Percona Server v5.6.30-76.3 发布，MySQL 数据库改进

   <p style="text-align: center;"><img alt="" src="https://simg.open-open.com/show/84c3deaa9a2f297b1ea345f7149449f6.jpg" /></p>    <p>Percona 为 MySQL 数据库服务器进行了改进，在功能和性能上较 MySQL 有着很显著的提升。该版本提升了在高负载情况下的 InnoDB 的性能、为 DBA 提供一些非常有用的性能诊断工具；另外有更多的参数和命令来控制服务器行为。</p>    <p>Percona Server 只包含 MySQL 的服务器版，并没有提供相应对 MySQL 的 Connector 和 GUI 工具进行改进。</p>    <p>Percona Server 使用了一些 google-mysql-tools, Proven Scaling, Open Query 对 MySQL 进行改造。</p>    <h2>更新日志</h2>    <p><strong>Bugs 修复:</strong></p>    <ul>     <li>When <a href="/misc/goto?guid=4958990789629882697">Read Free Replication</a> was enabled for TokuDB, and there was no explicit primary key for the replicated <em>TokuDB</em> table, there could be duplicated records in the table on update operation. The fix disables<a href="/misc/goto?guid=4958990789629882697">Read Free Replication</a> for tables without an explicit primary key and does rows lookup for <code>UPDATE</code> and<code>DELETE</code> binary log events and issues warning. Bug fixed <a href="/misc/goto?guid=4958990789766318485" rel="nofollow">#1536663</a> (<a href="/misc/goto?guid=4958990789867544417" rel="nofollow">#950</a>).</li>     <li>Attempting to execute a non-existing prepared statement with <a href="/misc/goto?guid=4958990789976587616">Response Time Distribution</a> plugin enabled could lead to a server crash. Bug fixed <a href="/misc/goto?guid=4958990790072117508" rel="nofollow">#1538019</a>.</li>     <li><em>TokuDB</em> was using using different memory allocators; this was causing <code>safemalloc</code> warnings in debug builds and crashes because memory accounting didn’t add up. Bug fixed <a href="/misc/goto?guid=4958990790188666920" rel="nofollow">#1546538</a> (<a href="/misc/goto?guid=4958990790308489548" rel="nofollow">#962</a>).</li>     <li>Fixed heap allocator/deallocator mismatch in <a href="/misc/goto?guid=4958990790413277385">Metrics for scalability measurement</a>. Bug fixed <a href="/misc/goto?guid=4958990790520382413" rel="nofollow">#1581051</a>.</li>     <li><em>Percona Server</em> is now built with system <code>zlib</code> library instead of the older bundled one. Bug fixed <a href="/misc/goto?guid=4958990790615139013" rel="nofollow">#1108016</a>.</li>     <li>Reduced the memory overhead per page in the <em>InnoDB</em> buffer pool. The fix was based on <em>非死book</em> patch<a href="/misc/goto?guid=4958990790739560861" rel="nofollow">#91e979e</a>. Bug fixed <a href="/misc/goto?guid=4958990790834623291" rel="nofollow">#1536693</a> (upstream <a href="/misc/goto?guid=4958990790937256417" rel="nofollow">#72466</a>).</li>     <li><code>CREATE TABLE ... LIKE ...</code> could create a system table with an unsupported enforced engine. Bug fixed<a href="/misc/goto?guid=4958990791046528188" rel="nofollow">#1540338</a>.</li>     <li>Change buffer merge could throttle to 5% of I/O capacity on an idle server. Bug fixed <a href="/misc/goto?guid=4958990791148255619" rel="nofollow">#1547525</a>.</li>     <li><code>Slave_open_temp_tables</code> would fail to decrement on the slave with a disabled binary log if the master was killed. Bug fixed <a href="/misc/goto?guid=4958990791256337249" rel="nofollow">#1567361</a>.</li>     <li>The server will now show a more descriptive error message when <em>Percona Server</em> fails with <code>errno == 22 "Invalid argument"</code>, if <a href="/misc/goto?guid=4958990791347664795"><code>innodb_flush_method</code></a> was set to <code>ALL_O_DIRECT</code>. Bug fixed <a href="/misc/goto?guid=4958990791450370446" rel="nofollow">#1578604</a>.</li>     <li>Killed connection threads could get their sockets closed twice on shutdown. Bug fixed <a href="/misc/goto?guid=4958990791542779803" rel="nofollow">#1580227</a>.</li>     <li><code>AddressSanitizer</code> build with <code>LeakSanitizer</code> enabled was failing at <code>gen_lex_hash</code> invocation. Bug fixed<a href="/misc/goto?guid=4958990791623492371" rel="nofollow">#1580993</a> (upstream <a href="/misc/goto?guid=4958990791708998721" rel="nofollow">#80014</a>).</li>     <li><code>apt-cache show</code> command for <code>percona-server-client</code> was showing <code>innotop</code> included as part of the package. Bug fixed <a href="/misc/goto?guid=4958990791804057974" rel="nofollow">#1201074</a>.