I am trying to install and configure hadoop in the system Ubuntu 16.04, as per the guidelines of https://data-flair.training/blogs/installation-of-hadoop-3-x-on-ubuntu/
all the steps were run successfully, but while trying to run the command hdfs namenode -format, I get a message
There is some problem with your bashrc file. Just check your variables inside bashrc. Even I faced the same problem when I started with hadoop. Mention correct path for each and every variable and afterwards use source ~/.bashrc to commit the changes done to your bashrc file
Related
I am looking for a guide regarding how to install spark on an existing virtual yarn cluster.
I have a yarn cluster consisting of two nodes, ran map-reduce job which worked perfect. Looked for results in log and everything is working fine.
Now I need to add the spark installation commands and configurations files in my vagrantfile. I can't find a good guide, could someone give me a good link ?
I used this guide for the yarn cluster
http://www.alexjf.net/blog/distributed-systems/hadoop-yarn-installation-definitive-guide/#single-node-installation
Thanks in advance!
I don't know about vagrant, but I have installed Spark on top of hadoop 2.6 (in the guide referred to as post-YARN) and I hope this helps.
Installing Spark on an existing hadoop is really easy, you just need to install it only on one machine. For that you have to download the one pre-built for your hadoop version from it's official website (I guess you can use the without hadoop version but you need to point it to the direction of hadoop binaries in your system). Then decompress it:
tar -xvf spark-2.0.0-bin-hadoop2.x.tgz -C /opt
Now you only need to set some environment variables. First in your ~/.bashrc (or ~/.zshrc) you can set SPARK_HOME and add it to your PATH if you want:
export SPARK_HOME=/opt/spark-2.0.0-bin-hadoop-2.x
export PATH=$PATH:$SPARK_HOME/bin
Also for this changes to take effect you can run:
source ~/.bashrc
Second you need to point Spark to your Hadoop configuartion directories. To do this set these two environmental variables in $SPARK_HOME/conf/spark-env.sh:
export HADOOP_CONF_DIR=[your-hadoop-conf-dir usually $HADOOP_PREFIX/etc/hadoop]
export YARN_CONF_DIR=[your-yarn-conf-dir usually the same as the last variable]
If this file doesn't exist, you can copy the contents of $SPARK_HOME/conf/spark-env.sh.template and start from there.
Now to start the shell in yarn mode you can run:
spark-shell --master yarn --deploy-mode client
(You can't run the shell in cluster deploy-mode)
----------- Update
I forgot to mention that you can also submit cluster jobs with this configuration like this (thanks #JulianCienfuegos):
spark-submit --master yarn --deploy-mode cluster project-spark.py
This way you can't see the output in the terminal, and the command exits as soon as the job is submitted (not completed).
You can also use --deploy-mode client to see the output right there in your terminal but just do this for testing, since the job gets canceled if the command is interrupted (e.g. you press Ctrl+C, or your session ends)
I have a small cluster (4 machines) set up with 3 slaves and a master node, all installed to /home/spark/spark. (I.e, $SPARK_HOME is /home/spark/spark)
When I use the spark shell: /home/spark/spark/bin/pyspark --master spark://192.168.0.11:7077 everything works fine. However I'd like for my colleagues to be able to connect to the cluster from a local instance of spark on their machine installed in whatever directory they wish.
Currently if somebody has spark installed in say /home/user12/spark and run /home/user12/spark/bin/pyspark --master spark://192.168.0.11:7077 the spark shell will connect to the master without problems but fails with an error when I try to run code:
class java.io.IOException: Cannot run program
"/home/user12/bin/compute-classpath.sh"
(in directory "."): error=2, No such file or directory)
The problem here is that Spark is looking for the spark installation in /home/user12/spark/, where as I'd like to just tell spark to look in /home/spark/spark/ instead.
How do I do this?
You need to edit three files, spark-submit, spark-class and pyspark (all in the bin folder).
Find the line
export SPARK_HOME = [...]
Then change it to
SPARK_HOME = [...]
Finally make sure you set SPARK_HOME to the directory where spark is installed on the cluster.
This works for me.
Here you can find a detailed explanation.
http://apache-spark-user-list.1001560.n3.nabble.com/executor-failed-cannot-find-compute-classpath-sh-td859.html
I am a student, interested in Hadoop and started to explore it recently.
