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Spark on Kubernetes : unable to write files to HDFS

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Loic DESCOTTE

Spark on Kubernetes : unable to write files to HDFS

Hello,

I am using Spark On Kubernetes and I have the following error when I try to write data on HDFS : "no filesystem for scheme hdfs"

More details :

I am submitting my application with Spark submit like this :

spark-submit --master k8s://https://myK8SMaster:6443 \

--deploy-mode cluster \

--name hello-spark \

--class Hello \

--conf spark.executor.instances=2 \

--conf spark.kubernetes.container.image.pullPolicy=IfNotPresent \

--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \

--conf spark.kubernetes.container.image=gradiant/spark:2.4.4 hdfs://hdfs-namenode/user/loic/jars/helloSpark.jar

Then the driver and the 2 executors are created in K8S.

But it fails when I look at the logs of the driver, I see this :

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds

at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)

at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)

at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)

at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)

at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)

at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)

at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)

at org.apache.spark.sql.execution.datasources.DataSource.planForWritingFileFormat(DataSource.scala:424)

at org.apache.spark.sql.execution.datasources.DataSource.planForWriting(DataSource.scala:524)

at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:290)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:229)

at Hello$.main(hello.scala:24)

at Hello.main(hello.scala)

As you can see , my application jar helloSpark.jar file is correctly loaded on HDFS by the Spark submit, but writing to HDFS fails.

I have also tried to add the hadoop client dand hdfs dependencies in the spark submit command:

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But the error is still here.

Here is the Scala code of my application :

import java.util.Calendar

import org.apache.spark.sql.SparkSession

case class Data(singleField: String)

object Hello

{

def main(args: Array[String])

{

val spark = SparkSession

.builder()

.appName("Hello Spark")

.getOrCreate()

import spark.implicits._

val now = Calendar.getInstance().getTime().toString

val data = List(Data(now)).toDF()

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

}

Thanks for your help,

Loïc

Loic DESCOTTE

RE: Spark on Kubernetes : unable to write files to HDFS

So I've tried several other things, including building a fat jar with hdfs dependency inside my app jar, and added this to the Spark configuration in the code :

val spark =
SparkSession
          .builder()
          .appName("Hello Spark 7")
          .config("fs.hdfs.impl",
classOf[org.apache.hadoop.hdfs.DistributedFileSystem].getName)
          .getOrCreate()

But still the same error...

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:27
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

I think it'll have to be part of the Spark distro, but I'm not 100% sure. I also think these get registered via manifest files in the JARs; if some process is stripping those when creating a bundled up JAR, could be it. Could be that it's failing to initialize too for some reason.

On Wed, Dec 16, 2020 at 7:24 AM Loic DESCOTTE <[hidden email]> wrote:

I've tried with this spark-submit option :

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But it did't solve the issue.

Should I add more jars?

Thanks

Loïc

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:20
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Seems like your Spark cluster doesn't somehow have the Hadoop JARs?

On Wed, Dec 16, 2020 at 6:45 AM Loic DESCOTTE <[hidden email]> wrote:

Hello,

I am using Spark On Kubernetes and I have the following error when I try to write data on HDFS : "no filesystem for scheme hdfs"

More details :

I am submitting my application with Spark submit like this :

spark-submit --master k8s://https://myK8SMaster:6443 \

--deploy-mode cluster \

--name hello-spark \

--class Hello \

--conf spark.executor.instances=2 \

--conf spark.kubernetes.container.image.pullPolicy=IfNotPresent \

--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \
--conf spark.kubernetes.container.image=gradiant/spark:2.4.4 hdfs://hdfs-namenode/user/loic/jars/helloSpark.jar

Then the driver and the 2 executors are created in K8S.

But it fails when I look at the logs of the driver, I see this :

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds
at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)

at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)

at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)

at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)

at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)

at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)

at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)

at org.apache.spark.sql.execution.datasources.DataSource.planForWritingFileFormat(DataSource.scala:424)

at org.apache.spark.sql.execution.datasources.DataSource.planForWriting(DataSource.scala:524)

at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:290)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:229)

at Hello$.main(hello.scala:24)

at Hello.main(hello.scala)

As you can see , my application jar helloSpark.jar file is correctly loaded on HDFS by the Spark submit, but writing to HDFS fails.

I have also tried to add the hadoop client dand hdfs dependencies in the spark submit command:

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But the error is still here.

Here is the Scala code of my application :

import java.util.Calendar

import org.apache.spark.sql.SparkSession

case class Data(singleField: String)

object Hello

{

def main(args: Array[String])

{

val spark = SparkSession

.builder()

.appName("Hello Spark")

.getOrCreate()

import spark.implicits._

val now = Calendar.getInstance().getTime().toString

val data = List(Data(now)).toDF()

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

}

}

Thanks for your help,

Loïc

German Schiavon Matteo

Re: Spark on Kubernetes : unable to write files to HDFS

Hi,

seems that you have a typo no?

