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197 | <a href="#%E6%A6%82%E8%BF%B0">æŠè¿°</a> |
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198 | </li> |
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200 | <a href="#%E4%BD%BF%E7%94%A8%E6%96%B9%E6%B3%95">䜿çšæ¹æ³</a> |
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202 | <li> |
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206 | <a href="#options">é项</a> |
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209 | <a href="#%E9%80%89%E9%A1%B9%E7%B4%A2%E5%BC%95">é项玢åŒ</a> |
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210 | </li> |
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211 | <li> |
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212 | <a href="#uo">æŽæ°åèŠç</a> |
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213 | </li> |
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214 | </ul> |
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215 | </li> |
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216 | </ul> |
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217 | </li> |
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218 | <li> |
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219 | <a href="#etc">éåœ</a> |
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221 | <li> |
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222 | <a href="#Map%E6%95%B0%E7%9B%AE">Mapæ°ç®</a> |
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223 | </li> |
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224 | <li> |
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225 | <a href="#cpver">äžåHDFSçæ¬éŽçæ·èŽ</a> |
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226 | </li> |
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227 | <li> |
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228 | <a href="#Map%2FReduce%E5%92%8C%E5%89%AF%E6%95%88%E5%BA%94">Map/Reduceåå¯æåº</a> |
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229 | </li> |
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230 | </ul> |
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231 | </li> |
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232 | </ul> |
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233 | </div> |
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234 | |
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235 | |
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236 | <a name="N1000D"></a><a name="%E6%A6%82%E8%BF%B0"></a> |
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237 | <h2 class="h3">æŠè¿°</h2> |
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238 | <div class="section"> |
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239 | <p>DistCpïŒååžåŒæ·èŽïŒæ¯çšäºå€§è§æš¡é矀å
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240 | å®äœ¿çšMap/Reduceå®ç°æ件ååïŒé误å€çåæ¢å€ïŒä»¥åæ¥åçæã |
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243 | è¿ç¯ææ¡£äŒäžºåžžçšDistCpæäœæäŸæå并éè¿°å®çå·¥äœæš¡åã |
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244 | </p> |
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245 | </div> |
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246 | |
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247 | |
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248 | <a name="N10017"></a><a name="%E4%BD%BF%E7%94%A8%E6%96%B9%E6%B3%95"></a> |
