start hdfs

Hadoop HDFS clusters are prone to unbalanced disk utilization between machines, such as adding new data nodes to clusters. When HDFS is unbalanced, many problems will occur, such as Mr.ProgramThe advantages of local computing cannot be well utilized, the network bandwidth usage between machines cannot be better, and the machine disk cannot be used. It can be seen that it is very important to ensure data bal

This paper mainly describes the principle of HDFs-architecture, replica mechanism, HDFS load balancing, rack awareness, robustness, file deletion and recovery mechanism 1: Detailed analysis of current HDFS architecture HDFS Architecture 1, Namenode 2, Datanode 3, Sencondary Namenode Data storage Details Namenode dire

Enable backup of files on HDFs via snapshotAPI address please see http://archive.cloudera.com/cdh5/cdh/5/hadoop-2.5.0-cdh5.2.0/hadoop-project-dist/hadoop-hdfs/HdfsSnapshots.html==========================================================================================1. Allow snapshot creationFirst, execute the command below the folder where you want to make the backup, allowing the folder to create a snapsh

multiple files into a large file to HDFs processing (high efficiency) after processing to meet the use of MapReduce, one of the principles of mapreduce processing is to cut the input data into chunks, which can be processed in parallel on more than one computer, In Hadoop terms these are referred to as input shards, which should be small enough to achieve granular parallelism. It can't be too small.Fsdatainputstream extended the Java.io.DataInputStre

(!_fs.exists (File_path)) {logger.error (file + "not exist!"); return false; }//Open data stream this._fsinputstream = This._fs.open (File_path); This._linereader = new Linereader (_fsinputstream, _fs.getconf ()); return true; } catch (Exception e) {logger.error ("Create line reader failed-" + e.getmessage (), E); return false; }}/** * Start reading data by line from File * * @param dataList * Read the file information * @param line

and so on. More on NameNode's design implementation analysis, which will be written separately.DataNodeDataNode's duties are as follows: Store file blocks (block) Service responds to Client's file read and write requests Perform file block creation, deletion, and replication From the frame composition, see a Block OPS operating arrows from NameNode point to DataNode, will make people mistakenly think NameNode will take the initiative to send command calls to DataNode. In f

HDFs File Upload: 8020 port denied connection problem solved!Copyfromlocal:call to localhost/127.0.0.1:8020 failed on connection exception:java.net.ConnectExceptionThe problem indicates that the 8020 port of this machine cannot be connected.The network above found an article is to change the configuration port inside the Core-site.xml to 8020, but we still use his default 9000 port, only need to configure eclipse when the port modified to 9000.My ques

Scenario: An error occurred running the Spark program 1. Error message:17/05/09 14:30:58 WARN Scheduler. Tasksetmanager:lost task 28162.1 in stage 0.0 (TID 30490, 127.0.0.1): Java.io.IOException:Cannot obtain block length for locatedblock{bp-203532773-dfsfdf-1476004795661:blk_1080431162_6762963; getblocksize () =411; corrupt=false; offset= 0; Locs=[datanodeinfowithstorage[127.0.0.1:1004,ds-e9905a06-4607-4113-b717-709a087b8b96,disk], Datanodeinfowithstorage[127.0.0.1:1004,ds-a5046b43-4416-45d9-8f

Hadoop Introduction: a distributed system infrastructure developed by the Apache Foundation. You can develop distributed programs without understanding the details of the distributed underlying layer. Make full use of the power of clusters for high-speed computing and storage. Hadoop implements a Distributed File System (HadoopDistributed File System), HDFS for short. HDFS features high fault tolerance and

Hadoop's HDFs clusters are prone to unbalanced disk utilization between machines and machines, such as adding new data nodes to a cluster. When there is an imbalance in HDFs, there are a lot of problems, such as the Mr Program does not take advantage of local computing, the machine is not able to achieve better network bandwidth utilization, the machine disk can not be used and so on. It is important to ens

