Alternative constructor that allows setting common Spark properties directly
Alternative constructor that allows setting common Spark properties directly
Cluster URL to connect to (e.g. mesos://host:port, spark://host:port, local[4]).
A name for your application, to display on the cluster web UI.
Location where Spark is installed on cluster nodes.
Collection of JARs to send to the cluster. These can be paths on the local file system or HDFS, HTTP, HTTPS, or FTP URLs.
Environment variables to set on worker nodes.
Alternative constructor that allows setting common Spark properties directly
Alternative constructor that allows setting common Spark properties directly
Cluster URL to connect to (e.g. mesos://host:port, spark://host:port, local[4]).
A name for your application, to display on the cluster web UI
a org.apache.spark.SparkConf object specifying other Spark parameters
:: DeveloperApi :: Alternative constructor for setting preferred locations where Spark will create executors.
:: DeveloperApi :: Alternative constructor for setting preferred locations where Spark will create executors.
used in YARN mode to select nodes to launch containers on. Can be generated using org.apache.spark.scheduler.InputFormatInfo.computePreferredLocations from a list of input files or InputFormats for the application.
Create a SparkContext that loads settings from system properties (for instance, when launching with .
Create a SparkContext that loads settings from system properties (for instance, when launching with ./bin/spark-submit).
a Spark Config object describing the application configuration. Any settings in this config overrides the default configs as well as system properties.
Create an org.apache.spark.Accumulable shared variable, with a name for display in the Spark UI.
Create an org.apache.spark.Accumulable shared variable, with a name for display in the
Spark UI. Tasks can add values to the accumuable using the +=
operator. Only the driver can
access the accumuable's value
.
accumulator type
type that can be added to the accumulator
Create an org.apache.spark.Accumulable shared variable, to which tasks can add values
with +=
.
Create an org.apache.spark.Accumulable shared variable, to which tasks can add values
with +=
. Only the driver can access the accumuable's value
.
accumulator type
type that can be added to the accumulator
Create an accumulator from a "mutable collection" type.
Create an accumulator from a "mutable collection" type.
Growable and TraversableOnce are the standard APIs that guarantee += and ++=, implemented by standard mutable collections. So you can use this with mutable Map, Set, etc.
Create an org.apache.spark.Accumulator variable of a given type, with a name for display in the Spark UI.
Create an org.apache.spark.Accumulator variable of a given type, with a name for display
in the Spark UI. Tasks can "add" values to the accumulator using the +=
method. Only the
driver can access the accumulator's value
.
Create an org.apache.spark.Accumulator variable of a given type, which tasks can "add"
values to using the +=
method.
Create an org.apache.spark.Accumulator variable of a given type, which tasks can "add"
values to using the +=
method. Only the driver can access the accumulator's value
.
Add a file to be downloaded with this Spark job on every node.
Add a file to be downloaded with this Spark job on every node.
The path
passed can be either a local file, a file in HDFS (or other Hadoop-supported
filesystems), or an HTTP, HTTPS or FTP URI. To access the file in Spark jobs,
use SparkFiles.get(path)
to find its download location.
Adds a JAR dependency for all tasks to be executed on this SparkContext in the future.
Adds a JAR dependency for all tasks to be executed on this SparkContext in the future.
The path
passed can be either a local file, a file in HDFS (or other Hadoop-supported
filesystems), an HTTP, HTTPS or FTP URI, or local:/path for a file on every worker node.
:: DeveloperApi :: Register a listener to receive up-calls from events that happen during execution.
:: DeveloperApi :: Register a listener to receive up-calls from events that happen during execution.
Broadcast a read-only variable to the cluster, returning a org.apache.spark.broadcast.Broadcast object for reading it in distributed functions.
Broadcast a read-only variable to the cluster, returning a org.apache.spark.broadcast.Broadcast object for reading it in distributed functions. The variable will be sent to each cluster only once.
Cancel all jobs that have been scheduled or are running.
Cancel active jobs for the specified group.
Cancel active jobs for the specified group. See org.apache.spark.SparkContext.setJobGroup for more information.
Support function for API backtraces.
Clear the current thread's job group ID and its description.
Default min number of partitions for Hadoop RDDs when not given by user
Default level of parallelism to use when not given by user (e.
Default level of parallelism to use when not given by user (e.g. parallelize and makeRDD).
