Heiko Wundram wrote: > Am Mittwoch, 26. März 2008 17:33:43 schrieb John Nagle: >> ... >> >> Using MySQL as a queueing engine across multiple servers is unusual, >> but it works well. It has the nice feature that the queue ordering >> can be anything you can write in a SELECT statement. So we put "fair >> queueing" in the rating scheduler; multiple requests from the same IP >> address compete with each other, not with those from other IP addresses. >> So no one site can use up all the rating capacity. >> ... >> Does anyone else architect their systems like this? > > A Xen(tm) management system I've written at least shares this aspect in that > the RPC subsystem for communication between the frontend and the backends is > basically a (MySQL) database table which is regularily queried by all > backends that work on VHosts to change the state (in the form of a command) > according to what the user specifies in the (Web-)UI.
I see nothing unusual with this: I vaguely remember that this database approach was teached at my former university as a basic mechanism for distributed systems at least since 1992, but I'd guess much longer... And in one of my projects a RDBMS-based queue was used for a PKI registration server (e.g. for handling the outbound CMP queue). IIRC Microsoft's Biztalk Server also stores inbound and outbound queues in its internal MS-SQL database (which then can be the bottleneck). Ciao, Michael. -- http://mail.python.org/mailman/listinfo/python-list
