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Web: http://www.cnblogs.com/panfeng412/archive/2013/03/22/hadoop-capacity-scheduler-configuration.html
Refer to capacity scheduler guide and summarize the configuration parameters of capacity scheduler based on your practical experience. Most of the parts marked as red below are places where they have been pitted, hoping to help you.
Mapred. capacity-scheduler.q
Tags: hadoop mapreduceFirst, to print logs without using log4j, you can directly use system. Out. println. The log information output to stdout can be found at the jobtracker site.Second, if you use system. Out. println to print the log when the main function is started, you can see it directly on the console.Second, the jobtracker site is very important.Http: // your_name_node: 50030/
datasets) concurrently in clusters with thousands of nodes ).
Mr Jobs usually divide datasets into independent chunks, which are processed by map tasks in parallel. The Mr framework sorts the map output and then uses the output as the input to reduce tasks for processing. A typical method is that the input and final output of a job are stored in the Distributed File System (HDFS.
During deployment, the computing node is also a storage node, and the Mr framework and HDFS run on the same cluster.
default, these nine attributes are not available to any users or groups.
The configuration file can be dynamically loaded using the following command:
(1) Update namenode attributes: Bin/hadoop dfsadmin-refreshserviceacl
(2) Update jobtracker attributes: Bin/hadoopmradmin-refreshserviceacl
2. Scheduler configuration
Modify mapred-site.xml
Property>Name>Mapred. jobtracker. taskschedulerName>Val
-source implementation of Google MapReduce) as the core, provides users with a Distributed infrastructure with transparent underlying system details.Hadoop clusters can be divided into Master and Salve roles. An HDFS cluster is composed of one NameNode and several DataNode. NameNode acts as the master server to manage the file system namespace and client access to the file system; DataNode in the cluster manages the stored data. The MapReduce framework is composed of a single
Run Hadoop WordCount. jar in Linux.
Run Hadoop WordCount in Linux
Enter the shortcut key of Ubuntu terminal: ctrl + Alt + t
Hadoop launch command: start-all.sh
The normal execution results are as follows:
Hadoop @ HADOOP :~ $ Start-all.sh
Warning: $ HADOOP_HOME is deprecated.
Starting namenode, logging to/home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-namenode-HADOOP.MAIN.out
HADOOP. MAIN: starting datanode, logging to/home/hadoop/hadoop-1.1.2/libexec/../logs/hadoop-hadoop-datanode-HAD
understanding of hadoop. Now, after I have just built the environment, my mind may flash and encounter errors from time to time. I will record the installation process here for my convenience in the future, on the other hand, we hope to inspire people who encounter the same problems in the future.First of all, let's explain why we should use tarball for installation. cdh provides a manager Method for installation, apt-get for the Debian series, and yum for the Redhat series, however, these inst
1. Cluster Introduction
1.1 Hadoop Introduction
Hadoop is an open-source distributed computing platform under the Apache Software Foundation. Hadoop, with Hadoop Distributed File System (HDFS, Hadoop Distributed Filesystem) and MapReduce (open-source implementation of Google MapReduce) as the core, provides users with a Distributed infrastructure with transparent underlying system details.
Hadoop clusters can be divided into Master and Salve roles. An HDFS cluster is composed of one NameNode and
Introduction to Hadoop
Hadoop is an open-source distributed computing platform under the Apache Software Foundation. Hadoop, with Hadoop Distributed File System (HDFS, Hadoop Distributed Filesystem) and MapReduce (open-source implementation of Google MapReduce) as the core, provides users with a Distributed infrastructure with transparent underlying system details.
Hadoop clusters can be divided into Master and Salve roles. An HDFS cluster is composed of one NameNode and several DataNode. NameNo
Scalability: In contrast to Jobtracker, each application instance, here can be said to be a mapreduce job has a managed application management that runs during application execution. This model is closer to the original Google paper.
