Issue while Running Hive in Cygwin - cygwin

I have followed the below steps to configure Hive 0.8.1 in Cygwin. Hive is started properly as I am getting Hive CLI when type hive. But while running any command in hive its not returning any response and the command is running into a infinite loop.
Please help if I miss anything.
Steps to configure Hive
Chown of the hive folder
Change permission of hive folder to 755
Set this to hive-site.xml
<property>
<name>hive.exec.scratchdir</name>
<value>/home/yourusername/mydir</value>
<description>Scratch space for Hive jobs</description>
</property>
Put the following in the hive lib folder:
hadoop-0.20-core.jar
hive/lib/hive-exec-0.7.1.jar
hive/lib/hive-jdbc-0.7.1.jar
hive/lib/hive-metastore-0.7.1.jar
hive/lib/hive-service-0.7.1.jar
hive/lib/libfb303.jar
lib/commons-logging-1.0.4.jar
slf4j-api-1.6.1.jar
slf4j-log4j12-1.6.1.jar
In hive-env.sh change following:
# Set HADOOP_HOME to point to a specific hadoop install directory
#here instead of path what i have given you give your own path where hadoop #isthere
export HADOOP_HOME=/home/user/Hadoop/hadoop-0.20.205
# Hive Configuration Directory can be controlled by:
#here you specify the conf directory path of hive
export HIVE_CONF_DIR=/home/user/Hadoop/hive-0.8.1/conf
#Folder containing extra ibraries required for hive compilation/execution
#can be controlled by:
#here you specify the lib file directory, here you can specify the lib

I had this issue, i could successfully run HIVE after starting all hadoop deamons like namenode,datanode,jobtracker & Task Tracker. And Run queries from files using "hive -f " insted of writing queries directly at hive command prompt. You may also use bin/hive -e 'SHOW TABLES'

Related

how do we copy file from hadoop to abfs remotely

how do we copy files from Hadoop to abfs (azure blob file system)
I want to copy from Hadoop fs to abfs file system but it throws an error
this is the command I ran
hdfs dfs -ls abfs://....
ls: No FileSystem for scheme "abfs"
java.lang.RuntimeException: java.lang.ClassNotFoundException: Class org.apache.hadoop.fs.azurebfs.AzureBlobFileSystem not found
any idea how this can be done ?
In the core-site.xml you need to add a config property for fs.abfs.impl with value org.apache.hadoop.fs.azurebfs.AzureBlobFileSystem, and then add any other related authentication configurations it may need.
More details on installation/configuration here - https://hadoop.apache.org/docs/current/hadoop-azure/abfs.html
the abfs binding is already in core-default.xml for any release with the abfs client present. however, the hadoop-azure jar and dependency is not in the hadoop common/lib dir where it is needed (it is in HDI, CDH, but not the apache one)
you can tell the hadoop script to pick it and its dependencies up by setting the HADOOP_OPTIONAL_TOOLS env var; you can do this in ~/.hadoop-env; just try on your command line first
export HADOOP_OPTIONAL_TOOLS="hadoop-azure,hadoop-aws"
after doing that, download the latest cloudstore jar and use its storediag command to attempt to connect to an abfs URL; it's the place to start debugging classpath and config issues
https://github.com/steveloughran/cloudstore

"Error: Could not find or load main class org.apache.spark.deploy.yarn.ExecutorLauncher" when running spark-submit or PySpark