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

On Wed, 16 Dec 2020 at 17:02, Loic DESCOTTE <[hidden email]> wrote:

So I've tried several other things, including building a fat jar with hdfs dependency inside my app jar, and added this to the Spark configuration in the code :

val spark = SparkSession

.builder()

.appName("Hello Spark 7")

.config("fs.hdfs.impl", classOf[org.apache.hadoop.hdfs.DistributedFileSystem].getName)

.getOrCreate()

But still the same error...

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:27
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

I think it'll have to be part of the Spark distro, but I'm not 100% sure. I also think these get registered via manifest files in the JARs; if some process is stripping those when creating a bundled up JAR, could be it. Could be that it's failing to initialize too for some reason.

On Wed, Dec 16, 2020 at 7:24 AM Loic DESCOTTE <[hidden email]> wrote:

I've tried with this spark-submit option :

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But it did't solve the issue.

Should I add more jars?

Thanks

Loïc

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:20
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Seems like your Spark cluster doesn't somehow have the Hadoop JARs?

On Wed, Dec 16, 2020 at 6:45 AM Loic DESCOTTE <[hidden email]> wrote:

Hello,

I am using Spark On Kubernetes and I have the following error when I try to write data on HDFS : "no filesystem for scheme hdfs"

More details :

I am submitting my application with Spark submit like this :

spark-submit --master k8s://https://myK8SMaster:6443 \

--deploy-mode cluster \

--name hello-spark \

--class Hello \

--conf spark.executor.instances=2 \

--conf spark.kubernetes.container.image.pullPolicy=IfNotPresent \

--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \
--conf spark.kubernetes.container.image=gradiant/spark:2.4.4 hdfs://hdfs-namenode/user/loic/jars/helloSpark.jar

Then the driver and the 2 executors are created in K8S.

But it fails when I look at the logs of the driver, I see this :

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds
at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)

at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)

at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)

at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)

at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)

at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)

at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)

at org.apache.spark.sql.execution.datasources.DataSource.planForWritingFileFormat(DataSource.scala:424)

at org.apache.spark.sql.execution.datasources.DataSource.planForWriting(DataSource.scala:524)

at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:290)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:229)

at Hello$.main(hello.scala:24)

at Hello.main(hello.scala)

As you can see , my application jar helloSpark.jar file is correctly loaded on HDFS by the Spark submit, but writing to HDFS fails.

I have also tried to add the hadoop client dand hdfs dependencies in the spark submit command:

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But the error is still here.

Here is the Scala code of my application :

import java.util.Calendar

import org.apache.spark.sql.SparkSession

case class Data(singleField: String)

object Hello

{

def main(args: Array[String])

{

val spark = SparkSession

.builder()

.appName("Hello Spark")

.getOrCreate()

import spark.implicits._

val now = Calendar.getInstance().getTime().toString

val data = List(Data(now)).toDF()

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

}

}

Thanks for your help,

Loïc

Loic DESCOTTE

RE: Spark on Kubernetes : unable to write files to HDFS

Oh thank you you're right!! I feel shameful ��

De : German Schiavon <[hidden email]>
Envoyé : mercredi 16 décembre 2020 18:01
À : Loic DESCOTTE <[hidden email]>
Cc : [hidden email] <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Hi,

seems that you have a typo no?

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

On Wed, 16 Dec 2020 at 17:02, Loic DESCOTTE <[hidden email]> wrote:

So I've tried several other things, including building a fat jar with hdfs dependency inside my app jar, and added this to the Spark configuration in the code :

val spark = SparkSession

.builder()

.appName("Hello Spark 7")

.config("fs.hdfs.impl", classOf[org.apache.hadoop.hdfs.DistributedFileSystem].getName)

.getOrCreate()

But still the same error...

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:27
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

I think it'll have to be part of the Spark distro, but I'm not 100% sure. I also think these get registered via manifest files in the JARs; if some process is stripping those when creating a bundled up JAR, could be it. Could be that it's failing to initialize too for some reason.

On Wed, Dec 16, 2020 at 7:24 AM Loic DESCOTTE <[hidden email]> wrote:

I've tried with this spark-submit option :

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But it did't solve the issue.

Should I add more jars?

Thanks

Loïc

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:20
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Seems like your Spark cluster doesn't somehow have the Hadoop JARs?

