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From:Johnny Withers Date:October 6 2011 1:15pm
Subject:Re: 4 minute slow on select count(*) from table - myisam type
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I think in order to solve your problem you will need to post the queries running against
this table along with the explain output of each problem query. Optimizing server
settings is a good start, however, individual query performance sounds like your problem
now. 

Sent from my iPad

On Oct 6, 2011, at 6:47 AM, Joey L <mjh2000@stripped> wrote:

> Just as an fyi - I have other databases and their corresponding apache
> websites on the same server - performing okay.
> It seems that apache/mysql server is just having a hard time dealing
> with the access to those pages that deal with the 9gig table on that
> particular site.  -- Most of the access is done by webcrawlers to the
> site - so there is a lot of activity occuring on the 9gig tables.
> 
> thanks
> mjh
> 
> On Thu, Oct 6, 2011 at 6:13 AM, Joey L <mjh2000@stripped> wrote:
>> guys - i am having such a hard time with this..it is killing me!!!
>> Sorry - had to vent.
>> my machine is running an tyan S2912G2NR  -- with 2 opterons and 12gig
>> of memory. I have 2 software raided drives 1gig each.
>> I run a couple of databases --- my largest table is about 9gig in
>> size. --it is being accessed a lot.
>> My my.cnf is as follows:
>> 
>> #
>> # The MySQL database server configuration file.
>> #
>> # You can copy this to one of:
>> # - "/etc/mysql/my.cnf" to set global options,
>> # - "~/.my.cnf" to set user-specific options.
>> #
>> # One can use all long options that the program supports.
>> # Run program with --help to get a list of available options and with
>> # --print-defaults to see which it would actually understand and use.
>> #
>> # For explanations see
>> # http://dev.mysql.com/doc/mysql/en/server-system-variables.html
>> 
>> # This will be passed to all mysql clients
>> # It has been reported that passwords should be enclosed with ticks/quotes
>> # escpecially if they contain "#" chars...
>> # Remember to edit /etc/mysql/debian.cnf when changing the socket location.
>> [client]
>> port            = 3306
>> socket          = /var/run/mysqld/mysqld.sock
>> 
>> # Here is entries for some specific programs
>> # The following values assume you have at least 32M ram
>> 
>> # This was formally known as [safe_mysqld]. Both versions are currently parsed.
>> [mysqld_safe]
>> socket          = /var/run/mysqld/mysqld.sock
>> nice            = 0
>> 
>> [mysqld]
>> #
>> # * Basic Settings
>> #
>> user            = mysql
>> pid-file        = /var/run/mysqld/mysqld.pid
>> socket          = /var/run/mysqld/mysqld.sock
>> port            = 3306
>> basedir         = /usr
>> datadir         = /var/lib/mysql
>> tmpdir          = /tmp
>> language        = /usr/share/mysql/english
>> skip-external-locking
>> #
>> # Instead of skip-networking the default is now to listen only on
>> # localhost which is more compatible and is not less secure.
>> bind-address            = 127.0.0.1
>> #
>> # * Fine Tuning
>> #
>> key_buffer              = 2G
>> key_buffer_size         = 2G
>> max_allowed_packet      = 16M
>> thread_stack            = 192K
>> thread_cache_size       = 8
>> join_buffer_size                = 128
>> # This replaces the startup script and checks MyISAM tables if needed
>> # the first time they are touched
>> myisam-recover         = BACKUP
>> max_connections        = 100
>> table_cache            = 1024
>> max_heap_table_size             = 32M
>> tmp_table_size                  = 32M
>> thread_concurrency     = 10
>> #
>> # * Query Cache Configuration
>> #
>> query_cache_limit       = 2M
>> query_cache_size        = 16M
>> #
>> # * Logging and Replication
>> #
>> # Both location gets rotated by the cronjob.
>> # Be aware that this log type is a performance killer.
>> # As of 5.1 you can enable the log at runtime!
>> general_log_file        = /var/log/mysql/mysql.log
>> general_log             = 2
>> #
>> # Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
>> #
>> # Here you can see queries with especially long duration
>> #log_slow_queries       = /var/log/mysql/mysql-slow.log
>> #long_query_time = 2
>> #log-queries-not-using-indexes
>> #
>> # The following can be used as easy to replay backup logs or for replication.
>> # note: if you are setting up a replication slave, see README.Debian about
>> #       other settings you may need to change.
