sslug-teknik team mailing list archive

[Robert Larsen <robert@xxxxxxxxxxxx>]

Martin Møller Skarbiniks Pedersen wrote:
> 2010/4/9 Martin Berg <martin@xxxxxxx>:
> 
>>> Tjah. Man kan flush ikke-dirty objecter fra cachen vha.
>>> echo 3 > /proc/sys/vm/drop_caches
>>>
>>> Mvh
>>> Martin
>>>
>>>
>> Tak - den kendte jeg ikke
>>
> 
> Husk forresten også sync før, så du har færre dirty objects.
> Et eksempel, hvor jeg sletter ca. 2GB fra hukommelsen.
> Kig på cached tallet,
> 
> root@quadcore:~# free | head -2
>              total       used       free     shared    buffers     cached
> Mem:       4057788    4020616      37172          0     394020    2110732
> 
> root@quadcore:~# sync ; echo 3 > /proc/sys/vm/drop_caches
> 
> root@quadcore:~# free | head -2
> 
>              total       used       free     shared    buffers     cached
> Mem:       4057788    1518816    2538972          0        432     119264
> 
> 

robert-desktop:~ $ sync ; echo 3 > /proc/sys/vm/drop_caches ; time mysql -u root gamelog -e "select count(*) from game_log_ng where match(log) against('+nano' in boolean mode)"
+----------+
| count(*) |
+----------+
|  5127025 |
+----------+

real	0m43.183s
user	0m0.008s
sys	0m0.000s
robert-desktop:~ $ sync ; echo 3 > /proc/sys/vm/drop_caches ; time mysql -u root gamelog -e "select count(*) from game_log_ng where log like '%nano%'"
+----------+
| count(*) |
+----------+
|  5127025 |
+----------+

real	0m11.886s
user	0m0.004s
sys	0m0.000s
robert-desktop:~ $

Det hjalp ikke meget. 43 sekunder når jeg bruger index, knap 12 når jeg ikke gør.