Re: Mysql pushing data to client
Thanks for pointing that out, I'll go with James solution. David Godsey David Godsey wrote: I am looking for a way to write a client program that will wake up when there is new data in the database, much like replication. So instead of my client pulling the database on some fixed interval, I would like the mysql daemon to push the data to my client when there is new data. I assume this is possible given that it is done with replication. Does anybody have information on how to implement a client program like this? I'm using PHP, but I'm not opposed to using C or C++ for this kind of functionality. James Neff wrote: I'm doing something similar now and I just have my clients (a java app) periodically check a small table that indicates theres data ready for them. It's a simple SELECT count(*) ... that is fairly inexpensive and the does this once every 5 seconds. I don't know if there is a built-in solution for mysql but this gets the job done for me. Let me know if you find a better way to do this. David Godsey wrote: That is a good work around, I appreciate the idea. The optimal would be a client that listens on the mysql thread the pushes data to the database. But if there is no way to tap into that thread, the select count(*) would do. There must be a way to do it though, since it is done with replication. Except that it isn't. The Master writes to its local binlog. The slave pulls updates from the master periodically. See the manual for all the details http://dev.mysql.com/doc/refman/4.1/en/replication-intro.html. You could write a daemon to run on the mysql server, which would watch for local changes and push them to your client, but that sounds overly complex to me compared to James' solution. Michael -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Mysql pushing data to client
David Godsey wrote: I am looking for a way to write a client program that will wake up when there is new data in the database, much like replication. So instead of my client pulling the database on some fixed interval, I would like the mysql daemon to push the data to my client when there is new data. I assume this is possible given that it is done with replication. Does anybody have information on how to implement a client program like this? I'm using PHP, but I'm not opposed to using C or C++ for this kind of functionality. James Neff wrote: I'm doing something similar now and I just have my clients (a java app) periodically check a small table that indicates theres data ready for them. It's a simple SELECT count(*) ... that is fairly inexpensive and the does this once every 5 seconds. I don't know if there is a built-in solution for mysql but this gets the job done for me. Let me know if you find a better way to do this. David Godsey wrote: That is a good work around, I appreciate the idea. The optimal would be a client that listens on the mysql thread the pushes data to the database. But if there is no way to tap into that thread, the select count(*) would do. There must be a way to do it though, since it is done with replication. Except that it isn't. The Master writes to its local binlog. The slave pulls updates from the master periodically. See the manual for all the details http://dev.mysql.com/doc/refman/4.1/en/replication-intro.html. You could write a daemon to run on the mysql server, which would watch for local changes and push them to your client, but that sounds overly complex to me compared to James' solution. Michael -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Mysql pushing data to client
That is a good work around, I appreciate the idea. The optimal would be a client that listens on the mysql thread the pushes data to the database. But if there is no way to tap into that thread, the select count(*) would do. There must be a way to do it though, since it is done with replication. Thanks David Godsey I'm doing something similar now and I just have my clients (a java app) periodically check a small table that indicates theres data ready for them. It's a simple SELECT count(*) ... that is fairly inexpensive and the does this once every 5 seconds. I don't know if there is a built-in solution for mysql but this gets the job done for me. Let me know if you find a better way to do this. Thanks, James Dave at Mysql wrote: I am looking for a way to write a client program that will wake up when there is new data in the database, much like replication. So instead of my client pulling the database on some fixed interval, I would like the mysql daemon to push the data to my client when there is new data. I assume this is possible given that it is done with replication. Does anybody have information on how to implement a client program like this? I'm using PHP, but I'm not opposed to using C or C++ for this kind of functionality. Thanks. David Godsey -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Mysql pushing data to client
I am looking for a way to write a client program that will wake up when there is new data in the database, much like replication. So instead of my client pulling the database on some fixed interval, I would like the mysql daemon to push the data to my client when there is new data. I assume this is possible given that it is done with replication. Does anybody have information on how to implement a client program like this? I'm using PHP, but I'm not opposed to using C or C++ for this kind of functionality. Thanks. David Godsey -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Mysql pushing data to client
Hi David Sybase and MS-SQL have a built-in stored procedure called xp_cmdshell which lets you execute shell commands from within a stored procedure or otherwise within the database process. MySQL doesn't (I'm fairly sure) provide anything like that (although I think someone had written a UDF in C that might do that). I don't think that's really a problem with MySQL, on the contrary it's a good thing because xp_cmdshell is potentially a big security issue, as any shell program would be running as the same user who's running the MySQL server. It will probably work better if you put the triggering code in the part of your application (like the PHP page, whatever) that changes the data you want to be notified about, instead of in the database itself. Douglas Sims [EMAIL PROTECTED] On Sep 21, 2006, at 3:14 PM, Dave at Mysql wrote: I am looking for a way to write a client program that will wake up when there is new data in the database, much like replication. So instead of my client pulling the database on some fixed interval, I would like the mysql daemon to push the data to my client when there is new data. I assume this is possible given that it is done with replication. Does anybody have information on how to implement a client program like this? I'm using PHP, but I'm not opposed to using C or C++ for this kind of functionality. Thanks. David Godsey -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
