Skip to content

Latest commit

 

History

History
80 lines (57 loc) · 5.6 KB

sparkr-migration-guide.md

File metadata and controls

80 lines (57 loc) · 5.6 KB
layout title displayTitle license
global
Migration Guide: SparkR (R on Spark)
Migration Guide: SparkR (R on Spark)
Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
  • Table of contents {:toc}

Note that this migration guide describes the items specific to SparkR. Many items of SQL migration can be applied when migrating SparkR to higher versions. Please refer Migration Guide: SQL, Datasets and DataFrame.

Upgrading from SparkR 3.1 to 3.2

  • Previously, SparkR automatically downloaded and installed the Spark distribution in user' cache directory to complete SparkR installation when SparkR runs in a plain R shell or Rscript, and the Spark distribution cannot be found. Now, it asks if users want to download and install or not. To restore the previous behavior, set SPARKR_ASK_INSTALLATION environment variable to FALSE.

Upgrading from SparkR 2.4 to 3.0

  • The deprecated methods parquetFile, saveAsParquetFile, jsonFile, jsonRDD have been removed. Use read.parquet, write.parquet, read.json instead.

Upgrading from SparkR 2.3 to 2.4

  • Previously, we don't check the validity of the size of the last layer in spark.mlp. For example, if the training data only has two labels, a layers param like c(1, 3) doesn't cause an error previously, now it does.

Upgrading from SparkR 2.3 to 2.3.1 and above

  • In SparkR 2.3.0 and earlier, the start parameter of substr method was wrongly subtracted by one and considered as 0-based. This can lead to inconsistent substring results and also does not match with the behaviour with substr in R. In version 2.3.1 and later, it has been fixed so the start parameter of substr method is now 1-based. As an example, substr(lit('abcdef'), 2, 4)) would result to abc in SparkR 2.3.0, and the result would be bcd in SparkR 2.3.1.

Upgrading from SparkR 2.2 to 2.3

  • The stringsAsFactors parameter was previously ignored with collect, for example, in collect(createDataFrame(iris), stringsAsFactors = TRUE)). It has been corrected.
  • For summary, option for statistics to compute has been added. Its output is changed from that from describe.
  • A warning can be raised if versions of SparkR package and the Spark JVM do not match.

Upgrading from SparkR 2.1 to 2.2

  • A numPartitions parameter has been added to createDataFrame and as.DataFrame. When splitting the data, the partition position calculation has been made to match the one in Scala.
  • The method createExternalTable has been deprecated to be replaced by createTable. Either methods can be called to create external or managed table. Additional catalog methods have also been added.
  • By default, derby.log is now saved to tempdir(). This will be created when instantiating the SparkSession with enableHiveSupport set to TRUE.
  • spark.lda was not setting the optimizer correctly. It has been corrected.
  • Several model summary outputs are updated to have coefficients as matrix. This includes spark.logit, spark.kmeans, spark.glm. Model summary outputs for spark.gaussianMixture have added log-likelihood as loglik.

Upgrading from SparkR 2.0 to 3.1

  • join no longer performs Cartesian Product by default, use crossJoin instead.

Upgrading from SparkR 1.6 to 2.0

  • The method table has been removed and replaced by tableToDF.
  • The class DataFrame has been renamed to SparkDataFrame to avoid name conflicts.
  • Spark's SQLContext and HiveContext have been deprecated to be replaced by SparkSession. Instead of sparkR.init(), call sparkR.session() in its place to instantiate the SparkSession. Once that is done, that currently active SparkSession will be used for SparkDataFrame operations.
  • The parameter sparkExecutorEnv is not supported by sparkR.session. To set environment for the executors, set Spark config properties with the prefix "spark.executorEnv.VAR_NAME", for example, "spark.executorEnv.PATH"
  • The sqlContext parameter is no longer required for these functions: createDataFrame, as.DataFrame, read.json, jsonFile, read.parquet, parquetFile, read.text, sql, tables, tableNames, cacheTable, uncacheTable, clearCache, dropTempTable, read.df, loadDF, createExternalTable.
  • The method registerTempTable has been deprecated to be replaced by createOrReplaceTempView.
  • The method dropTempTable has been deprecated to be replaced by dropTempView.
  • The sc SparkContext parameter is no longer required for these functions: setJobGroup, clearJobGroup, cancelJobGroup

Upgrading from SparkR 1.5 to 1.6

  • Before Spark 1.6.0, the default mode for writes was append. It was changed in Spark 1.6.0 to error to match the Scala API.
  • SparkSQL converts NA in R to null and vice-versa.
  • Since 1.6.1, withColumn method in SparkR supports adding a new column to or replacing existing columns of the same name of a DataFrame.