I know it might be trivial question, but I stuck with it for a while :) Basically, I am querying Hive tables from Spark. All connections settings for Hive I have in hive-site.xml file which is in SPARK_HOME/conf directory on my Windows PC. It works fine through spark-shell. However, when I run the same from IntelliJ Idea, it will query Hive locally instead connecting to remote metastore defined in hive-site.xml.
package main.scala
import org.apache.spark.sql.SparkSession
object Main {
def main(args: Array[String]) {
val spark = SparkSession
.builder()
.appName("Hive Tables")
.master("local")
.enableHiveSupport()
.getOrCreate()
import spark.sql
sql("show tables").show()
}
}
I have added environmental variables for HADOOP_HOME and SPARK_HOME. As I mentioned it works fine through spark-shell. But seems like hive-site.xml is not read in IntelliJ Idea.
Do you have any ideas what I may do wrong ?
Thanks
Related
I would like to export a DSE graph via a spark job , as per
https://docs.datastax.com/en/dse/6.0/dse-dev/datastax_enterprise/graph/graphAnalytics/dseGraphFrameExport.html
All this works fine within the spark-shell ,
I want to be doing this in Java using DseGraphFrame .
Unfortunately there is not much in the documentation
I am able to pack a jar with the following code and do a
spark-submit
SparkSession spark = SparkSession
.builder()
.appName("Datastax Java example")
.getOrCreate();
DseGraphFrame dseGraphFrame = DseGraphFrameBuilder.dseGraph(args[0], spark);
DataFrameWriter dataFrameWriter = dseGraphFrame.V().df().write();
dataFrameWriter.csv("vertices");
The above works fine ,
what I want to be doing is use a specific traversal to filter what I export.
That is use something like that
dseGraphFrame.V().hasLabel("label").df().write();
The above does not work as dseGraphFrame.V().hasLabel("label") does not have .df()
Is this the correct way of doing things
Any help would be appreciated
A late answer to this question, perhaps still of use:
In Java, you need to cast this to a DseGraphTraversal first. This can then be converted to a DataFrame with the .df() method:
((DseGraphTraversal)dseGraphFrame.V().hasLabel("label")).df().write();
I want to change the default memory, executor and core settings of a spark session.
The first code in my pyspark notebook on HDInsight cluster in Jupyter looks like this:
from pyspark.sql import SparkSession
spark = SparkSession\
.builder\
.appName("Juanita_Smith")\
.config("spark.executor.instances", "2")\
.config("spark.executor.cores", "2")\
.config("spark.executor.memory", "2g")\
.config("spark.driver.memory", "2g")\
.getOrCreate()
On completion, I read the parameters back, which looks like the statement worked
However if I look in yarn, the setting have indeed not worked.
Which settings or commands do I need to make to let the session configuration take effect ?
Thank you for help in advance
By the time your notebook kernel has started, the SparkSession is already created with parameters defined in a kernel configuration file. To change this, you will need to update or replace the kernel configuration file, which I believe is usually somewhere like <jupyter home>/kernels/<kernel name>/kernel.json.
Update
If you have access to the machine hosting your Jupyter server, you can find the location of the current kernel configurations using jupyter kernelspec list. You can then either edit one of the pyspark kernel configurations, or copy it to a new file and edit that. For your purposes, you will need to add the following arguments to the PYSPARK_SUBMIT_ARGS:
"PYSPARK_SUBMIT_ARGS": "--conf spark.executor.instances=2 --conf spark.executor.cores=2 --conf spark.executor.memory=2g --conf spark.driver.memory=2g"
With Spark 1.5.1, I've already been able to access spark-shell temporary tables from Beeline using Thrift Server. I've been able to do so by reading answers to related questions on Stackoverflow.
However, after upgrading to Spark 2.0, I can't see temporary tables from Beeline anymore, here are the steps I'm following.
I'm launching spark-shell using the following command:
./bin/spark-shell --master=myHost.local:7077 —conf spark.sql.hive.thriftServer.singleSession=true
Once the spark shell is ready I enter the following lines to launch thrift server and create a temporary view from a data frame taking its source in a json file
import org.apache.spark.sql.hive.thriftserver._
spark.sqlContext.setConf("hive.server2.thrift.port","10002")
HiveThriftServer2.startWithContext(spark.sqlContext)
val df = spark.read.json("examples/src/main/resources/people.json")
df.createOrReplaceTempView("people")
spark.sql("select * from people").show()
The last statement displays the table, it runs fine.
However when I start beeline and log to my thrift server instance, I can't see any temporary tables:
show tables;
+------------+--------------+--+
| tableName | isTemporary |
+------------+--------------+--+
+------------+--------------+--+
No rows selected (0,658 seconds)
Did I miss something regarding my spark upgrade from 1.5.1 to 2.0, how can I gain access to my temporary tables ?