I am trying to run the spark-submit command on my Hadoop cluster Here is a summary of my Hadoop Cluster:
The cluster is built using 5 VirtualBox VM's connected on an internal network
There is 1 namenode and 4 datanodes created.
All the VM's were built from the Bitnami Hadoop Stack VirtualBox image
I am trying to run one of the spark examples using the following spark-submit command
spark-submit --class org.apache.spark.examples.SparkPi $SPARK_HOME/examples/jars/spark-examples_2.12-3.0.3.jar 10
I get the following error:
[2022-07-25 13:32:39.253]Container exited with a non-zero exit code 1. Error file: prelaunch.err.
Last 4096 bytes of prelaunch.err :
Last 4096 bytes of stderr :
Error: Could not find or load main class org.apache.spark.deploy.yarn.ExecutorLauncher
I get the same error when trying to run a script with PySpark.
I have tried/verified the following:
environment variables: HADOOP_HOME, SPARK_HOME and HADOOP_CONF_DIR have been set in my .bashrc file
SPARK_DIST_CLASSPATH and HADOOP_CONF_DIR have been defined in spark-env.sh
Added spark.master yarn, spark.yarn.stagingDir hdfs://hadoop-namenode:8020/user/bitnami/sparkStaging and spark.yarn.jars hdfs://hadoop-namenode:8020/user/bitnami/spark/jars/ in spark-defaults.conf
I have uploaded the jars into hdfs (i.e. hadoop fs -put $SPARK_HOME/jars/* hdfs://hadoop-namenode:8020/user/bitnami/spark/jars/ )
The logs accessible via the web interface (i.e. http://hadoop-namenode:8042 ) do not provide any further details about the error.
This section of the Spark documentation seems relevant to the error since the YARN libraries should be included, by default, but only if you've installed the appropriate Spark version
For with-hadoop Spark distribution, since it contains a built-in Hadoop runtime already, by default, when a job is submitted to Hadoop Yarn cluster, to prevent jar conflict, it will not populate Yarn’s classpath into Spark. To override this behavior, you can set spark.yarn.populateHadoopClasspath=true. For no-hadoop Spark distribution, Spark will populate Yarn’s classpath by default in order to get Hadoop runtime. For with-hadoop Spark distribution, if your application depends on certain library that is only available in the cluster, you can try to populate the Yarn classpath by setting the property mentioned above. If you run into jar conflict issue by doing so, you will need to turn it off and include this library in your application jar.
https://spark.apache.org/docs/latest/running-on-yarn.html#preparations
Otherwise, yarn.application.classpath in yarn-site.xml refers to local filesystem paths in each of ResourceManager servers where JARs are available for all YARN applications (spark.yarn.jars or extra packages should get layered onto this)
Another problem could be file permissions. You probably shouldn't put Spark jars into an HDFS user folder if they're meant to be used by all users. Typically, I'd put it under hdfs:///apps/spark/<version>, then give that 744 HDFS permissions
In the Spark / YARN UI, it should show the complete classpath of the application for further debugging
I figured out why I was getting this error. It turns out that I made an error while specifying spark.yarn.jars in spark-defaults.conf
The value of this property must be
hdfs://hadoop-namenode:8020/user/bitnami/spark/jars/*
instead of
hdfs://hadoop-namenode:8020/user/bitnami/spark/jars/
i.e. Basically, we need to specify the jar files as the value to this property and not the folder containing the jar files.

How PYSPARK environmental setup is executed by YARN in launch_container.sh

While analyzing the yarn launch_container.sh logs for a spark job, I got confused by some part of log.
I will point out those asks step by step here
When you will submit a spark job with spark-submit having --pyfiles and --files on cluster mode on YARN:
The config files passed in --files , executable python files passed in --pyfiles are getting uploaded into .sparkStaging directory created under user hadoop home directory.
Along with these files pyspark.zip and py4j-version_number.zip from $SPARK_HOME/python/lib is also getting copied
into .sparkStaging directory created under user hadoop home directory
After this launch_container.sh is getting triggered by yarn and this will export all env variables required.
If we have exported anything explicitly such as PYSPARK_PYTHON in .bash_profile or at the time of building the spark-submit job in a shell script or in spark_env.sh , the default value will be replaced by the value which we
are providing
This PYSPARK_PYTHON is a path in my edge node.
Then how a container launched in another node will be able to use this python version ?
The default python version in data nodes of my cluster is 2.7.5.
So without setting this pyspark_python , containers are using 2.7.5.
But when I will set pyspark_python to 3.5.x , they are using what I have given.
It is defining PWD='/data/complete-path'
Where this PWD directory resides ?
This directory is getting cleaned up after job completion.
I have even tried to run the job in one session of putty
and kept the /data folder opened in another session of putty to see
if any directories are getting created on run time. but couldn't find any?
It is also setting the PYTHONPATH to $PWD/pyspark.zip:$PWD/py4j-version.zip
When ever I am doing a python specific operation
in spark code , its using PYSPARK_PYTHON. So for what purpose this PYTHONPATH is being used?
3.After this yarn is creating softlinks using ln -sf for all the files in step 1
soft links are created for for pyspark.zip , py4j-<version>.zip,
all python files mentioned in step 1.
Now these links are again pointing to '/data/different_directories'
directory (which I am not sure where they are present).
I know soft links can be used for accessing remote nodes ,
but here why the soft links are created ?
Last but not the least , whether this launch_container.sh will run for each container launch ?
Then how a container launched in another node will be able to use this python version ?
First of all, when we submit a Spark application, there are several ways to set the configurations for the Spark application.
Such as:
Setting spark-defaults.conf
Setting environment variables
Setting spark-submit options (spark-submit —help and —conf)
Setting a custom properties file (—properties-file)
Setting values in code (exposed in both SparkConf and SparkContext APIs)
Setting Hadoop configurations (HADOOP_CONF_DIR and spark.hadoop.*)
In my environment, the Hadoop configurations are placed in /etc/spark/conf/yarn-conf/, and the spark-defaults.conf and spark-env.sh is in /etc/spark/conf/.
As the order of precedence for configurations, this is the order that Spark will use:
Properties set on SparkConf or SparkContext in code
Arguments passed to spark-submit, spark-shell, or pyspark at run time
Properties set in /etc/spark/conf/spark-defaults.conf, a specified properties file
Environment variables exported or set in scripts
So broadly speaking:
For properties that apply to all jobs, use spark-defaults.conf,
for properties that are constant and specific to a single or a few applications use SparkConf or --properties-file,
for properties that change between runs use command line arguments.
Now, regarding the question:
In Cluster mode of Spark, the Spark driver is running in container in YARN, the Spark executors are running in container in YARN.
In Client mode of Spark, the Spark driver is running outside of the Hadoop cluster(out of YARN), and the executors are always in YARN.
So for your question, it is mostly relative with YARN.
When an application is submitted to YARN, first there will be an ApplicationMaster container, which nigotiates with NodeManager, and is responsible to control the application containers(in your case, they are Spark executors).
NodeManager will then create a local temporary directory for each of the Spark executors, to prepare to launch the containers(that's why the launch_container.sh has such a name).
We can find the location of the local temporary directory is set by NodeManager's ${yarn.nodemanager.local-dirs} defined in yarn-site.xml.
And we can set yarn.nodemanager.delete.debug-delay-sec to 10 minutes and review the launch_container.sh script.
In my environment, the ${yarn.nodemanager.local-dirs} is /yarn/nm, so in this directory, I can find the tempory directories of Spark executor containers, they looks like:
/yarn/nm/nm-local-dir/container_1603853670569_0001_01_000001.
And in this directory, I can find the launch_container.sh for this specific container and other stuffs for running this container.
Where this PWD directory resides ?
I think this is a special Environment Variable in Linux OS, so better not to modify it unless you know how it works percisely in your application.
As per above, if you export this PWD environment at the runtime, I think it is passed to Spark as same as any other Environment Variables.
I'm not sure how the PYSPARK_PYTHON Environment Variable is used in Spark's launch scripts chain, but here you can find the instruction in the official documentation, showing how to set Python binary executable while you are using spark-submit:
spark-submit --conf spark.pyspark.python=/<PATH>/<TO>/<FILE>
As for the last question, yes, YARN will create a temp dir for each of the containers, and the launch_container.sh is included in the dir.

