{"rsdb":{"rid":"309081","subhead":"","postdate":"0","aid":"224243","fid":"116","uid":"1","topic":"1","content":"
\n\t\t\t\t\t\t\t\t\n \t\t\t\t\t\t\t\t \n\t\t\t\t\t\t
\n

Spark \u4f5c\u4e3a\u4e00\u4e2a\u57fa\u4e8e\u5185\u5b58\u7684\u5206\u5e03\u5f0f\u8ba1\u7b97\u5f15\u64ce\uff0c\u5176\u5185\u5b58\u7ba1\u7406\u6a21\u5757\u5728\u6574\u4e2a\u7cfb\u7edf\u4e2d\u626e\u6f14\u7740\u975e\u5e38\u91cd\u8981\u7684\u89d2\u8272\u3002\u7406\u89e3 Spark \u5185\u5b58\u7ba1\u7406\u7684\u57fa\u672c\u539f\u7406\uff0c\u6709\u52a9\u4e8e\u66f4\u597d\u5730\u5f00\u53d1 Spark \u5e94\u7528\u7a0b\u5e8f\u548c\u8fdb\u884c\u6027\u80fd\u8c03\u4f18\u3002\u672c\u6587\u65e8\u5728\u68b3\u7406\u51fa Spark \u5185\u5b58\u7ba1\u7406\u7684\u8109\u7edc\uff0c\u629b\u7816\u5f15\u7389\uff0c\u5f15\u51fa\u8bfb\u8005\u5bf9\u8fd9\u4e2a\u8bdd\u9898\u7684\u6df1\u5165\u63a2\u8ba8\u3002\u672c\u6587\u4e2d\u9610\u8ff0\u7684\u539f\u7406\u57fa\u4e8e Spark 2.1 \u7248\u672c\uff0c\u9605\u8bfb\u672c\u6587\u9700\u8981\u8bfb\u8005\u6709\u4e00\u5b9a\u7684 Spark \u548c Java \u57fa\u7840\uff0c\u4e86\u89e3 RDD\u3001Shuffle\u3001JVM \u7b49\u76f8\u5173\u6982\u5ff5\u3002<\/p>\n\n

\u5728\u6267\u884c Spark \u7684\u5e94\u7528\u7a0b\u5e8f\u65f6\uff0cSpark \u96c6\u7fa4\u4f1a\u542f\u52a8 Driver \u548c Executor \u4e24\u79cd JVM \u8fdb\u7a0b\uff0c\u524d\u8005\u4e3a\u4e3b\u63a7\u8fdb\u7a0b\uff0c\u8d1f\u8d23\u521b\u5efa Spark \u4e0a\u4e0b\u6587\uff0c\u63d0\u4ea4 Spark \u4f5c\u4e1a\uff08Job\uff09\uff0c\u5e76\u5c06\u4f5c\u4e1a\u8f6c\u5316\u4e3a\u8ba1\u7b97\u4efb\u52a1\uff08Task\uff09\uff0c\u5728\u5404\u4e2a Executor \u8fdb\u7a0b\u95f4\u534f\u8c03\u4efb\u52a1\u7684\u8c03\u5ea6\uff0c\u540e\u8005\u8d1f\u8d23\u5728\u5de5\u4f5c\u8282\u70b9\u4e0a\u6267\u884c\u5177\u4f53\u7684\u8ba1\u7b97\u4efb\u52a1\uff0c\u5e76\u5c06\u7ed3\u679c\u8fd4\u56de\u7ed9 Driver\uff0c\u540c\u65f6\u4e3a\u9700\u8981\u6301\u4e45\u5316\u7684 RDD \u63d0\u4f9b\u5b58\u50a8\u529f\u80fd[1]\u3002\u7531\u4e8e Driver \u7684\u5185\u5b58\u7ba1\u7406\u76f8\u5bf9\u6765\u8bf4\u8f83\u4e3a\u7b80\u5355\uff0c\u672c\u6587\u4e3b\u8981\u5bf9 Executor \u7684\u5185\u5b58\u7ba1\u7406\u8fdb\u884c\u5206\u6790\uff0c\u4e0b\u6587\u4e2d\u7684 Spark \u5185\u5b58\u5747\u7279\u6307 Executor \u7684\u5185\u5b58\u3002<\/p>\n\n

1. \u5806\u5185\u548c\u5806\u5916\u5185\u5b58\u89c4\u5212<\/p>\n\n

\u4f5c\u4e3a\u4e00\u4e2a JVM \u8fdb\u7a0b\uff0cExecutor \u7684\u5185\u5b58\u7ba1\u7406\u5efa\u7acb\u5728 JVM \u7684\u5185\u5b58\u7ba1\u7406\u4e4b\u4e0a\uff0cSpark \u5bf9 JVM \u7684\u5806\u5185\uff08On-heap\uff09\u7a7a\u95f4\u8fdb\u884c\u4e86\u66f4\u4e3a\u8be6\u7ec6\u7684\u5206\u914d\uff0c\u4ee5\u5145\u5206\u5229\u7528\u5185\u5b58\u3002\u540c\u65f6\uff0cSpark \u5f15\u5165\u4e86\u5806\u5916\uff08Off-heap\uff09\u5185\u5b58\uff0c\u4f7f\u4e4b\u53ef\u4ee5\u76f4\u63a5\u5728\u5de5\u4f5c\u8282\u70b9\u7684\u7cfb\u7edf\u5185\u5b58\u4e2d\u5f00\u8f9f\u7a7a\u95f4\uff0c\u8fdb\u4e00\u6b65\u4f18\u5316\u4e86\u5185\u5b58\u7684\u4f7f\u7528\u3002\u3010\u5927\u6570\u636e\u5f00\u53d1\u5b66\u4e60\u8d44\u6599\u9886\u53d6\u65b9\u5f0f\u3011\uff1a\u52a0\u5165\u5927\u6570\u636e\u6280\u672f\u5b66\u4e60\u4ea4\u6d41\u7fa4458345782\uff0c\u70b9\u51fb\u52a0\u5165\u7fa4\u804a\uff0c\u79c1\u4fe1\u7ba1\u7406\u5458\u5373\u53ef\u514d\u8d39\u9886\u53d6<\/a><\/strong><\/p>\n\n

\u56fe 1 . \u5806\u5185\u548c\u5806\u5916\u5185\u5b58\u793a\u610f\u56fe<\/p>\n\n

\"\"<\/p>\n\n

1.1 \u5806\u5185\u5185\u5b58<\/p>\n\n

\u5806\u5185\u5185\u5b58\u7684\u5927\u5c0f\uff0c\u7531 Spark \u5e94\u7528\u7a0b\u5e8f\u542f\u52a8\u65f6\u7684 \u2013executor-memory \u6216 spark.executor.memory \u53c2\u6570\u914d\u7f6e\u3002Executor \u5185\u8fd0\u884c\u7684\u5e76\u53d1\u4efb\u52a1\u5171\u4eab JVM \u5806\u5185\u5185\u5b58\uff0c\u8fd9\u4e9b\u4efb\u52a1\u5728\u7f13\u5b58 RDD \u6570\u636e\u548c\u5e7f\u64ad\uff08Broadcast\uff09\u6570\u636e\u65f6\u5360\u7528\u7684\u5185\u5b58\u88ab\u89c4\u5212\u4e3a\u5b58\u50a8\uff08Storage\uff09\u5185\u5b58\uff0c\u800c\u8fd9\u4e9b\u4efb\u52a1\u5728\u6267\u884c Shuffle \u65f6\u5360\u7528\u7684\u5185\u5b58\u88ab\u89c4\u5212\u4e3a\u6267\u884c\uff08Execution\uff09\u5185\u5b58\uff0c\u5269\u4f59\u7684\u90e8\u5206\u4e0d\u505a\u7279\u6b8a\u89c4\u5212\uff0c\u90a3\u4e9b Spark \u5185\u90e8\u7684\u5bf9\u8c61\u5b9e\u4f8b\uff0c\u6216\u8005\u7528\u6237\u5b9a\u4e49\u7684 Spark \u5e94\u7528\u7a0b\u5e8f\u4e2d\u7684\u5bf9\u8c61\u5b9e\u4f8b\uff0c\u5747\u5360\u7528\u5269\u4f59\u7684\u7a7a\u95f4\u3002\u4e0d\u540c\u7684\u7ba1\u7406\u6a21\u5f0f\u4e0b\uff0c\u8fd9\u4e09\u90e8\u5206\u5360\u7528\u7684\u7a7a\u95f4\u5927\u5c0f\u5404\u4e0d\u76f8\u540c\uff08\u4e0b\u9762\u7b2c 2 \u5c0f\u8282\u4f1a\u8fdb\u884c\u4ecb\u7ecd\uff09\u3002<\/p>\n\n

Spark \u5bf9\u5806\u5185\u5185\u5b58\u7684\u7ba1\u7406\u662f\u4e00\u79cd\u903b\u8f91\u4e0a\u7684\"\u89c4\u5212\u5f0f\"\u7684\u7ba1\u7406\uff0c\u56e0\u4e3a\u5bf9\u8c61\u5b9e\u4f8b\u5360\u7528\u5185\u5b58\u7684\u7533\u8bf7\u548c\u91ca\u653e\u90fd\u7531 JVM \u5b8c\u6210\uff0cSpark \u53ea\u80fd\u5728\u7533\u8bf7\u540e\u548c\u91ca\u653e\u524d\u8bb0\u5f55<\/strong>\u8fd9\u4e9b\u5185\u5b58\uff0c\u6211\u4eec\u6765\u770b\u5176\u5177\u4f53\u6d41\u7a0b\uff1a<\/p>\n\n

\u7533\u8bf7\u5185\u5b58<\/strong>\uff1a<\/p>\n\n

Spark \u5728\u4ee3\u7801\u4e2d new \u4e00\u4e2a\u5bf9\u8c61\u5b9e\u4f8b<\/p>\n\n

JVM \u4ece\u5806\u5185\u5185\u5b58\u5206\u914d\u7a7a\u95f4\uff0c\u521b\u5efa\u5bf9\u8c61\u5e76\u8fd4\u56de\u5bf9\u8c61\u5f15\u7528<\/p>\n\n

