{"id":227,"title":"PHP\u89e3\u51b3\u62a2\u8d2d\u3001\u79d2\u6740\u3001\u62a2\u697c\u3001\u62bd\u5956\u7b49\u963b\u585e\u5f0f\u9ad8\u5e76\u53d1\u5e93\u5b58\u9632\u63a7\u8d85\u91cf\u7684\u601d\u8def\u65b9\u6cd5 ","good":0,"bad":0,"hit":2350,"created_at":"2016-05-10 22:13:48","content":"<p>\u5982\u4eca\u5728\u7535\u5546\u884c\u4e1a\u91cc,\u79d2\u6740\u62a2\u8d2d\u6d3b\u52a8\u5df2\u7ecf\u662f\u5546\u5bb6\u5e38\u7528\u4fc3\u9500\u624b\u6bb5\u3002\u4f46\u662f\u5e93\u5b58\u6570\u91cf\u6709\u9650\uff0c\u800c\u540c\u65f6\u4e0b\u5355\u4eba\u6570\u8d85\u8fc7\u4e86\u5e93\u5b58\u91cf\uff0c\u5c31\u4f1a\u5bfc\u81f4\u5546\u54c1\u8d85\u5356\u751a\u81f3\u5e93\u5b58\u53d8\u8d1f\u6570\u7684\u95ee\u9898\u3002<br\/>\u53c8\u6bd4\u5982\uff1a\u62a2\u8d2d\u706b\u8f66\u7968\u3001\u8bba\u575b\u62a2\u697c\u3001\u62bd\u5956\u4e43\u81f3\u7206\u7ea2\u5fae\u535a\u8bc4\u8bba\u7b49\u4e5f\u4f1a\u5f15\u53d1\u963b\u585e\u5f0f\u9ad8\u5e76\u53d1\u95ee\u9898\u3002\u5982\u679c\u4e0d\u505a\u4efb\u4f55\u63aa\u65bd\u53ef\u80fd\u5728\u9ad8\u77ac\u95f4\u9020\u6210\u670d\u52a1\u5668\u762b\u75ea\uff0c\u5982\u4f55\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u5462\uff1f<br\/>\u8fd9\u91cc\u63d0\u51fa\u4e2a\u4eba\u8ba4\u4e3a\u6bd4\u8f83\u53ef\u884c\u7684\u51e0\u4e2a\u601d\u8def\u65b9\u6cd5\uff1a<br\/><br\/>\u65b9\u6848\u4e00\uff1a\u4f7f\u7528\u6d88\u606f\u961f\u5217\u6765\u5b9e\u73b0<br\/><br\/>\u53ef\u4ee5\u57fa\u4e8e\u4f8b\u5982MemcacheQ\u7b49\u8fd9\u6837\u7684\u6d88\u606f\u961f\u5217\uff0c\u5177\u4f53\u7684\u5b9e\u73b0\u65b9\u6848\u8fd9\u4e48\u8868\u8ff0\u5427<br\/>\u6bd4\u5982\u6709100\u5f20\u7968\u53ef\u4f9b\u7528\u6237\u62a2\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u628a\u8fd9100\u5f20\u7968\u653e\u5230\u7f13\u5b58\u4e2d\uff0c\u8bfb\u5199\u65f6\u4e0d\u8981\u52a0\u9501\u3002 \r\n\u5f53\u5e76\u53d1\u91cf\u5927\u7684\u65f6\u5019\uff0c\u53ef\u80fd\u6709500\u4eba\u5de6\u53f3\u62a2\u7968\u6210\u529f\uff0c\u8fd9\u6837\u5bf9\u4e8e500\u540e\u9762\u7684\u8bf7\u6c42\u53ef\u4ee5\u76f4\u63a5\u8f6c\u5230\u6d3b\u52a8\u7ed3\u675f\u7684\u9759\u6001\u9875\u9762\u3002\u8fdb\u53bb\u7684500\u4e2a\u4eba\u4e2d\u6709400\u4e2a\u4eba\u662f\u4e0d\u53ef\u80fd\u83b7\u5f97\r\n\u5546\u54c1\u7684\u3002\u6240\u4ee5\u53ef\u4ee5\u6839\u636e\u8fdb\u5165\u961f\u5217\u7684\u5148\u540e\u987a\u5e8f\u53ea\u80fd\u524d100\u4e2a\u4eba\u8d2d\u4e70\u6210\u529f\u3002\u540e\u9762400\u4e2a\u4eba\u5c31\u76f4\u63a5\u8f6c\u5230\u6d3b\u52a8\u7ed3\u675f\u9875\u9762\u3002\u5f53\u7136\u8fdb\u53bb500\u4e2a\u4eba\u53ea\u662f\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u81f3\u4e8e\u591a\u5c11\u53ef\r\n\u4ee5\u81ea\u5df1\u8c03\u6574\u3002\u800c\u6d3b\u52a8\u7ed3\u675f\u9875\u9762\u4e00\u5b9a\u8981\u7528\u9759\u6001\u9875\u9762\uff0c\u4e0d\u8981\u7528\u6570\u636e\u5e93\u3002\u8fd9\u6837\u5c31\u51cf\u8f7b\u4e86\u6570\u636e\u5e93\u7684\u538b\u529b\u3002<br\/><br\/>\u65b9\u6848\u4e8c\uff1a\u5f53\u6709\u591a\u53f0\u670d\u52a1\u5668\u65f6\uff0c\u53ef\u4ee5\u91c7\u7528\u5206\u6d41\u7684\u5f62\u5f0f\u5b9e\u73b0<br\/><br\/>\u5047\u8bbe\u6709m\u5f20\u7968, \u6709n\u53f0\u4ea7\u54c1\u670d\u52a1\u5668\u63a5\u6536\u8bf7\u6c42,\u6709x\u4e2a\u8bf7\u6c42\u8def\u7531\u670d\u52a1\u5668\u968f\u673a\u8f6c\u53d1<br\/>\u76f4\u63a5\u7ed9\u6bcf\u53f0\u4ea7\u54c1\u670d\u52a1\u5668\u5206\u914d m\/n\u5f20\u7968<br\/>\u6bcf\u53f0\u4ea7\u54c1\u670d\u52a1\u5668\u5185\u5b58\u505a\u8ba1\u6570\u5668,\u6bd4\u5982\u5141\u8bb8m\/n*(1+0.1)\u4e2a\u4eba\u8fdb\u6765\u3002<br\/>\u5f53\u5185\u5b58\u8ba1\u6570\u5668\u5df2\u6ee1\uff1a<br\/>\u540e\u9762\u8fdb\u7684\u4eba, \u76f4\u63a5\u8df3\u5230\u5230\u8f6c\u5230\u6d3b\u52a8\u7ed3\u675f\u7684\u9759\u6001\u9875\u9762\uff0c<br\/>\u901a\u77e5\u8def\u7531\u670d\u52a1\u5668,\u4e0d\u5728\u8def\u7531\u5230\u8fd9\u53f0\u670d\u52a1\u5668(\u8fd9\u4e2a\u503c\u5f97\u5546\u8ba8)\u3002<br\/>\u6240\u6709\u4ea7\u54c1\u670d\u52a1\u5668\u8fdb\u6765\u7684m\/n*(1+0.1)\u4e2a\u4eba\u518d\u5168\u90e8\u8f6c\u53d1\u5230\u4e00\u53f0\u4ed8\u6b3e\u670d\u52a1\u5668\u4e0a,\u8fdb\u5165\u4ed8\u6b3e\u73af\u8282,\u770b\u8c01\u624b\u5feb\u4e86,\u8fd9\u65f6\u5019\u4eba\u5c11,\u52a0\u9501\u4ec0\u4e48\u7684\u5c31\u7b80\u5355\u7684\u3002<br\/><br\/>\u65b9\u6848\u4e09\u3001\u5982\u679c\u662f\u5355\u670d\u52a1\u5668\uff0c\u53ef\u4ee5\u4f7f\u7528Memcache\u9501\u6765\u5b9e\u73b0<br\/><br\/>product_key \u4e3a\u7968\u7684key<br\/>product_lock_key \u4e3a\u7968\u9501key<br\/>\u5f53product_key\u5b58\u5728\u4e8ememcached\u4e2d\u65f6\uff0c\u6240\u6709\u7528\u6237\u90fd\u53ef\u4ee5\u8fdb\u5165\u4e0b\u5355\u6d41\u7a0b\u3002<br\/>\u5f53\u8fdb\u5165\u652f\u4ed8\u6d41\u7a0b\u65f6\uff0c\u9996\u5148\u5f80memcached\u5b58\u653eadd(product_lock_key, \u201c1\u2033),<br\/>\u5982\u679c\u8fd4\u56de\u6210\u529f\uff0c\u8fdb\u5165\u652f\u4ed8\u6d41\u7a0b\u3002<br\/>\u5982\u679c\u4e0d\u6210\uff0c\u5219\u8bf4\u660e\u5df2\u7ecf\u6709\u4eba\u8fdb\u5165\u652f\u4ed8\u6d41\u7a0b\uff0c\u5219\u7ebf\u7a0b\u7b49\u5f85N\u79d2\uff0c\u9012\u5f52\u6267\u884cadd\u64cd\u4f5c\u3002<br\/><br\/>\u65b9\u6848\u56db\u3001\u501f\u52a9\u6587\u4ef6\u6392\u4ed6\u9501<br\/><br\/>\u5728\u5904\u7406\u4e0b\u5355\u8bf7\u6c42\u7684\u65f6\u5019\uff0c\u7528flock\u9501\u5b9a\u4e00\u4e2a\u6587\u4ef6\uff0c\u5982\u679c\u9501\u5b9a\u5931\u8d25\u8bf4\u660e\u6709\u5176\u4ed6\u8ba2\u5355\u6b63\u5728\u5904\u7406\uff0c\u6b64\u65f6\u8981\u4e48\u7b49\u5f85\u8981\u4e48\u76f4\u63a5\u63d0\u793a\u7528\u6237&quot;\u670d\u52a1\u5668\u7e41\u5fd9&quot;<br\/>\u672c\u6587\u8981\u8bf4\u7684\u662f\u7b2c4\u79cd\u65b9\u6848\uff0c\u5927\u81f4\u4ee3\u7801\u5982\u4e0b<br\/><br\/>\u963b\u585e(\u7b49\u5f85)\u6a21\u5f0f\uff1a<br\/><br\/>&lt;?php<br\/>$fp = fopen(&quot;lock.txt&quot;, &quot;w+&quot;);<br\/>if(flock($fp,LOCK_EX))<br\/>{<br\/>\/\/..\u5904\u7406\u8ba2\u5355<br\/>flock($fp,LOCK_UN);<br\/>}<br\/>fclose($fp);<br\/>?&gt;<br\/><br\/>\u975e\u963b\u585e\u6a21\u5f0f\uff1a<br\/><br\/>&lt;?php<br\/>$fp = fopen(&quot;lock.txt&quot;, &quot;w+&quot;);<br\/>if(flock($fp,LOCK_EX | LOCK_NB))<br\/>{<br\/>\/\/..\u5904\u7406\u8ba2\u5355<br\/>flock($fp,LOCK_UN);<br\/>}<br\/>else<br\/>{<br\/>echo &quot;\u7cfb\u7edf\u7e41\u5fd9\uff0c\u8bf7\u7a0d\u540e\u518d\u8bd5&quot;;<br\/>}<br\/><br\/>fclose($fp);<br\/>?&gt;<\/p>"}