{"id":1316,"date":"2010-02-04T12:57:17","date_gmt":"2010-02-04T04:57:17","guid":{"rendered":"http:\/\/www.orczhou.com\/?p=1316"},"modified":"2010-04-14T11:40:17","modified_gmt":"2010-04-14T03:40:17","slug":"innodb-double-write","status":"publish","type":"post","link":"https:\/\/www.orczhou.com\/index.php\/2010\/02\/innodb-double-write\/","title":{"rendered":"InnoDB Double write"},"content":{"rendered":"<p>\u8bb0\u5f97\u521a\u5f00\u59cb\u770bInnoDB\u6587\u6863\u7684\u65f6\u5019\uff0c<a href=\"http:\/\/dev.mysql.com\/doc\/refman\/5.0\/en\/innodb-disk-io.html\">Double Write\u4e00\u8282<\/a>\uff08\u5176\u5b9e\u53ea\u6709\u4e00\u5c0f\u6bb5\uff09\u5c31\u8ba9\u6211\u5f88\u56f0\u60d1\u3002\u65e0\u5948\u5f53\u65f6\u5185\u529b\u592a\u6d45\uff0c\u7ea0\u7f20\u4e86\u5f88\u4e45\u4e5f\u6ca1\u5f04\u660e\u767d\u3002\u65f6\u9694\u51e0\u4e2a\u6708\uff0c\u91cd\u65b0\u6765\u6574\u7406\u4e00\u4e0b\u3002<\/p>\n<p>\u6d89\u53ca\u5230\u7684\u6982\u5ff5\uff1a<a href=\"http:\/\/www.orczhou.com\/index.php\/2009\/08\/innodb-dirty-page-redo-log-2\/\">Buffer Pool<\/a>\u7b80\u79f0BP\uff0c<a href=\"http:\/\/www.orczhou.com\/index.php\/2009\/08\/innodb-dirty-page-redo-log-2\/\">Dirty Page<\/a>\uff0c<a href=\"http:\/\/www.orczhou.com\/index.php\/2009\/08\/innodb-dirty-page-redo-log-2\/\">Log file<\/a>\uff0c<a href=\"http:\/\/www.orczhou.com\/index.php\/2009\/08\/innodb_flush_method-file-io\/\">Flush<\/a>\uff0c<a href=\"http:\/\/www.orczhou.com\/index.php\/2009\/08\/image-innodb-tablespace\/\">innodb tablespace<\/a>\u3002<\/p>\n<p><font color=\"red\">1. \u4ec0\u4e48\u662fDouble Write<\/font><\/p>\n<p>\u5728InnoDB\u5c06BP\u4e2d\u7684Dirty Page\u5237\uff08flush\uff09\u5230\u78c1\u76d8\u4e0a\u65f6\uff0c\u9996\u5148\u4f1a\u5c06Page\u5237\u5230InnoDB tablespace\u7684\u4e00\u4e2a\u533a\u57df\u4e2d\uff0c\u6211\u4eec\u79f0\u8be5\u533a\u57df\u4e3aDouble write Buffer\u3002\u5728\u5411Double write Buffer\u5199\u5165\u6210\u529f\u540e\uff0c\u518d\u62e9\u673a\u5c06\u6570\u636e\u62f7\u8d1d\u5230\u6b63\u5728\u7684\u6570\u636e\u6587\u4ef6\u5bf9\u5e94\u7684\u4f4d\u7f6e\u3002<\/p>\n<p>\u548b\u4e00\u770b\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u6709\u4e9b\u591a\u4f59<!--more--><\/p>\n<p><font color=\"red\">2. \u4e3a\u4ec0\u4e48\u9700\u8981Double Write<\/font><\/p>\n<p>InnoDB\u4e2d\u6709\u8bb0\u5f55\uff08Row\uff09\u88ab\u66f4\u65b0\u65f6\uff0c\u5148\u5c06\u5176\u5728Buffer Pool\uff08\u7b80\u79f0<strong>BP<\/strong>\uff09\u4e2d\u7684page\u66f4\u65b0\uff0c\u5e76\u5c06\u8fd9\u6b21\u66f4\u65b0\u8bb0\u5f55\u5230Log file\u4e2d\uff0c\u8fd9\u65f6\u5019BP\u4e2d\u7684\u8be5page\u5c31\u662f\u88ab\u6807\u8bb0\u4e3aDirty\u3002\u5728\u9002\u5f53\u7684\u65f6\u5019\uff08BP\u4e0d\u591f\u3001\u7cfb\u7edf\u95f2\u7f6e\u7b49\uff09\uff0c\u8fd9\u4e9bDirty Page\u4f1a\u88abflush\u5230\u78c1\u76d8\u4e0a\u3002<\/p>\n<p>\u8bd5\u60f3\uff0c\u5728\u67d0\u4e2aDirty