hadoop job description

nodes. The primary node monitors their execution and re-executes previously failed tasks. The slave node is responsible only for the tasks assigned by the master node. When a job is submitted, Jobtracker receives the job and configuration information, distributes the configuration information to the slave node, dispatches the task, and monitors the execution of the Tasktracker. The Jobtracker can run on an

equivalent to that of HDFS. Use a sequence file that supports compression and segmentation ). For large files, do not use an unsupported compression format for the entire file, because this will cause loss of local advantages, thus reducing the performance of mapreduce applications. Hadoop supports splittable compression lzo Using lzo Compression Algorithm in hadoop can reduce data size and data di

Writing a job in hadoop generally adopts the following method: [java] Job job = new Job (); job. setXxx ();... in this way, there are a lot of codes, and the parameters are not easy to control. For example, I want to control the i

If more than one job is needed in MapReduce, and some dependencies need to be set between multiple jobs, such as JOB3 needs to rely on JOB1 and JOB2, this uses Jobcontrol, as follows: Jobcontrol jbcntrl=new Jobcontrol ("Jbcntrl"); Jbcntrl.addjob (JOB1); Jbcntrl.addjob (JOB2); Jbcntrl.addjob (JOB3); Job3.adddependingjob (JOB1); Job3.adddependingjob (JOB2); Thread Thecontroller = new Thread (Jbcntrl); Thecontroller.start (); while (!jbcntrl.allfin

--name Spark_scala--class WordCount--executor-memory 1G--total-executor-cores 2 ~/sparktest/spark_scala.jar/home/jiahong/jia.txtEnter Hadoop, then use the Spark-submit command to submit the jar package, if you do not understand the above command, you can use Spark-submit--help to view the HelpSpark://jiahong-optiplex-7010:7077 address of the primary nodeAddress of the Har package for export--class WordCount The object name for the word count--executo

Hadoop file system to the local file system in the Downloads folder. Note: For more information about file system commands and other important commands, see the Apache Hadoop FS Command sample article, or you can check the full documentation of the shell command in the documentation on the Apache Hadoop Web site: File system commands and HDFs command 7. Interac

Hadoop, HBase, Hive, zookeeper default port description Component Daemon Port Configuration Description Hdfs DataNode 50010 Dfs.datanode.address Datanode service port for data transfer 50075 Dfs.datanode.http.address Port for HTTP Service 50475 Dfs.data

Mapred.job.tracker Job-tracker Interactive Port 8021 Mapred-site.xml hdfs://master:8021/ Job Tracker Web Management Ports 50030 Mapred-site.xml 0.0.0.0:50030 Mapred.task.tracker.http.address HTTP port for Task-tracker 50060 Mapred-site.xml 0.0.0.0:50060 2.3 Other Ports Parameters Describe Defa

When a beginner runs a mapreduce job, often encounter a variety of errors, due to lack of experience, often unintelligible, generally directly to the terminal printing errors affixed to search engines to find, to learn from previous experience. However, for Hadoop, when encountering an error, the first time should be to view the log, the log in the production will have a detailed error cause prompt, this ar

' TRUNC (add_months (sysdate + 2/24, 3), ' Q ') -1/24 'Every Saturday and Sunday 6:10 A.M. ' TRUNC (LEAST (Next_day (sysdate, "SATURDAY"), Next_day (Sysdate, "SUNDAY")) + (6X60+10)/(24x60) 'first, set the initialization parameters job_queue_processesSql> alter system set job_queue_processes=n; (n>0)Job_queue_processes Maximum value is 1000 　　 View the job queue background processSql>select name,description

(HDFS) and must be accessible from both the server and client. Mapred. Local. dir List of comma-separated paths in the local file system, where MAP/reduce temporary data is stored. Multi-path facilitates the use of disk I/O. Mapred. tasktracker. {map | reduce}. Tasks. Maximum The maximum number of MAP/reduce tasks running on a tasktracker. These tasks run simultaneously. The default value is 2 (2 maps and 2 reduce), which can be changed based on hardwar

Hadoop port description:Default port location description8020 namenode RPC interactive Port8021 jt rpc interactive Port50030 mapred. Job. tracker. http. Address jobtracker administrative Web GUI jobtracker HTTP server and Port50070 DFS. http. Address namenode administrative Web GUI namenode HTTP server and Port50010 DFS. datanode. Address datanode control port (each datanode listens on this port and registe

I don't know much about oracle. Today, a friend said that oracle creates a job. I thought it was a job. As a result, oracle creates a job, let me introduce how to create a job instance in oracle. I. Simple Test of the job creation process case:1. Create a JOB_TEST table with

During online hadoop cluster O M, hadoop's balance tool is usually used to balance the distribution of file blocks in each datanode in the hadoop cluster, to avoid the high usage of some datanode disks (this problem may also lead to higher CPU usage of the node than other servers ). 1) usage of the hadoop balance tool: To start:bin/start-balancer.sh [-threshold

5. Check the error ======================== 1. Permission issues: At startup, you may see a series of errors without access permissions. Open hadoop-env.sh Note the following: Must have the read permission:Hadoop_conf_dir You must have the write permission:Hadoop_log_dir, hadoop_secure_dn_log_dir, hadoop_pid_dir, hadoop_secure_dn_pid_dir Hadoop_conf_dirIf you do not have the read permission, you cannot read the configuration file. Hadoop_log_dir, hado

[:nnnnn], blue part The follower is used to connect to the leader and only listens on the leader on the port. 3888 /etc/zookeeper/conf/zoo.cfg in server.x=[hostname]:nnnnn[:nnnnn], blue part Used for the leader election. Required only if ELECTIONALG is 3 (default). All port protocols are based on TCP.For all Hadoop daemon that exist in the Web UI (HTTP service), there are URLs like:/logsList of log fil

Two benefits of file compression: reducing the disk space required to store files and accelerating data transmission over networks and disksIn storage, all algorithms weigh space/time, and all algorithms weigh cpu/transfer speed when processing The following is a list of common compression methods used in conjunction with Hadoop: compression Format Tools algorithm file name extension is it possible to slice

Now the SEO industry has gradually formed their own rules, that is, for a keyword in how many days to optimize the amount of money you come up. However, because the site is different, seoer in doing optimization can not fully follow the optimization rules we know to change the site, that is, a site to take over, to optimize the place to change is not a lot. Most of the seoer in doing optimization work is to focus on updating content, looking for the chain, do a good

People who use hadoop have some knowledge about the detailed counters in hadoop, but many may not find any information when they want to fully understand all metrics. In addition, there are few introductions when searching in the code. List all items. DFS. datanode. blockchecksumop_avg_time block verification average time DFS. datanode. blockchecksumop_num_ops block check count DFS. datanode. blockreports_a

Org.quartz.threadPool.class = org.quartz.simpl.simplethreadpool# number of threads Org.quartz.threadPool.threadCount = 10# Thread Priority org.quartz.threadPool.threadPriority = AA Self-created parent thread Org.quartz.threadPool.threadsInheritContextClassLoaderOfInitializingThread = true# Set data Source Org.quartz.dataSource.myXADS.jndiURL = Ct#jbdi class name Org.quartz.dataSource.myXADS.java.naming.factory.initial = weblogic.jndi.WLInitialContextFactory # URLorg.quartz.dataSource.myXADS.jav