My
tests was inserting the file (insertion of 106669 blocks), downloading it
locally and deleting it several time.

Here is the results with BerkeleyDB (I've done it just 10 times, it took too
much time !!) :

First time :
 - insertion speed : 77 kb/s
 - download speed : 850 kb/s
 - deleting time : 34min (speed : 50 kb/s)
 - place used : 
      before : 180 ko
      after insert : 435Mo  
      after delete : 436 Mo

Second time :
 - insertion speed : 36 kb/s
 - download speed : 113 kb/s
 - deleting time : 1h (speed : 28 kb/s)
 - place used : 
      before : 436 Mo
      after insert : 437.9 Mo  
      after delete : 438.5 Mo

....

10th time :
 - insertion speed : 36 kb/s
 - download speed : 832 kb/s
 - deleting time : 49min (speed : 39 kb/s)
 - place used : 
      before : 438.6 Mo
      after insert : 438.7 Mo  
      after delete : 438.7 Mo

With BerkeleyDB the delete didn't reduce the database size but increase it a
little with a maximum of 438.7Mo. After deletion we gain download speed. The
BerkeleyDB is not really stable with test results, the deletion take from
29min to 4hours, not regular at all (strange). The insertion speed was
though more regular : from 22min to 47min.

Here is the results with MySQL (I've done it just 10 times, it took too much
time !!) :

First time :
 - insertion speed : 51 kb/s
 - download speed : 850 kb/s
 - deleting time : 10min (speed : 170 kb/s)
 - place used : 
      before : 150 ko
      after insert : 115Mo  
      after delete : 115 Mo

Second time :
 - insertion speed : 49 kb/s
 - download speed : 190 kb/s
 - deleting time : 9min (speed : 190 kb/s)
 - place used : 
      before : 115 Mo
      after insert : 115 Mo  
      after delete : 115 Mo

....

10th time :
 - insertion speed : 50 kb/s
 - download speed : 190 kb/s
 - deleting time : 10min (speed : 170 kb/s)
 - place used : 
      before : 115 Mo
      after insert : 115 Mo  
      after delete : 115 Mo

With MySQL the delete didn't reduce the database size and like TrivialDB not
increase it though. MySQL is the fastest for deletion and insertion.

I've remarked that when I delete the file previously downloaded before
calling gnunet-download, the speed was slower. I though gnunet didn't verify
the file's content when downloading to an existing file. Is it due to disk
access ? Is gnunet verifing file content if no IBlocks files is present ?
For my test, if the file is present the download speeds up to 850ko/s but
when not present it speeds up to 190ko/s(with mysql).

Eric.