Hi Jason,
As you noted and we also noted it, Linux uses the entire free memory
for disk caching. For
NDB this was not a very good manner since it meant that potentially
GBytes of writes was
cached before written. Once the writing started, the machine behaved
most displeasing.
To fix this we always ensure that we never have more than 16 MBytes of
outstanding dirty
writes before we start synching data to disk.
On your specific problem of how to change the behaviour of the Linux
Disk Cache I am afraid
I haven't heard of such tweaks (which of course is not an indicator
that they don't exist).
Rgrds Mikael
2004-10-13 kl. 08.06 skrev Jason Williams:
> Hey,
>
> This probably isn't the optimal place to ask this question, but I
> thought y'all might have some opinions on the subject. MySQL (NDB or
> InnoDB) pumps up the linux disk cache like no tomorrow, with all the
> read/write operations going on. I'd like to limit the disk cache size
> (especially since NDB shouldn't be reading from disk anyway...just
> checkpointing to it unless I'm mistaken), but can't for the life of me
> find the kernel tweak. Anybody found suitable satisfaction to this
> problem?
>
> Best Regards,
> Jason
>
Mikael Ronström, Senior Software Architect
MySQL AB, www.mysql.com
Clustering:
http://www.infoworld.com/article/04/04/14/HNmysqlcluster_1.html
http://www.eweek.com/article2/0,1759,1567546,00.asp
