Looks like the system is doing a lot of disk WRITES. Your writes/sec are
much higher than your reads/sec. But the time stuff waits in the queue is
low. Did you try top -i with the x option entered? That will produce a
colored line if a dask is I/O bound.
On Fri, February 27, 2009 11:51, dbrb2002-sql@stripped wrote:
> Thanks for the quick followup Baron..
>
> vmstat
> procs -----------memory---------- ---swap-- -----io---- --system--
> -----cpu------
> r b swpd free buff cache si so bi bo in cs us sy id
> wa st
> 3 0 100 499380 139256 5604000 0 0 190 693 11 11 20 2
> 70 8 0
>
> iostat -dx 5 5
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz
> avgqu-sz await svctm %util
> sda 0.02 187.72 0.28 10.36 4.66 1584.73 149.44
> 2.03 191.16 5.23 5.56
> sdb 1.85 371.84 21.72 56.86 1514.44 3956.67 69.63
> 2.63 33.43 3.44 27.03
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz
> avgqu-sz await svctm %util
> sda 0.00 1527.80 0.40 73.80 3.20 12812.80 172.72
> 1.59 21.46 0.24 1.76
> sdb 0.00 11.60 2.40 10.80 65.60 950.40 76.97
> 0.08 5.82 3.67 4.84
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz
> avgqu-sz await svctm %util
> sda 0.00 173.00 0.00 11.60 0.00 1476.80 127.31
> 0.58 50.24 8.22 9.54
> sdb 0.00 5.80 0.00 13.40 0.00 153.60 11.46
> 2.61 195.13 5.63 7.54
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz
> avgqu-sz await svctm %util
> sda 0.00 1624.40 0.00 126.00 0.00 14003.20 111.14
> 5.31 42.14 0.38 4.84
> sdb 0.00 599.60 0.00 82.20 0.00 15697.60 190.97
> 1.79 21.75 2.32 19.08
>
> Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz
> avgqu-sz await svctm %util
> sda 0.00 1538.80 0.20 61.60 1.60 12803.20 207.20
> 5.10 82.48 2.37 14.62
> sdb 0.20 1.00 7.40 2.40 200.00 27.20 23.18
> 0.22 22.73 10.73 10.52
>
>
> The above is when low to medium load..
>
>
>
> ________________________________
> From: Baron Schwartz <baron@stripped>
> To: dbrb2002-sql@stripped
> Cc: mysql@stripped
> Sent: Friday, February 27, 2009 5:50:11 AM
> Subject: Re: MySQL Closing/Opening tables
>
> On Fri, Feb 27, 2009 at 4:19 AM, <dbrb2002-sql@stripped> wrote:
>> Hi
>>
>> Recently I noticed the server takes lot of time on and off when opening
>> and closing tables. And I tried to increase the table_cache more the the
>> total tables (file_limit is properly set); and the problem still
>> continues and lowering it also continues.. and tried to set in middle..
>> same
>>
>> Any thoughts on fixing this ? I am going crazy..
>>
>> Sometimes the threads spin 10-60secs in just opening and closing tables
>> state..
>
> Have you checked to see if your disk is saturated with requests? Try
> this:
>
> vmstat 5 5
> iostat -dx 5 5
>
> Assuming you're on a Unix-like OS.
>
> --
> Baron Schwartz, Director of Consulting, Percona Inc.
> Our Blog: http://www.mysqlperformanceblog.com/
> Our Services: http://www.percona.com/services.html
>
