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Org. apache. hadoop-hadoopVersionAnnotation, org. apache. hadoop
Follow the order of classes in the package order, because I don't understand the relationship between the specific system of the
Org. apache. hadoop. filecache-*, org. apache. hadoop
I don't know why the package is empty. Should the package name be a class for managing File Cache?
No information was found on the internet, and no answers were answered fr
Org. apache. hadoop. fs-Seekable, org. apache. commons
I should have read BufferedFSInputStream first, but it implements the Seekable and PositionedReadable interfaces. Let's look at these two interfaces first and then it will be easier to understand.
1 package
compressed format based on the input file suffix. Therefore, when it reads an input file, it is ***. when gz is used, it is estimated that the file is a file compressed with gzip, so it will try to read it using gzip.
Public CompressionCodecFactory (Configuration conf) {codecs = new TreeMap
If other compression methods are used, this can be configured in the core-site.xml
Or in the code
Conf. set ("io. compression. codecs "," org.
Description: Compile hadoop program using eclipse in window and run on hadoop. the following error occurs:
11/10/28 16:05:53 info mapred. jobclient: running job: job_201110281103_000311/10/28 16:05:54 info mapred. jobclient: Map 0% reduce 0%11/10/28 16:06:05 info mapred. jobclient: task id: attempt_201110281103_0003_m_000002_0, status: FailedOrg. apache.
1. Preface
Hadoop RPC is mainly implemented through the dynamic proxy and reflection (reflect) of Java,Source codeUnder org. Apache. hadoop. IPC, there are the following main classes:
Client: the client of the RPC service
RPC: implements a simple RPC model.
Server: abstract class of the server
Rpc. S
method names and parameters as the data transmission layer. The key to remote calling is that invocation implements the writable interface. Invocation writes the called methodname to out in the write (dataoutput out) function, and writes the number of parameters of the called method to out, at the same time, the classname of the parameter is written out one by one, and all parameters are written out one by one. This determines that the parameters in the method called through RPC are either simp
Solve Exception: org. apache. hadoop. io. nativeio. NativeIO $ Windows. access0 (Ljava/lang/String; I) Z and other issues, ljavalangstring
I. Introduction
Windows Eclipse debugging Hadoop2 code, so we in windows Eclipse configuration hadoop-eclipse-plugin-2.6.0.jar plug-in, and when running
Reason:Hadoop-eclipse-plugin-2.7.3.jar compiled JDK versions are inconsistent with the JDK version used by Eclipse startup.Solution One :Modify the Myeclipse.ini file to resolve it. D:/java/myeclipse/common/binary/com.sun.java.jdk.win32.x86_1.6.0.013/jre/bin/client/jvm.dll to: D:/Program Files ( x86)/java/jdk1.7.0_45/jre/bin/client/jvm.dlljdk1.7.0_45 version of the JDK for your own installationIf it is not valid, check that the Hadoop version set in t
processing of batch and interactive data. TEZ is being adopted by other frameworks in Hive, Pig, and Hadoop ecosystems, and can also be used as the underlying execution engine with other commercial software, such as ETL tools, to replace Hadoop MapReduce. ZooKeeper: A high-performance distributed application Coordination Service. (The contents of the ZooKeeper are described in later chapters)
-distributed mode on a single node, where each Hadoop daemon runs as a standalone Java process.ConfigurationUse the following:Etc/hadoop/core-site.xml:123456Etc/hadoop/hdfs-site.xml:Interested can continue to see the next chapter
Many people know that I have big data training materials, all naïve thought I have a full set of big data development,
your cluster, and that installing a Hadoop cluster typically extracts the installation software to all the machines in the cluster, referring to the previous section, "Installation configuration on Apache Hadoop single node."Typically, a machine in a cluster is designated as a NameNode and another machine as a ResourceManager. These are all master. Other service
/mapreduce/hadoop-mapreduce-examples-2.7.3.jar grep input Output ' dfs[a-z. +1(7) View output fileCopy the output file from the Distributed file system to the local file system view:$ bin/hdfs dfs-get Output output$ cat output/*****12Alternatively, view the output file on the Distributed File system:$ Bin/hdfs Dfs-cat output/*1(8) After completing all the actions, stop the daemon:$ sbin/stop-dfs.sh* * You need to learn to continue reading the next cha
Although I have installed a Cloudera CDH cluster (see http://www.cnblogs.com/pojishou/p/6267616.html for a tutorial), I ate too much memory and the given component version is not optional. If only to study the technology, and is a single machine, the memory is small, or it is recommended to install Apache native cluster to play, production is naturally cloudera cluster, unless there is a very powerful opera
Install and deploy Apache Hadoop 2.6.0
Note: For this document, refer to the official documentation for the original article.
1. hardware environment
There are three machines in total, all of which use the linux system. Java uses jdk1.6.0. The configuration is as follows:Hadoop1.example.com: 172.20.115.1 (NameNode)Hadoop2.example.com: 172.20.1152 (DataNode)Hadoop3.example.com: 172.115.20.3 (DataNode)Hadoop4
Hadoop has always been the technology I want to learn, just as the recent project team to do e-mall, I began to study Hadoop, although the final identification of Hadoop is not suitable for our project, but I will continue to study, more and more do not press.The basic Hadoop tutor
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