Created 10-27-2022 09:42 AM
I am trying to use hbase-spark in order to query over Hbase with spark-sql, but I am stuck with some of these exceptions:
1- Details on the platform
2- Details on the problem
3- Description of the attached content
1- A Cloudera cluster running CDH-6.3.4
2- I run a (POC) Java application with spark-submit in yarn cluster mode. What the application does is to sequencially :
- Create a Hbase table and populate it using the Java API
- Use a spark-session to read the hbase table (using .format("org.apache.hadoop.hbase.spark") )
- Perform some queries on the Dataframe.
For now, I only got partial success on the last step. I can show the contents of the dataframe with this for example :
Dataset<Row> sqlDF1 = sqlContext.sql("SELECT * FROM census2");
But the following code fails with one of the two exceptions listed at the start of the post :
Dataset<Row> sqlDF2 = sqlContext.sql("SELECT * FROM census2 WHERE ID1 LIKE '____|001_|%'");
Concerning this exception :
I see that the class is provided by the hbase-protocol project, as can be seen here : hbase/ByteStringer.java at rel/2.1.0 · apache/hbase · GitHub
I included the jar with the --jar option in the spark-submit, and it is also present in the uber-jar that is launched. So I don't see why I get this error.
I tried to use both hbase-spark 2.1.0-cdh6.3.4 maven-central dependency as well as a hbase-spark library that I compiled myself, but it did not help.
I also tried to add this to my sparksession :
// .config("spark.jars", "hbase-spark-1.0.0.jar:hbase-protocol-2.1.0.jar")
But then I get NullPointerException and cannot even print the dataframes.
I also tried to add :
when reading the dataframe (as I found someone suggesting that) but it did not help either.
3- Description of the attached content
- Main.java.txt => the code of the sample application
- launcher.sh.txt => the bash code used to launch the application
- jars_and_classpaths.txt => the jars passed to the --jars command, as well as the java client classpath
- mvn_dependency_tree.txt => the results of the command mvn dependency:tree
I am stuck here, could someone help me ?
Thanks a lot
Created 10-27-2022 08:21 PM
You can try the following example code
Created 10-28-2022 01:24 AM
I looked into your solution, however I see that the only actions you perform to test the hbase-spark interaction is this :
But I already have success on both these actions.
What I want to do, is to perform "advanced" sql operations on the dataframe. Namely, filter on the rowkeys and qualifier values.
For example : sqlContext.sql("SELECT * FROM census2 WHERE ID1 LIKE '____|001_|%'");
Did you try to do that in your experiment ?
I found this on the branch master of hbase-connectors/spark (hbase-connectors/spark at master · apache/hbase-connectors · GitHub) :
Server-side (HBase region servers) configuration:
The following jars need to be in the CLASSPATH of the HBase region servers:
So the --jars option of the spark-submit does make the jars accessible to the spark driver and executors, but somehow when you make a qualifier filter operation, spark must be delegating some work to the hbase region servers, and the jars need to be in the classpath of the region servers's Java processes too ?
Created 12-08-2022 12:12 AM
Did you solve this?
Created 12-08-2022 08:15 PM
Nah I figure it out. First, go to /etc/spark/conf.cloudera.spark_on_yarn/classpath.txt then delete the last line (which contains the path to hbase-class.jar). Then you download hbase-spark-184.108.40.206.2.15.0-147.jar, then when you run spark-shell, add --jars pathToYourDownloadedjar, then you add option("hbase.spark.pushdown.columnfilter", false) before load data like this:
val sql = spark.sqlContext
val df = sql.read.format("org.apache.hadoop.hbase.spark").option("hbase.columns.mapping", "name STRING :key, email STRING c:email, " + "birthDate STRING p:birthDate, height FLOAT p:height").option("hbase.table", "person").option("hbase.spark.use.hbasecontext", false).option("hbase.spark.pushdown.columnfilter", false).load()
val results = sql.sql("SELECT * FROM personView where name = 'alice'")
Created 12-08-2022 08:30 PM
You have used CDP hbase-spark-220.127.116.11.2.15.0-147.jar instead of CDH. There is no guarantee it will work latest jar in CDH. Luckily for you it is worked.