Re: [PHP] [X-POST] PHP script to make sure MySQL is up?
Hello, Richard Lynch is right. mysql_pconnect is a good connection method. In this method, we use only open connections. We don't open a new connection. If you use mysql_pconnect , you don't need mysql_close because this is persistent connection. You can restart mysql with cron if your mysql server is down. Firstly, you can write a shell script to call from crontab file. In this shell script, you must call a php script that controls the connection. if your mysql connection is failed , the php script can set the your ENV variable (Envrimental Variables) true or false. In shell script , you can control that ENV variable. if ENV variable is false, your can start your mysql server:) -- Haydar TUNA Republic Of Turkey - Ministry of National Education Education Technology Department Ankara / TURKEY Web: http://www.haydartuna.net Richard Lynch [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On Thu, March 1, 2007 1:37 pm, Brian Dunning wrote: I host at Rackspace, and one thing that their monitoring service does NOT catch is a problem when too many connections hit MySQL, and for some reason it remains hung up until the service is manually restarted. In the meantime, this is happening to us once or twice a month. It gets hammered with a huge number of brief connections from other Apache servers. Slow queries and mysql_close() are NOT the problem. It's just too many connections, even though they're super fast. Are you using mysql_pconnect? Because that is essentially going to lock one MySQL connection to each Apache child, and if you have a bigger httpd.conf MAX_CHILDREN than you have /etc/my.cnf number of connections, then, by definition, you are going to have problems all the time, because you have more users than connections available. Note also that each username/password gets its own persistent connection, so if you have two DB roles in your application, then you have just doubled the number of connections needed. In something like a shared hosting environment, pconnect is probably a death knell, since every little user will be tying up a connection for their app. There are, of course, ways around this, such as dedicated apache pools per client, or super-short connection time-out on the persitence or... But most shared hosts aren't going to go to this length. Is there such a thing as a PHP script that I can put on a cron job to run every minute and make a test query, and upon failure, restart the service and maybe send an email to Rackspace support? I don't know how you'd check that the query was refused due to too many connections, and I also don't know how PHP would restart the MySQL service. I think mysql_connect should be providing you with a nice error message if this does happen. Are you checking mysql_error right after your mysql_connect call? And you almost-for-sure don't want any random old php script capable of bouncing the MySQL server... [shudder] -- Some people have a gift link here. Know what I want? I want you to buy a CD from some starving artist. http://cdbaby.com/browse/from/lynch Yeah, I get a buck. So? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] [X-POST] PHP script to make sure MySQL is up?
I host at Rackspace, and one thing that their monitoring service does NOT catch is a problem when too many connections hit MySQL, and for some reason it remains hung up until the service is manually restarted. In the meantime, this is happening to us once or twice a month. It gets hammered with a huge number of brief connections from other Apache servers. Slow queries and mysql_close() are NOT the problem. It's just too many connections, even though they're super fast. Is there such a thing as a PHP script that I can put on a cron job to run every minute and make a test query, and upon failure, restart the service and maybe send an email to Rackspace support? I don't know how you'd check that the query was refused due to too many connections, and I also don't know how PHP would restart the MySQL service. Thanks... :) -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] [X-POST] PHP script to make sure MySQL is up?
On Thu, March 1, 2007 1:37 pm, Brian Dunning wrote: I host at Rackspace, and one thing that their monitoring service does NOT catch is a problem when too many connections hit MySQL, and for some reason it remains hung up until the service is manually restarted. In the meantime, this is happening to us once or twice a month. It gets hammered with a huge number of brief connections from other Apache servers. Slow queries and mysql_close() are NOT the problem. It's just too many connections, even though they're super fast. Are you using mysql_pconnect? Because that is essentially going to lock one MySQL connection to each Apache child, and if you have a bigger httpd.conf MAX_CHILDREN than you have /etc/my.cnf number of connections, then, by definition, you are going to have problems all the time, because you have more users than connections available. Note also that each username/password gets its own persistent connection, so if you have two DB roles in your application, then you have just doubled the number of connections needed. In something like a shared hosting environment, pconnect is probably a death knell, since every little user will be tying up a connection for their app. There are, of course, ways around this, such as dedicated apache pools per client, or super-short connection time-out on the persitence or... But most shared hosts aren't going to go to this length. Is there such a thing as a PHP script that I can put on a cron job to run every minute and make a test query, and upon failure, restart the service and maybe send an email to Rackspace support? I don't know how you'd check that the query was refused due to too many connections, and I also don't know how PHP would restart the MySQL service. I think mysql_connect should be providing you with a nice error message if this does happen. Are you checking mysql_error right after your mysql_connect call? And you almost-for-sure don't want any random old php script capable of bouncing the MySQL server... [shudder] -- Some people have a gift link here. Know what I want? I want you to buy a CD from some starving artist. http://cdbaby.com/browse/from/lynch Yeah, I get a buck. So? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
