[Phpmyadmin-devel] Performance improvements for servers having large number of databases

[Madhura Jayaratne]

On Mon, Nov 3, 2014 at 10:31 AM, Madhura Jayaratne <madhura.cj at gmail.com>
wrote:

>
>
> On Mon, Nov 3, 2014 at 10:08 AM, Marc Delisle <marc at infomarc.info> wrote:
>
>> Madhura Jayaratne a écrit :
>> > Hi all,
>> >
>> > Today morning I spent some time testing the performance improvements
>> that
>> > were done for the servers having a large number of databases.
>> >
>> > My setup has about 5000 databases grouped in to database groups of 20
>> > databases. Navigation items at first level [1] is limited to 50 meaning
>> > that about 1000 databases are loaded in the initial page of navigation.
>> >
>> > While loading the initial page,
>> > QA_4_2: 1008 queries executed 1011 times in 1.00407 s
>> > master: 12 queries executed 17 times in 0.51211s
>> >
>> > Even though master is about 2 times faster in terms of the query
>> execution
>> > time, the overall time to load the page is dominated by the time taken
>> to
>> > render 1000 nodes in navigation, which is about 8s for master and 11s
>> for
>> > QA_4_2.
>> >
>> > However the rendering time can be significantly improved by setting [1]
>> to
>> > a lower value, which currently defaults to 250. If I remember right,
>> this
>> > directive was set to a higher value to prevent navigation from having
>> extra
>> > spaces below [2]. Since this issue is no longer there (now when [1] is
>> set
>> > to, say 50, 50 databases or database groups are displayed) I suggest to
>> set
>> > [1] to a lower value.
>> >
>> >
>> > [1]
>> >
>> http://docs.phpmyadmin.net/en/latest/config.html#cfg_FirstLevelNavigationItems
>> > [2] https://sourceforge.net/p/phpmyadmin/mailman/message/30077320/
>>
>> Hi Madhura,
>> Good idea.
>>
>
> I've set this to 25, which seemed to fit to the screen without showing
> scroll bars.
>
> --
> Thanks and Regards,
>
> Madhura Jayaratne
>
>
Now, that I got access to the test server of Ann + J.M. with I could test
the performance improvements done so far. Test server has more than 25000
databases.

For a privileged user:
As also reported by Marc, signing in take about 7-8 seconds while
navigating to pages in navigation now takes only about 3-4 seconds. This is
due to lower default value for 'FirstLevelNavigationItems' configuration.
Expanding a database in navigation also takes about 3 seconds. Similarly
going into a database (viewing database structure page) took about 4-5
seconds.

Other database level operation such as searching in a database, viewing
routines, events, triggers, going in to the designer took acceptable times.
Similarly table level operations such as browsing, grid editing, editing,
searching, inserting were also at an acceptable level. Editing the table
structure which took some long time now takes only 3 - 5 seconds depending
on the number of fields.

Database filters work normally as well.

For an unprivileged user:
Login in and other operations take staggering long times for an
unprivileged user. I tried viewing the list of databases (just 2,
information_schema and one database by the username) for such user with the
mysql console. Both SHOW DATABASES as well as SELECT  schema_name FROM
information_schema.schemata takes about 48 seconds.

On a positive note SHOW DATABASES LIKE '<username>%'; takes just a fraction
of seconds. However only for the users at large hosting providers we can
use such a query to retrieve the database list. If we are to take advantage
of this, we probably will have a add a new configuration to indicate that
unprivileged users are connecting to a particular installation of
phpMyAdmin and hosting providers will have to use two installations, one
for unprivileged users and one for privileged users.

I am working on such a solution today and I will be able to test it by
tonight or tomorrow morning. I would appreciate your feedback on whether
such a solution is practical.


-- 
Thanks and Regards,

Madhura Jayaratne
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