{"id":6547,"date":"2022-04-09T19:49:43","date_gmt":"2022-04-09T11:49:43","guid":{"rendered":"https:\/\/egonlin.com\/?p=6547"},"modified":"2022-04-09T19:49:43","modified_gmt":"2022-04-09T11:49:43","slug":"hdfs-namenode-%e9%ab%98%e5%8f%af%e7%94%a8","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=6547","title":{"rendered":"HDFS Namenode \u9ad8\u53ef\u7528"},"content":{"rendered":"

HDFS Namenode \u9ad8\u53ef\u7528<\/h1>\n

\u5728 Hadoop 2.0.0 \u4e4b\u524d\uff0c\u4e00\u4e2a\u96c6\u7fa4\u53ea\u6709\u4e00\u4e2aNamenode\uff0c\u8fd9\u5c06\u9762\u4e34\u5355\u70b9\u6545\u969c\u95ee\u9898\u3002\u5982\u679c Namenode \u673a\u5668\u6302\u6389\u4e86\uff0c\u6574\u4e2a\u96c6\u7fa4\u5c31\u7528\u4e0d\u4e86\u4e86\u3002\u53ea\u6709\u91cd\u542f Namenode \uff0c\u624d\u80fd\u6062\u590d\u96c6\u7fa4\u3002\u53e6\u5916\u6b63\u5e38\u8ba1\u5212\u7ef4\u62a4\u96c6\u7fa4\u7684\u65f6\u5019\uff0c\u8fd8\u5fc5\u987b\u5148\u505c\u7528\u6574\u4e2a\u96c6\u7fa4\uff0c\u8fd9\u6837\u6ca1\u529e\u6cd5\u8fbe\u5230 7 * 24\u5c0f\u65f6\u53ef\u7528\u72b6\u6001\u3002Hadoop 2.0 \u53ca\u4e4b\u540e\u7248\u672c\u589e\u52a0\u4e86 Namenode \u9ad8\u53ef\u7528\u673a\u5236\uff0c\u4e0b\u9762\u8be6\u7ec6\u4ecb\u7ecd\u3002
\nHadoop Namenode \u9ad8\u53ef\u7528\u67b6\u6784
\n

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

Hadoop 2.0 \u514b\u670d\u4e86 Namenode \u5355\u70b9\u6545\u969c\u95ee\u9898\uff0c\u5373\u5728\u4e00\u4e2a\u96c6\u7fa4\u4e2d\u67092\u4e2a Namenode \u8282\u70b9\uff0c\u4e00\u4e2a\u662f\u6d3b\u52a8\u7684Namenode\u8282\u70b9\uff08Active Namenode\uff09\uff0c\u5373\u4e3b\u8282\u70b9\uff0c\u4e00\u4e2a\u662f\u5907\u7528 Namenode\uff08Passive Namenode\uff09\uff0c\u5373\u5907\u7528\u8282\u70b9\uff0c\u800c\u4e14\u652f\u6301\u70ed\u5907\u4efd\u548c\u6545\u969c\u5207\u6362\u3002<\/p>\n

\u6d3b\u52a8 Namenode\uff1a\u8d1f\u8d23\u5904\u7406\u96c6\u7fa4\u4e2d\u6240\u6709\u5ba2\u6237\u7aef\u8bf7\u6c42\u3002
\n\u5907\u7528 Namenode\uff1a\u5907\u7528\u8282\u70b9\uff0c\u62e5\u6709\u548c\u6d3b\u52a8\u7684 Namenode \u4e00\u6837\u7684\u5143\u6570\u636e\u3002\u5728\u6d3b\u52a8 Namenode \u5931\u6548\u540e\uff0c\u4f1a\u63a5\u7ba1\u5b83\u7684\u5de5\u4f5c\u3002<\/p>\n

\u6d3b\u52a8 Namenode \u548c\u5907\u7528 Namenode \u4e4b\u95f4\u662f\u5982\u4f55\u540c\u6b65\u6570\u636e\u7684\u5462\uff1f\u5373\u4ed6\u4eec\u662f\u600e\u4e48\u4fdd\u6301\u4e00\u81f4\u6027\u7684\uff0c\u4e3b\u8981\u6709\u4e0b\u9762\u51e0\u70b9\uff1a<\/p>\n