Page\uff08\u4e00\u822c\u662f16K\uff09flush\u7684\u8fc7\u7a0b\u4e2d\uff0c\u53d1\u751f\u4e86\u7cfb\u7edf\u65ad\u7535\uff08\u6216\u8005OS\u5d29\u6e83\uff09\uff0c<strong>16K<\/strong>\u7684\u6570\u636e\u53ea\u6709<strong>8K<\/strong>\u88ab\u5199\u5230\u78c1\u76d8\u4e0a\uff0c\u8fd9\u79cd\u73b0\u8c61\u88ab\u79f0\u4e3a\uff08partial page writes\u3001torn pages\u3001fractured writes\uff09\u3002\u4e00\u65e6partial page writes\u53d1\u751f\uff0c\u90a3\u4e48\u5728InnoDB\u6062\u590d\u65f6\u5c31\u5f88\u5c34\u5c2c\uff1a\u5728InnoDB\u7684Log file\u4e2d\u867d\u7136\u77e5\u9053\u8fd9\u4e2a\u6570\u636e\u9875\u88ab\u4fee\u6539\u4e86\uff0c\u4f46\u662f\u5374\u65e0\u6cd5\u77e5\u9053\u8fd9\u4e2a\u9875\u88ab\u4fee\u6539\u5230\u4ec0\u4e48\u7a0b\u5ea6\uff0c\u548c\u8fd9\u4e2a\u9875\u9762\u76f8\u5173\u7684redo\u4e5f\u5c31\u65e0\u6cd5\u5e94\u7528\u4e86\u3002<\/p>\n<p>\u4e3e\u4e2a\u4f8b\u5b50\uff1a\u5728InnoDB\u7684log file\u4e2d\u6709\u5982\u4e0bLog\uff1a<\/p>\n<blockquote><p>\nLog sequence number 0 4285149977<br \/>\nLog sequence number 0 4287355447<br \/>\nLog sequence number 0 4289260680<br \/>\nLog sequence number 0 4291279900<br \/>\nLog sequence number 0 4293359020\n<\/p><\/blockquote>\n<p>\u5176\u4e2d\u7b2c1\u30013\u4e2aLog\u4fee\u6539\u4e86\u8be5page\uff0c\u4f46\u662f\u5728\u65ad\u7535\u65f6\uff0cBP\u4e2d\u8be5page\u53ea\u88abflush\u4e86\u4e00\u90e8\u5206\u3002\u90a3\u4e48InnoDB\u662f\u65e0\u6cd5\u51b3\u5b9a\u4e0a\u9762\u7684Log\u662f\u5426\u5e94\u8be5\u88ab\u5e94\u7528\u7684\u3002\u8fd9\u65f6\uff0c\u6570\u636e\u5c31\u51fa\u73b0\u4e86\u4e0d\u4e00\u81f4\u3002<\/p>\n<p>\u6240\u4ee5\uff0cLog file\u7684\u6709\u6548\u5e94\u7528\uff0c\u524d\u63d0\u662f<strong>InnoDB\u7684\u6570\u636e\u6587\u4ef6\u4e2d\u7684Page\u662f\u4e00\u81f4<\/strong>\u7684\u3002<\/p>\n<p>\u7b80\u800c\u8a00\u4e4b\uff0cDouble write\u5c31\u662f\u4e3a\u4e86\u907f\u514dPartial page writes\u800c\u8bbe\u8ba1\u7684\u3002<\/p>\n<p><font color=\"red\">3. Double Write\u5bf9\u6027\u80fd\u7684\u5f71\u54cd<\/font><\/p>\n<p>\u7cfb\u7edf\u9700\u8981\u5c06\u6570\u636e\u5199\u4e24\u4efd\uff0c\u4e00\u822c\u8ba4\u4e3a\uff0cDouble Write\u662f\u4f1a\u964d\u4f4e\u7cfb\u7edf\u6027\u80fd\u7684\u3002<a href=\"http:\/\/www.mysqlperformanceblog.com\/2006\/08\/04\/innodb-double-write\/\">peter<\/a>\u731c\u6d4b\u53ef\u80fd\u4f1a\u67095-10%\u7684\u6027\u80fd\u635f\u5931\uff0c\u4f46\u662f\u56e0\u4e3a\u5b9e\u73b0\u4e86\u6570\u636e\u7684\u4e00\u81f4\uff0c\u662f\u503c\u5f97\u7684\u3002<a href=\"http:\/\/www.facebook.com\/note.php?note_id=107329775932\">Mark Callaghan<\/a>\u8ba4\u4e3a\u8fd9\u5e94\u8be5\u662f\u5b58\u50a8\u5c42\u9762\u5e94\u8be5\u89e3\u51b3\u7684\u95ee\u9898\uff0c\u653e\u5728\u6570\u636e\u5e93\u5c42\u9762\u65e0\u7591\u662f\u727a\u7272\u4e86\u5f88\u591a\u6027\u80fd\u7684\u3002<\/p>\n<p>\u4e8b\u5b9e\u4e0a\uff0cDouble Write\u5bf9\u6027\u80fd\u5f71\u54cd\u5e76\u6ca1\u6709\u4f60\u60f3\u8c61\uff08\u5199\u4e24\u904d\u6027\u80fd\u5e94\u8be5\u964d\u4f4e\u4e8650%\u5427\uff1f\uff09\u7684\u90a3\u4e48\u5927\u3002\u5728BP\u4e2d\u4e00\u6b21\u6027\u5f80\u5f80\u4f1a\u6709\u5f88\u591a\u7684Dirty