2772d93caf
We deprecate and ignore the parameter innodb_buffer_pool_chunk_size and let the buffer pool size to be changed in arbitrary 1-megabyte increments, all the way up to innodb_buffer_pool_size_max, which must be specified at startup. If innodb_buffer_pool_size_max is not specified, it will default to twice the specified innodb_buffer_pool_size. The buffer pool will be mapped in a contiguous memory area that will be aligned and partitioned into extents of 8 MiB on 64-bit systems and 2 MiB on 32-bit systems. Within an extent, the first few innodb_page_size blocks contain buf_block_t objects that will cover the page frames in the rest of the extent. In this way, there is a trivial mapping between page frames and block descriptors and we do not need any lookup tables like buf_pool.zip_hash or buf_pool_t::chunk_t::map. We will always allocate the same number of block descriptors for an extent, even if we do not need all the buf_block_t in the last extent in case the innodb_buffer_pool_size is not an integer multiple of the of extents size. The minimum innodb_buffer_pool_size is 256*5/4 pages. At the default innodb_page_size=16k this corresponds to 5 MiB. However, now that the innodb_buffer_pool_size includes the memory allocated for the block descriptors, the minimum would be innodb_buffer_pool_size=6m. When the buffer pool is shrunk, InnoDB will try to inform the operating system that the underlying memory for part of the virtual address range is no longer needed and may be zeroed out. On many POSIX-like systems this is done by madvise(MADV_FREE) where available (Linux, FreeBSD, NetBSD, OpenBSD, Apple macOS). On Microsoft Windows, VirtualFree(MEM_DECOMMIT) is invoked. Innodb_buffer_pool_resize_status: Remove. We will execute buf_pool_t::resize() synchronously in the thread that is executing SET GLOBAL innodb_buffer_pool_size. That operation will run until it completes, or until a KILL statement is executed, the client is disconnected, the buf_flush_page_cleaner() thread notices that we are running out of memory, or the server is shut down. opt_super_large_pages: Declare only on Solaris. Actually, this is specific to the SPARC implementation of Solaris, but due to us not having a Solaris development environment, we will not revise this for other MMU and ISA. my_large_virtual_alloc(): A new function, similar to my_large_malloc(). On Microsoft Windows, buffer pool resizing is disabled if large pages are being used. buf_pool_t::chunk_t::create(): Remove. buf_pool_t::create(): Initialize all n_blocks of the buf_pool.free list. buf_pool_t::allocate(): Renamed from buf_LRU_get_free_only(). buf_pool_t::LRU_warned: Changed to Atomic_relaxed<bool>, only to be modified by the buf_flush_page_cleaner() thread. buf_pool_t::LRU_shrink(): Check if buffer pool shrinking needs to process a buffer page. buf_pool_t::resize(): Always zero out b->page.zip.data. Failure to do so would cause crashes or corruption in the test innodb.innodb_buffer_pool_resize due to duplicated allocation in the buddy system. Before tarting to shrink the buffer pool, run one batch of buf_flush_page_cleaner() in order to prevent LRU_warn(). Abort shrinking if the buf_flush_page_cleaner() has LRU_warned. buf_pool_t::first_to_withdraw: The first block descriptor that is out of the bounds of the shrunk buffer pool. buf_pool_t::withdrawn: The list of withdrawn blocks. If buf_pool_t::resize() is aborted, we must be able to resurrect the withdrawn blocks in the free list. buf_pool_t::contains_zip(): Added a parameter for the number of least significant pointer bits to disregard, so that we can find any pointers to within a block that is supposed to be free. buf_pool_t::is_shrinking(): Return the total number or blocks that were withdrawn or are to be withdrawn. buf_pool_t::to_withdraw(): Return the number of blocks that will need to be withdrawn. buf_pool_t::usable_size(): Number of usable pages, considering possible in-progress attempt at shrinking the buffer pool. buf_page_get_low(): Suppress a MemorySanitizer warning about an uninitialized (typically all-zero) block->page.id(). buf_pool_t::get_info(): Replaces buf_stats_get_pool_info(). innodb_init_param(): Refactored. We must first compute srv_page_size_shift and then determine the valid bounds of innodb_buffer_pool_size. buf_buddy_shrink(): Replaces buf_buddy_realloc(). Part