\u6d3b\u52a8\u548c\u5907\u7528 Namenode \u4e24\u8005\u603b\u662f\u540c\u6b65\u7684\uff0c\u4f8b\u5982\uff0c\u4ed6\u4eec\u5b58\u50a8\u7740\u4e00\u6837\u7684\u5143\u6570\u636e\uff0c\u8fd9\u53ef\u4ee5\u628a\u96c6\u7fa4\u6062\u590d\u5230\u7cfb\u7edf\u5954\u6e83\u65f6\u7684\u72b6\u6001\u3002\u800c\u4e14\u57fa\u4e8e\u6b64\u8fd8\u80fd\u5b9e\u73b0\u81ea\u52a8\u6545\u969c\u5207\u6362\u3002\n\u540c\u4e00\u65f6\u95f4\uff0c\u96c6\u7fa4\u53ea\u80fd\u6709\u4e00\u4e2a\u6d3b\u52a8\u7684 Namenode \u8282\u70b9\uff0c\u5426\u5219\uff0c\u4e24\u4e2a Namenode \u4f1a\u5bfc\u81f4\u6570\u636e\u53d1\u751f\u9519\u4e71\u5e76\u4e14\u65e0\u6cd5\u6062\u590d\u3002\u6211\u4eec\u628a\u8fd9\u79cd\u60c5\u51b5\u79f0\u4e3a\u201c\u8111\u88c2\u201d\u73b0\u8c61\uff0c\u5373\u4e00\u4e2a\u96c6\u7fa4\u88ab\u5206\u6210\u4e24\u4e2a\u5c0f\u96c6\u7fa4\uff0c\u5e76\u4e14\u4e24\u8fb9\u90fd\u8ba4\u4e3a\u81ea\u5df1\u662f\u552f\u4e00\u6d3b\u52a8\u7684\u96c6\u7fa4\u3002Zookeeper \u793e\u533a\u5bf9\u8fd9\u79cd\u95ee\u9898\u7684\u89e3\u51b3\u65b9\u6cd5\u53eb\u505a fencing\uff0c\u4e2d\u6587\u7ffb\u8bd1\u4e3a\u9694\u79bb\uff0c\u4e5f\u5c31\u662f\u60f3\u529e\u6cd5\u628a\u65e7\u7684 \u6d3b\u52a8 NameNode \u9694\u79bb\u8d77\u6765\uff0c\u4f7f\u5b83\u4e0d\u80fd\u6b63\u5e38\u5bf9\u5916\u63d0\u4f9b\u670d\u52a1\uff0c\u4f7f\u96c6\u7fa4\u59cb\u7ec8\u53ea\u6709\u4e00\u4e2a\u6d3b\u52a8\u7684 Namenode\u3002<\/code><\/pre>\n
\u4e86\u89e3\u5b8c Hadoop \u9ad8\u53ef\u7528\u67b6\u6784\u4e4b\u540e\uff0c\u8ba9\u6211\u4eec\u6765\u770b\u4e00\u4e0b Hadoop Namenode \u9ad8\u53ef\u7528\u662f\u600e\u4e48\u5b9e\u73b0\u7684\u3002<\/p>\n
Namenode \u9ad8\u53ef\u7528\u7684\u5b9e\u73b0<\/h2>\n
\u8fd9\u91cc\u4e3b\u8981\u4ecb\u7ecd\u901a\u8fc7\u9694\u79bb\uff08fencing\uff09\u548cQuorum Journal Manager\uff08QJM\uff09\u5171\u4eab\u5b58\u50a8\u5b9e\u73b0\u7684 HDFS \u9ad8\u53ef\u7528\u3002<\/p>\n
\u4e00 \u9694\u79bb\uff08Fencing\uff09<\/h3>\n
\u9694\u79bb\uff08Fencing\uff09\u662f\u4e3a\u4e86\u9632\u6b62\u8111\u88c2\uff0c\u5c31\u662f\u4fdd\u8bc1\u5728\u4efb\u4f55\u65f6\u5019HDFS\u53ea\u6709\u4e00\u4e2aActive NN\uff0c\u4e3b\u8981\u5305\u62ec\u4e09\u4e2a\u65b9\u9762\uff1a<\/p>\n