Spark \u4fdd\u5b58\u8be5\u5bf9\u8c61\u7684\u5f15\u7528\uff0c\u8bb0\u5f55\u8be5\u5bf9\u8c61\u5360\u7528\u7684\u5185\u5b58<\/p>\n\n

\u91ca\u653e\u5185\u5b58<\/strong>\uff1a<\/p>\n\n

Spark \u8bb0\u5f55\u8be5\u5bf9\u8c61\u91ca\u653e\u7684\u5185\u5b58\uff0c\u5220\u9664\u8be5\u5bf9\u8c61\u7684\u5f15\u7528<\/p>\n\n

\u7b49\u5f85 JVM \u7684\u5783\u573e\u56de\u6536\u673a\u5236\u91ca\u653e\u8be5\u5bf9\u8c61\u5360\u7528\u7684\u5806\u5185\u5185\u5b58<\/p>\n\n

\u6211\u4eec\u77e5\u9053\uff0cJVM \u7684\u5bf9\u8c61\u53ef\u4ee5\u4ee5\u5e8f\u5217\u5316\u7684\u65b9\u5f0f\u5b58\u50a8\uff0c\u5e8f\u5217\u5316\u7684\u8fc7\u7a0b\u662f\u5c06\u5bf9\u8c61\u8f6c\u6362\u4e3a\u4e8c\u8fdb\u5236\u5b57\u8282\u6d41\uff0c\u672c\u8d28\u4e0a\u53ef\u4ee5\u7406\u89e3\u4e3a\u5c06\u975e\u8fde\u7eed\u7a7a\u95f4\u7684\u94fe\u5f0f\u5b58\u50a8\u8f6c\u5316\u4e3a\u8fde\u7eed\u7a7a\u95f4\u6216\u5757\u5b58\u50a8\uff0c\u5728\u8bbf\u95ee\u65f6\u5219\u9700\u8981\u8fdb\u884c\u5e8f\u5217\u5316\u7684\u9006\u8fc7\u7a0b\u2014\u2014\u53cd\u5e8f\u5217\u5316\uff0c\u5c06\u5b57\u8282\u6d41\u8f6c\u5316\u4e3a\u5bf9\u8c61\uff0c\u5e8f\u5217\u5316\u7684\u65b9\u5f0f\u53ef\u4ee5\u8282\u7701\u5b58\u50a8\u7a7a\u95f4\uff0c\u4f46\u589e\u52a0\u4e86\u5b58\u50a8\u548c\u8bfb\u53d6\u65f6\u5019\u7684\u8ba1\u7b97\u5f00\u9500\u3002<\/p>\n\n

\u5bf9\u4e8e Spark \u4e2d\u5e8f\u5217\u5316\u7684\u5bf9\u8c61\uff0c\u7531\u4e8e\u662f\u5b57\u8282\u6d41\u7684\u5f62\u5f0f\uff0c\u5176\u5360\u7528\u7684\u5185\u5b58\u5927\u5c0f\u53ef\u76f4\u63a5\u8ba1\u7b97\uff0c\u800c\u5bf9\u4e8e\u975e\u5e8f\u5217\u5316\u7684\u5bf9\u8c61\uff0c\u5176\u5360\u7528\u7684\u5185\u5b58\u662f\u901a\u8fc7\u5468\u671f\u6027\u5730\u91c7\u6837\u8fd1\u4f3c\u4f30\u7b97\u800c\u5f97\uff0c\u5373\u5e76\u4e0d\u662f\u6bcf\u6b21\u65b0\u589e\u7684\u6570\u636e\u9879\u90fd\u4f1a\u8ba1\u7b97\u4e00\u6b21\u5360\u7528\u7684\u5185\u5b58\u5927\u5c0f\uff0c\u8fd9\u79cd\u65b9\u6cd5\u964d\u4f4e\u4e86\u65f6\u95f4\u5f00\u9500\u4f46\u662f\u6709\u53ef\u80fd\u8bef\u5dee\u8f83\u5927\uff0c\u5bfc\u81f4\u67d0\u4e00\u65f6\u523b\u7684\u5b9e\u9645\u5185\u5b58\u6709\u53ef\u80fd\u8fdc\u8fdc\u8d85\u51fa\u9884\u671f[2]\u3002\u6b64\u5916\uff0c\u5728\u88ab Spark \u6807\u8bb0\u4e3a\u91ca\u653e\u7684\u5bf9\u8c61\u5b9e\u4f8b\uff0c\u5f88\u6709\u53ef\u80fd\u5728\u5b9e\u9645\u4e0a\u5e76\u6ca1\u6709\u88ab JVM \u56de\u6536\uff0c\u5bfc\u81f4\u5b9e\u9645\u53ef\u7528\u7684\u5185\u5b58\u5c0f\u4e8e Spark \u8bb0\u5f55\u7684\u53ef\u7528\u5185\u5b58\u3002\u6240\u4ee5 Spark \u5e76\u4e0d\u80fd\u51c6\u786e\u8bb0\u5f55\u5b9e\u9645\u53ef\u7528\u7684\u5806\u5185\u5185\u5b58\uff0c\u4ece\u800c\u4e5f\u5c31\u65e0\u6cd5\u5b8c\u5168\u907f\u514d\u5185\u5b58\u6ea2\u51fa\uff08OOM, Out of Memory\uff09\u7684\u5f02\u5e38\u3002<\/p>\n\n

\u867d\u7136\u4e0d\u80fd\u7cbe\u51c6\u63a7\u5236\u5806\u5185\u5185\u5b58\u7684\u7533\u8bf7\u548c\u91ca\u653e\uff0c\u4f46 Spark \u901a\u8fc7\u5bf9\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u5404\u81ea\u72ec\u7acb\u7684\u89c4\u5212\u7ba1\u7406\uff0c\u53ef\u4ee5\u51b3\u5b9a\u662f\u5426\u8981\u5728\u5b58\u50a8\u5185\u5b58\u91cc\u7f13\u5b58\u65b0\u7684 RDD\uff0c\u4ee5\u53ca\u662f\u5426\u4e3a\u65b0\u7684\u4efb\u52a1\u5206\u914d\u6267\u884c\u5185\u5b58\uff0c\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u53ef\u4ee5\u63d0\u5347\u5185\u5b58\u7684\u5229\u7528\u7387\uff0c\u51cf\u5c11\u5f02\u5e38\u7684\u51fa\u73b0\u3002<\/p>\n\n

1.2 \u5806\u5916\u5185\u5b58<\/p>\n\n

\u4e3a\u4e86\u8fdb\u4e00\u6b65\u4f18\u5316\u5185\u5b58\u7684\u4f7f\u7528\u4ee5\u53ca\u63d0\u9ad8 Shuffle \u65f6\u6392\u5e8f\u7684\u6548\u7387\uff0cSpark \u5f15\u5165\u4e86\u5806\u5916\uff08Off-heap\uff09\u5185\u5b58\uff0c\u4f7f\u4e4b\u53ef\u4ee5\u76f4\u63a5\u5728\u5de5\u4f5c\u8282\u70b9\u7684\u7cfb\u7edf\u5185\u5b58\u4e2d\u5f00\u8f9f\u7a7a\u95f4\uff0c\u5b58\u50a8\u7ecf\u8fc7\u5e8f\u5217\u5316\u7684\u4e8c\u8fdb\u5236\u6570\u636e\u3002\u5229\u7528 JDK Unsafe API\uff08\u4ece Spark 2.0 \u5f00\u59cb\uff0c\u5728\u7ba1\u7406\u5806\u5916\u7684\u5b58\u50a8\u5185\u5b58\u65f6\u4e0d\u518d\u57fa\u4e8e Tachyon\uff0c\u800c\u662f\u4e0e\u5806\u5916\u7684\u6267\u884c\u5185\u5b58\u4e00\u6837\uff0c\u57fa\u4e8e JDK Unsafe API \u5b9e\u73b0[3]\uff09\uff0cSpark \u53ef\u4ee5\u76f4\u63a5\u64cd\u4f5c\u7cfb\u7edf\u5806\u5916\u5185\u5b58\uff0c\u51cf\u5c11\u4e86\u4e0d\u5fc5\u8981\u7684\u5185\u5b58\u5f00\u9500\uff0c\u4ee5\u53ca\u9891\u7e41\u7684 GC \u626b\u63cf\u548c\u56de\u6536\uff0c\u63d0\u5347\u4e86\u5904\u7406\u6027\u80fd\u3002\u5806\u5916\u5185\u5b58\u53ef\u4ee5\u88ab\u7cbe\u786e\u5730\u7533\u8bf7\u548c\u91ca\u653e\uff0c\u800c\u4e14\u5e8f\u5217\u5316\u7684\u6570\u636e\u5360\u7528\u7684\u7a7a\u95f4\u53ef\u4ee5\u88ab\u7cbe\u786e\u8ba1\u7b97\uff0c\u6240\u4ee5\u76f8\u6bd4\u5806\u5185\u5185\u5b58\u6765\u8bf4\u964d\u4f4e\u4e86\u7ba1\u7406\u7684\u96be\u5ea6\uff0c\u4e5f\u964d\u4f4e\u4e86\u8bef\u5dee\u3002<\/p>\n\n

\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u5806\u5916\u5185\u5b58\u5e76\u4e0d\u542f\u7528\uff0c\u53ef\u901a\u8fc7\u914d\u7f6e spark.memory.offHeap.enabled \u53c2\u6570\u542f\u7528\uff0c\u5e76\u7531 spark.memory.offHeap.size \u53c2\u6570\u8bbe\u5b9a\u5806\u5916\u7a7a\u95f4\u7684\u5927\u5c0f\u3002\u9664\u4e86\u6ca1\u6709 other \u7a7a\u95f4\uff0c\u5806\u5916\u5185\u5b58\u4e0e\u5806\u5185\u5185\u5b58\u7684\u5212\u5206\u65b9\u5f0f\u76f8\u540c\uff0c\u6240\u6709\u8fd0\u884c\u4e2d\u7684\u5e76\u53d1\u4efb\u52a1\u5171\u4eab\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u3002<\/p>\n\n

