List:Cluster« Previous MessageNext Message »
From:Jonas Oreland Date:October 21 2011 9:25am
Subject:Re: Slow session (connection) set-up using MySQLD API
View as plain text  
ok...so archeology-department has found this bug: http://bugs.mysql.com/bug.php?id=48832

we still haven't examined if this made it into 5.5

/Jonas

On 10/21/11 08:55, Magnus Blåudd wrote:
> Hi,
>
> I remember that we had a similar problem with the 5.1 based MySQL Cluster - holding a
> mutex while doing network IO to release resources when the session disconnected. Problem
> was  fixed with a custom patch and was supposed to be fixed in 5.5
>
> / Magnus
>
> ----- Reply message -----
> From: "Jonas Oreland"<jonas.oreland@stripped>
> Date: Thu, Oct 20, 2011 21:41
> Subject: Slow session (connection) set-up using MySQLD API
> To:<paul@stripped>
> Cc: "Johan Andersson"<johan@stripped>,<cluster@stripped>
>
>
> On 10/20/11 21:37, Johan Andersson wrote:
>> Hi Paul,
>>
>> Could you give an illustrative example of what the SELECT query looks like and
> what is the data model - roughly what the table(s) look like, and how it is indexed, and
> sizes, and if blobs/texts etc are used.
>>
>> I can try it then on my cluster.
>
> i'm also interested in what type of application it is...
>
> c program
> php
> perl
> something else cool
>
> /Jonas
>
>>
>> Best regards,
>> johan
>>
>> On 2011-10-20 17.38, paul@stripped wrote:
>>> Jonas,
>>>
>>> Attached are the config.ini file (for the management nodes), my.cnf file
>>> (for the MySQLD API nodes, in this case for node 55), and the ndbd.cnf
>>> file (for the data nodes).
>>>
>>> Unfortunately I am not allowed to share the source code of my test
>>> program, I'm sorry.
>>>
>>> Thanks for your help, Paul
>>>
>>>> -------- Original Message --------
>>>> Subject: Re: Slow session (connection) set-up using MySQLD API
>>>> From: Jonas Oreland<jonas.oreland@stripped>
>>>> Date: Thu, October 20, 2011 4:06 pm
>>>> To:paul@stripped
>>>> Cc:cluster@stripped
>>>>
>>>>
>>>> On 10/20/11 15:31,paul@stripped  wrote:
>>>>> Hello,
>>>>>
>>>>> I'm evaluating MySQL Cluster as a replacement for our current
> "normal"
>>>>> MySQL Server. The current server is processing many "update" queries
> per
>>>>> second, sent by a client application that always stays connected to
> the
>>>>> server. On the other hand, the server is serving "select" queries on
> the
>>>>> same table, using clients that disconnect after each query (i.e.,
>>>>> requests coming from a web server, without connection pooling).
>>>>>
>>>>> In my evaluation I have observed that MySQL Cluster with two data
> nodes
>>>>> offers a superior "update" performance compared to a MySQL Server
>>>>> instance running on identical hardware. However, performance for the
>>>>> "select" queries is much worse on MySQL Cluster (using MYSQLD as
> API).
>>>>>
>>>>> Apparently MySQL Cluster has much more "overhead" setting up a
> session
>>>>> (connection). The difference between MySQL Server and MySQL Cluster
> is
>>>>> quite dramatic: In our test set-up MySQL Cluster could only server
> about
>>>>> 65 connect-select-disconnect cycles, whereas MySQL Server can easily
>>>>> handle 1000 and more cycles per second. This is quite a show-stopper
> for
>>>>> our purposes...
>>>>>
>>>>> Note that all queries are done using the primary key, and all
> updates
>>>>> and selects work on exactly one row. In total our test table
> contains
>>>>> 100,000 rows. The MySQL Server version used to test was 5.1 and
> MySQL
>>>>> Cluster was version 7.2.1 with MySQLD 5.5.
>>>>>
>>>>> Does anyone else has the same experience with MySQL Cluster? Is
> there
>>>>> any way to improve this connect-select-disconnect cycles?
>>>>>
>>>>> Thanks for your help,
>>>>>
>>>>> Paul
>>>> Hi Paul,
>>>>
>>>> Could you share your my.cnf and maybe your application (that does the
> SELECT) so
>>>> I can test for my self ?
>>>>
>>>> /Jonas
>>>>
>>>>
>>>>
>>
>
>

Thread
Re: Slow session (connection) set-up using MySQLD APIMagnus Blåudd21 Oct
  • Re: Slow session (connection) set-up using MySQLD APIPaul van Diepen21 Oct
  • Re: Slow session (connection) set-up using MySQLD APIJonas Oreland21 Oct
RE: Slow session (connection) set-up using MySQLD APIpaul22 Oct
  • Re: Slow session (connection) set-up using MySQLD APIMagnus Blåudd25 Oct
    • Re: Slow session (connection) set-up using MySQLD APIMagnus Blåudd25 Oct
RE: Slow session (connection) set-up using MySQLD APIpaul25 Oct
  • Re: Slow session (connection) set-up using MySQLD APIMagnus Blåudd25 Oct
RE: Slow session (connection) set-up using MySQLD APIpaul25 Oct
RE: Slow session (connection) set-up using MySQLD APIpaul26 Oct