Hi, A program I recently re-written part of to use a MySQL database is having a lot of problems. The problems aren't very pronounced on my machine unless I run it under Rational Purify, but others report more problems. When doing mysql_query(&mysql,myquerystring), I am getting back randomly the errors "Commands out of sync", or "Lost connection to MySQL server during query". This happens within seconds from within Purify, so I don't think it's a time thing. Note Purify isn't complaining about memory access or leak errors, it just appears to do something to my program to make these errors more apparent (speed?) (after about 10 queries, but problems rarely at the same point) My program is a multithreaded, cross platform, C++ server application. I'm using a singleton Database class for access to the DB. On initialization, it connects to the DB. I was hoping that I could re-use just one connection for the lifetime of my server. To deal with the threads, all MySQL DB calls are protected within a common mutex. At first, with getting "Commands out of sync", I assumed I'd done something wrong with my mutexes but after review it appears I haven't. I also reviewed to make sure that I always called mysql_free_result(myresultset) after doing a query (SELECT, but not INSERT, UPDATE or DELETE), and within the mutex. The help files for Commands out of sync suggests I'm perhaps doing things out of order, but after review I can't find anything that might cause it...I just have 20+ different methods making queries and possibily examining and reparsing the results before returning. What strategy is recommended here? I'm sufficiently exasperated that it seems my only alternative is to change each call to do a mysql_init and real_connect for each database query. But this seems like a big performance hit to me. Or I could just attempt to reconnect, and reissue the query each time this happens (which seems often), but that is ugly (code-wise) and may not solve it, I'd rather fix the problem or the symptom entirely. But a possibility. Help, recommendations, please!? Maybe something I might be missing? Using MySQL client and server libraries 3.23.33. The other interesting note is that my application uses ACE libraries (http://www.cs.wustl.edu/~schmidt/ACE.html, very cool) to deal with platform specifics, threading, mutexes and other stuff...) Namespace collisions with ACE is why I'm not using the C++ libraries. I expect to make at least one query to the database every few minutes, so timeouts aren't really an issue. The errors have 99% been tested on, and noticed on, Windows 2000 Pro SP1 on x86 arch. TIA! Charlie --------------------------------------------------------------------- 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