1.3 \u5185\u5b58\u7ba1\u7406\u63a5\u53e3<\/p>\n\n

Spark \u4e3a\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u7684\u7ba1\u7406\u63d0\u4f9b\u4e86\u7edf\u4e00\u7684\u63a5\u53e3\u2014\u2014MemoryManager\uff0c\u540c\u4e00\u4e2a Executor \u5185\u7684\u4efb\u52a1\u90fd\u8c03\u7528\u8fd9\u4e2a\u63a5\u53e3\u7684\u65b9\u6cd5\u6765\u7533\u8bf7\u6216\u91ca\u653e\u5185\u5b58:<\/p>\n\n

\u6e05\u5355 1 . \u5185\u5b58\u7ba1\u7406\u63a5\u53e3\u7684\u4e3b\u8981\u65b9\u6cd5<\/p>\n\n

\/\/\u7533\u8bf7\u5b58\u50a8\u5185\u5b58<\/p>\n\n

def acquireStorageMemory(blockId: BlockId, numBytes: Long, memoryMode: MemoryMode): Boolean<\/p>\n\n

\/\/\u7533\u8bf7\u5c55\u5f00\u5185\u5b58<\/p>\n\n

def acquireUnrollMemory(blockId: BlockId, numBytes: Long, memoryMode: MemoryMode): Boolean<\/p>\n\n

\/\/\u7533\u8bf7\u6267\u884c\u5185\u5b58<\/p>\n\n

def acquireExecutionMemory(numBytes: Long, taskAttemptId: Long, memoryMode: MemoryMode): Long<\/p>\n\n

\/\/\u91ca\u653e\u5b58\u50a8\u5185\u5b58<\/p>\n\n

def releaseStorageMemory(numBytes: Long, memoryMode: MemoryMode): Unit<\/p>\n\n

\/\/\u91ca\u653e\u6267\u884c\u5185\u5b58<\/p>\n\n

def releaseExecutionMemory(numBytes: Long, taskAttemptId: Long, memoryMode: MemoryMode): Unit<\/p>\n\n

\/\/\u91ca\u653e\u5c55\u5f00\u5185\u5b58<\/p>\n\n

def releaseUnrollMemory(numBytes: Long, memoryMode: MemoryMode): Unit<\/p>\n\n

\u6211\u4eec\u770b\u5230\uff0c\u5728\u8c03\u7528\u8fd9\u4e9b\u65b9\u6cd5\u65f6\u90fd\u9700\u8981\u6307\u5b9a\u5176\u5185\u5b58\u6a21\u5f0f\uff08MemoryMode\uff09\uff0c\u8fd9\u4e2a\u53c2\u6570\u51b3\u5b9a\u4e86\u662f\u5728\u5806\u5185\u8fd8\u662f\u5806\u5916\u5b8c\u6210\u8fd9\u6b21\u64cd\u4f5c\u3002<\/p>\n\n

MemoryManager \u7684\u5177\u4f53\u5b9e\u73b0\u4e0a\uff0cSpark 1.6 \u4e4b\u540e\u9ed8\u8ba4\u4e3a\u7edf\u4e00\u7ba1\u7406\uff08Unified Memory Manager<\/a>\uff09\u65b9\u5f0f\uff0c1.6 \u4e4b\u524d\u91c7\u7528\u7684\u9759\u6001\u7ba1\u7406\uff08Static Memory Manager<\/a>\uff09\u65b9\u5f0f\u4ecd\u88ab\u4fdd\u7559\uff0c\u53ef\u901a\u8fc7\u914d\u7f6e spark.memory.useLegacyMode \u53c2\u6570\u542f\u7528\u3002\u4e24\u79cd\u65b9\u5f0f\u7684\u533a\u522b\u5728\u4e8e\u5bf9\u7a7a\u95f4\u5206\u914d\u7684\u65b9\u5f0f\uff0c\u4e0b\u9762\u7684\u7b2c 2 \u5c0f\u8282\u4f1a\u5206\u522b\u5bf9\u8fd9\u4e24\u79cd\u65b9\u5f0f\u8fdb\u884c\u4ecb\u7ecd\u3002<\/p>\n\n

2 . \u5185\u5b58\u7a7a\u95f4\u5206\u914d<\/p>\n\n

2.1 \u9759\u6001\u5185\u5b58\u7ba1\u7406<\/p>\n\n

\u5728 Spark \u6700\u521d\u91c7\u7528\u7684\u9759\u6001\u5185\u5b58\u7ba1\u7406\u673a\u5236\u4e0b\uff0c\u5b58\u50a8\u5185\u5b58\u3001\u6267\u884c\u5185\u5b58\u548c\u5176\u4ed6\u5185\u5b58\u7684\u5927\u5c0f\u5728 Spark \u5e94\u7528\u7a0b\u5e8f\u8fd0\u884c\u671f\u95f4\u5747\u4e3a\u56fa\u5b9a\u7684\uff0c\u4f46\u7528\u6237\u53ef\u4ee5\u5e94\u7528\u7a0b\u5e8f\u542f\u52a8\u524d\u8fdb\u884c\u914d\u7f6e\uff0c\u5806\u5185\u5185\u5b58\u7684\u5206\u914d\u5982\u56fe 2 \u6240\u793a\uff1a<\/p>\n\n

\u56fe 2 . \u9759\u6001\u5185\u5b58\u7ba1\u7406\u56fe\u793a\u2014\u2014\u5806\u5185<\/p>\n\n

\"\"<\/p>\n\n

\u53ef\u4ee5\u770b\u5230\uff0c\u53ef\u7528\u7684\u5806\u5185\u5185\u5b58\u7684\u5927\u5c0f\u9700\u8981\u6309\u7167\u4e0b\u9762\u7684\u65b9\u5f0f\u8ba1\u7b97\uff1a<\/p>\n\n

\u6e05\u5355 2 . \u53ef\u7528\u5806\u5185\u5185\u5b58\u7a7a\u95f4<\/p>\n\n

\u53ef\u7528\u7684\u5b58\u50a8\u5185\u5b58 = systemMaxMemory * spark.storage.memoryFraction * spark.storage.safetyFraction<\/p>\n\n

\u53ef\u7528\u7684\u6267\u884c\u5185\u5b58 = systemMaxMemory * spark.shuffle.memoryFraction * spark.shuffle.safetyFraction<\/p>\n\n

\u5176\u4e2d systemMaxMemory \u53d6\u51b3\u4e8e\u5f53\u524d JVM \u5806\u5185\u5185\u5b58\u7684\u5927\u5c0f\uff0c\u6700\u540e\u53ef\u7528\u7684\u6267\u884c\u5185\u5b58\u6216\u8005\u5b58\u50a8\u5185\u5b58\u8981\u5728\u6b64\u57fa\u7840\u4e0a\u4e0e\u5404\u81ea\u7684 memoryFraction \u53c2\u6570\u548c safetyFraction \u53c2\u6570\u76f8\u4e58\u5f97\u51fa\u3002\u4e0a\u8ff0\u8ba1\u7b97\u516c\u5f0f\u4e2d\u7684\u4e24\u4e2a safetyFraction \u53c2\u6570\uff0c\u5176\u610f\u4e49\u5728\u4e8e\u5728\u903b\u8f91\u4e0a\u9884\u7559\u51fa 1-safetyFraction \u8fd9\u4e48\u4e00\u5757\u4fdd\u9669\u533a\u57df\uff0c\u964d\u4f4e\u56e0\u5b9e\u9645\u5185\u5b58\u8d85\u51fa\u5f53\u524d\u9884\u8bbe\u8303\u56f4\u800c\u5bfc\u81f4 OOM \u7684\u98ce\u9669\uff08\u4e0a\u6587\u63d0\u5230\uff0c\u5bf9\u4e8e\u975e\u5e8f\u5217\u5316\u5bf9\u8c61\u7684\u5185\u5b58\u91c7\u6837\u4f30\u7b97\u4f1a\u4ea7\u751f\u8bef\u5dee\uff09\u3002\u503c\u5f97\u6ce8\u610f\u7684\u662f\uff0c\u8fd9\u4e2a\u9884\u7559\u7684\u4fdd\u9669\u533a\u57df\u4ec5\u4ec5\u662f\u4e00\u79cd\u903b\u8f91\u4e0a\u7684\u89c4\u5212\uff0c\u5728\u5177\u4f53\u4f7f\u7528\u65f6 Spark \u5e76\u6ca1\u6709\u533a\u522b\u5bf9\u5f85\uff0c\u548c\"\u5176\u5b83\u5185\u5b58\"\u4e00\u6837\u4ea4\u7ed9\u4e86 JVM \u53bb\u7ba1\u7406\u3002<\/p>\n\n

\u5806\u5916\u7684\u7a7a\u95f4\u5206\u914d\u8f83\u4e3a\u7b80\u5355\uff0c\u53ea\u6709\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\uff0c\u5982\u56fe 3 \u6240\u793a\u3002\u53ef\u7528\u7684\u6267\u884c\u5185\u5b58\u548c\u5b58\u50a8\u5185\u5b58\u5360\u7528\u7684\u7a7a\u95f4\u5927\u5c0f\u76f4\u63a5\u7531\u53c2\u6570 spark.memory.storageFraction \u51b3\u5b9a\uff0c\u7531\u4e8e\u5806\u5916\u5185\u5b58\u5360\u7528\u7684\u7a7a\u95f4\u53ef\u4ee5\u88ab\u7cbe\u786e\u8ba1\u7b97\uff0c\u6240\u4ee5\u65e0\u9700\u518d\u8bbe\u5b9a\u4fdd\u9669\u533a\u57df\u3002<\/p>\n\n

\u56fe 3 . \u9759\u6001\u5185\u5b58\u7ba1\u7406\u56fe\u793a\u2014\u2014\u5806\u5916<\/p>\n\n

