Ross Lewis Ross Lewis - 2 months ago 17
Scala Question

IllegalArgumentException, Wrong FS when writing ML model to s3 from Spark (Scala)

I've created a model:

val model = pipeline.fit(commentLower)


and I'm attempting to write it to s3:

sc.hadoopConfiguration.set("fs.s3.impl", "org.apache.hadoop.fs.s3native.NativeS3FileSystem")
sc.hadoopConfiguration.set("fs.s3.awsAccessKeyId", "MYACCESSKEY")
sc.hadoopConfiguration.set("fs.s3.awsSecretAccessKey", "MYSECRETKEY")
model.write.overwrite().save("s3n://sparkstore/model")


but I'm getting this error:

Name: java.lang.IllegalArgumentException
Message: Wrong FS: s3n://sparkstore/model, expected: file:///
StackTrace: org.apache.hadoop.fs.FileSystem.checkPath(FileSystem.java:645)
org.apache.hadoop.fs.RawLocalFileSystem.pathToFile(RawLocalFileSystem.java:80)
org.apache.hadoop.fs.RawLocalFileSystem.deprecatedGetFileStatus(RawLocalFileSystem.java:529)
org.apache.hadoop.fs.RawLocalFileSystem.getFileLinkStatusInternal(RawLocalFileSystem.java:747)
org.apache.hadoop.fs.RawLocalFileSystem.getFileStatus(RawLocalFileSystem.java:524)
org.apache.hadoop.fs.FilterFileSystem.getFileStatus(FilterFileSystem.java:409)
org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1400)
org.apache.spark.ml.util.MLWriter.save(ReadWrite.scala:80)


I also tried with my access key inline:

model.write.overwrite().save("s3n://MYACCESSKEY:MYSECRETKEY@/sparkstore/model")


How do I write a model (or any file for that matter) to s3 from Spark?

Answer

This isn't exactly what I wanted to do, but I found a similar thread with a similar problem:

How to save models from ML Pipeline to S3 or HDFS?

This is what I ended up doing:

sc.parallelize(Seq(model), 1).saveAsObjectFile("swift://RossL.keystone/model")
val modelx = sc.objectFile[PipelineModel]("swift://RossL.keystone/model").first()