Re: running multiple mysqld's
On Friday 08 June 2001 22:16, Rohit Peyyeti wrote: Hello All: I have two mysqld runnning in ports: 3307 3308 respectively. I started the second one by using 'mysqld_multi start 2'. whereas mysqld running on port 3307 is the default mysqld started at the boot time. when i issue command such as: mysql -u root -p (it connects to my new mysqld running on 3307). Why is that it won't connect to mysqld running on port 3308. I also tried giving in port / socket options to mysql but to no luck! I cannot connect to mysqld running on port 3307 (default mysqld which is started at boot time) (anti-s_p_a_m_b_o_t fodder: database, query) MySQL runs with two methods of connection. The first is via Unix sockets (assuming that you are using Linux here). The second is via Internet sockets. The port numbers you have above apply only to Internet sockets. You should see two instances of MySQL running if you connect from a different machine. If you connect on the machine which is running the two instances, you'll need to specify host and port, or you'll need to make sure that the Unix sockets are in different places. For each instance, make sure that the default Unix socket location (usually something like /var/lib/mysql/mysql.sock or /tmp/mysql.sock) is different! MySQL will happily run with two instances using the same Unix socket. Unfortunately, your results may not be what you want. We run multiple instances all the time. The hard part is not configuring MySQL, it is getting the clients to talk to the right one :-) We set up a main directory where all the instances have subdirectories. You could use something like /databases. Put each instance into a subdirectory. We put the logs, Unix socket, pid file, configuration file and databases into directories of the main subdirectory: /database/instance1/etc/my.cnf config file /database/instance1/log/... log files /database/instance1/run/mysql.pid pid file /database/instance1/run/mysql.sock Unix socket /database/instance1/db_files/...database table files /database/instance2/etc/my.cnf config file ... etc... Then, if we are on the same machine and need to connect with the MySQL command-line client, we can just type this: $ mysql --defaults-file=/database/instance1/etc/my.cnf -u root -p... You could easily make wrapper scripts to make this easier: $ mysql_wrapper --instance=1 -uroot -p ... We run multiple instances for several reasons. The primary reason is that we need to take some down on a nightly basis for various purposes and others need to stay up. We cannot do this with a single instance. We can also control resource usage on a per-type-of-use basis. Some instances just perform dumb data logging, others are used for heavy queries. Best, Kyle - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: running multiple mysqld's
Running two copies of mysqld in one single machine *HAS* its purpose. What if, for whatever reason, mysqld died? I personally havent seen mysqld died on me, but on a rare occasion, the database got corrupted and it made mysql useless. but if I made my application to be a bit more intelligent and either communicate with two mysqld or use a backup database file you know what i mean. jaime At 03:02 AM 6/9/01 -0230, Neil Zanella wrote: Sorry about this questions but why would you want to run two copies of mysqld when it is capable of hosting as many different databases as you need? Even if you needed two databases with the same name you could still just create two different MySQL users for it. Thanks, Neil On Sat, 9 Jun 2001, Rohit Peyyeti wrote: Hello All: I have two mysqld runnning in ports: 3307 3308 respectively. I started the second one by using 'mysqld_multi start 2'. whereas mysqld running on port 3307 is the default mysqld started at the boot time. when i issue command such as: mysql -u root -p (it connects to my new mysqld running on 3307). Why is that it won't connect to mysqld running on port 3308. I also tried giving in port / socket options to mysql but to no luck! I cannot connect to mysqld running on port 3307 (default mysqld which is started at boot time) Can any one help here? ...Rohit - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: running multiple mysqld's
Neil Zanella wrote: Sorry about this questions but why would you want to run two copies of mysqld when it is capable of hosting as many different databases as you need? Even if you needed two databases with the same name you could still just create two different MySQL users for it. Thanks, Hi, I see several reasons for that: - mysqld is a multithreaded single process. That meens it cannot use more than 4Gb of RAM on 32 bits OS (and if fact much less, 2G to 3.5Gb depending on OS configuration). Since you can have highend Intel servers with more than 4Gb of RAM, you will make much better use of your RAM with multiple mysqld instances. - If you want to have a very high number of simultaneous connections, you must have several mysqld running. For instance, mysqld on Linux is limited to ~1500 simultaneous connections; if you want more, you have to use several mysqld. (Of course, you can do that only if all your clients don't use the same database). - Minimising MySQL downtime: Each time one mysqld process crashes, you just have to repair the databases it was managing. For instance, if you have 4 databases served by 4 mysqld, you just repair one database instead of 4 before restarting. (Please no flames here, I know that MySQL is considered as very stable; however, it sometimes crashes: there were several reports of mysqld killed by signal 11 on this list) Of course, most MySQL users don't need to run more than one mysqld, but you asked, so here are some reasons. Regards -- Joseph Bueno NetClub/Trader.com - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: running multiple mysqld's
Sorry about this questions but why would you want to run two copies of mysqld when it is capable of hosting as many different databases as you need? Even if you needed two databases with the same name you could still just create two different MySQL users for it. Thanks, Neil On Sat, 9 Jun 2001, Rohit Peyyeti wrote: Hello All: I have two mysqld runnning in ports: 3307 3308 respectively. I started the second one by using 'mysqld_multi start 2'. whereas mysqld running on port 3307 is the default mysqld started at the boot time. when i issue command such as: mysql -u root -p (it connects to my new mysqld running on 3307). Why is that it won't connect to mysqld running on port 3308. I also tried giving in port / socket options to mysql but to no luck! I cannot connect to mysqld running on port 3307 (default mysqld which is started at boot time) Can any one help here? ...Rohit - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