\u5171\u4eab\u5b58\u50a8fencing\uff1a\u786e\u4fdd\u53ea\u6709\u4e00\u4e2aNN\u53ef\u4ee5\u5199\u5165edits\u3002QJM\u4e2d\u6bcf\u4e00\u4e2aJournalNode\u4e2d\u5747\u6709\u4e00\u4e2aepochnumber\uff0c\u5339\u914depochnumber\u7684QJM\u624d\u6709\u6743\u9650\u66f4\u65b0 JN\u3002\u5f53 Namenode \u7531 standby \u72b6\u6001\u5207\u6362\u6210 active \u72b6\u6001\u65f6\uff0c\u4f1a\u91cd\u65b0\u751f\u6210\u4e00\u4e2a epochnumber\uff0c\u5e76\u66f4\u65b0 JN \u4e2d\u7684 epochnumber\uff0c\u4ee5\u81f3\u4e8e\u4ee5\u524d\u7684 Active Namenode \u4e2d\u7684QJM \u4e2d\u7684 epoch number \u548c JN \u7684 epochnumber \u4e0d\u5339\u914d\uff0c\u6545\u800c\u539f Active Namenode\u4e0a\u7684 QJM \u6ca1\u6cd5\u5f80 JN \u4e2d\u5199\u5165\u6570\u636e\uff08\u540e\u9762\u4f1a\u4ecb\u7ecd\u6e90\u7801\uff09\uff0c\u5373\u5f62\u6210\u4e86 fencing\u3002\n\u5ba2\u6237\u7aeff encing\uff1a\u786e\u4fdd\u53ea\u6709\u4e00\u4e2a Namenode \u53ef\u4ee5\u54cd\u5e94\u5ba2\u6237\u7aef\u7684\u8bf7\u6c42\u3002\nDataNode fencing\uff1a\u786e\u4fdd\u53ea\u6709\u4e00\u4e2a Namenode \u53ef\u4ee5\u5411 Datanode \u4e0b\u53d1\u547d\u4ee4\uff0c\u8b6c\u5982\u5220\u9664\u5757\uff0c\u590d\u5236\u5757\uff0c\u7b49\u7b49\u3002<\/code><\/pre>\n
QJM \u7684 Fencing \u65b9\u6848\u53ea\u80fd\u8ba9\u539f\u6765\u7684 Active Namenode \u5931\u53bb\u5bf9 JN \u7684\u5199\u6743\u9650\uff0c\u4f46\u662f\u539f\u6765\u7684 Active Namenode \u8fd8\u662f\u53ef\u4ee5\u54cd\u5e94\u5ba2\u6237\u7aef\u7684\u8bf7\u6c42\uff0c\u5bf9 Datanode \u8fdb\u884c\u8bfb\u3002\u5bf9\u5ba2\u6237\u7aef\u548c DataNode \u7684 fence \u662f\u901a\u8fc7\u914d\u7f6e dfs.ha.fencing.methods \u5b9e\u73b0\u7684\u3002<\/p>\n
Hadoop \u516c\u5171\u5e93\u4e2d\u6709\u4e24\u79cdFencing\u5b9e\u73b0\uff1asshfence\u3001shell<\/p>\n
sshfence\uff1assh\u5230\u539fActive NN\u4e0a\uff0c\u4f7f\u7528fuser\u7ed3\u675f\u8fdb\u7a0b\uff08\u901a\u8fc7tcp\u7aef\u53e3\u53f7\u5b9a\u4f4d\u8fdb\u7a0b pid\uff0c\u8be5\u65b9\u6cd5\u6bd4 jps \u547d\u4ee4\u66f4\u51c6\u786e\uff09\u3002\nshell\uff1a\u5373\u6267\u884c\u4e00\u4e2a\u7528\u6237\u4e8b\u5148\u5b9a\u4e49\u7684shell\u547d\u4ee4\uff08\u811a\u672c\uff09\u5b8c\u6210\u9694\u79bb\u3002<\/code><\/pre>\n
\u4e8c QJM\u5171\u4eab\u5b58\u50a8<\/h3>\n
Qurom Journal Manager\uff08QJM\uff09\u662f\u4e00\u4e2a\u57fa\u4e8e Paxos \u7b97\u6cd5\u5b9e\u73b0\u7684 HDFS \u5143\u6570\u636e\u5171\u4eab\u5b58\u50a8\u7684\u65b9\u6848\u3002QJM \u7684\u57fa\u672c\u539f\u7406\u5c31\u662f\u7528 2N+1 \u53f0 JournalNode \u5b58\u50a8 EditLog\uff0c\u6bcf\u6b21\u5199\u6570\u636e\u64cd\u4f5c\u6709\u5927\u591a\u6570\uff08>=N+1\uff09\u8fd4\u56de\u6210\u529f\u65f6\u5373\u8ba4\u4e3a\u8be5\u6b21\u5199\u6210\u529f\uff0c\u6570\u636e\u4e0d\u4f1a\u4e22\u5931\u3002\u8fd9\u4e2a\u7b97\u6cd5\u6240\u80fd\u5bb9\u5fcd\u7684\u662f\u6700\u591a\u6709 N \u53f0\u673a\u5668\u6302\u6389\uff0c\u5982\u679c\u591a\u4e8e N \u53f0\u6302\u6389\uff0c\u8fd9\u4e2a\u7b97\u6cd5\u5c31\u5931\u6548\u4e86\u3002\u8fd9\u4e2a\u539f\u7406\u662f\u57fa\u4e8e Paxos \u7b97\u6cd5\u7684\u3002