\"\"<\/p>\n\n

\u9759\u6001\u5185\u5b58\u7ba1\u7406\u673a\u5236\u5b9e\u73b0\u8d77\u6765\u8f83\u4e3a\u7b80\u5355\uff0c\u4f46\u5982\u679c\u7528\u6237\u4e0d\u719f\u6089 Spark \u7684\u5b58\u50a8\u673a\u5236\uff0c\u6216\u6ca1\u6709\u6839\u636e\u5177\u4f53\u7684\u6570\u636e\u89c4\u6a21\u548c\u8ba1\u7b97\u4efb\u52a1\u6216\u505a\u76f8\u5e94\u7684\u914d\u7f6e\uff0c\u5f88\u5bb9\u6613\u9020\u6210\"\u4e00\u534a\u6d77\u6c34\uff0c\u4e00\u534a\u706b\u7130\"\u7684\u5c40\u9762\uff0c\u5373\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u4e2d\u7684\u4e00\u65b9\u5269\u4f59\u5927\u91cf\u7684\u7a7a\u95f4\uff0c\u800c\u53e6\u4e00\u65b9\u5374\u65e9\u65e9\u88ab\u5360\u6ee1\uff0c\u4e0d\u5f97\u4e0d\u6dd8\u6c70\u6216\u79fb\u51fa\u65e7\u7684\u5185\u5bb9\u4ee5\u5b58\u50a8\u65b0\u7684\u5185\u5bb9\u3002\u7531\u4e8e\u65b0\u7684\u5185\u5b58\u7ba1\u7406\u673a\u5236\u7684\u51fa\u73b0\uff0c\u8fd9\u79cd\u65b9\u5f0f\u76ee\u524d\u5df2\u7ecf\u5f88\u5c11\u6709\u5f00\u53d1\u8005\u4f7f\u7528\uff0c\u51fa\u4e8e\u517c\u5bb9\u65e7\u7248\u672c\u7684\u5e94\u7528\u7a0b\u5e8f\u7684\u76ee\u7684\uff0cSpark \u4ecd\u7136\u4fdd\u7559\u4e86\u5b83\u7684\u5b9e\u73b0\u3002<\/p>\n\n

2.2 \u7edf\u4e00\u5185\u5b58\u7ba1\u7406<\/p>\n\n

Spark 1.6 \u4e4b\u540e\u5f15\u5165\u7684\u7edf\u4e00\u5185\u5b58\u7ba1\u7406\u673a\u5236\uff0c\u4e0e\u9759\u6001\u5185\u5b58\u7ba1\u7406\u7684\u533a\u522b\u5728\u4e8e\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u5171\u4eab\u540c\u4e00\u5757\u7a7a\u95f4\uff0c\u53ef\u4ee5\u52a8\u6001\u5360\u7528\u5bf9\u65b9\u7684\u7a7a\u95f2\u533a\u57df\uff0c\u5982\u56fe 4 \u548c\u56fe 5 \u6240\u793a<\/p>\n\n

\u56fe 4 . \u7edf\u4e00\u5185\u5b58\u7ba1\u7406\u56fe\u793a\u2014\u2014\u5806\u5185<\/p>\n\n

\"\"<\/p>\n\n

\u56fe 5 . \u7edf\u4e00\u5185\u5b58\u7ba1\u7406\u56fe\u793a\u2014\u2014\u5806\u5916<\/p>\n\n

\"\"<\/p>\n\n

\u5176\u4e2d\u6700\u91cd\u8981\u7684\u4f18\u5316\u5728\u4e8e\u52a8\u6001\u5360\u7528\u673a\u5236\uff0c\u5176\u89c4\u5219\u5982\u4e0b\uff1a<\/p>\n\n

\u8bbe\u5b9a\u57fa\u672c\u7684\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u533a\u57df\uff08spark.storage.storageFraction \u53c2\u6570\uff09\uff0c\u8be5\u8bbe\u5b9a\u786e\u5b9a\u4e86\u53cc\u65b9\u5404\u81ea\u62e5\u6709\u7684\u7a7a\u95f4\u7684\u8303\u56f4<\/p>\n\n

\u53cc\u65b9\u7684\u7a7a\u95f4\u90fd\u4e0d\u8db3\u65f6\uff0c\u5219\u5b58\u50a8\u5230\u786c\u76d8\uff1b\u82e5\u5df1\u65b9\u7a7a\u95f4\u4e0d\u8db3\u800c\u5bf9\u65b9\u7a7a\u4f59\u65f6\uff0c\u53ef\u501f\u7528\u5bf9\u65b9\u7684\u7a7a\u95f4;\uff08\u5b58\u50a8\u7a7a\u95f4\u4e0d\u8db3\u662f\u6307\u4e0d\u8db3\u4ee5\u653e\u4e0b\u4e00\u4e2a\u5b8c\u6574\u7684 Block\uff09<\/p>\n\n

\u6267\u884c\u5185\u5b58\u7684\u7a7a\u95f4\u88ab\u5bf9\u65b9\u5360\u7528\u540e\uff0c\u53ef\u8ba9\u5bf9\u65b9\u5c06\u5360\u7528\u7684\u90e8\u5206\u8f6c\u5b58\u5230\u786c\u76d8\uff0c\u7136\u540e\"\u5f52\u8fd8\"\u501f\u7528\u7684\u7a7a\u95f4<\/p>\n\n

\u5b58\u50a8\u5185\u5b58\u7684\u7a7a\u95f4\u88ab\u5bf9\u65b9\u5360\u7528\u540e\uff0c\u65e0\u6cd5\u8ba9\u5bf9\u65b9\"\u5f52\u8fd8\"\uff0c\u56e0\u4e3a\u9700\u8981\u8003\u8651 Shuffle \u8fc7\u7a0b\u4e2d\u7684\u5f88\u591a\u56e0\u7d20\uff0c\u5b9e\u73b0\u8d77\u6765\u8f83\u4e3a\u590d\u6742[4]<\/p>\n\n

\u56fe 6 . \u52a8\u6001\u5360\u7528\u673a\u5236\u56fe\u793a<\/p>\n\n

\"\"<\/p>\n\n

\u51ed\u501f\u7edf\u4e00\u5185\u5b58\u7ba1\u7406\u673a\u5236\uff0cSpark \u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u63d0\u9ad8\u4e86\u5806\u5185\u548c\u5806\u5916\u5185\u5b58\u8d44\u6e90\u7684\u5229\u7528\u7387\uff0c\u964d\u4f4e\u4e86\u5f00\u53d1\u8005\u7ef4\u62a4 Spark \u5185\u5b58\u7684\u96be\u5ea6\uff0c\u4f46\u5e76\u4e0d\u610f\u5473\u7740\u5f00\u53d1\u8005\u53ef\u4ee5\u9ad8\u6795\u65e0\u5fe7\u3002\u8b6c\u5982\uff0c\u6240\u4ee5\u5982\u679c\u5b58\u50a8\u5185\u5b58\u7684\u7a7a\u95f4\u592a\u5927\u6216\u8005\u8bf4\u7f13\u5b58\u7684\u6570\u636e\u8fc7\u591a\uff0c\u53cd\u800c\u4f1a\u5bfc\u81f4\u9891\u7e41\u7684\u5168\u91cf\u5783\u573e\u56de\u6536\uff0c\u964d\u4f4e\u4efb\u52a1\u6267\u884c\u65f6\u7684\u6027\u80fd\uff0c\u56e0\u4e3a\u7f13\u5b58\u7684 RDD \u6570\u636e\u901a\u5e38\u90fd\u662f\u957f\u671f\u9a7b\u7559\u5185\u5b58\u7684[5]\u3002\u6240\u4ee5\u8981\u60f3\u5145\u5206\u53d1\u6325 Spark \u7684\u6027\u80fd\uff0c\u9700\u8981\u5f00\u53d1\u8005\u8fdb\u4e00\u6b65\u4e86\u89e3\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u5404\u81ea\u7684\u7ba1\u7406\u65b9\u5f0f\u548c\u5b9e\u73b0\u539f\u7406\u3002<\/p>\n\n

3. \u5b58\u50a8\u5185\u5b58\u7ba1\u7406<\/p>\n\n

3.1 RDD \u7684\u6301\u4e45\u5316\u673a\u5236<\/p>\n\n

\u5f39\u6027\u5206\u5e03\u5f0f\u6570\u636e\u96c6\uff08RDD\uff09\u4f5c\u4e3a Spark \u6700\u6839\u672c\u7684\u6570\u636e\u62bd\u8c61\uff0c\u662f\u53ea\u8bfb\u7684\u5206\u533a\u8bb0\u5f55\uff08Partition\uff09\u7684\u96c6\u5408\uff0c\u53ea\u80fd\u57fa\u4e8e\u5728\u7a33\u5b9a\u7269\u7406\u5b58\u50a8\u4e2d\u7684\u6570\u636e\u96c6\u4e0a\u521b\u5efa\uff0c\u6216\u8005\u5728\u5176\u4ed6\u5df2\u6709\u7684 RDD \u4e0a\u6267\u884c\u8f6c\u6362\uff08Transformation\uff09\u64cd\u4f5c\u4ea7\u751f\u4e00\u4e2a\u65b0\u7684 RDD\u3002\u8f6c\u6362\u540e\u7684 RDD \u4e0e\u539f\u59cb\u7684 RDD \u4e4b\u95f4\u4ea7\u751f\u7684\u4f9d\u8d56\u5173\u7cfb\uff0c\u6784\u6210\u4e86\u8840\u7edf\uff08Lineage\uff09\u3002\u51ed\u501f\u8840\u7edf\uff0cSpark \u4fdd\u8bc1\u4e86\u6bcf\u4e00\u4e2a RDD \u90fd\u53ef\u4ee5\u88ab\u91cd\u65b0\u6062\u590d\u3002\u4f46 RDD \u7684\u6240\u6709\u8f6c\u6362\u90fd\u662f\u60f0\u6027\u7684\uff0c\u5373\u53ea\u6709\u5f53\u4e00\u4e2a\u8fd4\u56de\u7ed3\u679c\u7ed9 Driver \u7684\u884c\u52a8\uff08Action\uff09\u53d1\u751f\u65f6\uff0cSpark \u624d\u4f1a\u521b\u5efa\u4efb\u52a1\u8bfb\u53d6 RDD\uff0c\u7136\u540e\u771f\u6b63\u89e6\u53d1\u8f6c\u6362\u7684\u6267\u884c\u3002<\/p>\n\n

Task \u5728\u542f\u52a8\u4e4b\u521d\u8bfb\u53d6\u4e00\u4e2a\u5206\u533a\u65f6\uff0c\u4f1a\u5148\u5224\u65ad\u8fd9\u4e2a\u5206\u533a\u662f\u5426\u5df2\u7ecf\u88ab\u6301\u4e45\u5316\uff0c\u5982\u679c\u6ca1\u6709\u5219\u9700\u8981\u68c0\u67e5 Checkpoint \u6216\u6309\u7167\u8840\u7edf\u91cd\u65b0\u8ba1\u7b97\u3002\u6240\u4ee5\u5982\u679c\u4e00\u4e2a RDD \u4e0a\u8981\u6267\u884c\u591a\u6b21\u884c\u52a8\uff0c\u53ef\u4ee5\u5728\u7b2c\u4e00\u6b21\u884c\u52a8\u4e2d\u4f7f\u7528 persist \u6216 cache \u65b9\u6cd5\uff0c\u5728\u5185\u5b58\u6216\u78c1\u76d8\u4e2d\u6301\u4e45\u5316\u6216\u7f13\u5b58\u8fd9\u4e2a RDD\uff0c\u4ece\u800c\u5728\u540e\u9762\u7684\u884c\u52a8\u65f6\u63d0\u5347\u8ba1\u7b97\u901f\u5ea6\u3002\u4e8b\u5b9e\u4e0a\uff0ccache \u65b9\u6cd5\u662f\u4f7f\u7528\u9ed8\u8ba4\u7684 MEMORY_ONLY \u7684\u5b58\u50a8\u7ea7\u522b\u5c06 RDD \u6301\u4e45\u5316\u5230\u5185\u5b58\uff0c\u6545\u7f13\u5b58\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u6301\u4e45\u5316\u3002\u5806\u5185\u548c\u5806\u5916\u5b58\u50a8\u5185\u5b58\u7684\u8bbe\u8ba1\uff0c\u4fbf\u53ef\u4ee5\u5bf9\u7f13\u5b58<\/strong>RDD<\/strong>\u65f6\u4f7f\u7528\u7684\u5185\u5b58\u505a\u7edf\u4e00\u7684\u89c4\u5212\u548c\u7ba1<\/strong>\u7406<\/strong>\uff08\u5b58\u50a8\u5185\u5b58\u7684\u5176\u4ed6\u5e94\u7528\u573a\u666f\uff0c\u5982\u7f13\u5b58 broadcast \u6570\u636e\uff0c\u6682\u65f6\u4e0d\u5728\u672c\u6587\u7684\u8ba8\u8bba\u8303\u56f4\u4e4b\u5185\uff09\u3002<\/p>\n\n

RDD \u7684\u6301\u4e45\u5316\u7531 Spark \u7684 Storage \u6a21\u5757[7]\u8d1f\u8d23\uff0c\u5b9e\u73b0\u4e86 RDD \u4e0e\u7269\u7406\u5b58\u50a8\u7684\u89e3\u8026\u5408\u3002Storage \u6a21\u5757\u8d1f\u8d23\u7ba1\u7406 Spark \u5728\u8ba1\u7b97\u8fc7\u7a0b\u4e2d\u4ea7\u751f\u7684\u6570\u636e\uff0c\u5c06\u90a3\u4e9b\u5728\u5185\u5b58\u6216\u78c1\u76d8\u3001\u5728\u672c\u5730\u6216\u8fdc\u7a0b\u5b58\u53d6\u6570\u636e\u7684\u529f\u80fd\u5c01\u88c5\u4e86\u8d77\u6765\u3002\u5728\u5177\u4f53\u5b9e\u73b0\u65f6 Driver \u7aef\u548c Executor \u7aef\u7684 Storage \u6a21\u5757\u6784\u6210\u4e86\u4e3b\u4ece\u5f0f\u7684\u67b6\u6784\uff0c\u5373 Driver \u7aef\u7684 BlockManager \u4e3a Master\uff0cExecutor \u7aef\u7684 BlockManager \u4e3a Slave\u3002Storage \u6a21\u5757\u5728\u903b\u8f91\u4e0a\u4ee5 Block \u4e3a\u57fa\u672c\u5b58\u50a8\u5355\u4f4d\uff0cRDD \u7684\u6bcf\u4e2a Partition \u7ecf\u8fc7\u5904\u7406\u540e\u552f\u4e00\u5bf9\u5e94\u4e00\u4e2a Block\uff08BlockId \u7684\u683c\u5f0f\u4e3a rdd_RDD-ID_PARTITION-ID \uff09\u3002Master \u8d1f\u8d23\u6574\u4e2a Spark \u5e94\u7528\u7a0b\u5e8f\u7684 Block \u7684\u5143\u6570\u636e\u4fe1\u606f\u7684\u7ba1\u7406\u548c\u7ef4\u62a4\uff0c\u800c Slave \u9700\u8981\u5c06 Block \u7684\u66f4\u65b0\u7b49\u72b6\u6001\u4e0a\u62a5\u5230 Master\uff0c\u540c\u65f6\u63a5\u6536 Master \u7684\u547d\u4ee4\uff0c\u4f8b\u5982\u65b0\u589e\u6216\u5220\u9664\u4e00\u4e2a RDD\u3002<\/p>\n\n

\u56fe 7 . Storage \u6a21\u5757\u793a\u610f\u56fe<\/p>\n\n

\"\"<\/p>\n\n

\u5728\u5bf9 RDD \u6301\u4e45\u5316\u65f6\uff0cSpark \u89c4\u5b9a\u4e86 MEMORY_ONLY\u3001MEMORY_AND_DISK \u7b49 7 \u79cd\u4e0d\u540c\u7684 \u5b58\u50a8\u7ea7\u522b<\/a>\uff0c\u800c\u5b58\u50a8\u7ea7\u522b\u662f\u4ee5\u4e0b 5 \u4e2a\u53d8\u91cf\u7684\u7ec4\u5408\uff1a<\/p>\n\n

\u6e05\u5355 3 . \u5b58\u50a8\u7ea7\u522b<\/p>\n\n

class StorageLevel private(<\/p>\n\n

private var _useDisk: Boolean, \/\/\u78c1\u76d8<\/p>\n\n

private var _useMemory: Boolean, \/\/\u8fd9\u91cc\u5176\u5b9e\u662f\u6307\u5806\u5185\u5185\u5b58<\/p>\n\n

private var _useOffHeap: Boolean, \/\/\u5806\u5916\u5185\u5b58<\/p>\n\n

private var _deserialized: Boolean, \/\/\u662f\u5426\u4e3a\u975e\u5e8f\u5217\u5316<\/p>\n\n

private var _replication: Int = 1 \/\/\u526f\u672c\u4e2a\u6570<\/p>\n\n

)<\/p>\n\n

\u901a\u8fc7\u5bf9\u6570\u636e\u7ed3\u6784\u7684\u5206\u6790\uff0c\u53ef\u4ee5\u770b\u51fa\u5b58\u50a8\u7ea7\u522b\u4ece\u4e09\u4e2a\u7ef4\u5ea6\u5b9a\u4e49\u4e86 RDD \u7684 Partition\uff08\u540c\u65f6\u4e5f\u5c31\u662f Block\uff09\u7684\u5b58\u50a8\u65b9\u5f0f\uff1a<\/p>\n\n

\u5b58\u50a8\u4f4d\u7f6e\uff1a\u78c1\u76d8\uff0f\u5806\u5185\u5185\u5b58\uff0f\u5806\u5916\u5185\u5b58\u3002\u5982 MEMORY_AND_DISK \u662f\u540c\u65f6\u5728\u78c1\u76d8\u548c\u5806\u5185\u5185\u5b58\u4e0a\u5b58\u50a8\uff0c\u5b9e\u73b0\u4e86\u5197\u4f59\u5907\u4efd\u3002OFF_HEAP \u5219\u662f\u53ea\u5728\u5806\u5916\u5185\u5b58\u5b58\u50a8\uff0c\u76ee\u524d\u9009\u62e9\u5806\u5916\u5185\u5b58\u65f6\u4e0d\u80fd\u540c\u65f6\u5b58\u50a8\u5230\u5176\u4ed6\u4f4d\u7f6e\u3002<\/p>\n\n

\u5b58\u50a8\u5f62\u5f0f\uff1aBlock \u7f13\u5b58\u5230\u5b58\u50a8\u5185\u5b58\u540e\uff0c\u662f\u5426\u4e3a\u975e\u5e8f\u5217\u5316\u7684\u5f62\u5f0f\u3002\u5982 MEMORY_ONLY \u662f\u975e\u5e8f\u5217\u5316\u65b9\u5f0f\u5b58\u50a8\uff0cOFF_HEAP \u662f\u5e8f\u5217\u5316\u65b9\u5f0f\u5b58\u50a8\u3002<\/p>\n\n

\u526f\u672c\u6570\u91cf\uff1a\u5927\u4e8e 1 \u65f6\u9700\u8981\u8fdc\u7a0b\u5197\u4f59\u5907\u4efd\u5230\u5176\u4ed6\u8282\u70b9\u3002\u5982 DISK_ONLY_2 \u9700\u8981\u8fdc\u7a0b\u5907\u4efd 1 \u4e2a\u526f\u672c\u3002<\/p>\n\n

