ambari journalnode异常Can't scan a pre-transactional edit log
今天在删日志文件，不知道删错哪个地方了。
该目录下一直报错，这个日志文件增长很快，
/var/log/hadoop/hdfs/ hadoop-hdfs-journalnode-xx.log
先备份/hadoop/hdfs/journal/这个目录
方式一：
然后删除除version之外的文件，重启之后就没有错误日志了，但是从文件大小来看，是少了很多
方式二：
备份别的服务器上的文件，删除当前机器的除version之外的文件，并将别的机器的文件拷贝至journal目录下(不要覆盖version)
https://blog.csdn.net/liu82327114/article/details/78601153?locationNum=8&fps=1
https://blog.csdn.net/u010936936/article/details/74199306
2017-11-22 11:08:30,510 WARN namenode.FSImage (EditLogFileInputStream.java:scanEditLog(364)) - After resync, position is 1044480
2017-11-22 11:08:30,510 WARN namenode.FSImage (EditLogFileInputStream.java:scanEditLog(359)) - Caught exception after scanning through 0 ops from /hadoop/hdfs/journal/ha/current/edits_inprogress_0000000000008164541 while determining its valid length. Position was 1044480
java.io.IOException: Can't scan a pre-transactional edit log.
at org.apache.hadoop.hdfs.server.namenode.FSEditLogOp$LegacyReader.scanOp(FSEditLogOp.java:4592)
at org.apache.hadoop.hdfs.server.namenode.EditLogFileInputStream.scanNextOp(EditLogFileInputStream.java:245)
at org.apache.hadoop.hdfs.server.namenode.EditLogFileInputStream.scanEditLog(EditLogFileInputStream.java:355)
at org.apache.hadoop.hdfs.server.namenode.FileJournalManager$EditLogFile.scanLog(FileJournalManager.java:551)
at org.apache.hadoop.hdfs.qjournal.server.Journal.scanStorageForLatestEdits(Journal.java:193)
at org.apache.hadoop.hdfs.qjournal.server.Journal.<init>(Journal.java:153)
at org.apache.hadoop.hdfs.qjournal.server.JournalNode.getOrCreateJournal(JournalNode.java:93)
at org.apache.hadoop.hdfs.qjournal.server.JournalNode.getOrCreateJournal(JournalNode.java:102)
at org.apache.hadoop.hdfs.qjournal.server.JournalNodeRpcServer.getJournalState(JournalNodeRpcServer.java:124)
at org.apache.hadoop.hdfs.qjournal.protocolPB.QJournalProtocolServerSideTranslatorPB.getJournalState(QJournalProtocolServerSideTranslatorPB.java:118)
at org.apache.hadoop.hdfs.qjournal.protocol.QJournalProtocolProtos$QJournalProtocolService$2.callBlockingMethod(QJournalProtocolProtos.java:25415)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:617)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1073)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2086)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2082)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1693)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2080)，
第一种方案
此节点的journalnode的元数据出现了问题，需要从其他正常节点的journalnode的元数据拷贝过来重启服务，需要注意各个文件的权限
第二种方案
先停止journalnode服务
删除此节点journalnode元数据存储路径中current文件夹中version以外的文件，启动journalnode