>> #server-id              = 1
>> #log_bin                        = /var/log/mysql/mysql-bin.log
>> expire_logs_days        = 10
>> max_binlog_size         = 100M
>> #binlog_do_db           = include_database_name
>> #binlog_ignore_db       = include_database_name
>> #
>> # * InnoDB
>> #
>> # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
>> # Read the manual for more InnoDB related options. There are many!
>> #
>> # * Security Features
>> #
>> # Read the manual, too, if you want chroot!
>> # chroot = /var/lib/mysql/
>> #
>> # For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
>> #
>> # ssl-ca=/etc/mysql/cacert.pem
>> # ssl-cert=/etc/mysql/server-cert.pem
>> # ssl-key=/etc/mysql/server-key.pem
>> 
>> 
>> 
>> [mysqldump]
>> quick
>> quote-names
>> max_allowed_packet      = 64M
>> 
>> [mysql]
>> #no-auto-rehash # faster start of mysql but no tab completition
>> 
>> [isamchk]
>> key_buffer              = 16M
>> 
>> #
>> # * IMPORTANT: Additional settings that can override those from this file!
>> #   The files must end with '.cnf', otherwise they'll be ignored.
>> #
>> !includedir /etc/mysql/conf.d/
>> 
>> any thoughts or help would be appricated.
>> thanks
>> 
>> 
>> On Mon, Oct 3, 2011 at 1:22 PM, Eric Bergen <eric.bergen@stripped> wrote:
>>> Can you run show processlist in another connection while the select
>>> count(*) query is running and say what the state column is?
>>> 
>>> On Mon, Oct 3, 2011 at 7:00 AM, Joey L <mjh2000@stripped> wrote:
>>>> this is not a real query on the site - it is just a way i am measuring
>>>> performance on mysql - I do not know if it is such a great way to test.
>>>> Looking for a better way to get a performance read on my site...do you
> have
>>>> any ?? besides just viewing pages on it.
>>>> thanks
>>>> mjh
>>>> 
>>>> 
>>>> On Mon, Oct 3, 2011 at 9:58 AM, Andrés Tello
> <mr.criptos@stripped> wrote:
>>>> 
>>>>> have you tried
>>>>> 
>>>>> select count(yourindex) instead of select count(*) ?
>>>>> 
>>>>> 
>>>>> On Mon, Oct 3, 2011 at 7:53 AM, Joey L <mjh2000@stripped>
> wrote:
>>>>> 
>>>>>> Thanks for the input -
>>>>>> 1. I will wait 48 hours and see what happens.
>>>>>> 2. can you tell me what are some performance tests I can do to
> help me
>>>>>> better tune my server ?
>>>>>> 3. I am concerned about this table : | w6h8a_sh404sef_urls
>>>>>> |
>>>>>> MyISAM |      10 | Dynamic    | 8908402 |            174 | 
> 1551178184 |
>>>>>>  281474976710655 |   2410850304 |         0 |        8908777 |
> 2011-09-22
>>>>>> 11:16:03 | 2011-10-02 21:17:20 | 2011-10-02 10:12:04 |
> utf8_general_ci   |
>>>>>>  NULL |                |                                   |
>>>>>> what can I do to make it run faster - i did not write the
> code...but need
>>>>>> to
>>>>>> optimize server to handle this table when it gets larger.  It is
> used for
>>>>>> url re-writes - so it has a lot of urls.
>>>>>> thanks
>>>>>> mjh
>>>>>> 
>>>>>> On Mon, Oct 3, 2011 at 12:38 AM, Bruce Ferrell
> <bferrell@stripped
>>>>>>> wrote:
>>>>>> 
>>>>>>> 
>>>>>>> The meaning is:
>>>>>>> 
>>>>>>> increase max_connections
>>>>>>> reduce wait_timeout
>>>>>>> -- 28800 is wait 8 hours before closing out dead connections
>>>>>>> same for interactive_timeout
>>>>>>> 
>>>>>>> 
>>>>>>> increase key_buffer_size (> 7.8G) increase
> join_buffer_size
>>>>>>> -- This keeps mysql from having to run to disk constantly for
> keys
>>>>>>> -- Key buffer size / total MyISAM indexes: 256.0M/7.8G
>>>>>>> -- You have a key buffer of 256M and 7.8G of keys
>>>>>>> 
>>>>>>> join_buffer_size (> 128.0K, or always use indexes with
> joins)
>>>>>>> Joins performed without indexes: 23576 of 744k queries.