I tried adding an additional DataNode in the pseudo-distributed mode but failed.
I am following the Yahoo developer tutorial and so the version of Hadoop I am using is hadoop-0.18.0
I tried to start up using 2 methods I found online:
Method 1 (link)
I have a problem with this line
bin/hadoop-daemon.sh --script bin/hdfs $1 datanode $DN_CONF_OPTS
--script bin/hdfs doesn't seem to be valid in the version I am using. I changed it to --config $HADOOP_HOME/conf2 with all the configuration files in that directory, but when the script is ran it gave the error:
Usage: Java DataNode [-rollback]
Any idea what does the error mean? The log files are created but DataNode did not start.
Method 2 (link)
Basically I duplicated conf folder to conf2 folder, making necessary changes documented on the website to hadoop-site.xml and hadoop-env.sh. then I ran the command
./hadoop-daemon.sh --config ..../conf2 start datanode
it gives the error:
datanode running as process 4190. stop it first.
So I guess this is the 1st DataNode that was started, and the command failed to start another DataNode.
Is there anything I can do to start additional DataNode in the Yahoo VM Hadoop environment? Any help/advice would be greatly appreciated.
Hadoop start/stop scripts use /tmp as a default directory for storing PIDs of already started daemons. In your situation, when you start second datanode, startup script finds /tmp/hadoop-someuser-datanode.pid file from the first datanode and assumes that the datanode daemon is already started.
The plain solution is to set HADOOP_PID_DIR env variable to something else (but not /tmp). Also do not forget to update all network port numbers in conf2.
The smart solution is start a second VM with hadoop environment and join them in a single cluster. It's the way hadoop is intended to use.
I'm trying to install Hadoop 1.1.2.21 on CentOS 6.3
I've configured dfs.name.dir in /etc/hadoop/conf/hdfs-site.xml file
<name>dfs.name.dir</name>
<value>/mnt/ext/hadoop/hdfs/namenode</value>
But when I run "hadoop namenode -format" command, it formats /tmp/hadoop-hadoop/dfs/name instead.
What am I missing?
I ran into this problem and solved it. So updating this answer.
Make sure your environment variable HADOOP_CONF_DIR points to the directory where it can find all you xml files for used for configuration. It solved it for me.
It might be taking the path /tmp/hadoop-hadoop/dfs/name from hdfs-default.xml. Not sure why the value from hdfs-site.xml is not taken. Is dfs.name.dir marked as final in hdfs-default.xml?
Check if some Hadoop Process is running in the background already. This happens if you have aborted a previous process and it has not been killed and has become a ZOMBIE process
If that is the case kill the process and then again try to format the system
Also you can check the permission of the Directory.
Try to give a different location for the directory, if it is reflected
Please don't set HADOOP_CONF_DIR. You can check .bashrc file and remove it.
Hi I am trying to run hadoop on a server that has hadoop installed but I have no idea the directory where hadoop resides. The server was configure by the server admin.
In order to load hadoop I use the use command from the dotkit package.
There may be several solutions but wanted to know where the hadoop package was installed, how to set up the $HADOOP_HOME variable, and how to approp run a hadoop streaming job, such as $HADOOP_HOME/bin/hadoop jar $HADOOP_HOME/mapred/contrib/streaming/hadoop-streaming.jar, aka, http://wiki.apache.org/hadoop/HadoopStreaming.
Thanks! any help would be greatly appreciated!
If you're using a cloudera distribution then it's most probably in /usr/lib/hadoop, otherwise it could be anywhere (at the discretion of your system admin).
There are some tricks you can use to try and locate it:
locate hadoop-env.sh (assuming that locate has been installed and updatedb has been run recently)
If the machine you're running this on is running a hadoop service (such as data node, job tracker, task tracker, name node), then you can perform a process list and grep for the hadoop command: ps axww | grep hadoop
Failing the above two, look for the hadoop root directory in some common locations such as: /usr/lib, /usr/local, /opt
Failing all this, and assuming your current user has the permissions: find / -name hadoop-env.sh
If you're install with rpm then it's most probably in /etc/hadoop.
Why don't you try:
echo $HADOOP_HOME
Obiviously the above env variable has to be set before you could even issue hadoop executables from anywhere on the box.