Обсуждение: Trouble with conections between php and postgre
Hi !, first of all: sorry about my english, i'm not from us. I 'm using latest versions of postgre 7.4 with php4 and apache2, on a debian system. I'm working with a really big database, so there are many querys that takes too much time to be executed (And there's nothig to do about it). These querys blocks the php page while's being loaded. The problem is that usually, one excepcts to stop those querys or even close the conection if the user stops the explorer or closes the window. However, this isn't hapening, the query keeps running in the database, using resources. I already try uselessly ignore_user_abort(False), and I don't want to set a time limit. ¿Any ideas? ¿Am I missing something ? Thnxs ! (Please, try avoiding those messages like "Get more resources", "Optimize your querys", "/etc/init.d/postgresql restart", etc.)
On Oct 3, 2005, at 9:59 AM, luis linietsky wrote: > Hi !, first of all: sorry about my english, i'm not from us. > I 'm using latest versions of postgre 7.4 with php4 and apache2, on a > debian system. I'm working with a really big database, so there are > many querys that takes too much time to be executed (And there's > nothig to do about it). These querys blocks the php page while's being > loaded. The problem is that usually, one excepcts to stop those querys > or even close the conection if the user stops the explorer or closes > the window. However, this isn't hapening, the query keeps running in > the database, using resources. > I already try uselessly ignore_user_abort(False), and I don't want to > set a time limit. > ¿Any ideas? ¿Am I missing something ? There is a specific protocol for canceling a query in progress. Maybe this PHP function will work for you: http://www.php.net/manual/en/function.pg-cancel-query.php John DeSoi, Ph.D. http://pgedit.com/ Power Tools for PostgreSQL
The lock is caused by PHP the page running the queries locking the user's SESSION file. The php script execution suspends when running each query so the lock remains. Subsequent page requests will all pause at session_start(); while waiting for the lock to be removed. A session_write_close(); (call it before any db_query is run) can be of assistance because it writes out the session file and thus no lock will be kept. The problem is that this will send a cookie header to the client. Multiple calls send further cookie headers :( IE will die with an unhelpful error page if it receives around 25 of these headers... What they really need to implement is a session_pause() and session_restart(). This has been suggested before and there was even documentation for these functions but it never made it into a PHP as far I was aware and the documentation has since been removed from more recent PHP documentation. A more permanent way around this might be to use a database to hold the sessions so you are not subject to the file-locking limitations. Alternatively you could overide the file based session handling with your own implementation and choose to discard session data from pages if a more recent page has tried to access the session. Regards, Daniel Walters -----Original Message----- From: pgsql-php-owner@postgresql.org [mailto:pgsql-php-owner@postgresql.org] On Behalf Of luis linietsky Sent: Tuesday, October 04, 2005 12:00 AM To: pgsql-php@postgresql.org Subject: [PHP] Trouble with conections between php and postgre Hi !, first of all: sorry about my english, i'm not from us. I 'm using latest versions of postgre 7.4 with php4 and apache2, on a debian system. I'm working with a really big database, so there are many querys that takes too much time to be executed (And there's nothig to do about it). These querys blocks the php page while's being loaded. The problem is that usually, one excepcts to stop those querys or even close the conection if the user stops the explorer or closes the window. However, this isn't hapening, the query keeps running in the database, using resources. I already try uselessly ignore_user_abort(False), and I don't want to set a time limit. ¿Any ideas? ¿Am I missing something ? Thnxs ! (Please, try avoiding those messages like "Get more resources", "Optimize your querys", "/etc/init.d/postgresql restart", etc.) ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
Hi John, I have some clarification on your suggestion... This function is specifically for asynchronous queries though - if Luis is not using asynchronous queries the mileage may vary. The other issue is that even if the query can be cancelled how does Luis accurately determine when to do this? To detect a closed or stopped/cancelled browser (see the notes in the php manual under connection_status();) the script actually needs to poll the client (this can be done by flushing a single character in a loop down to the browser - this is ugly for a lot of fairly obvious reasons). I think the key to issue is the session locking (as per my previous post). There is quite a history to this issue (browsing the archives of this list and Usenet reveals this) and it is in fact the reason why I am on this list. The issue has also been raised as bugs at http://bugs.php.net but have been systematically closed without fixes since as early as 2001. Requests have been made for the addition of functions to pause a session (remove the file lock while a query is running because you know the session wont be written to during this time) and then restart the session (once the query has completed). This type of functionality can be somewhat achieved with session_write_close() except that this function unfortunately sends a cookie header automatically and this causes issues for IE if done repeatedly. I have made some suggestions in my previous post (which is being moderated currently) which may help but they are certainly not clean solutions. Hopefully someone will take notice (this time) of this thread and work on making php deal with this better. Regards, Daniel Walters. -----Original Message----- From: pgsql-php-owner@postgresql.org [mailto:pgsql-php-owner@postgresql.org] On Behalf Of John DeSoi Sent: Tuesday, October 04, 2005 11:17 AM To: luis linietsky Cc: pgsql-php@postgresql.org Subject: Re: [PHP] Trouble with conections between php and postgre On Oct 3, 2005, at 9:59 AM, luis linietsky wrote: > Hi !, first of all: sorry about my english, i'm not from us. > I 'm using latest versions of postgre 7.4 with php4 and apache2, on a > debian system. I'm working with a really big database, so there are > many querys that takes too much time to be executed (And there's > nothig to do about it). These querys blocks the php page while's being > loaded. The problem is that usually, one excepcts to stop those querys > or even close the conection if the user stops the explorer or closes > the window. However, this isn't hapening, the query keeps running in > the database, using resources. > I already try uselessly ignore_user_abort(False), and I don't want to > set a time limit. > ¿Any ideas? ¿Am I missing something ? There is a specific protocol for canceling a query in progress. Maybe this PHP function will work for you: http://www.php.net/manual/en/function.pg-cancel-query.php John DeSoi, Ph.D. http://pgedit.com/ Power Tools for PostgreSQL ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq