[Pvfs2-developers] Multiqueue/threaded metadata results

[Julian Martin Kunkel]

Hi,
I did some tests in order to compare the multi threaded (separated read 
thread) with the single threaded version of my branch.
Unfortunately, I have no nice diagrams this time :(

In this test each modifying op syncs the db.
I used 15 clients and one server. I modified the request scheduler to schedule 
all operations. Otherwise LOOKUP_PATH requests can be stalled by CRDIRENT and 
RMDIRENT ops which is what should be prevented by the threaded version.

The multithreaded metadata results are a bit slower, maybe due to the 
randomness of the test, note that I just changed the internal handling which 
just puts all ops into one queue for the single threaded version. However, 
for lookups the threaded version keeps up to much better values >200 ops vs 
25ops of the non threaded version. I also did some comparision with CVS-head 
which showed that the speed of the versions without sched modification is 
comparable. Thus, the multithread version should not be much slower in any 
case :)

Single thread:
Prefill done, time 74.144683
Preoperations done time: 139.267928
CREATE_SUC:  
Min_time 0.109737  Max_time 0.789411  Average_time 0.476488 
1995 operations:    2.10 operations per second
CREATE_ERR:
Min_time 0.002751  Max_time 0.269011  Average_time 0.038828 
1995 operations:   25.75 operations per second
LOOKUP_SUC:
Min_time 0.002366  Max_time 0.231808  Average_time 0.038944 
1995 operations:   25.68 operations per second
LOOKUP_ERR:
Min_time 0.006469  Max_time 0.262257  Average_time 0.064593 
1995 operations:   15.48 operations per second
DELETE_SUC:
Min_time 0.029250  Max_time 0.647775  Average_time 0.248129 
1995 operations:    4.03 operations per second
DELETE_ERR:
Min_time 0.002310  Max_time 0.212471  Average_time 0.033294 
1995 operations:   30.04 operations per second

Separate RW and read thread: 
Prefill done, time 80.511238
Preoperations done time: 161.126937
CREATE_SUC:  
 Min_time 0.468345  Max_time 2.808074  Average_time 0.922336 
1995 operations:    1.08 operations per second
CREATE_ERR: 
Min_time 0.001169  Max_time 1.022032  Average_time 0.004649 
1995 operations:  215.10 operations per second
LOOKUP_SUC:  
Min_time 0.000922  Max_time 1.034277  Average_time 0.003711 
1995 operations:  269.48 operations per second
LOOKUP_ERR:  
Min_time 0.001935  Max_time 1.042539  Average_time 0.007305 
1995 operations:  136.89 operations per second
DELETE_SUC:  
Min_time 0.172478  Max_time 4.952750  Average_time 0.552871 
1995 operations:    1.81 operations per second
DELETE_ERR:  
Min_time 0.002785  Max_time 1.253799  Average_time 0.130337 
1995 operations:    7.67 operations per second

Julian