3.2 RDD \u7f13\u5b58\u7684\u8fc7\u7a0b<\/p>\n\n

RDD \u5728\u7f13\u5b58\u5230\u5b58\u50a8\u5185\u5b58\u4e4b\u524d\uff0cPartition \u4e2d\u7684\u6570\u636e\u4e00\u822c\u4ee5\u8fed\u4ee3\u5668\u7684\u6570\u636e\u7ed3\u6784\u6765\u8bbf\u95ee\uff0c\u8fd9\u662f Scala \u8bed\u8a00\u4e2d\u4e00\u79cd\u904d\u5386\u6570\u636e\u96c6\u5408\u7684\u65b9\u6cd5\u3002\u901a\u8fc7 Iterator \u53ef\u4ee5\u83b7\u53d6\u5206\u533a\u4e2d\u6bcf\u4e00\u6761\u5e8f\u5217\u5316\u6216\u8005\u975e\u5e8f\u5217\u5316\u7684\u6570\u636e\u9879(Record)\uff0c\u8fd9\u4e9b Record \u7684\u5bf9\u8c61\u5b9e\u4f8b\u5728\u903b\u8f91\u4e0a\u5360\u7528\u4e86 JVM \u5806\u5185\u5185\u5b58\u7684 other \u90e8\u5206\u7684\u7a7a\u95f4\uff0c\u540c\u4e00 Partition \u7684\u4e0d\u540c Record \u7684\u7a7a\u95f4\u5e76\u4e0d\u8fde\u7eed\u3002<\/p>\n\n

RDD \u5728\u7f13\u5b58\u5230\u5b58\u50a8\u5185\u5b58\u4e4b\u540e\uff0cPartition \u88ab\u8f6c\u6362\u6210 Block\uff0cRecord \u5728\u5806\u5185\u6216\u5806\u5916\u5b58\u50a8\u5185\u5b58\u4e2d\u5360\u7528\u4e00\u5757\u8fde\u7eed\u7684\u7a7a\u95f4\u3002\u5c06<\/strong>Partition<\/strong>\u7531\u4e0d\u8fde\u7eed\u7684\u5b58\u50a8\u7a7a\u95f4\u8f6c\u6362\u4e3a\u8fde\u7eed\u5b58\u50a8\u7a7a\u95f4\u7684\u8fc7\u7a0b\uff0cSpark<\/strong>\u79f0\u4e4b\u4e3a\"\u5c55\u5f00\"\uff08Unroll\uff09<\/strong>\u3002Block \u6709\u5e8f\u5217\u5316\u548c\u975e\u5e8f\u5217\u5316\u4e24\u79cd\u5b58\u50a8\u683c\u5f0f\uff0c\u5177\u4f53\u4ee5\u54ea\u79cd\u65b9\u5f0f\u53d6\u51b3\u4e8e\u8be5 RDD \u7684\u5b58\u50a8\u7ea7\u522b\u3002\u975e\u5e8f\u5217\u5316\u7684 Block \u4ee5\u4e00\u79cd DeserializedMemoryEntry \u7684\u6570\u636e\u7ed3\u6784\u5b9a\u4e49\uff0c\u7528\u4e00\u4e2a\u6570\u7ec4\u5b58\u50a8\u6240\u6709\u7684\u5bf9\u8c61\u5b9e\u4f8b\uff0c\u5e8f\u5217\u5316\u7684 Block \u5219\u4ee5 SerializedMemoryEntry\u7684\u6570\u636e\u7ed3\u6784\u5b9a\u4e49\uff0c\u7528\u5b57\u8282\u7f13\u51b2\u533a\uff08ByteBuffer\uff09\u6765\u5b58\u50a8\u4e8c\u8fdb\u5236\u6570\u636e\u3002\u6bcf\u4e2a Executor \u7684 Storage \u6a21\u5757\u7528\u4e00\u4e2a\u94fe\u5f0f Map \u7ed3\u6784\uff08LinkedHashMap\uff09\u6765\u7ba1\u7406\u5806\u5185\u548c\u5806\u5916\u5b58\u50a8\u5185\u5b58\u4e2d\u6240\u6709\u7684 Block \u5bf9\u8c61\u7684\u5b9e\u4f8b[6]\uff0c\u5bf9\u8fd9\u4e2a LinkedHashMap \u65b0\u589e\u548c\u5220\u9664\u95f4\u63a5\u8bb0\u5f55\u4e86\u5185\u5b58\u7684\u7533\u8bf7\u548c\u91ca\u653e\u3002<\/p>\n\n

\u56e0\u4e3a\u4e0d\u80fd\u4fdd\u8bc1\u5b58\u50a8\u7a7a\u95f4\u53ef\u4ee5\u4e00\u6b21\u5bb9\u7eb3 Iterator \u4e2d\u7684\u6240\u6709\u6570\u636e\uff0c\u5f53\u524d\u7684\u8ba1\u7b97\u4efb\u52a1\u5728 Unroll \u65f6\u8981\u5411 MemoryManager \u7533\u8bf7\u8db3\u591f\u7684 Unroll \u7a7a\u95f4\u6765\u4e34\u65f6\u5360\u4f4d\uff0c\u7a7a\u95f4\u4e0d\u8db3\u5219 Unroll \u5931\u8d25\uff0c\u7a7a\u95f4\u8db3\u591f\u65f6\u53ef\u4ee5\u7ee7\u7eed\u8fdb\u884c\u3002\u5bf9\u4e8e\u5e8f\u5217\u5316\u7684 Partition\uff0c\u5176\u6240\u9700\u7684 Unroll \u7a7a\u95f4\u53ef\u4ee5\u76f4\u63a5\u7d2f\u52a0\u8ba1\u7b97\uff0c\u4e00\u6b21\u7533\u8bf7\u3002\u800c\u975e\u5e8f\u5217\u5316\u7684 Partition \u5219\u8981\u5728\u904d\u5386 Record \u7684\u8fc7\u7a0b\u4e2d\u4f9d\u6b21\u7533\u8bf7\uff0c\u5373\u6bcf\u8bfb\u53d6\u4e00\u6761 Record\uff0c\u91c7\u6837\u4f30\u7b97\u5176\u6240\u9700\u7684 Unroll \u7a7a\u95f4\u5e76\u8fdb\u884c\u7533\u8bf7\uff0c\u7a7a\u95f4\u4e0d\u8db3\u65f6\u53ef\u4ee5\u4e2d\u65ad\uff0c\u91ca\u653e\u5df2\u5360\u7528\u7684 Unroll \u7a7a\u95f4\u3002\u5982\u679c\u6700\u7ec8 Unroll \u6210\u529f\uff0c\u5f53\u524d Partition \u6240\u5360\u7528\u7684 Unroll \u7a7a\u95f4\u88ab\u8f6c\u6362\u4e3a\u6b63\u5e38\u7684\u7f13\u5b58 RDD \u7684\u5b58\u50a8\u7a7a\u95f4\uff0c\u5982\u4e0b\u56fe 8 \u6240\u793a\u3002<\/p>\n\n

\u56fe 8. Spark Unroll \u793a\u610f\u56fe<\/p>\n\n

\"\"<\/p>\n\n

\u5728\u56fe 3 \u548c\u56fe 5 \u4e2d\u53ef\u4ee5\u770b\u5230\uff0c\u5728\u9759\u6001\u5185\u5b58\u7ba1\u7406\u65f6\uff0cSpark \u5728\u5b58\u50a8\u5185\u5b58\u4e2d\u4e13\u95e8\u5212\u5206\u4e86\u4e00\u5757 Unroll \u7a7a\u95f4\uff0c\u5176\u5927\u5c0f\u662f\u56fa\u5b9a\u7684\uff0c\u7edf\u4e00\u5185\u5b58\u7ba1\u7406\u65f6\u5219\u6ca1\u6709\u5bf9 Unroll \u7a7a\u95f4\u8fdb\u884c\u7279\u522b\u533a\u5206\uff0c\u5f53\u5b58\u50a8\u7a7a\u95f4\u4e0d\u8db3\u65f6\u4f1a\u6839\u636e\u52a8\u6001\u5360\u7528\u673a\u5236\u8fdb\u884c\u5904\u7406\u3002<\/p>\n\n

3.3 \u6dd8\u6c70\u548c\u843d\u76d8<\/p>\n\n

\u7531\u4e8e\u540c\u4e00\u4e2a Executor \u7684\u6240\u6709\u7684\u8ba1\u7b97\u4efb\u52a1\u5171\u4eab\u6709\u9650\u7684\u5b58\u50a8\u5185\u5b58\u7a7a\u95f4\uff0c\u5f53\u6709\u65b0\u7684 Block \u9700\u8981\u7f13\u5b58\u4f46\u662f\u5269\u4f59\u7a7a\u95f4\u4e0d\u8db3\u4e14\u65e0\u6cd5\u52a8\u6001\u5360\u7528\u65f6\uff0c\u5c31\u8981\u5bf9 LinkedHashMap \u4e2d\u7684\u65e7 Block \u8fdb\u884c\u6dd8\u6c70\uff08Eviction\uff09\uff0c\u800c\u88ab\u6dd8\u6c70\u7684 Block \u5982\u679c\u5176\u5b58\u50a8\u7ea7\u522b\u4e2d\u540c\u65f6\u5305\u542b\u5b58\u50a8\u5230\u78c1\u76d8\u7684\u8981\u6c42\uff0c\u5219\u8981\u5bf9\u5176\u8fdb\u884c\u843d\u76d8\uff08Drop\uff09\uff0c\u5426\u5219\u76f4\u63a5\u5220\u9664\u8be5 Block\u3002<\/p>\n\n

\u5b58\u50a8\u5185\u5b58\u7684\u6dd8\u6c70\u89c4\u5219\u4e3a\uff1a<\/p>\n\n

\u88ab\u6dd8\u6c70\u7684\u65e7 Block \u8981\u4e0e\u65b0 Block \u7684 MemoryMode \u76f8\u540c\uff0c\u5373\u540c\u5c5e\u4e8e\u5806\u5916\u6216\u5806\u5185\u5185\u5b58<\/p>\n\n

\u65b0\u65e7 Block \u4e0d\u80fd\u5c5e\u4e8e\u540c\u4e00\u4e2a RDD\uff0c\u907f\u514d\u5faa\u73af\u6dd8\u6c70<\/p>\n\n

\u65e7 Block \u6240\u5c5e RDD \u4e0d\u80fd\u5904\u4e8e\u88ab\u8bfb\u72b6\u6001\uff0c\u907f\u514d\u5f15\u53d1\u4e00\u81f4\u6027\u95ee\u9898<\/p>\n\n