On Wed, Dec 16, 2020 at 6:45 AM Loic DESCOTTE <[hidden email]> wrote:

Hello,

I am using Spark On Kubernetes and I have the following error when I try to write data on HDFS : "no filesystem for scheme hdfs"

More details :

I am submitting my application with Spark submit like this :

spark-submit --master k8s://https://myK8SMaster:6443 \

--deploy-mode cluster \

--name hello-spark \

--class Hello \

--conf spark.executor.instances=2 \

--conf spark.kubernetes.container.image.pullPolicy=IfNotPresent \

--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \
--conf spark.kubernetes.container.image=gradiant/spark:2.4.4 hdfs://hdfs-namenode/user/loic/jars/helloSpark.jar

Then the driver and the 2 executors are created in K8S.

But it fails when I look at the logs of the driver, I see this :

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds
at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)

at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)

at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)

at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)

at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)

at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)

at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)

at org.apache.spark.sql.execution.datasources.DataSource.planForWritingFileFormat(DataSource.scala:424)

at org.apache.spark.sql.execution.datasources.DataSource.planForWriting(DataSource.scala:524)

at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:290)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:229)

at Hello$.main(hello.scala:24)

at Hello.main(hello.scala)

As you can see , my application jar helloSpark.jar file is correctly loaded on HDFS by the Spark submit, but writing to HDFS fails.

I have also tried to add the hadoop client dand hdfs dependencies in the spark submit command:

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But the error is still here.

Here is the Scala code of my application :

import java.util.Calendar

import org.apache.spark.sql.SparkSession

case class Data(singleField: String)

object Hello

{

def main(args: Array[String])

{

val spark = SparkSession

.builder()

.appName("Hello Spark")

.getOrCreate()

import spark.implicits._

val now = Calendar.getInstance().getTime().toString

val data = List(Data(now)).toDF()

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

}

}

Thanks for your help,

Loïc

German Schiavon Matteo

Re: Spark on Kubernetes : unable to write files to HDFS

We all been there! no reason to be ashamed :)

On Wed, 16 Dec 2020 at 18:14, Loic DESCOTTE <[hidden email]> wrote:

Oh thank you you're right!! I feel shameful 😄

De : German Schiavon <[hidden email]>
Envoyé : mercredi 16 décembre 2020 18:01
À : Loic DESCOTTE <[hidden email]>
Cc : [hidden email] <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Hi,

seems that you have a typo no?

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

On Wed, 16 Dec 2020 at 17:02, Loic DESCOTTE <[hidden email]> wrote:

So I've tried several other things, including building a fat jar with hdfs dependency inside my app jar, and added this to the Spark configuration in the code :

val spark = SparkSession

.builder()

.appName("Hello Spark 7")

.config("fs.hdfs.impl", classOf[org.apache.hadoop.hdfs.DistributedFileSystem].getName)

.getOrCreate()

But still the same error...

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:27
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

I think it'll have to be part of the Spark distro, but I'm not 100% sure. I also think these get registered via manifest files in the JARs; if some process is stripping those when creating a bundled up JAR, could be it. Could be that it's failing to initialize too for some reason.

On Wed, Dec 16, 2020 at 7:24 AM Loic DESCOTTE <[hidden email]> wrote:

I've tried with this spark-submit option :

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But it did't solve the issue.

Should I add more jars?

Thanks

Loïc

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:20
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Seems like your Spark cluster doesn't somehow have the Hadoop JARs?

On Wed, Dec 16, 2020 at 6:45 AM Loic DESCOTTE <[hidden email]> wrote:

Hello,

I am using Spark On Kubernetes and I have the following error when I try to write data on HDFS : "no filesystem for scheme hdfs"

More details :

I am submitting my application with Spark submit like this :

spark-submit --master k8s://https://myK8SMaster:6443 \

--deploy-mode cluster \

--name hello-spark \

--class Hello \

--conf spark.executor.instances=2 \

--conf spark.kubernetes.container.image.pullPolicy=IfNotPresent \

--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \
--conf spark.kubernetes.container.image=gradiant/spark:2.4.4 hdfs://hdfs-namenode/user/loic/jars/helloSpark.jar

Then the driver and the 2 executors are created in K8S.

But it fails when I look at the logs of the driver, I see this :

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds
at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)

at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)

at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)

at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)

at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)

at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)

at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)

at org.apache.spark.sql.execution.datasources.DataSource.planForWritingFileFormat(DataSource.scala:424)

at org.apache.spark.sql.execution.datasources.DataSource.planForWriting(DataSource.scala:524)

at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:290)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:229)

at Hello$.main(hello.scala:24)

at Hello.main(hello.scala)

As you can see , my application jar helloSpark.jar file is correctly loaded on HDFS by the Spark submit, but writing to HDFS fails.

I have also tried to add the hadoop client dand hdfs dependencies in the spark submit command:

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But the error is still here.