\n\u7528QJM\u7684\u65b9\u5f0f\u6765\u5b9e\u73b0HA\u7684\u4e3b\u8981\u597d\u5904\u6709\uff1a<\/p>\n
\u4e0d\u9700\u8981\u914d\u7f6e\u989d\u5916\u7684\u9ad8\u5171\u4eab\u5b58\u50a8\uff0c\u8fd9\u6837\u5bf9\u4e8e\u57fa\u4e8e\u5546\u7528\u786c\u4ef6\u7684\u4e91\u8ba1\u7b97\u6570\u636e\u4e2d\u5fc3\u6765\u8bf4\uff0c\u964d\u4f4e\u4e86\u590d\u6742\u5ea6\u548c\u7ef4\u62a4\u6210\u672c\uff1b\n\u4e0d\u5728\u9700\u8981\u5355\u72ec\u914d\u7f6e fencing \u5b9e\u73b0\uff0c\u56e0\u4e3a QJM \u672c\u8eab\u5185\u7f6e\u4e86 fencing \u7684\u529f\u80fd\uff1b\n\u4e0d\u5b58\u5728\u5355\u70b9\u6545\u969c\u95ee\u9898\uff1b\n\u7cfb\u7edf\u9c81\u68d2\u6027\u7684\u7a0b\u5ea6\u662f\u53ef\u914d\u7f6e\u7684\uff08 QJM \u57fa\u4e8e Paxos \u7b97\u6cd5\uff0c\u6240\u4ee5\u5982\u679c\u914d\u7f6e 2N+1 \u53f0 JournalNode \u7ec4\u6210\u7684\u96c6\u7fa4\uff0c\u80fd\u5bb9\u5fcd\u6700\u591a N \u53f0\u673a\u5668\u6302\u6389\uff09\uff1b\nQJM \u4e2d\u5b58\u50a8\u65e5\u5fd7\u7684 JournalNode \u4e0d\u4f1a\u56e0\u4e3a\u5176\u4e2d\u4e00\u53f0\u7684\u5ef6\u8fdf\u800c\u5f71\u54cd\u6574\u4f53\u7684\u5ef6\u8fdf\uff0c\u800c\u4e14\u4e5f\u4e0d\u4f1a\u56e0\u4e3a JournalNode \u7684\u6570\u91cf\u589e\u591a\u800c\u5f71\u54cd\u6027\u80fd\uff08\u56e0\u4e3a Namenode \u5411 JournalNode \u53d1\u9001\u65e5\u5fd7\u662f\u5e76\u884c\u7684\uff09\u3002<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
HDFS Namenode \u9ad8\u53ef\u7528 \u5728 Hadoop 2.0.0 \u4e4b\u524d\uff0c\u4e00\u4e2a\u96c6\u7fa4\u53ea\u6709\u4e00\u4e2aNamenode\uff0c\u8fd9\u5c06 […]<\/p>\n","protected":false},"author":3,"featured_media":6548,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[411],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/6547"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6547"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/6547\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/media\/6548"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6547"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6547"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6547"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}