High availability: Highly available (high availability) usually after a service process fails, another daemon (daemon) can replicate the state and take over the work. However, for a large number of rapidly complex stat
In the image of Hadoop Technology Insider: An in-depth analysis of the principles of MapReduce architecture design and implementation, I've drawn a similar figure with my hand-_-4 Majority: Hdfs,client,jobtracker,tasktrackerYarn's idea is to separate resource scheduling from job control, thereby reducing the burden on a single node (jobtracker). Applicationmaster equivalent to
1. HDFS (Distributed File system system)1.1, NameNode: (Name node)HDFs DaemonHow the record files are partitioned into chunks, and on which nodes the data blocks are storedCentralized management of memory and I/Ois a single point, failure will cause the cluster to crash1.2, Secondarynamenode (auxiliary name node): Failure to manually set up to achieve cluster crash problemAuxiliary daemon for monitoring HDFs statusEach cluster has aCommunicate with Namenode to save HDFs metadata snapshots on a r
Cluster behavior of MapReduceThe cluster behavior of MapReduce includes:1. Task Scheduling and executionThe MapReduce task is controlled by a jobtracker and multiple tasktracker nodes.(1) Jobtracker node(2) Tasktracker node(3) Relationship between the Jobtracker node and the Tasktracker node2. Local calculation3, Shuffle shuffle process4. Combined Mapper Output5.
I recently on the windows to write a test program maxmappertemper, and then no server around, so want to configure on the Win7.It worked. Here, write down your notes and hope it helps.The steps to install and configure are:Mine is MyEclipse 8.5.Hadoop-1.2.2-eclipse-plugin.jar1, install the Hadoop development plug-in Hadoop installation package contrib/directory has a plug-in Hadoop-1.2.2-eclipse-plugin.jar, copied to the MyEclipse root directory under the/dropins directory. 2, start MyEclipse, o
installed HADOOPGPL or kevinweil, comma separated, snappy also need to be installed separately
Io.compression.codec.lzo.class
Com.hadoop.compression.lzo.LzoCodec
Compression encoder used by the Lzo
Topology.script.file.name
/hadoop/bin/rackaware.py
Rack-Aware Scripting location
Topology.script.number.args
1000
The number of hosts that the rack-aware script manages, the IP address
Fs.trash.interval
10800
The running process of MapReduce
The running process of MapReduceBasic concepts:
Jobtask: To complete a job, it will be divided into a number of task,task and divided into Maptask and Reducetask
Jobtracker
Tasktracker
Hadoop MapReduce ArchitectureThe role of Jobtracker
Job scheduling
Assign tasks, monitor task execution progress
Monitor the status of Tasktracker
The role of T
The VERSIONEDPROTOCOL protocol is the abstraction of the top-level protocol interface for Hadoop; 5--3--3 A total of 11 protocols, hehe1) HDFs Related
Clientdatanodeprotocol:client interface with Datanode, the operation is not much, only a block recovery method. So what about the other methods of data requests? Client and Datanode main interaction is through the flow of socket implementation, the source code in Dataxceiver, here first not to say;
Clientprotocol:client and Namenode i
In hadoop1.2.1 installation instructions have instructions to install Java in advance, I installed a lot of Java and many versions of hadoop, and then found that oracle-java7 and hadoop1.2.1 can match. 1. The installation steps are as follows: 1. install Java: sudo apt-Get install oracle-java7-installer 2. Installation hadoop1.2.1: http://hadoop.apache.org/docs/r1.2.1/single_node_setup.html#Download 2. test whether the installation is successful (in pseudo-distributed mode ): Format a ne
Hadoop wordcount instance code, hadoopwordcount
A simple example is provided to illustrate what MapReduce is:
We need to count the number of times each word appears in a large file. The file is too large. We split the file into small files and arrange multiple people to collect statistics. This process is "Map ". Then combine the statistics of each person. This is "Reduce ".
In the preceding example, if MapReduce is used, a job needs to be created to split the file into several independent data
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