hadoop 的HDFS 的 standby namenode无法启动事故处理

standby namenode无法启动

现象:线上使用的2.5.0-cdh5.3.2版本Hadoop,开启了了NameNode HA,HA采用QJM方式。hadoop的集群的namenode的standby节点宕掉,重启无法启动成功。

1. standby namenode出现异常时的现象

异常现象1:

hadoop的集群的namenode的standby节点宕掉,重启无法启动成功。查看hadoop-hdfs-namenode-hostname.log,发现报出如下异常:" org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader: Encountered exception on operation ReassignLeaseOp "

2016-12-02 04:00:50,567 INFO BlockStateChange: BLOCK* addStoredBlock: blockMap updated: 10.10.110.110:50010 is added to blk_1189739479_116038994{blockUCState=UNDER_CONSTRUCTION, primaryNodeIndex=-1, replicas=[ReplicaUnderConstruction[[DISK]DS-5830f95b-cb53-4de4-977c-96b3eef06603:NORMAL|FINALIZED], ReplicaUnderConstruction[[DISK]DS-cf11c8ea-95b7-43f7-979f-a4a78c612b61:NORMAL|FINALIZED], ReplicaUnderConstruction[[DISK]DS-9e9b856f-6364-44b7-bc5a-b277423a6eda:NORMAL|FINALIZED], ReplicaUnderConstruction[[DISK]DS-dafd3788-bf7b-4512-8839-154a718a4297:NORMAL|FINALIZED]]} size 0
2016-12-02 04:00:50,568 ERROR org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader: Encountered exception on operation ReassignLeaseOp [leaseHolder=DFSClient_NONMAPREDUCE_-1432667135_1, path=/home/baoxin/hive/AccessToken/Token/20161202/2016120202, newHolder=HDFS_NameNode, opCode=OP_REASSIGN_LEASE, txid=746502271]
java.lang.IllegalStateException
at com.google.common.base.Preconditions.checkState(Preconditions.java:129)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.applyEditLogOp(FSEditLogLoader.java:648)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:228)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadFSEdits(FSEditLogLoader.java:137)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:820)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:801)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer.doTailEdits(EditLogTailer.java:232)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.doWork(EditLogTailer.java:331)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.access$200(EditLogTailer.java:284)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread$1.run(EditLogTailer.java:301)
at org.apache.hadoop.security.SecurityUtil.doAsLoginUserOrFatal(SecurityUtil.java:411)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.run(EditLogTailer.java:297)
2016-12-02 04:00:50,607 WARN org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:lei.chen (auth:SIMPLE) cause:org.apache.hadoop.ipc.StandbyException: Operation category READ is not supported in state standby
2016-12-02 04:00:50,607 INFO org.apache.hadoop.ipc.Server: IPC Server handler 23 on 8020, call org.apache.hadoop.hdfs.protocol.ClientProtocol.getEZForPath from 10.10.110.152:40258 Call#0 Retry#0: org.apache.hadoop.ipc.StandbyException: Operation category READ is not supported in state standby
2016-12-02 04:00:50,722 WARN org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:lei.chen (auth:SIMPLE) cause:org.apache.hadoop.ipc.StandbyException: Operation category WRITE is not supported in state standby
2016-12-02 04:00:50,723 INFO org.apache.hadoop.ipc.Server: IPC Server handler 55 on 8020, call org.apache.hadoop.hdfs.protocol.ClientProtocol.mkdirs from 10.10.110.152:40258 Call#1 Retry#0: org.apache.hadoop.ipc.StandbyException: Operation category WRITE is not supported in state standby
2016-12-02 04:00:51,050 FATAL org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer: Unknown error encountered while tailing edits. Shutting down standby NN.
java.io.IOException: java.lang.IllegalStateException
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:238)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadFSEdits(FSEditLogLoader.java:137)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:820)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:801)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer.doTailEdits(EditLogTailer.java:232)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.doWork(EditLogTailer.java:331)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.access$200(EditLogTailer.java:284)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread$1.run(EditLogTailer.java:301)
at org.apache.hadoop.security.SecurityUtil.doAsLoginUserOrFatal(SecurityUtil.java:411)
at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.run(EditLogTailer.java:297)
Caused by: java.lang.IllegalStateException
at com.google.common.base.Preconditions.checkState(Preconditions.java:129)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.applyEditLogOp(FSEditLogLoader.java:648)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:228)
... 9 more
2016-12-02 04:00:51,054 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1
2016-12-02 04:00:51,057 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at db-nn1.inc.mtime.com/1xx.1xx.11x.10x
************************************************************/

通过上面异常日志,发现namenode的standby节点无法重启,是因为加载 /home/baoxin/hive/AccessToken/Token/20161202/2016120202 遇到了异常。

从 HDFS 下载 /home/baoxin/hive/AccessToken/Token/20161202/2016120202这个文件,打开发现这个文件的最后一行是不完整的hive记录,说明该hdfs文件是损坏的。

于是,我们通过hadoop 命令,将这个文件删除了。然后重启standby 的namenode,发现问题依旧,异常依然是在加载home/baoxin/hive/AccessToken/Token/20161202/2016120202日志时,而且 使用 hadoop fsck -blocks 命令检查hdfs,发现出现了一个名字叫“null”的异常块。

** 异常现象2:**

hive sql 任务报出:“org.apache.hadoop.ipc.RemoteException(java.lang.ArrayIndexOutOfBoundsException): java.lang.ArrayIndexOutOfBoundsException”异常。

hive任务,hbase相关读写操作任务,都会报出"ArrayIndexOutOfBoundsException"的异常.

并且hive相关的MR任务根本无法成功提交到hadoop上。

但是workcout之类的纯MapReduce程序可以成功提交到hadoop集群的(hadoop jar的方式)。

hive> select count(*) from ECommerce.GoodsSubOrder;
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks determined at compile time: 1
In order to change the average load for a reducer (in bytes):
set hive.exec.reducers.bytes.per.reducer=<number>
In order to limit the maximum number of reducers:
set hive.exec.reducers.max=<number>
In order to set a constant number of reducers:
set mapreduce.job.reduces=<number>
org.apache.hadoop.ipc.RemoteException(java.lang.ArrayIndexOutOfBoundsException): java.lang.ArrayIndexOutOfBoundsException at org.apache.hadoop.ipc.Client.call(Client.java:1411)
at org.apache.hadoop.ipc.Client.call(Client.java:1364)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)
at com.sun.proxy.$Proxy15.delete(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.delete(ClientNamenodeProtocolTranslatorPB.java:513)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
at com.sun.proxy.$Proxy16.delete(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient.delete(DFSClient.java:1853)
at org.apache.hadoop.hdfs.DistributedFileSystem$11.doCall(DistributedFileSystem.java:599)
at org.apache.hadoop.hdfs.DistributedFileSystem$11.doCall(DistributedFileSystem.java:595)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.delete(DistributedFileSystem.java:595)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:539)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1295)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1292)
at java.security.AccessController.doPrivileged(Native Method)

2.异常处理过程:

1. 将报错的文件从Hadoop上删除(先备份),standby NN仍然起不来,错误信息一样

hadoop fs -rm /home/baoxin/hive/AccessToken/Token/20161202/2016120202

2.怀疑是Standby NameNode的editlog有问题

怀疑可能只是Standby上的fsimage文件或edits文件有问题,于是我们在Standby上执行了.


hdfs hadoop namenode -bootstrapStandby ##改过程会自动从Active Namenode上获取最新的fsimage文件,
#并从Journalnode日志服务器上下载并执行新的edits文件。 加载edits时仍然遇到上面相同的报错。

因为NameNOde每次启动都需要加载editlog,所以为了跳过此操作,我们将Active进入安全模式,并进行

saveNameSpace操作将dump出来的fsimage和txid等拷贝到Standby NN上,重启就可以避免加载editlog了。

hadoop dfsadmin -safemode enter
hadoop dfsadmin -saveNamespace ## 将namenode的fsimage信息dump出来,
hadoop dfsadmin -safemode leave

但namenode无法进⼊入安全模式,报错信息:无法连接standby服务

safemode: Call From db-nn1.inc.mtime.com/10.10.110.100 to db-nn1.inc.mtime.com:802
0 failed on connection exception: java.net.ConnectException: Connection refused; F
or more details see: http://wiki.apache.org/hadoop/ConnectionRefused

于是,查看etc/hadoop/hdfs-site.xml配置文件dfs.namenode.name.dir配置项下对应的NN的配置。

 <property>
<name>dfs.namenode.name.dir</name>
<value>/home/hadoop/apache-hadoop/hadoop/var/dfs/nn</value>
</property>

直接将active nn的 "${dfs.namenode.name.dir}/current"目录下的fsimage和editlog等copy到standby上,启动,仍然报同样的错。