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249 | <h2 class="h3">䜿çšæ¹æ³</h2> |
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250 | <div class="section"> |
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251 | <a name="N1001D"></a><a name="%E5%9F%BA%E6%9C%AC%E4%BD%BF%E7%94%A8%E6%96%B9%E6%B3%95"></a> |
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252 | <h3 class="h4">åºæ¬äœ¿çšæ¹æ³</h3> |
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253 | <p>DistCpæåžžçšåšé矀ä¹éŽçæ·èŽïŒ</p> |
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254 | <p> |
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255 | <span class="codefrag">bash$ hadoop distcp hdfs://nn1:8020/foo/bar \</span> |
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256 | <br> |
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257 | |
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258 | <span class="codefrag"> |
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259 | |
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260 | hdfs://nn2:8020/bar/foo</span> |
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261 | </p> |
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262 | <p>è¿æ¡åœä»€äŒænn1é矀ç<span class="codefrag">/foo/bar</span>ç®åœäžçæææ件æç®åœåå±åŒå¹¶ååšå°äžäžªäžŽæ¶æ件äžïŒè¿äºæ件å
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264 | </p> |
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265 | <p>åœä»€è¡äžå¯ä»¥æå®å€äžªæºç®åœïŒ</p> |
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266 | <p> |
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267 | <span class="codefrag">bash$ hadoop distcp hdfs://nn1:8020/foo/a \</span> |
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268 | <br> |
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269 | |
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270 | <span class="codefrag"> |
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271 | |
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272 | hdfs://nn1:8020/foo/b \</span> |
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273 | <br> |
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274 | |
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275 | <span class="codefrag"> |
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276 | |
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277 | hdfs://nn2:8020/bar/foo</span> |
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278 | </p> |
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279 | <p>æè
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280 | |
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281 | <span class="codefrag">bash$ hadoop distcp -f hdfs://nn1:8020/srclist \</span> |
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282 | <br> |
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283 | |
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284 | <span class="codefrag"> |
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285 | |
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286 | hdfs://nn2:8020/bar/foo</span> |
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287 | <br> |
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288 | </p> |
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289 | <p>å
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290 | |
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291 | <span class="codefrag"> hdfs://nn1:8020/foo/a</span> |