:/HOME/GRID/HADOOP-2.7.2/ETC/HADOOP/SCP Hdfs-site.xml slave2:/home/grid/hadoop-2.7.2/etc/ hadoop/3. Copy the Java directory, Hadoop directory, environment variable files from master to Kettlescp-rp/home/grid/hadoop-2.7.2 kettle:/home/grid/scp-rp/home/grid/jdk1.7.0_75 kettle:/home/grid/# Execute scp-p/etc with Root /profile.d/* kettle:/etc/profile.d/4. Start a new Namenode, Secondarynamenode# Execute Source/

, for subsequent data mining and analysis. The data is collected to HDFS and a file is generated on a regular basis every day (the file prefix is the date, and the suffix is the serial number starting from 0). When the file size exceeds the specified size, A new file is automatically generated. The file prefix is the current date, And the suffix is the current serial number. The system running architecture diagram and related descriptions are as follo

Realpath is the full pathname after the regular parse timestamp, the filepath parameter is "Hdfs.path" in the configuration file, Realname is the filename prefix after the regular parse timestamp, and the filename parameter is the " Hdfs.fileprefix ". The other parameters are the same, event.getheaders () is a map with a timestamp (can be set by interceptor, customizing, using the Uselocaltimestamp parameter of HDFs sink three ways), other parameters

= Netcata1.sources.r1.bind = Hadoop-mastera1.sources.r1.port = 44444 A1.sources.r1.interceptors = I1a1.sources.r1.interceptors.i1.type =regex_ Filtera1.sources.r1.interceptors.i1.regex =^[0-9]* $a 1.sources.r1.interceptorS.i1.excludeevents =true# Describe The Sink#a1.sinks.k1.type = Loggera1.channels = C1a1.sinks = K1a1.sinks.k1.type = Hdfsa1.sinks.k1.channel = C1a1.sinks.k1.hdfs.path = hdfs:/flume/events # Location of files stored in the

enough to achieve granularity parallelism or too smallFsdatainputstream expands the Java.io.DataInputStream to support random reads, and MapReduce requires this feature because a machine may be assigned to start processing a shard from the middle of the input file, and if there is no random access, it needs to be read from the beginning to the location of the ShardHDFs is designed to store data that is fragmented and processed by MapReduce, and

); Desc.put ("ByteSize", 0l); NewThread (NewRunnable () {@Override Public voidrun () {//TODO auto-generated Method Stub while(true) { Try{Thread.Sleep (500); System.out.printf ("Maxl:%d\tcurrent:%d\tsurplus:%d\tprogressbar:%s\n", Desc.get ("ByteSize"), Desc.get ("current"), Desc.get (" ByteSize ")-desc.get (" current "), Df.format ((Desc.get (" current ") +0.0)/desc.get (" ByteSize "))); } Catch(interruptedexception e) {//TODO auto-generated Catch blockE.prints

file storage location: Getfileblocklocations * * @throws IOException */@Test public void testlocations () throws IOException {path Path = new Path ("/hadoop-2.6.4.tar.gz"); Filestatus filestatus = fs.getfilestatus (path); Parameters are: File path offset start position file length blocklocation[] locations = fs.getfileblocklocations (path, 0, Filestatus.getlen ()); SYSTEM.OUT.PRINTLN (locations); for (Blocklocation

I. Basic concepts of HDFS 1.1. Data blocks) HDFS (Hadoop Distributed File System) uses 64 mb data blocks by default. Similar to common file systems, HDFS files are divided into 64 mb data block storage. In HDFS, if a file is smaller than the size of a data block, it does not occupy the entire data block storage spa

Xshell run into the graphical interface in xmanager 1 sh spoon. SHCreate a new job1. write data into HDFs 1) kettle writes data to HDFs in LinuxDouble-click hadoop copy FilesRun this jobView data:1) kettle Write Data to HDFs in WindowsHDFs writes data to the power server in WindowsLog:2016/07/28 16:21:14-version CHECKER-OK2016/07/28 16:21:57-Data integrat

Pass"Filesystem. getfileblocklocation (filestatus file, long start, long Len)"You can find the location of the specified file on the HDFS cluster. file is the complete path of the file, and start and Len are used to identify the path of the file to be searched. The following are JavaCodeImplementation: Package com. njupt. hadoop; Import org. Apache. hadoop.