Page\u540c\u65f6\u88abflush\uff0cDouble Write\u5219\u628a\u8fd9\u4e9b\u5199\u64cd\u4f5c\uff0c\u7531\u968f\u673a\u5199\u8f6c\u5316\u4e3a\u4e86\u987a\u5e8f\u5199\u3002\u800c\u5728Double Write\u7684\u7b2c\u4e8c\u4e2a\u9636\u6bb5\uff0c\u56e0\u4e3aDouble Write Buffer\u4e2d\u79ef\u7d2f\u4e86\u5f88\u591aDirty Page\uff0c\u6240\u4ee5\u5411\u771f\u6b63\u7684\u6570\u636e\u6587\u4ef6\u4e2d\u5199\u6570\u636e\u7684\u65f6\u5019\uff0c\u53ef\u80fd\u6709\u5f88\u591a\u5199\u64cd\u4f5c\u53ef\u4ee5\u5408\u5e76\uff0c\u8fd9\u6837\u6709\u53ef\u80fd\u4f1a\u964d\u4f4eFsync\u7684\u8c03\u7528\u6b21\u6570\u3002<\/p>\n<p>\u57fa\u4e8e\u4e0a\u9762\u7684\u539f\u56e0\uff0cDouble Write\u5e76\u6ca1\u6709\u60f3\u8c61\u7684\u90a3\u4e48\u7cdf\u3002\u53e6\u5916\uff0cDimitri\u5728<a href=\"http:\/\/dimitrik.free.fr\/blog\/archives\/2009\/08\/entry_86.html\">\u6d4b\u8bd5<\/a>\u540e\uff0c\u53d1\u73b0\u6253\u5f00\u548c\u5173\u95edDouble Write\u5bf9\u6548\u7387\u7684\u5f71\u54cd\u5e76\u4e0d\u5927\u3002<\/p>\n<p><font color=\"red\">4. \u76f8\u5173\u53c2\u6570\u4e0e\u72b6\u6001<\/font> <\/p>\n<p>\u662f\u5426\u6253\u5f00\u4e86double write:<\/p>\n<pre><div class=\"mycode\">\r\nroot@(none) 07:16:16>show variables like \"%double%\";\r\n+--------------------+-------+\r\n| Variable_name      | Value |\r\n+--------------------+-------+\r\n| innodb_doublewrite | ON    | \r\n+--------------------+-------+\r\n<\/div><\/pre>\n<p>Double write\u7684\u4f7f\u7528\u60c5\u51b5\uff1a<\/p>\n<pre><div class=\"mycode\">\r\nroot@(none) 07:15:50>SHOW STATUS LIKE \"%innodb_dblwr%\";\r\n+----------------------------+-----------+\r\n| Variable_name              | Value     |\r\n+----------------------------+-----------+\r\n| Innodb_dblwr_pages_written | 145373349 | \r\n| Innodb_dblwr_writes        | 2249336   | \r\n+----------------------------+-----------+\r\n<\/div><\/pre>\n<p>\u4e0a\u9762\u53ef\u4ee5\u770b\u5230\uff0c\u4eceBP\u5171Flush\u4e86145373349\u4e2aPages\u5230double write buffer\u4e2d\uff1b\u4e00\u5171\u8c03\u7528\u4e862249336\u6b21write\u5199\u5230\u771f\u6b63\u7684\u6570\u636e\u6587\u4ef6\u3002\u53ef\u89c1\uff0c\u76f8\u5f53\u4e8e\u6bcf\u6b21write\u5408\u5e76\u4e86 145373349 \/ 2249336 = 64.6\u6b21Flush\u3002\uff08\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48double write buffer\u4e3a\u4ec0\u4e48\u5e76\u4e0d\u4f1a\u5bf9\u6548\u7387\u6709\u5f88\u5927\u5f71\u54cd\u7684\u539f\u56e0\uff09<\/p>\n<p><font color=\"red\">5. \u6211\u7684\u770b\u6cd5<\/font> <\/p>\n<p>\u5728\u67d0\u4e9b\u6587\u4ef6\u7cfb\u7edf\uff08<a href=\"http:\/\/dev.mysql.com\/tech-resources\/articles\/mysql-zfs.html\">ZFS<\/a>\u7b49\uff09\u5c42\u9762\u80fd\u591f\u4fdd\u8bc1\u4e0d\u51fa\u73b0Partial page writes\u65f6\uff0c\u53ef\u4ee5\u5173\u95edDouble