a thought about performance!

Anon

hi,
i am using a complete db based system for my website. everysingle text is imported from the db to the webpage, which is generated by using PHP.

right now i am using simple mysql_connect(), and not pconnect().

every hit on a link makes a new connection to db -> gets the data -> and displays on the page -> then closes the connection.

i am wondering if its wiser to have it this way. i recieve an average of 5000 hits a day. using pconnect() or not, i am not sure if that makes that much difference becuase the SQL server is on same machine.

secondly i how does the system works with pconnect()? if a script has pconnect() included in it, so whenever a link is clicked or the script is accessed, it will make another pconnect() connection. or not?

thanks for reading,
regards,
Daarius...

Anon

You can establish a lot of "pconnections". If the script ends, the pconnection is still opened, you have to close it obligatory with mysql_close().

If you use mysql_connect, only a conection is opened. If you try to open a second, it will be the same. Also, when the script end, the connection closes.

If the SQL Server is in the same machine that the scripts, I suposse that the speed would be the same. For make sure, make the loop open-read-close of a MySQL database a lot of times with mysql_connect() and store the time it takes. Do similar with mysql_pconnect() and compare the two times.

Anon

Hi,
the php manual said that :
"mysql_close() will not close links established by mysql_pconnect()"
but i don't know who is correct.

As i know 'persistent connection' will be closed itself after an idle time.
Since open and close a db connection will cost a constant time, but pconnect will cost memery space even it's idle.
so if your will access db frequently between script. Using pconnect() should be a better way. Otherwise, if you access db just in a special script and it should not be re-request(reload) within a short time. Using connect() will be better.
Also you can config persistent connection in php.ini(php4) or php3.ini(php3). try to find "persistent" in the ini file to get more detail.

if i'm wrong, pls correct me. 😛

Anon

The manual says:
"...In case a second call is made to mysql_connect() with the same arguments, no new link will be established...". It is the same for mysql_pconnect()

Ziong was right (I have to pay more attention to the text that I read 🙂. mysql_pconnect() will not be closed by mysql_close(). Sorry.

Anon

thanks for the tips.

on my script, when it recieves a request, it makes a conection and prints out the page. and then drops the connetion.

and if the user clicks on anyother link on the page, it makes connecion again and gets the relevant data for that request, and then the connection is closed.

this is what i am using. hope its the right way.

Anon

after i read this topic, my understanding is:
the second call of mysql_connect() is mean the second call within a script and the 1st connection is not closed before.
also "The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close()."
Therefore, if u call mysql_connect() in 2 difference scripts, it will make a new connection even with the same arguments. But pconnect() will not. Since it will not close after the execution of the script ends.

pls correct me if i'm wrong.🙂

Anon

yes, you are right. when the script activates, and if the connection was called with pconnect(), then the connection doesnt disconect even if it finds mysql_close() in the code, untill the script has reached exit();

Anon

IF You are going to use persistant connects, be sure and recompile/reconfigure whatever DB you are running to hand hundreds of connections at once, otherwise you are likely to run out of handles quickly under even light loads.

also, add lots and lots of swap space so your box won't go down due to lack of memory if those hundreds of backends start getting spawned. If you can afford the RAM, increase that too.

Anon

what's your URL btw (curious)?