Get an RDD that has no partitions or elements.
:: DeveloperApi :: Return pools for fair scheduler
:: DeveloperApi :: Return pools for fair scheduler
Return a copy of this SparkContext's configuration.
Return a copy of this SparkContext's configuration. The configuration cannot be changed at runtime.
Return a map from the slave to the max memory available for caching and the remaining memory available for caching.
:: DeveloperApi :: Return information about blocks stored in all of the slaves
:: DeveloperApi :: Return information about blocks stored in all of the slaves
Get a local property set in this thread, or null if it is missing.
Get a local property set in this thread, or null if it is missing. See org.apache.spark.SparkContext.setLocalProperty.
Returns an immutable map of RDDs that have marked themselves as persistent via cache() call.
Returns an immutable map of RDDs that have marked themselves as persistent via cache() call. Note that this does not necessarily mean the caching or computation was successful.
:: DeveloperApi :: Return the pool associated with the given name, if one exists
:: DeveloperApi :: Return the pool associated with the given name, if one exists
:: DeveloperApi :: Return information about what RDDs are cached, if they are in mem or on disk, how much space they take, etc.
:: DeveloperApi :: Return information about what RDDs are cached, if they are in mem or on disk, how much space they take, etc.
Return current scheduling mode
A default Hadoop Configuration for the Hadoop code (e.
A default Hadoop Configuration for the Hadoop code (e.g. file systems) that we reuse.
Smarter version of hadoopFile() that uses class tags to figure out the classes of keys, values and the InputFormat so that users don't need to pass them directly.
Smarter version of hadoopFile() that uses class tags to figure out the classes of keys, values and the InputFormat so that users don't need to pass them directly. Instead, callers can just write, for example,
val file = sparkContext.hadoopFile[LongWritable, Text, TextInputFormat](path)
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Smarter version of hadoopFile() that uses class tags to figure out the classes of keys, values and the InputFormat so that users don't need to pass them directly.
Smarter version of hadoopFile() that uses class tags to figure out the classes of keys, values and the InputFormat so that users don't need to pass them directly. Instead, callers can just write, for example,
val file = sparkContext.hadoopFile[LongWritable, Text, TextInputFormat](path, minPartitions)
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Get an RDD for a Hadoop file with an arbitrary InputFormat
Get an RDD for a Hadoop file with an arbitrary InputFormat
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Get an RDD for a Hadoop-readable dataset from a Hadoop JobConf given its InputFormat and other necessary info (e.
Get an RDD for a Hadoop-readable dataset from a Hadoop JobConf given its InputFormat and other
necessary info (e.g. file name for a filesystem-based dataset, table name for HyperTable),
using the older MapReduce API (org.apache.hadoop.mapred
).
JobConf for setting up the dataset
Class of the InputFormat
Class of the keys
Class of the values
Minimum number of Hadoop Splits to generate.
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Distribute a local Scala collection to form an RDD, with one or more location preferences (hostnames of Spark nodes) for each object.
Distribute a local Scala collection to form an RDD, with one or more location preferences (hostnames of Spark nodes) for each object. Create a new partition for each collection item.
Distribute a local Scala collection to form an RDD.
Distribute a local Scala collection to form an RDD.
This method is identical to parallelize
.
Get an RDD for a given Hadoop file with an arbitrary new API InputFormat and extra configuration options to pass to the input format.
Get an RDD for a given Hadoop file with an arbitrary new API InputFormat and extra configuration options to pass to the input format.
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Get an RDD for a Hadoop file with an arbitrary new API InputFormat.
Get an RDD for a given Hadoop file with an arbitrary new API InputFormat and extra configuration options to pass to the input format.
Get an RDD for a given Hadoop file with an arbitrary new API InputFormat and extra configuration options to pass to the input format.
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Load an RDD saved as a SequenceFile containing serialized objects, with NullWritable keys and BytesWritable values that contain a serialized partition.
Load an RDD saved as a SequenceFile containing serialized objects, with NullWritable keys and BytesWritable values that contain a serialized partition. This is still an experimental storage format and may not be supported exactly as is in future Spark releases. It will also be pretty slow if you use the default serializer (Java serialization), though the nice thing about it is that there's very little effort required to save arbitrary objects.
Distribute a local Scala collection to form an RDD.
Distribute a local Scala collection to form an RDD.