>>>>>>> -- You probably want to look at the slow query log. 
> Generalize the
>>>>>> queries
>>>>>>> and the do an explain on the query.  I have seen instances
> where a query
>>>>>> I
>>>>>>> thought was using an index wasn't and I had to re-write...
> with help
>>>>>> from
>>>>>>> this list :-)  Thanks gang!
>>>>>>> 
>>>>>>> 
>>>>>>> increase tmp_table_size (> 16M)
>>>>>>> increase max_heap_table_size (> 16M)
>>>>>>> -- When making adjustments, make
> tmp_table_size/max_heap_table_size
>>>>>> equal
>>>>>>> 
>>>>>>> increase table_cache ( > 1k )
>>>>>>> -- Table cache hit rate: 7% (1K open / 14K opened)
>>>>>>> -- Increase table_cache gradually to avoid file descriptor
> limits
>>>>>>> 
>>>>>>> All of the aside, you need to let this run for at least 24
> hours. I
>>>>>>> prefer 48 hours.  The first line says mysql has only been
> running 9
>>>>>>> hours.   You can reset the timeouts interactivly by entering
> at the
>>>>>>> mysql prompt:
>>>>>>> 
>>>>>>> set global wait_timeout=<some value>
>>>>>>> 
>>>>>>> You can do the same for the interactive_timeout.
>>>>>>> 
>>>>>>> Setting these values too low will cause long running queries
> to abort
>>>>>>> 
>>>>>>> 
>>>>>>> On 10/02/2011 07:02 PM, Joey L wrote:
>>>>>>>> Variables to adjust:
>>>>>>>>>     max_connections (> 100)
>>>>>>>>>     wait_timeout (< 28800)
>>>>>>>>>     interactive_timeout (< 28800)
>>>>>>>>>     key_buffer_size (> 7.8G)
>>>>>>>>>     join_buffer_size (> 128.0K, or always use
> indexes with joins)
>>>>>>>>>     tmp_table_size (> 16M)
>>>>>>>>>     max_heap_table_size (> 16M)
>>>>>>>>>     table_cache (> 1024)
>>>>>>> 
>>>>>>> 
>>>>>>> --
>>>>>>> MySQL General Mailing List
>>>>>>> For list archives: http://lists.mysql.com/mysql
>>>>>>> To unsubscribe:    http://lists.mysql.com/mysql?unsub=1
>>>>>>> 
>>>>>>> 
>>>>>> 
>>>>> 
>>>>> 
>>>> 
>>> 
>>> 
>>> 
>>> --
>>> Eric Bergen
>>> eric.bergen@stripped
>>> http://www.ebergen.net
>>> 
>> 
> 
> -- 
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:    http://lists.mysql.com/mysql?unsub=1
> 
Thread
4 minute slow on select count(*) from table - myisam typeJoey L2 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore2 Oct
    • Re: 4 minute slow on select count(*) from table - myisam typeJoey L2 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeBruce Ferrell2 Oct
Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore2 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
    • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
      • Re: 4 minute slow on select count(*) from table - myisam typeBruce Ferrell3 Oct
        • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
          • Re: 4 minute slow on select count(*) from table - myisam typeAndrĂ©s Tello3 Oct
            • Re: 4 minute slow on select count(*) from table - myisam typeJoey L3 Oct
              • Re: 4 minute slow on select count(*) from table - myisam typeEric Bergen3 Oct
                • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                    • Re: 4 minute slow on select count(*) from table - myisam typeJohnny Withers6 Oct
                      • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                        • Re: 4 minute slow on select count(*) from table - myisam typeJohnny Withers6 Oct
                        • Re: 4 minute slow on select count(*) from table - myisam typeJohan De Meersman6 Oct
                        • Re: 4 minute slow on select count(*) from table - myisam typeRik Wasmus6 Oct
                          • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                            • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore6 Oct
                              • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore6 Oct
                                • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
                                  • Re: 4 minute slow on select count(*) from table - myisam typeMichael Dykman6 Oct
Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore6 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L6 Oct
Re: 4 minute slow on select count(*) from table - myisam typeJohnny Withers6 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJohan De Meersman7 Oct
Re: 4 minute slow on select count(*) from table - myisam typeJan Steinman7 Oct
  • Re: 4 minute slow on select count(*) from table - myisam typeJoey L7 Oct
    • Re: 4 minute slow on select count(*) from table - myisam typeAndrew Moore7 Oct