| Bug #47549 | mysqld_safe: add support for preloading tcmalloc | ||
|---|---|---|---|
| Submitted: | 23 Sep 2009 11:44 | Modified: | 28 Oct 2009 21:26 |
| Reporter: | Lars Heill | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: General | Severity: | S4 (Feature request) |
| Version: | 5.4 | OS: | Linux |
| Assigned to: | Timothy Smith | CPU Architecture: | Any |
[23 Sep 2009 11:44]
Lars Heill
[1 Oct 2009 23:15]
Paul DuBois
Noted in 5.4.3 changelog. On Linux (and perhaps other systems), the performance of MySQL Server can be improved by using a different malloc() implementation, developed by Google and called tcmalloc. The gain is noticeable with a higher number of simultaneous users. MySQL 5.4.1 was linked against this library, which improved performance but imposed some restrictions. As a result of these restrictions, MySQL 5.4.3 uses a different approach: * The server is linked against the default malloc() provided by the respective platform. * Binary distributions for Linux include libtcmalloc_minimal.so (the shared library that can be linked against at runtime) in pkglibdir (that is, the same directory within the package where server plugins and similar object files are located). The version of tcmalloc included with MySQL 5.4.3 comes from google-perftools 1.4. If you want to try tcmalloc but are using a binary distribution for a non-Linux platform or a source distribution, you can install Google's tcmalloc_minimal. Some distributions provide it in a google-perftools package or with a similar name, or you can download it from Google at http://code.google.com/p/google-perftools/ and compile it yourself. * mysqld_safe now supports a --malloc-lib option that enables administrators to specify that mysqld should use tcmalloc. The --malloc-lib option works by modifying the LD_PRELOAD environment value to affect dynamic linking so that the loader will find tcmalloc when mysqld runs: * If the option is not given, or is given without a value (--malloc-lib=), LD_PRELOAD is not modified and no attempt is made to use tcmalloc. * If the option is given as --malloc-lib=tcmalloc, mysqld_safe looks for a tcmalloc library in /usr/lib and then in the MySQL pkglibdir location (for example, /usr/local/mysql/lib or whatever is appropriate). If tmalloc is found, its path name is added to the beginning of the LD_PRELOAD value for mysqld. If tcmalloc is not found, mysqld_safe aborts with an error. * If the option is given as --malloc-lib=/path/to/some/library, that full path is added to the beginning of the LD_PRELOAD value. If the full path points to a nonexistent or unreadable file, mysqld_safe aborts with an error. * For cases where mysqld_safe adds a path name to LD_PRELOAD, it adds the path to the beginning of any existing value the variable already has. As a result of the preceding changes, Linux users can use the libtcmalloc_minimal.so now included in binary packages by adding these lines to their my.cnf file: [mysqld_safe] malloc-lib=tcmalloc Those lines also suffice for users on any platform who have installed a tcmalloc package in /usr/lib. To use a specific tcmalloc library, specify its full path name. Example: [mysqld_safe] malloc-lib=/opt/lib/libtcmalloc_minimal.so
[1 Oct 2009 23:18]
Paul DuBois
Noted in 5.4.3 changelog. On Linux (and perhaps other systems), the performance of MySQL Server can be improved by using a different malloc() implementation, developed by Google and called tcmalloc. The gain is noticeable with a higher number of simultaneous users. MySQL 5.4.1 was linked against this library, which improved performance but imposed some restrictions. As a result of these restrictions, MySQL 5.4.3 uses a different approach: * The server is linked against the default malloc() provided by the respective platform. * Binary distributions for Linux include libtcmalloc_minimal.so (the shared library that can be linked against at runtime) in pkglibdir (that is, the same directory within the package where server plugins and similar object files are located). The version of tcmalloc included with MySQL 5.4.3 comes from google-perftools 1.4. If you want to try tcmalloc but are using a binary distribution for a non-Linux platform or a source distribution, you can install Google's tcmalloc_minimal. Some distributions provide it in a google-perftools package or with a similar name, or you can download it from Google at http://code.google.com/p/google-perftools/ and compile it yourself. * mysqld_safe now supports a --malloc-lib option that enables administrators to specify that mysqld should use tcmalloc. The --malloc-lib option works by modifying the LD_PRELOAD environment value to affect dynamic linking so that the loader will find tcmalloc when mysqld runs: * If the option is not given, or is given without a value (--malloc-lib=), LD_PRELOAD is not modified and no attempt is made to use tcmalloc. * If the option is given as --malloc-lib=tcmalloc, mysqld_safe looks for a tcmalloc library in /usr/lib and then in the MySQL pkglibdir location (for example, /usr/local/mysql/lib or whatever is appropriate). If tmalloc is found, its path name is added to the beginning of the LD_PRELOAD value for mysqld. If tcmalloc is not found, mysqld_safe aborts with an error. * If the option is given as --malloc-lib=/path/to/some/library, that full path is added to the beginning of the LD_PRELOAD value. If the full path points to a nonexistent or unreadable file, mysqld_safe aborts with an error. * For cases where mysqld_safe adds a path name to LD_PRELOAD, it adds the path to the beginning of any existing value the variable already has. As a result of the preceding changes, Linux users can use the libtcmalloc_minimal.so now included in binary packages by adding these lines to their my.cnf file: [mysqld_safe] malloc-lib=tcmalloc Those lines also suffice for users on any platform who have installed a tcmalloc package in /usr/lib. To use a specific tcmalloc library, specify its full path name. Example: [mysqld_safe] malloc-lib=/opt/lib/libtcmalloc_minimal.so
[1 Oct 2009 23:21]
Paul DuBois
Noted in 5.4.3 changelog. On Linux (and perhaps other systems), the performance of MySQL Server can be improved by using a different malloc() implementation, developed by Google and called tcmalloc. The gain is noticeable with a higher number of simultaneous users. MySQL 5.4.1 was linked against this library, which improved performance but imposed some restrictions. As a result of these restrictions, MySQL 5.4.3 uses a different approach: * The server is linked against the default malloc() provided by the respective platform. * Binary distributions for Linux include libtcmalloc_minimal.so (the shared library that can be linked against at runtime) in pkglibdir (that is, the same directory within the package where server plugins and similar object files are located). The version of tcmalloc included with MySQL 5.4.3 comes from google-perftools 1.4. If you want to try tcmalloc but are using a binary distribution for a non-Linux platform or a source distribution, you can install Google's tcmalloc_minimal. Some distributions provide it in a google-perftools package or with a similar name, or you can download it from Google at http://code.google.com/p/google-perftools/ and compile it yourself. * mysqld_safe now supports a --malloc-lib option that enables administrators to specify that mysqld should use tcmalloc. The --malloc-lib option works by modifying the LD_PRELOAD environment value to affect dynamic linking so that the loader will find tcmalloc when mysqld runs: * If the option is not given, or is given without a value (--malloc-lib=), LD_PRELOAD is not modified and no attempt is made to use tcmalloc. * If the option is given as --malloc-lib=tcmalloc, mysqld_safe looks for a tcmalloc library in /usr/lib and then in the MySQL pkglibdir location (for example, /usr/local/mysql/lib or whatever is appropriate). If tmalloc is found, its path name is added to the beginning of the LD_PRELOAD value for mysqld. If tcmalloc is not found, mysqld_safe aborts with an error. * If the option is given as --malloc-lib=/path/to/some/library, that full path is added to the beginning of the LD_PRELOAD value. If the full path points to a nonexistent or unreadable file, mysqld_safe aborts with an error. * For cases where mysqld_safe adds a path name to LD_PRELOAD, it adds the path to the beginning of any existing value the variable already has. As a result of the preceding changes, Linux users can use the libtcmalloc_minimal.so now included in binary packages by adding these lines to their my.cnf file: [mysqld_safe] malloc-lib=tcmalloc Those lines also suffice for users on any platform who have installed a tcmalloc package in /usr/lib. To use a specific tcmalloc library, specify its full path name. Example: [mysqld_safe] malloc-lib=/opt/lib/libtcmalloc_minimal.so
[28 Oct 2009 21:26]
Timothy Smith
This was committed and included in mysql-5.4.3, and is present in the mysql-trunk branch.