\u904d\u5386 LinkedHashMap \u4e2d Block\uff0c\u6309\u7167\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\uff08LRU\uff09\u7684\u987a\u5e8f\u6dd8\u6c70\uff0c\u76f4\u5230\u6ee1\u8db3\u65b0 Block \u6240\u9700\u7684\u7a7a\u95f4\u3002\u5176\u4e2d LRU \u662f LinkedHashMap \u7684\u7279\u6027\u3002<\/p>\n\n

\u843d\u76d8\u7684\u6d41\u7a0b\u5219\u6bd4\u8f83\u7b80\u5355\uff0c\u5982\u679c\u5176\u5b58\u50a8\u7ea7\u522b\u7b26\u5408_useDisk \u4e3a true \u7684\u6761\u4ef6\uff0c\u518d\u6839\u636e\u5176_deserialized \u5224\u65ad\u662f\u5426\u662f\u975e\u5e8f\u5217\u5316\u7684\u5f62\u5f0f\uff0c\u82e5\u662f\u5219\u5bf9\u5176\u8fdb\u884c\u5e8f\u5217\u5316\uff0c\u6700\u540e\u5c06\u6570\u636e\u5b58\u50a8\u5230\u78c1\u76d8\uff0c\u5728 Storage \u6a21\u5757\u4e2d\u66f4\u65b0\u5176\u4fe1\u606f\u3002<\/p>\n\n

4. \u6267\u884c\u5185\u5b58\u7ba1\u7406<\/p>\n\n

4.1 \u591a\u4efb\u52a1\u95f4\u5185\u5b58\u5206\u914d<\/p>\n\n

Executor \u5185\u8fd0\u884c\u7684\u4efb\u52a1\u540c\u6837\u5171\u4eab\u6267\u884c\u5185\u5b58\uff0cSpark \u7528\u4e00\u4e2a HashMap \u7ed3\u6784\u4fdd\u5b58\u4e86\u4efb\u52a1\u5230\u5185\u5b58\u8017\u8d39\u7684\u6620\u5c04\u3002\u6bcf\u4e2a\u4efb\u52a1\u53ef\u5360\u7528\u7684\u6267\u884c\u5185\u5b58\u5927\u5c0f\u7684\u8303\u56f4\u4e3a 1\/2N ~ 1\/N\uff0c\u5176\u4e2d N \u4e3a\u5f53\u524d Executor \u5185\u6b63\u5728\u8fd0\u884c\u7684\u4efb\u52a1\u7684\u4e2a\u6570\u3002\u6bcf\u4e2a\u4efb\u52a1\u5728\u542f\u52a8\u4e4b\u65f6\uff0c\u8981\u5411 MemoryManager \u8bf7\u6c42\u7533\u8bf7\u6700\u5c11\u4e3a 1\/2N \u7684\u6267\u884c\u5185\u5b58\uff0c\u5982\u679c\u4e0d\u80fd\u88ab\u6ee1\u8db3\u8981\u6c42\u5219\u8be5\u4efb\u52a1\u88ab\u963b\u585e\uff0c\u76f4\u5230\u6709\u5176\u4ed6\u4efb\u52a1\u91ca\u653e\u4e86\u8db3\u591f\u7684\u6267\u884c\u5185\u5b58\uff0c\u8be5\u4efb\u52a1\u624d\u53ef\u4ee5\u88ab\u5524\u9192\u3002<\/p>\n\n

4.2 Shuffle \u7684\u5185\u5b58\u5360\u7528<\/p>\n\n

\u6267\u884c\u5185\u5b58\u4e3b\u8981\u7528\u6765\u5b58\u50a8\u4efb\u52a1\u5728\u6267\u884c Shuffle \u65f6\u5360\u7528\u7684\u5185\u5b58\uff0cShuffle \u662f\u6309\u7167\u4e00\u5b9a\u89c4\u5219\u5bf9 RDD \u6570\u636e\u91cd\u65b0\u5206\u533a\u7684\u8fc7\u7a0b\uff0c\u6211\u4eec\u6765\u770b Shuffle \u7684 Write \u548c Read \u4e24\u9636\u6bb5\u5bf9\u6267\u884c\u5185\u5b58\u7684\u4f7f\u7528\uff1a<\/p>\n\n

Shuffle Write<\/p>\n\n

\u82e5\u5728 map \u7aef\u9009\u62e9\u666e\u901a\u7684\u6392\u5e8f\u65b9\u5f0f\uff0c\u4f1a\u91c7\u7528 ExternalSorter \u8fdb\u884c\u5916\u6392\uff0c\u5728\u5185\u5b58\u4e2d\u5b58\u50a8\u6570\u636e\u65f6\u4e3b\u8981\u5360\u7528\u5806\u5185\u6267\u884c\u7a7a\u95f4\u3002<\/p>\n\n

\u82e5\u5728 map \u7aef\u9009\u62e9 Tungsten \u7684\u6392\u5e8f\u65b9\u5f0f\uff0c\u5219\u91c7\u7528 ShuffleExternalSorter \u76f4\u63a5\u5bf9\u4ee5\u5e8f\u5217\u5316\u5f62\u5f0f\u5b58\u50a8\u7684\u6570\u636e\u6392\u5e8f\uff0c\u5728\u5185\u5b58\u4e2d\u5b58\u50a8\u6570\u636e\u65f6\u53ef\u4ee5\u5360\u7528\u5806\u5916\u6216\u5806\u5185\u6267\u884c\u7a7a\u95f4\uff0c\u53d6\u51b3\u4e8e\u7528\u6237\u662f\u5426\u5f00\u542f\u4e86\u5806\u5916\u5185\u5b58\u4ee5\u53ca\u5806\u5916\u6267\u884c\u5185\u5b58\u662f\u5426\u8db3\u591f\u3002<\/p>\n\n

Shuffle Read<\/p>\n\n

\u5728\u5bf9 reduce \u7aef\u7684\u6570\u636e\u8fdb\u884c\u805a\u5408\u65f6\uff0c\u8981\u5c06\u6570\u636e\u4ea4\u7ed9 Aggregator \u5904\u7406\uff0c\u5728\u5185\u5b58\u4e2d\u5b58\u50a8\u6570\u636e\u65f6\u5360\u7528\u5806\u5185\u6267\u884c\u7a7a\u95f4\u3002<\/p>\n\n

\u5982\u679c\u9700\u8981\u8fdb\u884c\u6700\u7ec8\u7ed3\u679c\u6392\u5e8f\uff0c\u5219\u8981\u5c06\u518d\u6b21\u5c06\u6570\u636e\u4ea4\u7ed9 ExternalSorter \u5904\u7406\uff0c\u5360\u7528\u5806\u5185\u6267\u884c\u7a7a\u95f4\u3002<\/p>\n\n

\u5728 ExternalSorter \u548c Aggregator \u4e2d\uff0cSpark \u4f1a\u4f7f\u7528\u4e00\u79cd\u53eb AppendOnlyMap \u7684\u54c8\u5e0c\u8868\u5728\u5806\u5185\u6267\u884c\u5185\u5b58\u4e2d\u5b58\u50a8\u6570\u636e\uff0c\u4f46\u5728 Shuffle \u8fc7\u7a0b\u4e2d\u6240\u6709\u6570\u636e\u5e76\u4e0d\u80fd\u90fd\u4fdd\u5b58\u5230\u8be5\u54c8\u5e0c\u8868\u4e2d\uff0c\u5f53\u8fd9\u4e2a\u54c8\u5e0c\u8868\u5360\u7528\u7684\u5185\u5b58\u4f1a\u8fdb\u884c\u5468\u671f\u6027\u5730\u91c7\u6837\u4f30\u7b97\uff0c\u5f53\u5176\u5927\u5230\u4e00\u5b9a\u7a0b\u5ea6\uff0c\u65e0\u6cd5\u518d\u4ece MemoryManager \u7533\u8bf7\u5230\u65b0\u7684\u6267\u884c\u5185\u5b58\u65f6\uff0cSpark \u5c31\u4f1a\u5c06\u5176\u5168\u90e8\u5185\u5bb9\u5b58\u50a8\u5230\u78c1\u76d8\u6587\u4ef6\u4e2d\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u88ab\u79f0\u4e3a\u6ea2\u5b58(Spill)\uff0c\u6ea2\u5b58\u5230\u78c1\u76d8\u7684\u6587\u4ef6\u6700\u540e\u4f1a\u88ab\u5f52\u5e76(Merge)\u3002<\/p>\n\n

