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Description of problem: When making calls to a mysql gear (using php, as an example) the calls or connections to provide adequate performance when threaded. How reproducible: PHP SCRIPT: <?php // Create connection $dns = '127.10.1.2'; $port = '3306'; $user = 'admin8gNAWKu'; $pass = 'FqWI5TxtkYw8'; $db = 'mysql'; echo "DNS='$dns', PORT='$port', USER='$user', PASS='$pass', DB='$db' \n"; echo "Testing connection..."; $start = microtime(true); $mysqli = new mysqli($dns, $user, $pass, $db, $port); // $con=mysqli_connect($dns,$user,$pass,$db,$port); // Check connection if ($mysqli->connect_errno) { echo "Failed to connect to MySQL: " . mysqli_connect_error(); } else { echo "Connected!"; } echo $mysqli->host_info . "\n"; $result = $mysqli->query("SELECT COUNT(*) FROM user"); while ($row = $result->fetch_assoc()) { echo " id = " . $row["COUNT(*)"] . "\n"; } $time_taken = microtime(true) - $start; echo $time_taken; ?> Steps to Reproduce: 1. rhc app create bench php-5.3 mysql-5.1 2. Copy code (script above) into gear - I ssh in, create a file in app-root/data/ and copy its contents into that file. 3. Average the time against sequential calls vs threaded calls. - Sequential: for x in $(seq 1 2); do php -f test.php; done | grep TIME | awk '{ total += $2; count++ } END { print total/count }' - Threaded: for x in $(seq 1 2); do php -f test.php & done | grep TIME | awk '{ total += $2; count++ } END { print total/count }' You will see that by treading the calls (or backgrounding each test) they queue up and cause performance issues to be noticed. This is likely caused by queuing of the database connections. Are there any best practices for avoiding this, or things that can be done to improve the databases performance in threaded scenarios.
All I was able to get data from the customer regarding this and if I review (average the times) for sequential calls vs threaded calls the results are roughly the same. 14:28:12 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' baseline_data.dat 0.014702 14:28:29 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' baseline-2_data.dat 0.0835006 14:28:35 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' sql1_data.dat 0.213246 14:29:08 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' sql1-2_data.dat 0.228275 14:29:12 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' sql2_data.dat 0.203016 14:29:29 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' sql2-2_data.dat 0.207391 14:29:36 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' sql3_data.dat 0.110054 14:29:43 erich@fenrir:~/Downloads/run2 $ --> awk '{ total += $2; count++ } END { print total/count }' sql3-2_data.dat 0.110654 This to me points to an issue with the sql queries and not with OpenShift, can engineering confirm.
Created attachment 820700 [details] Data set Data set for review (run 1 is thought to be a bad collection).
We will need to see the select plan for the queries the customer is using.