Spark Streaming reading from local file gives NullPointerException

Using Spark 2.2.0 on OS X High Sierra. I'm running a Spark Streaming application to read a local file:
val lines = ssc.textFileStream("file:///Users/userName/Documents/Notes/MoreNotes/sampleFile")
lines.print()
This gives me
org.apache.spark.streaming.dstream.FileInputDStream logWarning - Error finding new files
java.lang.NullPointerException
at scala.collection.mutable.ArrayOps$ofRef$.length$extension(ArrayOps.scala:192)
The file exists, and I am able to read it using SparkContext (sc) from spark-shell on the terminal. For some reason going through the Intellij application and Spark Streaming is not working. Any ideas appreciated!
Quoting the doc comments of textFileStream:
Create an input stream that monitors a Hadoop-compatible filesystem
for new files and reads them as text files (using key as LongWritable, value
as Text and input format as TextInputFormat). Files must be written to the
monitored directory by "moving" them from another location within the same
file system. File names starting with . are ignored.
#param directory HDFS directory to monitor for new file
So, the method expects the path to a directory in the parameter.
So I believe this should avoid that error:
ssc.textFileStream("file:///Users/userName/Documents/Notes/MoreNotes/")
Spark streaming will not read old files, so first run the spark-submit command and then create the local file in the specified directory. Make sure in the spark-submit command, you give only directory name and not the file name. Below is a sample command. Here, I am passing the directory name through the spark command as my first parameter. You can specify this path in your Scala program as well.
spark-submit --class com.spark.streaming.streamingexample.HdfsWordCount --jars /home/cloudera/pramod/kafka_2.12-1.0.1/libs/kafka-clients-1.0.1.jar--master local[4] /home/cloudera/pramod/streamingexample-0.0.1-SNAPSHOT.jar /pramod/hdfswordcount.txt

Hive Tables are created from spark but are not visible in hive

From spark using:
DataFrame.write().mode(SaveMode.Ignore).format("orc").saveAsTable("myTableName")
Table is getting saved I can see using below command's hadoop fs -ls /apps/hive/warehouse\test.db' where test is my database name
drwxr-xr-x - psudhir hdfs 0 2016-01-04 05:02
/apps/hive/warehouse/test.db/myTableName
but when I trying to check tables in Hive I cannot view them either with command SHOW TABLES from hiveContext.
sudo cp /etc/hive/conf.dist/hive-site.xml /etc/spark/conf/
This worked for me in a Cloudera quick start Virtual Box.
You have to copy the hive-site.xml file (mine is located at /etc/hive/conf.dist/hive-site.xml) to Spark conf folder (mine is located at /etc/spark/conf/)
sudo cp /etc/hive/conf.dist/hive-site.xml /etc/spark/conf/
Restart Spark and it should work.
I think you need to run INVALIDATE METADATA; in the hive console to refresh the databases and view your new table.

Resources