Shuffle Write \u9636\u6bb5\u4e2d\u7528\u5230\u7684 Tungsten \u662f Databricks \u516c\u53f8\u63d0\u51fa\u7684\u5bf9 Spark \u4f18\u5316\u5185\u5b58\u548c CPU \u4f7f\u7528\u7684\u8ba1\u5212[9]\uff0c\u89e3\u51b3\u4e86\u4e00\u4e9b JVM \u5728\u6027\u80fd\u4e0a\u7684\u9650\u5236\u548c\u5f0a\u7aef\u3002Spark \u4f1a\u6839\u636e Shuffle \u7684\u60c5\u51b5\u6765\u81ea\u52a8\u9009\u62e9\u662f\u5426\u91c7\u7528 Tungsten \u6392\u5e8f\u3002Tungsten \u91c7\u7528\u7684\u9875\u5f0f\u5185\u5b58\u7ba1\u7406\u673a\u5236\u5efa\u7acb\u5728 MemoryManager \u4e4b\u4e0a\uff0c\u5373 Tungsten \u5bf9\u6267\u884c\u5185\u5b58\u7684\u4f7f\u7528\u8fdb\u884c\u4e86\u4e00\u6b65\u7684\u62bd\u8c61\uff0c\u8fd9\u6837\u5728 Shuffle \u8fc7\u7a0b\u4e2d\u65e0\u9700\u5173\u5fc3\u6570\u636e\u5177\u4f53\u5b58\u50a8\u5728\u5806\u5185\u8fd8\u662f\u5806\u5916\u3002\u6bcf\u4e2a\u5185\u5b58\u9875\u7528\u4e00\u4e2a MemoryBlock \u6765\u5b9a\u4e49\uff0c\u5e76\u7528 Object obj \u548c long offset \u8fd9\u4e24\u4e2a\u53d8\u91cf\u7edf\u4e00\u6807\u8bc6\u4e00\u4e2a\u5185\u5b58\u9875\u5728\u7cfb\u7edf\u5185\u5b58\u4e2d\u7684\u5730\u5740\u3002\u5806\u5185\u7684 MemoryBlock \u662f\u4ee5 long \u578b\u6570\u7ec4\u7684\u5f62\u5f0f\u5206\u914d\u7684\u5185\u5b58\uff0c\u5176 obj \u7684\u503c\u4e3a\u662f\u8fd9\u4e2a\u6570\u7ec4\u7684\u5bf9\u8c61\u5f15\u7528\uff0coffset \u662f long \u578b\u6570\u7ec4\u7684\u5728 JVM \u4e2d\u7684\u521d\u59cb\u504f\u79fb\u5730\u5740\uff0c\u4e24\u8005\u914d\u5408\u4f7f\u7528\u53ef\u4ee5\u5b9a\u4f4d\u8fd9\u4e2a\u6570\u7ec4\u5728\u5806\u5185\u7684\u7edd\u5bf9\u5730\u5740\uff1b\u5806\u5916\u7684 MemoryBlock \u662f\u76f4\u63a5\u7533\u8bf7\u5230\u7684\u5185\u5b58\u5757\uff0c\u5176 obj \u4e3a null\uff0coffset \u662f\u8fd9\u4e2a\u5185\u5b58\u5757\u5728\u7cfb\u7edf\u5185\u5b58\u4e2d\u7684 64 \u4f4d\u7edd\u5bf9\u5730\u5740\u3002Spark \u7528 MemoryBlock \u5de7\u5999\u5730\u5c06\u5806\u5185\u548c\u5806\u5916\u5185\u5b58\u9875\u7edf\u4e00\u62bd\u8c61\u5c01\u88c5\uff0c\u5e76\u7528\u9875\u8868(pageTable)\u7ba1\u7406\u6bcf\u4e2a Task \u7533\u8bf7\u5230\u7684\u5185\u5b58\u9875\u3002<\/p>\n\n

Tungsten \u9875\u5f0f\u7ba1\u7406\u4e0b\u7684\u6240\u6709\u5185\u5b58\u7528 64 \u4f4d\u7684\u903b\u8f91\u5730\u5740\u8868\u793a\uff0c\u7531\u9875\u53f7\u548c\u9875\u5185\u504f\u79fb\u91cf\u7ec4\u6210\uff1a<\/p>\n\n

\u9875\u53f7\uff1a\u5360 13 \u4f4d\uff0c\u552f\u4e00\u6807\u8bc6\u4e00\u4e2a\u5185\u5b58\u9875\uff0cSpark \u5728\u7533\u8bf7\u5185\u5b58\u9875\u4e4b\u524d\u8981\u5148\u7533\u8bf7\u7a7a\u95f2\u9875\u53f7\u3002<\/p>\n\n

\u9875\u5185\u504f\u79fb\u91cf\uff1a\u5360 51 \u4f4d\uff0c\u662f\u5728\u4f7f\u7528\u5185\u5b58\u9875\u5b58\u50a8\u6570\u636e\u65f6\uff0c\u6570\u636e\u5728\u9875\u5185\u7684\u504f\u79fb\u5730\u5740\u3002<\/p>\n\n

\u6709\u4e86\u7edf\u4e00\u7684\u5bfb\u5740\u65b9\u5f0f\uff0cSpark \u53ef\u4ee5\u7528 64 \u4f4d\u903b\u8f91\u5730\u5740\u7684\u6307\u9488\u5b9a\u4f4d\u5230\u5806\u5185\u6216\u5806\u5916\u7684\u5185\u5b58\uff0c\u6574\u4e2a Shuffle Write \u6392\u5e8f\u7684\u8fc7\u7a0b\u53ea\u9700\u8981\u5bf9\u6307\u9488\u8fdb\u884c\u6392\u5e8f\uff0c\u5e76\u4e14\u65e0\u9700\u53cd\u5e8f\u5217\u5316\uff0c\u6574\u4e2a\u8fc7\u7a0b\u975e\u5e38\u9ad8\u6548\uff0c\u5bf9\u4e8e\u5185\u5b58\u8bbf\u95ee\u6548\u7387\u548c CPU \u4f7f\u7528\u6548\u7387\u5e26\u6765\u4e86\u660e\u663e\u7684\u63d0\u5347[10]\u3002<\/p>\n\n

Spark \u7684\u5b58\u50a8\u5185\u5b58\u548c\u6267\u884c\u5185\u5b58\u6709\u7740\u622a\u7136\u4e0d\u540c\u7684\u7ba1\u7406\u65b9\u5f0f\uff1a\u5bf9\u4e8e\u5b58\u50a8\u5185\u5b58\u6765\u8bf4\uff0cSpark \u7528\u4e00\u4e2a LinkedHashMap \u6765\u96c6\u4e2d\u7ba1\u7406\u6240\u6709\u7684 Block\uff0cBlock \u7531\u9700\u8981\u7f13\u5b58\u7684 RDD \u7684 Partition \u8f6c\u5316\u800c\u6210\uff1b\u800c\u5bf9\u4e8e\u6267\u884c\u5185\u5b58\uff0cSpark \u7528 AppendOnlyMap \u6765\u5b58\u50a8 Shuffle \u8fc7\u7a0b\u4e2d\u7684\u6570\u636e\uff0c\u5728 Tungsten \u6392\u5e8f\u4e2d\u751a\u81f3\u62bd\u8c61\u6210\u4e3a\u9875\u5f0f\u5185\u5b58\u7ba1\u7406\uff0c\u5f00\u8f9f\u4e86\u5168\u65b0\u7684 JVM \u5185\u5b58\u7ba1\u7406\u673a\u5236\u3002<\/p>\n\n

\u7ed3\u675f\u8bed<\/p>\n\n

Spark \u7684\u5185\u5b58\u7ba1\u7406\u662f\u4e00\u5957\u590d\u6742\u7684\u673a\u5236\uff0c\u4e14 Spark \u7684\u7248\u672c\u66f4\u65b0\u6bd4\u8f83\u5feb\uff0c\u7b14\u8005\u6c34\u5e73\u6709\u9650\uff0c\u96be\u514d\u6709\u53d9\u8ff0\u4e0d\u6e05\u3001\u9519\u8bef\u7684\u5730\u65b9\uff0c\u82e5\u8bfb\u8005\u6709\u597d\u7684\u5efa\u8bae\u548c\u66f4\u6df1\u7684\u7406\u89e3\uff0c\u8fd8\u671b\u4e0d\u541d\u8d50\u6559\u3002\u3010\u5927\u6570\u636e\u5f00\u53d1\u5b66\u4e60\u8d44\u6599\u9886\u53d6\u65b9\u5f0f\u3011\uff1a\u52a0\u5165\u5927\u6570\u636e\u6280\u672f\u5b66\u4e60\u4ea4\u6d41\u7fa4458345782\uff0c\u70b9\u51fb\u52a0\u5165\u7fa4\u804a\uff0c\u79c1\u4fe1\u7ba1\u7406\u5458\u5373\u53ef\u514d\u8d39\u9886\u53d6<\/a><\/strong>\"\"<\/p>\n <\/div>\n <\/div>","orderid":"0","title":"\u3010\u5927\u6570\u636e\u6280\u672f\u3011Apache Spark \u5185\u5b58\u7ba1\u7406\u8be6\u89e3","smalltitle":"","mid":"0","fname":"Spark","special_id":"0","bak_id":"0","info":"0","hits":"414","pages":"1","comments":"0","posttime":"2019-05-15 13:27:48","list":"1557898068","username":"admin","author":"","copyfrom":"","copyfromurl":"","titlecolor":"","fonttype":"0","titleicon":"0","picurl":"https:\/\/www.cppentry.com\/upload_files\/","ispic":"0","yz":"1","yzer":"","yztime":"0","levels":"0","levelstime":"0","keywords":"\u6570\u636e<\/A> \u6280\u672f<\/A> Apache<\/A> Spark<\/A> \u5185\u5b58<\/A> \u7ba1\u7406<\/A> \u8be6\u89e3<\/A>","jumpurl":"","iframeurl":"","style":"","template":"a:3:{s:4:\"foot\";s:0:\"\";s:8:\"bencandy\";s:0:\"\";s:4:\"head\";s:0:\"\";}","target":"0","ip":"47.106.78.186","lastfid":"0","money":"0","buyuser":"","passwd":"","allowdown":"","allowview":"","editer":"","edittime":"0","begintime":"0","endtime":"0","description":" Spark \u4f5c\u4e3a\u4e00\u4e2a\u57fa\u4e8e\u5185\u5b58\u7684\u5206\u5e03\u5f0f\u8ba1\u7b97\u5f15\u64ce\uff0c\u5176\u5185\u5b58\u7ba1\u7406\u6a21\u5757\u5728\u6574\u4e2a\u7cfb\u7edf\u4e2d\u626e\u6f14\u7740\u975e\u5e38\u91cd\u8981\u7684\u89d2\u8272\u3002\u7406\u89e3 Spark \u5185\u5b58\u7ba1\u7406\u7684\u57fa\u672c\u539f\u7406\uff0c\u6709\u52a9\u4e8e\u66f4\u597d\u5730\u5f00\u53d1 Spark \u5e94\u7528\u7a0b\u5e8f\u548c\u8fdb\u884c\u6027\u80fd\u8c03\u4f18\u3002\u672c\u6587\u65e8\u5728\u68b3\u7406\u51fa Spark \u5185\u5b58\u7ba1\u7406\u7684\u8109\u7edc\uff0c\u629b\u7816\u5f15\u7389..","lastview":"1713534671","digg_num":"0","digg_time":"0","forbidcomment":"0","ifvote":"0","heart":"","htmlname":"","city_id":"0"},"page":"1"}