I have a customer where we have hadoop installation managed by us. In the current setup all the nodes in the cluster have all the ports open for each other. But the customer is quite reluctant to keep all the ports open. Can anyone let me know if any such configuration is at all possible where we instruct hadoop to use only restricted number of ports.
My Findings : I have been able to configure a test setup where I have opened only the required port as per the mentioned blog
https://hadoop.apache.org/docs/r2.6.2/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml
But I still see the MR jobs are not executed in distributed manner.
Related
My question is pretty trivial but didnt find anyone actually asking it.
We have a ambari cluster with spark storm hbase and hdfs(among other things).
I dont understand how a user that want to use that cluster use it.
for example, a user want to copy a file to hdfs, run a spark-shell or create new table in hbase shell.
should he get a local account on the server that run the cooresponded service? shouldn't he use a 3rd party machine(his own laptop for example)?
If so ,how one should use hadoop fs, there is no way to specify the server ip like spark-shell has.
what is the normal/right/expected way to run all these tasks from a user prespective.
Thanks.
The expected way to run the described tasks from the command line is as follows.
First, gain access to the command line of a server that has the required clients installed for the services you want to use, e.g. HDFS, Spark, HBase et cetera.
During the process of provisioning a cluster via Ambari, it is possible to define one or more servers where the clients will be installed.
Here you can see an example of an Ambari provisioning process step. I decided to install the clients on all servers.
Afterwards, one way to figure out which servers have the required clients installed is to check your hosts views in Ambari. Here you can find an example of an Ambari hosts view: check the green rectangle to see the installed clients.
Once you have installed the clients on one or more servers, these servers will be able to utilize the services of your cluster via the command line.
Just to be clear, the utilization of a service by a client is location-independent from the server where the service is actually running.
Second, make sure that you are compliant with the security mechanisms of your cluster. In relation to HDFS, this could influence which users you are allowed to use and which directories you can access by using them. If you do not use security mechanisms like e.g. Kerberos, Ranger and so on, you should be able to directly run your stated tasks from the command line.
Third, execute your tasks via command line.
Here is a short example of how to access HDFS without considering security mechanisms:
ssh user#hostxyz # Connect to the server that has the required HDFS client installed
hdfs dfs -ls /tmp # Command to list the contents of the HDFS tmp directory
Take a look on Ambari views, especially on Files view that allows browsing HDFS
I am looking for an open-source system for me to manage my big-data cluster which is composed of 50+ machines including components like hadoop, hdfs, hive, spark, oozie, hbase, zookeeper, kylin.
I want to manage them in a web system .The meaning of "manage" is :
I can restart the component one-by-one with only one click ,such
as when I click the "restart" button ,the component zookeeper will
be restarted one machine by another
I can deploy a component with only one click, such as when I
deploy a new zookeeper , I can make a compiled zookeeper prepared in
one machine ,then I click "deploy", it will deployed to all machines
automatically.
I can upgrade a component with only one click ,such as when I
want to update a zookeeper cluster, I can put the updated zookeeper
in a machine ,then I click "update" ,then the updated zookeeper will
override all the old version of zookeeper in other machines.
all in all , what I want is a management system for my big-data cluster like restart,deploy,upgrade,view the log ,modify the configuration and so on , or at least some of them .
I have considered Ambari, but it can only be used to deploy my whole system from absolute scratch, but my big-data cluster is already running for 1 years.
Any suggestions?
Ambari is what you want. It's the only open source solution for managing hadoop stacks that meets your listed requirements. You are correct that it doesn't work with already provisioned clusters, this is because to achieve such a tight integration with all those services it must know how they were provisioned and where everything is and know what configurations exist for each. The only way Ambari will know that is if it was used to provision those services.
Investing the time to recreate your cluster with Ambari may feel like its painful but in the long run it will payoff due to the added ability to upgrade and manage services so easily going forward.
I am student and doing computer science. As a part of my research i am working on the hadoop environment. The person who was working on this research before me has configured 9 Datanode with a namenode and a stand by node. we have our network traffic data stored in the hive and i am developing hive queries to identify network attack. The person who was working on this already left from our place and working somewhere else and busy with job. so i have couple of questions :
1) how can I understand the architecture on HDFS of my environment i.e how the machines are connected to build this environment. Also what services for this environment installed on which machines?
2) Now we have 9 datanodes in the environement and my professor wants to reduce the datanodes. her goal is to do the research with 2-3 (minimal) machine in this environment.
3) What are the good and easy source to get understanding about the cloudera and hadoop ? Also the commands which can be used to explicitly start and stop a service.
4) Right now in cloudera manager I am not able to start the Namenode server, Secondary datanode and one more. I stop all the services in order from cloudera and now starting in order and in that order the HDFS service comes first so while starting it, it gives the failure message for namenode datanode and datanode8.
I tried several ways but no luck. Please suggest me some ways I can solve issues and good resource(for beginner), I can refer to dig into this more.