Here is the Scala code of my application :

import java.util.Calendar

import org.apache.spark.sql.SparkSession

case class Data(singleField: String)

object Hello

{

def main(args: Array[String])

{

val spark = SparkSession

.builder()

.appName("Hello Spark")

.getOrCreate()

import spark.implicits._

val now = Calendar.getInstance().getTime().toString

val data = List(Data(now)).toDF()

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

}

}

Thanks for your help,

Loïc

Loic DESCOTTE

RE: Spark on Kubernetes : unable to write files to HDFS

Everything is working fine now 🙂

Thanks again

Loïc

De : German Schiavon <[hidden email]>
Envoyé : mercredi 16 décembre 2020 19:23
À : Loic DESCOTTE <[hidden email]>
Cc : [hidden email] <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

We all been there! no reason to be ashamed :)

On Wed, 16 Dec 2020 at 18:14, Loic DESCOTTE <[hidden email]> wrote:

Oh thank you you're right!! I feel shameful 😄

De : German Schiavon <[hidden email]>
Envoyé : mercredi 16 décembre 2020 18:01
À : Loic DESCOTTE <[hidden email]>
Cc : [hidden email] <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Hi,

seems that you have a typo no?

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

On Wed, 16 Dec 2020 at 17:02, Loic DESCOTTE <[hidden email]> wrote:

So I've tried several other things, including building a fat jar with hdfs dependency inside my app jar, and added this to the Spark configuration in the code :

val spark = SparkSession

.builder()

.appName("Hello Spark 7")

.config("fs.hdfs.impl", classOf[org.apache.hadoop.hdfs.DistributedFileSystem].getName)

.getOrCreate()

But still the same error...

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:27
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

I think it'll have to be part of the Spark distro, but I'm not 100% sure. I also think these get registered via manifest files in the JARs; if some process is stripping those when creating a bundled up JAR, could be it. Could be that it's failing to initialize too for some reason.

On Wed, Dec 16, 2020 at 7:24 AM Loic DESCOTTE <[hidden email]> wrote:

I've tried with this spark-submit option :

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But it did't solve the issue.

Should I add more jars?

Thanks

Loïc

De : Sean Owen <[hidden email]>
Envoyé : mercredi 16 décembre 2020 14:20
À : Loic DESCOTTE <[hidden email]>
Objet : Re: Spark on Kubernetes : unable to write files to HDFS

Seems like your Spark cluster doesn't somehow have the Hadoop JARs?

On Wed, Dec 16, 2020 at 6:45 AM Loic DESCOTTE <[hidden email]> wrote:

Hello,

I am using Spark On Kubernetes and I have the following error when I try to write data on HDFS : "no filesystem for scheme hdfs"

More details :

I am submitting my application with Spark submit like this :

spark-submit --master k8s://https://myK8SMaster:6443 \

--deploy-mode cluster \

--name hello-spark \

--class Hello \

--conf spark.executor.instances=2 \

--conf spark.kubernetes.container.image.pullPolicy=IfNotPresent \

--conf spark.kubernetes.authenticate.driver.serviceAccountName=spark \
--conf spark.kubernetes.container.image=gradiant/spark:2.4.4 hdfs://hdfs-namenode/user/loic/jars/helloSpark.jar

Then the driver and the 2 executors are created in K8S.

But it fails when I look at the logs of the driver, I see this :

Exception in thread "main" java.io.IOException: No FileSystem for scheme: hfds
at org.apache.hadoop.fs.FileSystem.getFileSystemClass(FileSystem.java:2660)

at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)

at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)

at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)

at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)

at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)

at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)

at org.apache.spark.sql.execution.datasources.DataSource.planForWritingFileFormat(DataSource.scala:424)

at org.apache.spark.sql.execution.datasources.DataSource.planForWriting(DataSource.scala:524)

at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:290)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)

at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:229)

at Hello$.main(hello.scala:24)

at Hello.main(hello.scala)

As you can see , my application jar helloSpark.jar file is correctly loaded on HDFS by the Spark submit, but writing to HDFS fails.

I have also tried to add the hadoop client dand hdfs dependencies in the spark submit command:

--packages org.apache.hadoop:hadoop-client:2.6.5,org.apache.hadoop:hadoop-hdfs:2.6.5 \

But the error is still here.

Here is the Scala code of my application :

import java.util.Calendar

import org.apache.spark.sql.SparkSession

case class Data(singleField: String)

object Hello

{

def main(args: Array[String])

{

val spark = SparkSession

.builder()

.appName("Hello Spark")

.getOrCreate()

import spark.implicits._

val now = Calendar.getInstance().getTime().toString

val data = List(Data(now)).toDF()

data.write.mode("overwrite").format("text").save("hfds://hdfs-namenode/user/loic/result.txt")

}

}

Thanks for your help,

Loïc