RE: [PHP-DEV] How much load...

On Thu, 12 Aug 1999, Andres K?tt wrote: > > > ... can PHP3/4 handle? Provided we have an Apache server and > > > appropriate hardware, can PHP handle a load of >200 simultaneous > > > connections? I have developed some small-scale PHP apps, but now we > > > are looking for a tool to create heavily loaded database solutions for > > > > With the appropriate hardware, PHP can handle loads like that. The > > question is really how much hardware is "appropriate"? It'll all depend > > Let's be more specific. We expect something like 50 users making > 5000-row queries (Oracle database) on a _huge_ table simultaneously ( > plus more that 200 of them doing smaller ones). There are currently > 200-300 new user connections per minute and it's growing. Hardware is > not a problem, but I'm concerned about what happens to a > Apache/PHP3(4) server handling that load (stability problems, certain > bugs showing, etc?). Anyone wanna share experiences? The highest-volume PHP-driven site I have experience with has around 30 hits per second. The first thing that hit me was the fact that reading from socket file descriptors was done by one read system call for every byte. Only the number of system calls per second were enough to choke the service. This has since been fixed, but other parts of PHP may not have been tested under such load, and it is possible we have room for more such optimization. If I were you, I would set up a test system and simulate the load to identify whether you are bitten by any bottlenecks in PHP. As for Apache, as long as you compile with a high enough HARD_SERVER_LIMIT (see src/include/httpd.h) and have enough memory, it should not give you any problems. There are some tricks though, take a look at http://www.apache.org/docs/misc/perf-tuning.html. > > on how much code has to be parsed and how heavy processing is done. It > > sounds to me like you need PHP 4.0 and ZendPersistentRegistry. > > ZendPersistentRegistry? What's that? Does it allow to to have > persistent variables that preserve their values while PHP parses > several documents? It stores the compiled version of files in memory in each httpd process, so files are not re-parsed unless they are changed. It does not provide persistent variables in the sense that they have the same value as when another user "left" the same page or process. It simply lets PHP skip an expensive step (parsing and compiling files) for most requests, at the expense of some memory. You'll have to ask the Zend team (zend@zend.com) for availability details. > > PHP does currently not know CORBA, but several people have expressed > > interst in implementing it. > > OK, but I need CORBA just for limiting the count of concurrent > database connections and for intelligent request queuing. Are there > any other (already implemented) solutions for that? PHP has System V semaphore and shared memory support. - Stig