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292 | <br> |
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293 | |
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294 | <span class="codefrag"> hdfs://nn1:8020/foo/b</span> |
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295 | </p> |
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296 | <p>åœä»å€äžªæºæ·èŽæ¶ïŒåŠæ䞀䞪æºå²çªïŒDistCpäŒåæ¢æ·èŽå¹¶æ瀺åºéä¿¡æ¯ïŒ |
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297 | åŠæåšç®çäœçœ®åçå²çªïŒäŒæ ¹æ®<a href="#options">é项讟眮</a>解å³ã |
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298 | é»è®€æ
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301 | </p> |
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302 | <p>æ¯äžªTaskTrackerå¿
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309 | äœçšæ·åšåŠæ€æäœä¹ååºè¯¥å¯¹è¯¥åœä»€çè¯æ³åŸçæã |
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310 | </p> |
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311 | <p>åŒåŸæ³šæçæ¯ïŒåœåŠäžäžªå®¢æ·ç«¯åæ¶åšåæºæ件åå
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313 | åŠæäžäžªæºæ件åšæ·èŽä¹å被移åšæå é€äºïŒæ·èŽå€±èŽ¥åæ¶èŸåºåŒåžž |
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314 | FileNotFoundExceptionã</p> |
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315 | <a name="N1007B"></a><a name="options"></a> |
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316 | <h3 class="h4">é项</h3> |
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317 | <a name="N10081"></a><a name="%E9%80%89%E9%A1%B9%E7%B4%A2%E5%BC%95"></a> |
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318 | <h4>é项玢åŒ</h4> |
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319 | <table class="ForrestTable" cellspacing="1" cellpadding="4"> |
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320 | |
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321 | <tr> |
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322 | <th colspan="1" rowspan="1"> æ è¯ </th><th colspan="1" rowspan="1"> æè¿° </th><th colspan="1" rowspan="1"> å€æ³š </th> |
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323 | </tr> |
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324 | |
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325 | |
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326 | <tr> |
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327 | <td colspan="1" rowspan="1"><span class="codefrag">-p[rbugp]</span></td> |
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328 | <td colspan="1" rowspan="1">Preserve<br> |
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329 | r: replication number<br> |
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330 | b: block size<br> |
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331 | u: user<br> |
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332 | g: group<br> |
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333 | p: permission<br> |
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334 | </td> |
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335 | <td colspan="1" rowspan="1">ä¿®æ¹æ¬¡æ°äžäŒè¢«ä¿çã并äžåœæå® |
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336 | <span class="codefrag">-update</span> æ¶ïŒæŽæ°çç¶æ<strong>äž</strong>äŒ |
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337 | 被åæ¥ïŒé€éæ件倧å°äžåïŒæ¯åŠæ件被éæ°å建ïŒã |