</li>     <li><code>mysql-systemd</code> would fail with PAM authentication and proxies due to a regression introduced when fixing<a href="/misc/goto?guid=4958990791882720588" rel="nofollow">#1534825</a> in Percona Server 5.6.29-76.2. Bug fixed <a href="/misc/goto?guid=4958990791967846540" rel="nofollow">#1558312</a>.</li>     <li>Upgrade logic for figuring if <em>TokuDB</em> upgrade can be performed from the version on disk to the current version was broken due to a regression introduced when fixing bug <a href="/misc/goto?guid=4958990792061722851" rel="nofollow">#684</a> in <em>Percona Server</em> <a href="/misc/goto?guid=4958990792142686446">5.6.27-75.0</a>. Bug fixed<a href="/misc/goto?guid=4958990792226595818" rel="nofollow">#717</a>.</li>     <li>If <code>ALTER TABLE</code> was run while <a href="/misc/goto?guid=4958990792319306409"><code>tokudb_auto_analyze</code></a> variable was enabled it would trigger auto-analysis, which could lead to a server crash if <code>ALTER TABLE DROP KEY</code> was used because it would be operating on the old table/key meta-data. Bug fixed <a href="/misc/goto?guid=4958990792403482485" rel="nofollow">#945</a>.</li>     <li>The <em>TokuDB</em> storage engine with <a href="/misc/goto?guid=4958990792497569525"><code>tokudb_pk_insert_mode</code></a> set to <code>1</code> is safe to use in all conditions. On<code>INSERT IGNORE</code> or <code>REPLACE INTO</code>, it tests to see if triggers exist on the table, or replication is active with<code>!BINLOG_FORMAT_STMT</code> before it allows the optimization. If either of these conditions is met, then it falls back to the “safe” operation of looking up the target row first. Bug fixed <a href="/misc/goto?guid=4958990792584686771" rel="nofollow">#952</a>.</li>     <li>Bug in <em>TokuDB</em> Index Condition Pushdown was causing <code>ORDER BY DESC</code> to reverse the scan outside of the<code>WHERE</code> bounds. This would cause a query to hang in a <code>sending data</code> state for several minutes in some environments with large amounts of data (3 billion records) if the <code>ORDER BY DESC</code> statement was used. Bugs fixed <a href="/misc/goto?guid=4958990792671030875" rel="nofollow">#988</a>, <a href="/misc/goto?guid=4958990792762238210" rel="nofollow">#233</a>, and <a href="/misc/goto?guid=4958990792850474995" rel="nofollow">#534</a>.</li>     <li>其他Bug修复 <a href="/misc/goto?guid=4958990792937814497" rel="nofollow">#1399562</a> (upstream <a href="/misc/goto?guid=4958990793019987523" rel="nofollow">#75112</a>), <a href="/misc/goto?guid=4958990793100907336" rel="nofollow">#1510564</a> (upstream <a href="/misc/goto?guid=4958990793212605901" rel="nofollow">#78981</a>), <a href="/misc/goto?guid=4958990793300589198" rel="nofollow">#1496282</a> (<a href="/misc/goto?guid=4958990793390230696" rel="nofollow">#964</a>), <a href="/misc/goto?guid=4958990793479912657" rel="nofollow">#1496786</a> (<a href="/misc/goto?guid=4958990793564503798" rel="nofollow">#956</a>), <a href="/misc/goto?guid=4958990793647390236" rel="nofollow">#1566790</a>,<a href="/misc/goto?guid=4958990793735554914" rel="nofollow">#1552673</a>, <a href="/misc/goto?guid=4958990793822967712" rel="nofollow">#1567247</a>, <a href="/misc/goto?guid=4958990793904505778" rel="nofollow">#1567869</a>, <a href="/misc/goto?guid=4958990793992798811" rel="nofollow">#718</a>, <a href="/misc/goto?guid=4958990794072560326" rel="nofollow">#914</a>, <a href="/misc/goto?guid=4958990794180833027" rel="nofollow">#970</a>, <a href="/misc/goto?guid=4958990794303659861" rel="nofollow">#971</a>, <a href="/misc/goto?guid=4958990794422420501" rel="nofollow">#972</a>, <a href="/misc/goto?guid=4958990794545316709" rel="nofollow">#976</a>, <a href="/misc/goto?guid=4958990794663156891" rel="nofollow">#977</a>, <a href="/misc/goto?guid=4958990794781147726" rel="nofollow">#981</a>, <a href="/misc/goto?guid=4958990794899018099" rel="nofollow">#637</a>, and <a href="/misc/goto?guid=4958990795006306678" rel="nofollow">#982</a>.</li>    </ul>    <h2>下载</h2>    <ul>     <li><a href="/misc/goto?guid=4958990795131378027">安装下载</a></li>     <li><a href="/misc/goto?guid=4958990795249920025" rel="nofollow"><strong>Source code</strong> (zip)</a></li>     <li><a href="/misc/goto?guid=4958990795365586065" rel="nofollow"><strong>Source code</strong> (tar.gz)</a></li>    </ul>    <p> </p>    <p> </p>