Introduction
Assumptions and Goals
Hardware Failure
Streaming Data Access
Large Data Sets
Simple Coherency Model
“Moving Computation is Cheaper than Moving Data”
Portability Across Heterogeneous Hardware and Software Platforms
NameNode and DataNodes
The File System Namespa
1、客户端连接ZK出现下面的异常信息
2017-11-02 15:36:42,489 [myid:] - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:ZooKeeperServer@873] - Refusing session request for client /127.0.0.1:49912 as it has seen zxid 0x2a1 our last zxid is 0x0 client must try another server
2017-11-02 1
Retrying connect to server: localhost/127.0.0.1:8020. Already tried 1 time(s)
14/11/30 18:28:22 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=
14/11/30 18:28:22 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applicatio
下文中没有特殊说明,环境都是CentOS下Hadoop 2.2.0。
1、伪分布模式下执行start-dfs.sh脚本启动HDFS时出现如下错误:
vi打开libexec/hadoop-config.sh中,查找JAVA_HOME is not set and could not be found,找到后在这一行if [[ -z $JAVA_HOME ]]; then的前面添加如下语句即可:
&
在Windows下连接虚拟机CentOS64位系统上的Hadoop进行开发,运行程序出现下面的异常:
14/11/30 22:14:51 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=
14/11/30 22:15:24 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool fo
14/11/30 21:04:37 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=
14/11/30 21:04:37 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
Eannot delete /tmp/hadoop-
集群出现大面积任务失败,表现为mapreduce刚启动不久,就抛出异常,查看log可以看到,
Status : FAILED
java.lang.Throwable: Child Error
at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:271)
Caused by: java.io.IOException: Task process exit with nonzero status of 1.
at org.apache.hadoop.map