ID: 49511 Updated by: u...@php.net Reported By: casper at procurios dot nl Status: Assigned Bug Type: MySQL related Operating System: * PHP Version: 5.3, 6 (2009-09-09) Assigned To: mysql New Comment:
On the bug itself: The MySQL Client Library (libmysql) sets a limit of 365 * 24 * 3600 seconds as a default timeout for select() etc. One will hardly ever get into that timeout but see a TCP/IP timeout happening before (e.g. after 10 minutes). mysqlnd does currently set no PHP streams timeout and therefore the default PHP setting applies. To get the same behaviour in mysql as with libmysql, we would need to set the streams timeout to 1 year upon connect and wait. We may wait longer than max_execution_time. However, it seems that by default default_socket_timeout > max_execution_time and thus it may be irrelevant to take care of it. Only ext/mysqli is more or less prepared to allow users to set the timeout via an API call - one would need to introduce MYSQLI_READ_TIMEOUT. While it may be easy to add that option also to PDO_MYSQL there is easy way to make the read timeout configurable via API in ext/mysql. My current thinking is to introduce mysqlnd.read_timeout with a default value equal to libmysql (= huuuuuugggggeeee) and make it SYSTEM_INI only: no API changes required and admins can set it to max_execution_time if they want. Regarding default_socket_timeout = -1 -> endless: I could not find it in the documentation either. It may need documentation. Previous Comments: ------------------------------------------------------------------------ [2009-09-15 16:45:05] u...@php.net Pierre, 1) is an aside discussion. I assume 2) is about binaries offered for download from mysql.com? CRT is a runtime dependency specific to the Windows platform. Windows binaries can have those dependencies. Educate me about the details but if any Windows binary has such a dependency there can be trouble using it with other Windows binaries that use other CRTs. In the worst case users needs to compile the library from source. Now, if you compile the MySQL Client Library from source to ensure that it uses the CRT you want and that self-compiled library cannot be used together with ext/mysql, ext/mysqli or PDO_MYSQL, it is a bug and should be reported - at bugs.php.net or at bugs.mysql.com. ------------------------------------------------------------------------ [2009-09-15 15:32:59] paj...@php.net It canont be compiled against libmysql. Their libraries are not compatible. I don't choose to do it but they did. I also reported the issue upstream but they don't care much about this problem, for two reasons: 1. they gave php a new driver so they won't worry anymore about such troubles (or licensing issues) 2. libmysql latest version CRT (5.0 or 5.1) can only be built only for vc8+ There is even BC breaks as latest libmysql.dll makes php 5.2 crashes. But that's not the problem here, there is a bug in mysqlnd and it has to be addressed. It is not even a windows only issue. ------------------------------------------------------------------------ [2009-09-15 15:18:27] u...@php.net On the available options on Windows: ext/mysql, ext/mysqli and PDO_MYSQL can either be compiled against the MySQL Client Library or mysqlnd. That is also true for Windows in general. If not, it is a bug. Windows users do have a choice. Pierre, php.net restricts itself on Windows to mysqlnd for a reason. The reason is that you cannot compile current versions of the MySQL Client Library using Visual Studio 6, just like you cannot compile current versions of the MySQL Server using Visual Studio 6. Visual Studio 6 is old - it is from 1998. As far as I know, Microsoft has stopped to support this compiler. Consequently, MySQL has dropped support for it. To my understanding VC 6 is still of relevance for php.net because other projects have or still do use VC 6. I would not want to use an unsupported compiler for my project but they do although there are superior and free offering from Microsoft. Using their products together with a PHP binary that is not compiled with VC 6 can lead to crashes. Therefore, you are looking to support VC 6, which is not possible when using the MySQL Client Library. If one fails to use a recent version of the MySQL Client Library together with ext/mysql, ext/mysqli or PDO_MYSQL on Windows using a recent Visual Studio it should be reported as a bug. ------------------------------------------------------------------------ [2009-09-15 14:12:51] paj...@php.net It is not correct to say that mysqlnd on windows differs from libmysql. Libmysql uses native APIs directly no matter the platform while mysqlnd always uses php's stream, on every platform. The different between windows and unix is that windows relies on mysqlnd only (no choice, no compatible library available). ------------------------------------------------------------------------ [2009-09-15 13:34:28] u...@php.net Note: MYSQL_OPT_READ_TIMEOUT != MYSQL_OPT_CONNECT_TIMEOUT . What you are saying is that you query times out. The report is not about a connection timeout. Your timeout happens after the connection has been established and therefore setting MYSQLI_OPT_CONNECT_TIMEOUT won't change anything. In the end ext/mysqli is a wrapper of the MySQL C API and thus we can consult the C API documentation on the difference. The docs at http://dev.mysql.com/doc/refman/5.1/en/mysql-options.html explain: MYSQL_OPT_CONNECT_TIMEOUT (argument type: unsigned int *) Connect timeout in seconds. MYSQL_OPT_READ_TIMEOUT (argument type: unsigned int *) The timeout in seconds for attempts to read from the server. Each attempt uses this timeout value and there are retries if necessary, so the total effective timeout value is three times the option value. You can set the value so that a lost connection can be detected earlier than the TCP/IP Close_Wait_Timeout value of 10 minutes. This option works only for TCP/IP connections and, prior to MySQL 5.1.12, only for Windows. MYSQL_OPT_READ_TIMEOUT has never been supported by ext/mysqli. You can easily check that by "grepping" through the source of ext/mysqli as contained in, for example, PHP 5.2.10. nixn...@ulflinux:~/ftp/php-5.2.10> grep -i -R MYSQL_OPT_READ_TIMEOUT ext/ nixn...@ulflinux:~/ftp/php-5.2.10> grep -i -R MYSQLI_OPT_READ_TIMEOUT ext/ nixn...@ulflinux:~/ftp/php-5.2.10> However, mysqlnd is not the MySQL Client Library, mysqlnd makes use of PHP Streams. Looks like PHP Streams use different default timeouts than the MySQL Client Library on Windows. That is a problem for you as a user, no doubt. Question is how to solve that problem. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/49511 -- Edit this bug report at http://bugs.php.net/?id=49511&edit=1