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338 | </td> |
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339 | </tr> |
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340 | |
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341 | <tr> |
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342 | <td colspan="1" rowspan="1"><span class="codefrag">-i</span></td> |
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343 | <td colspan="1" rowspan="1">å¿œç¥å€±èŽ¥</td> |
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344 | <td colspan="1" rowspan="1">å°±ååš <a href="#etc">éåœ</a>äžæå°çïŒè¿äžªé项äŒæ¯é»è®€æ
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345 | </td> |
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346 | </tr> |
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347 | |
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348 | <tr> |
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349 | <td colspan="1" rowspan="1"><span class="codefrag">-log <logdir></span></td> |
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350 | <td colspan="1" rowspan="1">è®°åœæ¥å¿å° <logdir></td> |
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351 | <td colspan="1" rowspan="1">DistCp䞺æ¯äžªæ件çæ¯æ¬¡å°è¯æ·èŽæäœéœè®°åœæ¥å¿ïŒå¹¶ææ¥å¿äœäžºmapçèŸåºã |
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352 | åŠæäžäžªmap倱莥äºïŒåœéæ°æ§è¡æ¶è¿äžªæ¥å¿äžäŒè¢«ä¿çã |
---|
353 | </td> |
---|
354 | </tr> |
---|
355 | |
---|
356 | <tr> |
---|
357 | <td colspan="1" rowspan="1"><span class="codefrag">-m <num_maps></span></td> |
---|
358 | <td colspan="1" rowspan="1">åæ¶æ·èŽçæ倧æ°ç®</td> |
---|
359 | <td colspan="1" rowspan="1">æå®äºæ·èŽæ°æ®æ¶mapçæ°ç®ã请泚æ并äžæ¯mapæ°è¶å€ååéè¶å€§ã |
---|
360 | </td> |
---|
361 | </tr> |
---|
362 | |
---|
363 | <tr> |
---|
364 | <td colspan="1" rowspan="1"><span class="codefrag">-overwrite</span></td> |
---|
365 | <td colspan="1" rowspan="1">èŠçç®æ </td> |
---|
366 | <td colspan="1" rowspan="1">åŠæäžäžªmap倱莥并äžæ²¡æ䜿çš<span class="codefrag">-i</span>é项ïŒäžä»
ä»
é£äºæ·èŽå€±èŽ¥çæ件ïŒè¿äžªååä»»å¡äžçæææ件éœäŒè¢«éæ°æ·èŽã |
---|
367 | å°±å<a href="#uo">äžé¢</a>æå°çïŒå®äŒæ¹åçæç®æ è·¯åŸçè¯ä¹ïŒæ以 |
---|
368 | çšæ·èŠå°å¿äœ¿çšè¿äžªé项ã |
---|
369 | </td> |
---|
370 | </tr> |
---|
371 | |
---|
372 | <tr> |
---|
373 | <td colspan="1" rowspan="1"><span class="codefrag">-update</span></td> |
---|
374 | <td colspan="1" rowspan="1">åŠææºåç®æ ç倧å°äžäžæ ·åè¿è¡èŠç</td> |
---|
375 | <td colspan="1" rowspan="1">åä¹åæå°çïŒè¿äžæ¯"åæ¥"æäœã |
---|
376 | æ§è¡èŠççå¯äžæ åæ¯æºæ件åç®æ æ件倧å°æ¯åŠçžåïŒåŠæäžåïŒåæºæ件æ¿æ¢ç®æ æ件ã |
---|
377 | å <a href="#uo">äžé¢</a>æå°çïŒå®ä¹æ¹åçæç®æ è·¯åŸçè¯ä¹ïŒ |
---|
378 | çšæ·äœ¿çšèŠå°å¿ã |
---|
379 | </td> |
---|
380 | </tr> |
---|
381 | |
---|
382 | <tr> |
---|
383 | <td colspan="1" rowspan="1"><span class="codefrag">-f <urilist_uri></span></td> |
---|
384 | <td colspan="1" rowspan="1">䜿çš<urilist_uri> äœäžºæºæ件åè¡š</td> |
---|
385 | <td colspan="1" rowspan="1">è¿çä»·äºææææ件åååšåœä»€è¡äžã |
---|
386 | <span class="codefrag">urilist_uri</span> åè¡šåºè¯¥æ¯å®æŽåæ³çURIã |
---|
387 | </td> |
---|
388 | </tr> |
---|
389 | |
---|
390 | |
---|
391 | </table> |
---|
392 | <a name="N10133"></a><a name="uo"></a> |
---|
393 | <h4>æŽæ°åèŠç</h4> |
---|
394 | <p>è¿éç»åºäžäº <span class="codefrag">-update</span>å <span class="codefrag">-overwrite</span>çäŸåã |
---|
395 | èèäžäžªä»<span class="codefrag">/foo/a</span> å |
---|
