0ce01635cc
SPARK-13774: IllegalArgumentException: Can not create a Path from an empty string for incorrect file path
**Overview:**
- If a non-existent path is given in this call
``
scala> sqlContext.read.format("csv").load("file-path-is-incorrect.csv")
``
it throws the following error:
`java.lang.IllegalArgumentException: Can not create a Path from an empty string` …..
`It gets called from inferSchema call in org.apache.spark.sql.execution.datasources.DataSource.resolveRelation`
- The purpose of this JIRA is to throw a better error message.
- With the fix, you will now get a _Path does not exist_ error message.
```
scala> sqlContext.read.format("csv").load("file-path-is-incorrect.csv")
org.apache.spark.sql.AnalysisException: Path does not exist: file:/Users/ksunitha/trunk/spark/file-path-is-incorrect.csv;
at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$12.apply(DataSource.scala:215)
at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$12.apply(DataSource.scala:204)
...
at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:204)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:131)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:141)
... 49 elided
```
**Details**
_Changes include:_
- Check if path exists or not in resolveRelation in DataSource, and throw an AnalysisException with message like “Path does not exist: $path”
- AnalysisException is thrown similar to the exceptions thrown in resolveRelation.
- The glob path and the non glob path is checked with minimal calls to path exists. If the globPath is empty, then it is a nonexistent glob pattern and an error will be thrown. In the scenario that it is not globPath, it is necessary to only check if the first element in the Seq is valid or not.
_Test modifications:_
- Changes went in for 3 tests to account for this error checking.
- SQLQuerySuite:test("run sql directly on files") – Error message needed to be updated.
- 2 tests failed in MetastoreDataSourcesSuite because they had a dummy path and so test is modified to give a tempdir and allow it to move past so it can continue to test the codepath it meant to test
_New Tests:_
2 new tests are added to DataFrameSuite to validate that glob and non-glob path will throw the new error message.
_Testing:_
Unit tests were run with the fix.
**Notes/Questions to reviewers:**
- There is some code duplication in DataSource.scala in resolveRelation method and also createSource with respect to getting the paths. I have not made any changes to the createSource codepath. Should we make the change there as well ?
- From other JIRAs, I know there is restructuring and changes going on in this area, not sure how that will affect these changes, but since this seemed like a starter issue, I looked into it. If we prefer not to add the overhead of the checks, or if there is a better place to do so, let me know.
I would appreciate your review. Thanks for your time and comments.
Author: Sunitha Kambhampati <skambha@us.ibm.com>
Closes #11775 from skambha/improve_errmsg.
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| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| README.md | ||
Spark SQL
This module provides support for executing relational queries expressed in either SQL or a LINQ-like Scala DSL.
Spark SQL is broken up into four subprojects:
- Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
- Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
- Hive Support (sql/hive) - Includes an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allows users to run queries that include Hive UDFs, UDAFs, and UDTFs.
- HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.
Other dependencies for developers
In order to create new hive test cases (i.e. a test suite based on HiveComparisonTest),
you will need to setup your development environment based on the following instructions.
If you are working with Hive 0.12.0, you will need to set several environmental variables as follows.
export HIVE_HOME="<path to>/hive/build/dist"
export HIVE_DEV_HOME="<path to>/hive/"
export HADOOP_HOME="<path to>/hadoop"
If you are working with Hive 0.13.1, the following steps are needed:
- Download Hive's 0.13.1 and set
HIVE_HOMEwithexport HIVE_HOME="<path to hive>". Please do not setHIVE_DEV_HOME(See SPARK-4119). - Set
HADOOP_HOMEwithexport HADOOP_HOME="<path to hadoop>" - Download all Hive 0.13.1a jars (Hive jars actually used by Spark) from here and replace corresponding original 0.13.1 jars in
$HIVE_HOME/lib. - Download Kryo 2.21 jar (Note: 2.22 jar does not work) and Javolution 5.5.1 jar to
$HIVE_HOME/lib. - This step is optional. But, when generating golden answer files, if a Hive query fails and you find that Hive tries to talk to HDFS or you find weird runtime NPEs, set the following in your test suite...
val testTempDir = Utils.createTempDir()
// We have to use kryo to let Hive correctly serialize some plans.
sql("set hive.plan.serialization.format=kryo")
// Explicitly set fs to local fs.
sql(s"set fs.default.name=file://$testTempDir/")
// Ask Hive to run jobs in-process as a single map and reduce task.
sql("set mapred.job.tracker=local")
Using the console
An interactive scala console can be invoked by running build/sbt hive/console.
From here you can execute queries with HiveQl and manipulate DataFrame by using DSL.
catalyst$ build/sbt hive/console
[info] Starting scala interpreter...
import org.apache.spark.sql.catalyst.analysis._
import org.apache.spark.sql.catalyst.dsl._
import org.apache.spark.sql.catalyst.errors._
import org.apache.spark.sql.catalyst.expressions._
import org.apache.spark.sql.catalyst.plans.logical._
import org.apache.spark.sql.catalyst.rules._
import org.apache.spark.sql.catalyst.util._
import org.apache.spark.sql.execution
import org.apache.spark.sql.functions._
import org.apache.spark.sql.hive._
import org.apache.spark.sql.hive.test.TestHive._
import org.apache.spark.sql.types._
Type in expressions to have them evaluated.
Type :help for more information.
scala> val query = sql("SELECT * FROM (SELECT * FROM src) a")
query: org.apache.spark.sql.DataFrame = org.apache.spark.sql.DataFrame@74448eed
Query results are DataFrames and can be operated as such.
scala> query.collect()
res2: Array[org.apache.spark.sql.Row] = Array([238,val_238], [86,val_86], [311,val_311], [27,val_27]...
You can also build further queries on top of these DataFrames using the query DSL.
scala> query.where(query("key") > 30).select(avg(query("key"))).collect()
res3: Array[org.apache.spark.sql.Row] = Array([274.79025423728814])