1

Say I have very standard mysql connection code:

$dbhost = '192.168.1.99';
$dbuser = 'dbuser';
$dbpass = 'dbuserpass';
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die('Error connecting to mysql');
$dbname = 'mydb';
mysql_select_db($dbname);

This would connect from the web server to the database server (say the web server is at 192.168.1.98 or something). Typically, how long would the above code run? Currently, I'm seeing about 2 seconds. Is that slow?

HoldOffHunger
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slim
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  • How are you measuring the connection time? Are you sure it's the mysql part that's slow, not something else (e.g. if you're rendering a web page as well). Also, please, for the love of god, stop using the old mysql library. It needs to die a quick, merciful death. PDO or, if you must, mysqli, is a better approach. – El Yobo Nov 30 '10 at 00:33
  • I use microtime to get the time before and after the connection is made. The code is just for demonstration. Please keep in mind that I'm only trying to connect to the server, nothing more. – slim Nov 30 '10 at 02:46
  • I kept that in mind, I just wanted to check that you were measuring the right thing :) See my answer below. – El Yobo Nov 30 '10 at 03:35

5 Answers5

3

One possibility is that mysql is doing a DNS lookup to find the name of the connecting server; depending on your setup, this could take a long time. There's not really much benefit to it, aside from being able to specify the users by hostname rather than IP address (e.g. user@example.com rather than user@192.168.1.1).

This can be disabled in the configuration or when starting up MySQL with the --skip-name-resolve parameter. More information is available on the MySQL site.

El Yobo
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  • I'm going to add this flag and see what happens. Thanks for the info. – slim Nov 30 '10 at 17:13
  • I added this flag and my connection time went from 2 seconds to 7.7 ms. Thanks. – slim Nov 30 '10 at 22:20
  • You're welcome. You might want to look into how your DNS is working on the server though; this indicates that there is also some sort of DNS problem, otherwise things would still be quick. – El Yobo Nov 30 '10 at 22:30
1

2 seconds does seem slow, but it depends on your server and database server. Depending on what else they are doing, where they are located and many other factors it could actually be fast.

I usually get times of less than a second.

Conceited Code
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1

For local LAN, unless you're using antiquated equipment, or something is wrong, it should typically be on the order of (a) millisecond(s).

Riedsio
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0

Do you have lots of tables? It may be spending time looking around after connecting. Is the command line mysql client slow too? Is it fast if you're connecting from localhost?

Joshua Martell
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  • There shouldn't be any scanning of tables when you connect to the database. I'm running a website with hundreds of tables on a remote MySQL server and I've never noticed any delay like this. – GolezTrol Nov 30 '10 at 00:17
0

That is very slow. On avarage websites, the entire page renders within two seconds. That is, connecting to the database, running the queries, retrieving results and rendering the page.

GolezTrol
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