396 | <span class="codefrag">/foo/b</span> å° <span class="codefrag">/bar/foo</span>çæ·èŽïŒæºè·¯åŸå
æ¬ïŒ |
---|
397 | </p> |
---|
398 | <p> |
---|
399 | <span class="codefrag"> hdfs://nn1:8020/foo/a</span> |
---|
400 | <br> |
---|
401 | |
---|
402 | <span class="codefrag"> hdfs://nn1:8020/foo/a/aa</span> |
---|
403 | <br> |
---|
404 | |
---|
405 | <span class="codefrag"> hdfs://nn1:8020/foo/a/ab</span> |
---|
406 | <br> |
---|
407 | |
---|
408 | <span class="codefrag"> hdfs://nn1:8020/foo/b</span> |
---|
409 | <br> |
---|
410 | |
---|
411 | <span class="codefrag"> hdfs://nn1:8020/foo/b/ba</span> |
---|
412 | <br> |
---|
413 | |
---|
414 | <span class="codefrag"> hdfs://nn1:8020/foo/b/ab</span> |
---|
415 | </p> |
---|
416 | <p>åŠæ没讟眮<span class="codefrag">-update</span>æ <span class="codefrag">-overwrite</span>éé¡¹ïŒ |
---|
417 | é£ä¹äž€äžªæºéœäŒæ å°å°ç®æ 端ç |
---|
418 | <span class="codefrag">/bar/foo/ab</span>ã |
---|
419 | åŠæ讟眮äºè¿äž€äžªé项ïŒæ¯äžªæºç®åœçå
容éœäŒåç®æ ç®åœç |
---|
420 | <strong>å
容</strong> åæ¯èŸãDistCp碰å°è¿ç±»å²çªçæ
åµäŒç»æ¢æäœå¹¶éåºã</p> |
---|
421 | <p>é»è®€æ
åµäžïŒ<span class="codefrag">/bar/foo/a</span> å |
---|
422 | <span class="codefrag">/bar/foo/b</span> ç®åœéœäŒè¢«å建ïŒæ以并äžäŒæå²çªã</p> |
---|
423 | <p>ç°åšèèäžäžªäœ¿çš<span class="codefrag">-update</span>åæ³çæäœ:<br> |
---|
424 | |
---|
425 | <span class="codefrag">distcp -update hdfs://nn1:8020/foo/a \</span> |
---|
426 | <br> |
---|
427 | |
---|
428 | <span class="codefrag"> |
---|
429 | |
---|
430 | hdfs://nn1:8020/foo/b \</span> |
---|
431 | <br> |
---|
432 | |
---|
433 | <span class="codefrag"> |
---|
434 | |
---|
435 | hdfs://nn2:8020/bar</span> |
---|
436 | </p> |
---|
437 | <p>å
¶äžæºè·¯åŸ/倧å°:</p> |
---|
438 | <p> |
---|
439 | <span class="codefrag"> hdfs://nn1:8020/foo/a</span> |
---|
440 | <br> |
---|
441 | |
---|
442 | <span class="codefrag"> hdfs://nn1:8020/foo/a/aa 32</span> |
---|
443 | <br> |
---|
444 | |
---|
445 | <span class="codefrag"> hdfs://nn1:8020/foo/a/ab 32</span> |
---|
446 | <br> |
---|
447 | |
---|
448 | <span class="codefrag"> hdfs://nn1:8020/foo/b</span> |
---|
449 | <br> |
---|
450 | |
---|
451 | <span class="codefrag"> hdfs://nn1:8020/foo/b/ba 64</span> |
---|
452 | <br> |
---|
453 | |
---|
454 | <span class="codefrag"> hdfs://nn1:8020/foo/b/bb 32</span> |
---|
455 | </p> |
---|
456 | <p>åç®çè·¯åŸ/倧å°:</p> |
---|
457 | <p> |
---|
458 | <span class="codefrag"> hdfs://nn2:8020/bar</span> |
---|
459 | <br> |
---|
460 | |
---|
461 | <span class="codefrag"> hdfs://nn2:8020/bar/aa 32</span> |
---|
462 | <br> |
---|
463 | |
---|
464 | <span class="codefrag"> hdfs://nn2:8020/bar/ba 32</span> |
---|
465 | <br> |
---|
466 | |
---|
467 | <span class="codefrag"> hdfs://nn2:8020/bar/bb 64</span> |
---|
468 | </p> |
---|
469 | <p>äŒäº§ç:</p> |
---|
470 | <p> |
---|
471 | <span class="codefrag"> hdfs://nn2:8020/bar</span> |
---|
472 | <br> |
---|
473 | |
---|
474 | <span class="codefrag"> hdfs://nn2:8020/bar/aa 32</span> |
---|
475 | <br> |
---|
476 | |
---|
477 | <span class="codefrag"> hdfs://nn2:8020/bar/ab 32</span> |
---|
478 | <br> |
---|
479 | |
---|
480 | <span class="codefrag"> hdfs://nn2:8020/bar/ba 64</span> |
---|
481 | <br> |
---|
482 | |
---|
483 | <span class="codefrag"> hdfs://nn2:8020/bar/bb 32</span> |
---|
484 | </p> |
---|
485 | <p>åªænn2ç<span class="codefrag">aa</span>æ件没æ被èŠçãåŠææå®äº |
---|
486 | <span class="codefrag">-overwrite</span>é项ïŒæææ件éœäŒè¢«èŠçã |
---|
487 | </p> |
