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From:Eric Robinson Date:May 9 2013 10:25pm
Subject:RE: Slow Response -- What Does This Sound Like to You?
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> 
> > -----Original Message-----
> > From: Robinson, Eric [mailto:eric.robinson@stripped]
> > Sent: Thursday, May 09, 2013 1:58 PM
> > To: mysql@stripped
> > Subject: Slow Response -- What Does This Sound Like to You?
> > 
> > We have a situation where users complain that the system 
> periodically 
> > freezes for 30-90 seconds. We check the slow query logs and 
> find that 
> > one user issued a complex query that did indeed take 30-90 
> seconds to 
> > complete. However, NO slow queries are recorded for the other 50 
> > users, before, during, or after the freeze. Note that the complex 
> > query in question always shows: "Lock_time: 0".
> > 
> > Q: What conditions could cause single query to lock up a 
> database for 
> > a while for all users (even though it shows "lock time: 0")  but no 
> > other slow queries would show in the logs for any other 
> users who are 
> > hitting the database at the same time?
> > 
> > OS: RHEL3 x64
> > CPU: 8 x 2.9GHz Xeon
> > RAM: 32GB
> > Disk: RAID 5 (6 x 512GB SSD)
> > MySQL: 5.0.95 x64
> > Engine: MyISAM
> > 


> MyISAM?  Or InnoDB?
> Lock_time perhaps applies only to table locks on MyISAM.
> 
> SHOW ENGINE InnoDB STATUS;
> You may find some deadlocks.
> 
> Is Replication involved?
> 
> Anyone doing an ALTER?



MyISAM, no replication involved, and nobody is altering the database. This happens
whenever people run certain reports.


--Eric







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Thread
Slow Response -- What Does This Sound Like to You?Eric Robinson9 May
  • RE: Slow Response -- What Does This Sound Like to You?Rick James9 May
    • RE: Slow Response -- What Does This Sound Like to You?Eric Robinson9 May
      • RE: Slow Response -- What Does This Sound Like to You?Wm Mussatto9 May
        • RE: Slow Response -- What Does This Sound Like to You?Eric Robinson9 May
          • Re: Slow Response -- What Does This Sound Like to You?shawn green9 May
      • Re: Slow Response -- What Does This Sound Like to You?Bruce Ferrell10 May
        • RE: Slow Response -- What Does This Sound Like to You?Rick James10 May
          • RE: [>Suspected Spam<][Characteristics] RE: Slow Response -- What Does This Sound Like to You?Eric Robinson10 May
            • RE: Slow Response -- What Does This Sound Like to You?Rick James10 May
  • Re: Slow Response -- What Does This Sound Like to You?Johnny Withers9 May
  • Re: Slow Response -- What Does This Sound Like to You?Denis Jedig9 May
RE: Slow Response -- What Does This Sound Like to You?Vikas Shukla10 May