of the work is deferred to buf_buddy_condense_free(), which is being executed when we are not holding any buf_pool.page_hash latch. buf_buddy_condense_free(): Do not relocate blocks. buf_buddy_free_low(): Do not care about buffer pool shrinking. This will be handled by buf_buddy_shrink() and buf_buddy_condense_free(). buf_buddy_alloc_zip(): Assert !buf_pool.contains_zip() when we are allocating from the binary buddy system. Previously we were asserting this on multiple recursion levels. buf_buddy_block_free(), buf_buddy_free_low(): Assert !buf_pool.contains_zip(). buf_buddy_alloc_from(): Remove the redundant parameter j. buf_flush_LRU_list_batch(): Add the parameter shrinking. If we are shrinking, invoke buf_pool_t::LRU_shrink() to see if we must keep going. buf_do_LRU_batch(): Skip buf_free_from_unzip_LRU_list_batch() if we are shrinking the buffer pool. In that case, we want to minimize the page relocations and just finish as quickly as possible. trx_purge_attach_undo_recs(): Limit purge_sys.n_pages_handled() in every iteration, in case the buffer pool is being shrunk in the middle of a purge batch. |
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| client | ||
| cmake | ||
| dbug | ||
| debian | ||
| Docs | ||
| extra | ||
| include | ||
| libmariadb@2d56f340c4 | ||
| libmysqld | ||
| libservices | ||
| man | ||
| mysql-test | ||
| mysys | ||
| mysys_ssl | ||
| plugin | ||
| randgen/conf | ||
| scripts | ||
| sql | ||
| sql-bench | ||
| sql-common | ||
| storage | ||
| strings | ||
| support-files | ||
| tests | ||
| tpool | ||
| unittest | ||
| vio | ||
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| wsrep-lib@70cd967f5e | ||
| zlib | ||
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| appveyor.yml | ||
| BUILD-CMAKE | ||
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| config.h.cmake | ||
| configure.cmake | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| CREDITS | ||
| INSTALL-SOURCE | ||
| INSTALL-WIN-SOURCE | ||
| KNOWN_BUGS.txt | ||
| README.md | ||
| THIRDPARTY | ||
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Code status:
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MariaDB: The innovative open source database
MariaDB was designed as a drop-in replacement of MySQL(R) with more features, new storage engines, fewer bugs, and better performance.
MariaDB is brought to you by the MariaDB Foundation and the MariaDB Corporation. Please read the CREDITS file for details about the MariaDB Foundation, and who is developing MariaDB.
MariaDB is developed by many of the original developers of MySQL who now work for the MariaDB Corporation, the MariaDB Foundation and by many people in the community.
MySQL, which is the base of MariaDB, is a product and trademark of Oracle Corporation, Inc. For a list of developers and other contributors, see the Credits appendix. You can also run 'SHOW authors' to get a list of active contributors.
A description of the MariaDB project and a manual can be found at:
https://mariadb.com/kb/en/mariadb-vs-mysql-features/
https://mariadb.com/kb/en/mariadb-versus-mysql-compatibility/
https://mariadb.com/kb/en/new-and-old-releases/
Getting the code, building it and testing it
Refer to the following guide: https://mariadb.org/get-involved/getting-started-for-developers/get-code-build-test/ which outlines how to build the source code correctly and run the MariaDB testing framework, as well as which branch to target for your contributions.
Help
More help is available from the Maria Discuss mailing list https://lists.mariadb.org/postorius/lists/discuss.lists.mariadb.org/ and MariaDB's Zulip instance, https://mariadb.zulipchat.com/
Licensing
MariaDB is specifically available only under version 2 of the GNU General Public License (GPLv2). (I.e. Without the "any later version" clause.) This is inherited from MySQL. Please see the README file in the MySQL distribution for more information.
License information can be found in the COPYING file. Third party license information can be found in the THIRDPARTY file.
Bug Reports
Bug and/or error reports regarding MariaDB should be submitted at: https://jira.mariadb.org
For reporting security vulnerabilities see: https://mariadb.org/about/security-policy/
The code for MariaDB, including all revision history, can be found at: https://github.com/MariaDB/server