3.参考博客:http://heylinux.com/archives/3398.html对edit log 文件进行修复和修复。

在修复edit log 之前,需要现将active的namenode进入安全模式,或者先停止,避免有namenode上新的操作

,会更新editlog文件。

进入安全模式

hadoop dfsadmin -safemode enter  ##将active namenode 进入安全模式,或者直接关闭
#hadoop dfsadmin -safemode leave

将editlog文件翻译成xml文件

##将editlog文件翻译成xml文件
hdfs oev -i edits_0000000000075549590-0000000000075551044 -o edits_0000000000075549590-0000000000075551044.xml

** vi 打开edits_0000000000075549590-0000000000075551044.xml 文件**

在XML文件中搜索 找到如下操作

[leaseHolder=DFSClient_NONMAPREDUCE_-1432667135_1, path=/home/baoxin/hive/AccessToken/Token/20161202/2016120202, newHolder=HDFS_NameNode, opCode=OP_REASSIGN_LEASE, txid=746502271]

的edit log 记录,直接删掉。

##将editlog xml文件转换成原来的二进制文件
hdfs oev -i edits_0000000000075549590-0000000000075551044.xml -o edits_0000000000075549590-0000000000075551044_new -p binary

然后将新生成的binary文件同步到journalnode日志服务器中。重启standby的namenode,发现报如下错误:

2016-12-02 15:39:20,933 WARN org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Encountered exception loading fsimage
java.io.IOException: There appears to be a gap in the edit log. We expected txid 746515168, but got txid 746515169.
at org.apache.hadoop.hdfs.server.namenode.MetaRecoveryContext.editLogLoaderPrompt(MetaRecoveryContext.java:94)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:209)
at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadFSEdits(FSEditLogLoader.java:137)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:820)
at org.apache.hadoop.hdfs.server.namenode.FSImage.loadFSImage(FSImage.java:678)
at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:281)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:1006)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:736)
at org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:531)
at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:587)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:754)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:738)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1427)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1493)
2016-12-02 15:39:20,937 INFO org.mortbay.log: Stopped HttpServer2$SelectChannelConnectorWithSafeStartup@db-nn1.inc.mtime.com:50070
2016-12-02 15:39:21,037 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Stopping NameNode metrics system...

原来edit log的txid是连续的,我们手工把编辑日志中的异常操作删掉,edit log的txid就变成是不连续的,namenode启动是时加载editlog就会报出期望的txid不一致的异常。

因此,不能直接把异常操作删掉, 可以将原有操作替换成其它的内容,比如无关痛痒的修改一个现有文件的权限"opCode=OP_SET_PERMISSIONS",并保留TXID 240823292以确保edits文件的完整性。

修改完成后,重新打包成二进制的edit log文件,并同步到journalnode日志服务器中,重启standby的namenode。发现报错的操作日志记录已经不在报错,但下一个editlog 日志记录又有问题,同样性质的异常:

2016-12-02 15:21:35,184 ERROR org.apache.hadoop.hdfs.server.namenode.FSEditLogLoad
er: Encountered exception on operation ReassignLeaseOp [leaseHolder=HDFS_NameNode,
path=/home/baoxin/hive/AccessToken/Token/20161202/2016120202, newHolder=HDFS_Name
Node, opCode=OP_REASSIGN_LEASE, txid=746544405]

于是,重复上面的动作,发现还有很多hdfs文件的对应操作日志对应的动作都有问题,而hdfs文件本身是没有问题的,就写了一个工具程序,将出现问题时间点后的操作日志都改成了"opCode=OP_SET_PERMISSIONS"动作。

修改edit log文件的工具程序如下:

package temp;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map; public class ReplaceXML { static List<String> list = new ArrayList<String>(); /**
* 1 : editlog
* 2 : 需要替换的文件
* 3 : 替换为
* 4 : 目的文件
* @param args
* @throws UnsupportedEncodingException
* @throws FileNotFoundException
*/
public static void main(String[] args) throws Exception {
System.out.println("---------------------");
readFileByLines(args[1]);
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(args[3], true), "UTF-8"));
PrintWriter printWriter = new PrintWriter(bw);
String recordTemplate =
"<RECORD>\n" +
" <OPCODE>OP_SET_PERMISSIONS</OPCODE>\n" +
" <DATA>\n" +
" #TXID#\n" +
" <SRC>/home/baoxin/hive/AccessToken/Token/20161202/2016120202</SRC>\n" +
" <MODE>504</MODE>\n" +
" </DATA>\n" +
"</RECORD>"; String header="<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<EDITS>\n" +
" <EDITS_VERSION>-59</EDITS_VERSION>\n";
String tail="</EDITS>";
File file = new File(args[0]);
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(file));
int line = 0;
// 一次读一条记录,读入记录为null时,
printWriter.write(header);
Map<String,String> info = null;
while( (info = readRecord(reader ) ) != null){
line++;
String record = info.get("RECORD");
String txid = info.get("TXID");
record = recordTemplate.replace("#TXID#",txid.trim());
System.out.println("line " + line);
printWriter.write(record + "\n");
printWriter.flush();
}
} catch (IOException e) {
e.printStackTrace();
} finally { if (reader != null) {
try {
reader.close();
printWriter.write(tail);
} catch (IOException e1) {
}
}
if (printWriter != null) {
printWriter.close();
}
}
} public static Map<String,String> readRecord(BufferedReader reader) throws IOException { Map<String,String> map = new HashMap<String,String>();
StringBuilder record = new StringBuilder();
String tempStr = null;
while ((tempStr = reader.readLine()) != null) {
record.append(tempStr).append("\n");
if (tempStr.trim().equals("<RECORD>")) { ///开始
}else if (tempStr.trim().equals("</RECORD>")){ ///结束
map.put("RECORD",record.toString());
return map;
}else{
// if(tempStr.trim().contains("<PATH>")){
// map.put("PATH",tempStr);
// }
if(tempStr.trim().contains("<TXID>")){
map.put("TXID",tempStr);
}
}
}
return null;
} public static void readFileByLines(String fileName) {
File file = new File(fileName);
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(file));
String tempString = null;
int line = 1;
// 一次读一行,读入null时文件结束
while ((tempString = reader.readLine()) != null) {
// 把当前行号显示出来
line++;
list.add(tempString);
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e1) {
}
}
}
} }

修改完成后,重namdenode,能成功启动了。

然后。

手工执行dfsadmin -safemode leave

手工删除损坏的块fsck —delete

namenode启动后,没重启datanode,提交hivejob时报错,重启datanode即可。报错信息如下:

java.io.EOFException: Premature EOF: no length prefix available
at org.apache.hadoop.hdfs.protocolPB.PBHelper.vintPrefixed(PBHelper.java:2109)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.createBlockOutputStream
(DFSOutputStream.java:1380)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.nextBlockOutputStream(D
FSOutputStream.java:1302)
at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.jav
a:536)
Job Submission failed with exception 'java.io.EOFException(Premature EOF: no lengt
h prefix available)'
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.mr.MapR
edTask
``` 至此,standby namenode启动异常解决,集群恢复正常。分析出现本次异常的原因是:集群规划比较简单,集群的
的压力较大,造成整个HDFS集群频繁重启,引起hdfs文件损坏,namenode的editlog 出现损坏造成的。 ###3.其他解决办法:
*1.正常情况下,saveNamespace操作时可以用的。将dump出来文件替换standby namenode即可。*
```
hadoop dfsadmin -saveNamespace ## 将namenode的fsimage信息 dump出来,
``` *2.使用 HDFS数据恢复模式使用* HDFS数据恢复模式实质上是一种NameNode的启动方式,我们可以通过指定启动NameNode的参数来选择是否以这样的方式启动NameNode,输入hdfs namenode -help即可获取这些参数,
```
$ hdfs namenode -help
Usage: java NameNode [-backup] |
[-checkpoint] |
...
[-bootstrapStandby] |
[-recover [ -force] ] | // 以数据恢复模式的启动方式,force参数表示后面所有的提醒都默认选择第一个
[-metadataVersion ] ]
``` 此种方式与之前脚本启动方式略有不同的一点在于,此类方式是前台启动的,用户能直观地看到NameNode的启动过程。 ###参考文档和文章:
[HDFS QJM方式的官方文档(HDFS High Availability Using the Quorum Journal Manager)](http://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-hdfs/HDFSHighAvailabilityWithQJM.html) [[HADOOP] Standby NN无法启动](https://www.thinksaas.cn/group/topic/399536/) [Hadoop运维笔记 之 Namenode异常停止后无法正常启动](http://ju.outofmemory.cn/entry/98888) [HDFS数据恢复模式](http://blog.****.net/androidlushangderen/article/details/52679606)
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