This worked for me after upgrading to spark 2.0.1
val sparkConf =
new SparkConf()
.setAppName("Spark Thrift Server Demo")
.setMaster(sparkMaster)
.set("hive.metastore.warehouse.dir", hdfsDataUri + "/hive")
val spark = SparkSession
.builder()
.enableHiveSupport()
.config(sparkConf)
.getOrCreate()
val sqlContext = new org.apache.spark.sql.SQLContext(spark.sparkContext)
HiveThriftServer2.startWithContext(sqlContext)
I keep getting
java.lang.NoClassDefFoundError: org/apache/avro/mapred/AvroWrapper
when calling show() on a DataFrame object. I'm attempting to do this through the shell (spark-shell --master yarn). I can see that the shell recognizes the schema when creating the DataFrame object, but if I execute any actions on the data it will always throw the NoClassDefFoundError when trying to instantiate the AvroWrapper. I've tried adding avro-mapred-1.8.0.jar in my $HDFS_USER/lib directory on the cluster and even included it using the --jar option when launching the shell. Neither of these options worked. Any advice would be greatly appreciated. Below is example code:
scala> import org.apache.spark.sql._
scala> import com.databricks.spark.avro._
scala> val sqc = new SQLContext(sc)
scala> val df = sqc.read.avro("my_avro_file") // recognizes the schema and creates the DataFrame object
scala> df.show // this is where I get NoClassDefFoundError
The DataFrame object itself is created at the val df =... line, but data is not read yet. Spark only starts reading and processing the data, when you ask for some kind of output (like a df.count(), or df.show()).
So the original issue is that the avro-mapred package is missing.
Try launching your Spark Shell like this:
spark-shell --packages org.apache.avro:avro-mapred:1.7.7,com.databricks:spark-avro_2.10:2.0.1
The Spark Avro package marks the Avro Mapred package as provided, but it is not available on your system (or classpath) for one or other reason.
If anyone else runs into this problem, I finally solved it. I removed the CDH spark package and downloaded it from http://spark.apache.org/downloads.html. After that everything worked fine. Not sure what the issues was with the CDH version, but I'm not going to waste anymore time trying to figure it out.
How do you set a hive property like: hive.metastore.warehouse.dir at runtime? Or at least a more dynamic way of setting a property like the above, than putting it in a file like spark_home/conf/hive-site.xml
I faced the same issue and for me it worked by setting Hive properties from Spark (2.4.0). Please find below all the options through spark-shell, spark-submit and SparkConf.
Option 1 (spark-shell)
spark-shell --conf spark.hadoop.hive.metastore.warehouse.dir=some_path\metastore_db_2
Initially I tried with spark-shell with hive.metastore.warehouse.dir set to some_path\metastore_db_2. Then I get the next warning:
Warning: Ignoring non-spark config property:
hive.metastore.warehouse.dir=C:\winutils\hadoop-2.7.1\bin\metastore_db_2
Although when I create a Hive table with:
bigDf.write.mode("overwrite").saveAsTable("big_table")
The Hive metadata are stored correctly under metastore_db_2 folder.
When I use spark.hadoop.hive.metastore.warehouse.dir the warning disappears and the results are still saved in the metastore_db_2 directory.
Option 2 (spark-submit)
In order to use hive.metastore.warehouse.dir when submitting a job with spark-submit I followed the next steps.
First I wrote some code to save some random data with Hive:
import org.apache.spark.SparkConf
import org.apache.spark.sql.SparkSession
val sparkConf = new SparkConf().setAppName("metastore_test").setMaster("local")
val spark = SparkSession.builder().config(sparkConf).getOrCreate()
import spark.implicits._
var dfA = spark.createDataset(Seq(
(1, "val1", "p1"),
(2, "val1", "p2"),
(3, "val2", "p3"),
(3, "val3", "p4"))).toDF("id", "value", "p")
dfA.write.mode("overwrite").saveAsTable("metastore_test")
spark.sql("select * from metastore_test").show(false)
Next I submitted the job with:
spark-submit --class org.tests.Main \
--conf spark.hadoop.hive.metastore.warehouse.dir=C:\winutils\hadoop-2.7.1\bin\metastore_db_2
spark-scala-test_2.11-0.1.jar
The metastore_test table was properly created under the C:\winutils\hadoop-2.7.1\bin\metastore_db_2 folder.
Option 3 (SparkConf)
Via SparkSession in the Spark code.
val sparkConf = new SparkConf()
.setAppName("metastore_test")
.set("spark.hadoop.hive.metastore.warehouse.dir", "C:\\winutils\\hadoop-2.7.1\\bin\\metastore_db_2")
.setMaster("local")
This attempt was successful as well.
The question which still remains is why I have to extend the property with spark.hadoop in order to work as expected?