Thanks.
There are several resources to start. For everything Cloudera/CDH, the place to go is Cloudera Documentation. For Hadoop, the place to go is Hadoop Documentation. Now, I reckon, this is a rather big bite to chew. If you're new to Hadoop, better start with a book, some introduction (I can't recommend one since I haven't read any).
For your specific problem, it seems that the some services don't start. You need to look at the services' logs, on the respective nodes. I can't tell you where those logs are, because it depends on the your distribution version and on how it was configured. I suspect one vital service does not start (probably HDFS, looks like namenode is down) and this causes every other service to fail. Hadoop Wiki has a troubsleshooting guide, try to follow that and see if it helps you.
As for the question on how to adjust the cluster size, first get it up and running and then consider changing it. Refer to Decommissioning and Recommissioning Hosts.
Hi i have a small doubt , I have started to use in my curiosity but now i have the following problem
My scenario is like this - i have 10 machines connected in LAN and i need to create Name Node in one system and Data Nodes in remaining 9 machines . So do i need to install Hadoop on all the 10 machines ?
For example i have ( 1.. 10 ) machines , where machine1 is Server and from machine(2..9) are slaves[Data Nodes] so do i need to install hadoop on all 10 machines ?
And i have searched a lot On Hadoop cluster network on commodity machine but i dint get any thing related to Installation [ that is configuration]. Some of them given like how to config and install Hadoop on own system but not on the clustered environment
Can any one help me ? and give me the detailed idea or article suggested links to do the above process
Thanks
Yes, you need Hadoop installed in every node and each node should have the services started as for appropriate for its role. Also the configuration files, present on each node, have to coherently describe the topology of the cluster, including location/name/port for various common used resources (eg. namenode). Doing this manually, from scratch, is error prone, specially if you never did this before and you don't know exactly what you're trying to do. Also would be good to decide on a specific distribution of Hadoop (HortonWorks, Cloudera, HDInsight, Intel, etc)
I would recommend use one of the many deployment solutions out there. My favorite is Puppet, but I'm sure Chef will do too.
A different (perhaps better?) alternative is to use Ambari, which is a Hadoop specialized deployment and administering solution. See Deploying and Managing Hadoop Clusters with AMBARI.
Some Puppet resources to get you started: Using Vagrant, Puppet, Testing & Hadoop
Please verify below tutorial
http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-multi-node-cluster/
Hope it helps
Yes hadoop needs to be there on all the computers
For clustered Environment please go through the video
I am new to cloudera, I installed cloudera in my system successfully I have two doubts,
Consider a machine with some nodes already using hadoop with some data, Can we install Cloudera to use the existing Hadoop without made any changes or modifaction on data stored existing hadooop.
I installed Cloudera in my machine, I have another three machines to add those as clusters, I want to know, Am i want install cloudera in those three machines before add those machines as clusters ?, or Can we add a node as clusters without installing cloudera on that purticular nodes?.
Thanks in advance can anyone, please give some information about the above questions.
Answer to questions -
1. If you want to migrate to CDH from existing Apache Distribution, you can follow this link
Excerpt:
Overview
The migration process does require a moderate understanding of Linux
system administration. You should make a plan before you start. You
will be restarting some critical services such as the name node and
job tracker, so some downtime is necessary. Given the value of the
data on your cluster, you’ll also want to be careful to take recent
back ups of any mission-critical data sets as well as the name node
meta-data.
Backing up your data is most important if you’re upgrading from a
version of Hadoop based on an Apache Software Foundation release
earlier than 0.20.
2.CDH binary needs be installed and configured in all the nodes to have a CDH based cluster up and running.
From the Cloudera Manual
You can migrate the data from a CDH3 (or any Apache Hadoop) cluster to a CDH4 cluster by
using a tool that copies out data in parallel, such as the DistCp tool
offered in CDH4.
Other sources
Regarding your second question,
Again from the manual page
Important:
Before proceeding, you need to decide:
As a general rule:
The NameNode and JobTracker run on the the same "master" host unless
the cluster is large (more than a few tens of nodes), and the master
host (or hosts) should not
run the Secondary NameNode (if used), DataNode or TaskTracker
services. In a large cluster, it is especially important that the
Secondary NameNode (if used) runs on a separate machine from the
NameNode. Each node in the cluster except the master host(s) should
run the DataNode and TaskTracker services.
Additionally, if you use Cloudera Manager it will automatically do all the setup necessary i.e install the necessary selected components on the nodes in the cluster.
Off-topic: I had a bad habit of not referrring the manual properly. Have a clear look at it, it answers all our questions
Answer to your second question,
you can add directly, with installation few pre requisites like openssh-clients and firewalls and java.
these machines( existing node, new three nodes) should accept same username and password (or) you should set passwordless ssh to these hosts..
you should connect to the internet while adding the nodes.
I hope it will help you:)