---|
488 | </div> <!-- Usage --> |
---|
489 | |
---|
490 | |
---|
491 | <a name="N101E4"></a><a name="etc"></a> |
---|
492 | <h2 class="h3">éåœ</h2> |
---|
493 | <div class="section"> |
---|
494 | <a name="N101EA"></a><a name="Map%E6%95%B0%E7%9B%AE"></a> |
---|
495 | <h3 class="h4">Mapæ°ç®</h3> |
---|
496 | <p>DistCpäŒå°è¯çååéèŠæ·èŽçå
容ïŒè¿æ ·æ¯äžªmapæ·èŽå·®äžå€çžç倧å°çå
容ã |
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497 | äœå 䞺æ件æ¯æå°çæ·èŽç²åºŠïŒæ以é
眮å¢å åæ¶æ·èŽïŒåŠmapïŒçæ°ç®äžäžå®äŒå¢å å®é
åæ¶æ·èŽçæ°ç®ä»¥åæ»ååéã |
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498 | </p> |
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499 | <p>åŠæ没䜿çš<span class="codefrag">-m</span>é项ïŒDistCpäŒå°è¯åšè°åºŠå·¥äœæ¶æå®mapçæ°ç® |
---|
500 | 䞺 <span class="codefrag">min (total_bytes / bytes.per.map, 20 * num_task_trackers)</span>ïŒ |
---|
501 | å
¶äž<span class="codefrag">bytes.per.map</span>é»è®€æ¯256MBã</p> |
---|
502 | <p>建议对äºé¿æ¶éŽè¿è¡æå®æè¿è¡çäœäžïŒæ ¹æ®æºåç®æ é矀倧å°ãæ·èŽæ°é倧å°ä»¥å垊宜è°æŽmapçæ°ç®ã |
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503 | </p> |
---|
504 | <a name="N10203"></a><a name="cpver"></a> |
---|
505 | <h3 class="h4">äžåHDFSçæ¬éŽçæ·èŽ</h3> |
---|
506 | <p>对äºäžåHadoopçæ¬éŽçæ·èŽïŒçšæ·åºè¯¥äœ¿çšHftpFileSystemã |
---|
507 | è¿æ¯äžäžªåªè¯»æ件系ç»ïŒæ以DistCpå¿
é¡»è¿è¡åšç®æ 端é矀äžïŒæŽç¡®åç诎æ¯åšèœå€åå
¥ç®æ é矀çTaskTrackeräžïŒã |
---|
508 | æºçæ ŒåŒæ¯ |
---|
509 | <span class="codefrag">hftp://<dfs.http.address>/<path></span> |
---|
510 | ïŒé»è®€æ
åµ<span class="codefrag">dfs.http.address</span>æ¯ |
---|
511 | <namenode>:50070ïŒã</p> |
---|
512 | <a name="N10213"></a><a name="Map%2FReduce%E5%92%8C%E5%89%AF%E6%95%88%E5%BA%94"></a> |
---|
513 | <h3 class="h4">Map/Reduceåå¯æåº</h3> |
---|
514 | <p>ååé¢æå°çïŒmapæ·èŽèŸå
¥æ件倱莥æ¶ïŒäŒåžŠæ¥äžäºå¯æåºã |
---|
515 | </p> |
---|
516 | <ul> |
---|
517 | |
---|
518 | |
---|
519 | <li>é€é䜿çšäº<span class="codefrag">-i</span>ïŒä»»å¡äº§ççæ¥å¿äŒè¢«æ°çå°è¯æ¿æ¢æã |
---|
520 | </li> |
---|
521 | |
---|
522 | |
---|
523 | <li>é€é䜿çšäº<span class="codefrag">-overwrite</span>ïŒæ件被ä¹åçmapæåæ·èŽååœåäžæ¬¡æ§è¡æ·èŽæ¶äŒè¢«æ 记䞺 |
---|
524 | "被応ç¥"ã</li> |
---|
525 | |
---|
526 | |
---|
527 | <li>åŠæmap倱莥äº<span class="codefrag">mapred.map.max.attempts</span>次ïŒå©äžçmapä»»å¡äŒè¢«ç»æ¢ïŒé€é䜿çšäº<span class="codefrag">-i</span>)ã |
---|
528 | </li> |
---|
529 | |
---|
530 | |
---|
531 | <li>åŠæ<span class="codefrag">mapred.speculative.execution</span>被讟眮䞺 |
---|
532 | <span class="codefrag">final</span>å<span class="codefrag">true</span>ïŒåæ·èŽçç»ææ¯æªå®ä¹çã</li> |
---|
533 | |
---|
534 | |
---|
535 | </ul> |
---|
536 | </div> <!-- Appendix --> |
---|
537 | |
---|
538 | |
---|
539 | </div> |
---|
540 | <!--+ |
---|
541 | |end content |
---|
542 | +--> |
---|
543 | <div class="clearboth"> </div> |
---|
544 | </div> |
---|
545 | <div id="footer"> |
---|
546 | <!--+ |
---|
547 | |start bottomstrip |
---|
548 | +--> |
---|
549 | <div class="lastmodified"> |
---|
550 | <script type="text/javascript"><!-- |
---|
551 | document.write("Last Published: " + document.lastModified); |
---|
552 | // --></script> |
---|
553 | </div> |
---|
554 | <div class="copyright"> |
---|
555 | Copyright © |
---|
556 | 2007 <a href="http://www.apache.org/licenses/">The Apache Software Foundation.</a> |
---|
557 | </div> |
---|
558 | <!--+ |
---|
559 | |end bottomstrip |
---|
560 | +--> |
---|
561 | </div> |
---|
562 | </body> |
---|
563 | </html> |
---|