Add extra Hard Disk/Phisical memory at Data Node

                             Add extra Hard Disk/Phisical memory at datanode

As we are processing data on hadoop cluster we need to configure many things. The main thing is to manage temporary files which is generation in between map reduce. We can set map-reduce intermediate compression and map-reduce output compression. After setting every things we need atleat double/tripple space on datanode with respect to existing dataset on HDFS. So we can add some memory on hadoop cluster in 2 ways:

1. Add 1 or more datanode datanode
2. Add harddisk on the exising datanodes


How to add extra HDD:

First add a HardDisk on all datanode machine and mount on a point/name(example: /hdd2)

Now create datanode directory in new harddisk (example: /hdd2/datanode)

Now change ownership of /hdd2/datanode to hdfs/hadoop user

then

Stop one datanode and add the new Harddisk location in hdfs-site.xml

<property>
<name>dfs.datanode.data.dir</name>
<value>/hdd/datanode,/hdd2/datanode</value>
</property>

NOTE: here "/hdd/datanode" was the old datanode path, so we will keep that as it was.


then save file and start datanode.

do the same steps on all the datanode one by one.

Thats it.

Thanks,

Comments

Post a Comment

Popular posts from this blog

Setup Nginx as a Reverse Proxy for Thingsboard running on different port/server

In this blog, we will Setup Nginx as a Reverse Proxy for Thingsboard IOT dashboard running on different port Requirement: Ubuntu Server Thingsboard installed on Ubuntu server Nginx installed on Ubuntu server For installing please refer thingsboard documentation page windows:  https://thingsboard.io/docs/user-guide/install/windows/ Linux:  https://thingsboard.io/docs/user-guide/install/linux/ Let us know in comment if you face any issue in installation we will help you. NGINX installation: sudo apt-get install nginx sudo service nginx status sudo service nginx start Open your browser and you will see the default NGinx home page, nginx also runs on default port 80 In some case if you don't see default page up then check: If using cloud machine then need to open "http port 80" on 0.0.0.0/0 or a specific ip If still don't see UI then restart server, sometime it comes after restart. Configure
Read more

How to auto re-launch a YARN Application Master on a failure.

1)Use Case: The fundamental idea of Hadoop2 (Map-Reduce + Yarn) is to split up the two major functionalities of the JobTracker, resource management and job scheduling/monitoring, into separate daemons. The idea is to have a global ResourceManager ( RM ) and per-application ApplicationMaster ( AM ). An application is either a single job in the classical sense of Map-Reduce jobs or a DAG of jobs. The ResourceManager and per-node slave, the NodeManager ( NM ), form the data-computation framework. The ResourceManager is the ultimate authority that arbitrates resources among all the applications in the system. The per-application ApplicationMaster is, in effect, a framework specific library and is tasked with negotiating resources from the ResourceManager and working with the NodeManager(s) to execute and monitor the tasks. The ResourceManager has two main components: 1. Scheduler: is responsible for allocating resources to the various running applications. 2. Appl
Read more

Read JSON File in Cassandra

Image
INSERT/Load Json data File in Cassandra (3.0+) table Requirement: Create Cassandra table where we can load json data into it. Here some of the column name is separated by space(like 'a b'). Load JSON file into the table. Challenge:  Cassandra support only 'CSV file' load in Table(As per my understanding and searched till now) by using 'COPY' command but not 'JSON' file. Resolution: As per the Cassandra document page, Cassandra supports CSV record level insert and file level insert both operation but for JSON it only support Record level insert by following command: cqlsh> INSERT INTO keyspace1.table1 JSON '{   "id" : "12",    "DB" : "Cassandra",    "ops" : "Insert",   "Project" : "Hadoop" }'; So If we want to insert whole file in the table then we need to loop for each object in JSON file and need to call insert query every tim
Read more