List:General Discussion« Previous MessageNext Message »
From:Mauricio Pellegrini Date:March 9 2005 11:38pm
Subject:Re: Query_cache_size Question
View as plain text  
Thanks these are fresh results

| query_cache_limit            | 1048576  |
| query_cache_min_res_unit     | 4096     |


show  status like "ques%";
+---------------+----------+
| Variable_name | Value    |
+---------------+----------+
| Questions     | 14189604 |
+---------------+----------+


show  status like "qcache%";
+-------------------------+----------+
| Variable_name           | Value    |
+-------------------------+----------+
| Qcache_free_blocks      | 2731     |
| Qcache_free_memory      | 12372064 |
| Qcache_hits             | 11156553 |
| Qcache_inserts          | 1945643  |
| Qcache_lowmem_prunes    | 372898   |
| Qcache_not_cached       | 509594   |
| Qcache_queries_in_cache | 4101     |
| Qcache_total_blocks     | 11000    |
+-------------------------+----------+


On Wed, 2005-03-09 at 20:19, Jocelyn Fournier wrote:
> Hi,
> 
> How many questions for thoses results ?
> There's a lot of lowmem_prunes, so I would indeed increase the memory 
> size to reduce the risk of lowmem_prunes.
> What is your query_cache_limit ?
> 
>    Jocelyn
> 
> Mauricio Pellegrini a écrit :
> > Thanks,  this the result of show status like "qcache%"
> > 
> > +-------------------------+----------+
> > | Variable_name           | Value    |
> > +-------------------------+----------+
> > | Qcache_free_blocks      | 3330     |
> > | Qcache_free_memory      | 13372320 |
> > | Qcache_hits             | 11119149 |
> > | Qcache_inserts          | 1942009  |
> > | Qcache_lowmem_prunes    | 372898   |
> > | Qcache_not_cached       | 508528   |
> > | Qcache_queries_in_cache | 3160     |
> > | Qcache_total_blocks     | 9711     |
> > +-------------------------+----------+
> > 
> > Am I right at saying that the value (16Mb)is ok ?
> > 
> > Qcache_not_cached means the number of query results that didn't get into
> > the cache because of a space limitation ? 
> > If so, perhaps adding few more Mb would improve that number , isn't it?
> > 
> > 
> > 
> > 
> > On Wed, 2005-03-09 at 19:30, Dan Nelson wrote:
> > 
> >>In the last episode (Mar 09), Mauricio Pellegrini said:
> >>
> >>>Hi, I'm trying to tweak the execution time for querys on my mysql
> >>>server which is using InnoDB.
> >>>
> >>>I know that there are a lot of things to check but one of them,
> >>>perhaps not the most important, is the query_cache_size.
> >>>
> >>>I have a dual Xeon cpu with 4gb of ram and this is a Linux dedicated
> >>>server which runs only Apache and Mysql 4.1.5
> >>>
> >>>I've declared Query_cache_size = 16M in the my.cnf file and I would
> >>>say that in the whole we have 60% of select querys and a 40% of
> >>>update querys.
> >>>
> >>>Is Query_cache_size=16M too conservative considering that I have 4Gb
> >>>of ram ?
> >>
> >>A better question is: what is your current utilization of that 16MB
> >>cache?  The query cache flushes any results dependant on a table when
> >>that table is modified, so if you really have 40% updates, chances are
> >>that very few queries are cachable at all.  Run
> >>
> >>  show status like 'qcache%';
> >>
> >>, and take a look at free_memory, inserts, and hits.
> >> 
> >>-- 
> >>	Dan Nelson
> >>	dnelson@stripped
> > 
> > 
> > 

Thread
Query_cache_size QuestionMauricio Pellegrini9 Mar
  • Re: Query_cache_size QuestionDan Nelson9 Mar
    • Re: Query_cache_size QuestionMauricio Pellegrini9 Mar
      • Re: Query_cache_size QuestionJocelyn Fournier10 Mar
        • Re: Query_cache_size QuestionMauricio Pellegrini10 Mar
          • Re: Query_cache_size QuestionJocelyn Fournier10 Mar
      • Re: Query_cache_size QuestionDan Nelson10 Mar
RE: Query_cache_size QuestionKostas Pyliouras9 Mar