现网运行过程中,某些高负载集群的 NN 频繁打印下面的 “block is COMMITTED but not COMPLETE" 日志,且客户端经常会关闭文件失败,导致业务异常退出,如下所示: HDFS 基本逻辑 这实际是一个 block 无法及时到达 COMPLETE 状态的问题,在 HDFS 中,一个 block 只有达到最小副本数之后,才能变为 COMPLETE 状态。HDFS ...
committed-allowedparameter of HDFS to close files in advance to improve data write performance. However, data may fail to be read because the block cannot be found or the data block information recorded in the NameNode metadata is inconsistent with that stored in the DataNode. Therefore, this ...
+ src + " but file is already closed."; NameNode.stateChangeLog.warn(message); throw new IOException(message); } // The last block is not COMPLETE, and // that the penultimate block if exists is either COMPLETE or COMMITTED final BlockInfoContiguous lastBlock = pendingFile.getLastBlock()...
Add a new datanode only if r is greater than or equal to 3 and either (1) floor(r/2) is greater than or equal to n; or (2) r is greater than n and the block is hflushed/appended. dfs.client.block.write.replace-datanode-on-failure.best-effort FALSE This property is used only ...
*/COMMITTED} 数据块的length(长度)和gc(时间戳)不再发生变化,并且Namenode已经收到至少一个Datanode报告有FINALIZED状态的副本(Datanode上的副本状态发生变化时会通过blockReveivedAndDeleted()方法向Namenode汇报)。只有当HDFS文件的所有数据块都处于COMPLETE状态时,该HDFS文件才能被关闭。
HDFS-7342reports a case that Lease Recovery can not succeed when the second-to-last block is COMMITTED and the last block is COMPLETE. One suggested solution is to force the the lease to be recovered, which is similar to how we handle when the last block is COMMITTED. One can see that...
* 当一个文件租约到期,它的最后一个数据块可能不是COMPLETE状态,并且需要经历一个恢复过程,它将同步存在的副本目录。 */ UNDER_RECOVERY, /** * The block is committed. * The client reported that all bytes are written to data-nodes * with the given generation stamp and block length, but no * ...
Once a task has successfully completed, all topics pulled are committed to their final output directories. If a task doesn't complete successfully, then none of the output is committed. This allows the hadoop job to use speculative execution. Speculative execution happens when a task appears to ...
Java org.apache.hadoop.hdfs.protocol.AlreadyBeingCreatedException类属于org.apache.hadoop.hdfs.protocol包。使用说明:当您要求创建已创建但尚未关闭的...
These are also not needed yet, but we are going to setup our SDK chain object fully. Step 6. At this point the SDK is fully configured and ready to interact with the blockchain. Code Structure This application has 3 coding environments to juggle. The Chaincode Part - This is GoLang ...