Write\u3002\u56e0\u4e3a\u5b83\u5bf9\u6027\u80fd\u5f71\u54cd\u5e76\u4e0d\u5927\uff0c\u4e00\u822c\u60c5\u51b5\u90fd\u5efa\u8bae\u6253\u5f00\uff0c\u6bd5\u7adf\u5e26\u6765\u7684\u6570\u636e\u5b89\u5168\u6027\u4fdd\u969c\u53ef\u80fd\u662f\u6211\u4eec\u66f4\u5173\u5fc3\u7684\u3002<\/p>\n<p>\u53c2\u8003\u6587\u732e\uff1a<\/p>\n<p>[0]. <a href=\"http:\/\/dev.mysql.com\/doc\/refman\/5.0\/en\/innodb-disk-io.html\">Manual about Double Write<\/a><\/p>\n<p>[1]. <a href=\"http:\/\/www.mysqlperformanceblog.com\/2006\/08\/04\/innodb-double-write\/\">Innodb Double Write<\/a><\/p>\n<p>[2]. <a href=\"http:\/\/www.facebook.com\/note.php?note_id=107329775932\">Do you need the InnoDB doublewrite buffer<\/a><\/p>\n<p>[3]. <a href=\"http:\/\/dimitrik.free.fr\/blog\/archives\/2009\/08\/entry_86.html\">MySQL Performance: InnoDB Doublewrite Buffer Impact<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8bb0\u5f97\u521a\u5f00\u59cb\u770bInnoDB\u6587\u6863\u7684\u65f6\u5019\uff0cDouble Write\u4e00\u8282\uff08\u5176\u5b9e\u53ea\u6709\u4e00\u5c0f\u6bb5\uff09\u5c31\u8ba9\u6211\u5f88\u56f0\u60d1\u3002\u65e0\u5948\u5f53\u65f6\u5185\u529b\u592a\u6d45\uff0c\u7ea0\u7f20\u4e86\u5f88\u4e45\u4e5f\u6ca1\u5f04\u660e\u767d\u3002\u65f6\u9694\u51e0\u4e2a\u6708\uff0c\u91cd\u65b0\u6765\u6574\u7406\u4e00\u4e0b\u3002 \u6d89\u53ca\u5230\u7684\u6982\u5ff5\uff1aBuffer Pool\u7b80\u79f0BP\uff0cDirty Page\uff0cLog file\uff0cFlush\uff0cinnodb tablespace\u3002 1. \u4ec0\u4e48\u662fDouble Write \u5728InnoDB\u5c06BP\u4e2d\u7684Dirty Page\u5237\uff08flush\uff09\u5230\u78c1\u76d8\u4e0a\u65f6\uff0c\u9996\u5148\u4f1a\u5c06Page\u5237\u5230InnoDB tablespace\u7684\u4e00\u4e2a\u533a\u57df\u4e2d\uff0c\u6211\u4eec\u79f0\u8be5\u533a\u57df\u4e3aDouble write Buffer\u3002\u5728\u5411Double write Buffer\u5199\u5165\u6210\u529f\u540e\uff0c\u518d\u62e9\u673a\u5c06\u6570\u636e\u62f7\u8d1d\u5230\u6b63\u5728\u7684\u6570\u636e\u6587\u4ef6\u5bf9\u5e94\u7684\u4f4d\u7f6e\u3002 \u548b\u4e00\u770b\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u6709\u4e9b\u591a\u4f59<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_eb_attr":"","inline_featured_image":false,"_tocer_settings":[],"footnotes":""},"categories":[6],"tags":[120],"class_list":["post-1316","post","type-post","status-publish","format-standard","hentry","category-mysql","tag-innodb"],"_links":{"self":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts\/1316","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/comments?post=1316"}],"version-history":[{"count":22,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts\/1316\/revisions"}],"predecessor-version":[{"id":1390,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/posts\/1316\/revisions\/1390"}],"wp:attachment":[{"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/media?parent=1316"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/categories?post=1316"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.orczhou.com\/index.php\/wp-json\/wp\/v2\/tags?post=1316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}