Log to file via PHP or log to MySQL database - which is quicker?

Question

I have a database driven website serving about 50,000 pages.

I want to track each webpage/record hit. I will do this by creating logs, and then batch processing the logs

Answer 1

Use a database - it is the only sane option. Even if it takes a little longer. Once you start with logfiles then you are on a track where it will cause you pain - e.g. moving servers, file permissions, precludes load balancing etc...

If you've got the database open then I reckon that it would be probably quicker to insert a single row.

However with all this performance related the only way to be sure is to write a simple test and measure it....

Update: I've done a quick test - and sure enough if you have to open and close the file it's about the same speed or slower using a test of 10,000 lines:

However when you start to have multiple processes doing this it slows down as can be seen below. This is with 10 concurrent processes (all timings in seconds)

DB time: 2.1695
DB time: 2.3869
DB time: 2.4305
DB time: 2.5864
DB time: 2.7465
DB time: 3.0182
DB time: 3.1451
DB time: 3.3298
DB time: 3.4483
DB time: 3.7812
File open time: 0.1538
File open time: 0.5478
File open time: 0.7252
File open time: 3.0453
File open time: 4.2661
File open time: 4.4247
File open time: 4.5484
File open time: 4.6319
File open time: 4.6501
File open time: 4.6646
Open close file time: 11.3647
Open close file time: 12.2849
Open close file time: 18.4093
Open close file time: 18.4202
Open close file time: 21.2621
Open close file time: 22.7267
Open close file time: 23.4597
Open close file time: 25.6293
Open close file time: 26.1119
Open close file time: 29.1471

function debug($d)
{
    static $start_time = NULL;
    static $start_code_line = 0;

    if( $start_time === NULL )
    {
        $start_time = time() + microtime();
        $start_code_line = $code_line;
        return 0;
    }

    printf("$d time: %.4f\n", (time() + microtime() - $start_time));
    $fp = @fopen('dbg.txt','a');
    fprintf($fp,"$d time: %.4f\n", (time() + microtime() - $start_time));
    fclose($fp);

    $start_time = time() + microtime();
    $start_code_line = $code_line;
}

function tfile()
{
    $fp = @fopen('t1.txt','a');
    for ($i=0;$i<10000;$i++)
    {
        $txt = $i."How would you log, which do you think is quicker:How would you log, which do you think is quicker:";
        fwrite($fp,$txt);
    }
    fclose($fp);
}
function tfile_openclose()
{
    for ($i=0;$i<10000;$i++)
    {
        $fp = @fopen('t1.txt','a');
        $txt = $i."How would you log, which do you think is quicker:How would you log, which do you think is quicker:";
        fwrite($fp,$txt);
        fclose($fp);
    }
}

function tdb()
{
    $db = mysql_connect('localhost','tremweb','zzxxcc');

    $select_db = mysql_select_db('scratch');

    if (!$select_db) 
        die('Error selecting database.');

    for ($i=0;$i<10000;$i++)
    {
        $txt = $i."How would you log, which do you think is quicker:How would you log, which do you think is quicker:";
        mysql_query("INSERT INTO tlog values('".$txt."')");
    }
}

debug("");

tfile();
debug("File open");

tfile_openclose();
debug("Open close file");

tdb();
debug("DB");