Parallelize acts lazily. If seq
is a mutable collection and is
altered after the call to parallelize and before the first action on the
RDD, the resultant RDD will reflect the modified collection. Pass a copy of
the argument to avoid this.
:: DeveloperApi :: Run a job that can return approximate results.
:: DeveloperApi :: Run a job that can return approximate results.
Run a job on all partitions in an RDD and pass the results to a handler function.
Run a job on all partitions in an RDD and pass the results to a handler function.
Run a job on all partitions in an RDD and return the results in an array.
Run a job on all partitions in an RDD and return the results in an array.
Run a job on a given set of partitions of an RDD, but take a function of type
Iterator[T] => U
instead of (TaskContext, Iterator[T]) => U
.
Run a function on a given set of partitions in an RDD and return the results as an array.
Run a function on a given set of partitions in an RDD and return the results as an array. The allowLocal flag specifies whether the scheduler can run the computation on the driver rather than shipping it out to the cluster, for short actions like first().
Run a function on a given set of partitions in an RDD and pass the results to the given handler function.
Run a function on a given set of partitions in an RDD and pass the results to the given handler function. This is the main entry point for all actions in Spark. The allowLocal flag specifies whether the scheduler can run the computation on the driver rather than shipping it out to the cluster, for short actions like first().
Version of sequenceFile() for types implicitly convertible to Writables through a WritableConverter.
Version of sequenceFile() for types implicitly convertible to Writables through a WritableConverter. For example, to access a SequenceFile where the keys are Text and the values are IntWritable, you could simply write
sparkContext.sequenceFile[String, Int](path, ...)
WritableConverters are provided in a somewhat strange way (by an implicit function) to support both subclasses of Writable and types for which we define a converter (e.g. Int to IntWritable). The most natural thing would've been to have implicit objects for the converters, but then we couldn't have an object for every subclass of Writable (you can't have a parameterized singleton object). We use functions instead to create a new converter for the appropriate type. In addition, we pass the converter a ClassTag of its type to allow it to figure out the Writable class to use in the subclass case.
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Get an RDD for a Hadoop SequenceFile with given key and value types.
Get an RDD for a Hadoop SequenceFile with given key and value types.
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Get an RDD for a Hadoop SequenceFile with given key and value types.
Get an RDD for a Hadoop SequenceFile with given key and value types.
Note: Because Hadoop's RecordReader class re-uses the same Writable object for each
record, directly caching the returned RDD will create many references to the same object.
If you plan to directly cache Hadoop writable objects, you should first copy them using
a map
function.
Support function for API backtraces.
Set the directory under which RDDs are going to be checkpointed.
Set the directory under which RDDs are going to be checkpointed. The directory must be a HDFS path if running on a cluster.
Assigns a group ID to all the jobs started by this thread until the group ID is set to a different value or cleared.
Assigns a group ID to all the jobs started by this thread until the group ID is set to a different value or cleared.
Often, a unit of execution in an application consists of multiple Spark actions or jobs. Application programmers can use this method to group all those jobs together and give a group description. Once set, the Spark web UI will associate such jobs with this group.
The application can also use org.apache.spark.SparkContext.cancelJobGroup to cancel all running jobs in this group. For example,
// In the main thread: sc.setJobGroup("some_job_to_cancel", "some job description") sc.parallelize(1 to 10000, 2).map { i => Thread.sleep(10); i }.count() // In a separate thread: sc.cancelJobGroup("some_job_to_cancel")
If interruptOnCancel is set to true for the job group, then job cancellation will result in Thread.interrupt() being called on the job's executor threads. This is useful to help ensure that the tasks are actually stopped in a timely manner, but is off by default due to HDFS-1208, where HDFS may respond to Thread.interrupt() by marking nodes as dead.
Set a local property that affects jobs submitted from this thread, such as the Spark fair scheduler pool.
Shut down the SparkContext.
:: Experimental :: Submit a job for execution and return a FutureJob holding the result.
:: Experimental :: Submit a job for execution and return a FutureJob holding the result.
Read a text file from HDFS, a local file system (available on all nodes), or any Hadoop-supported file system URI, and return it as an RDD of Strings.
Build the union of a list of RDDs passed as variable-length arguments.
Build the union of a list of RDDs.
The version of Spark on which this application is running.
Read a directory of text files from HDFS, a local file system (available on all nodes), or any Hadoop-supported file system URI.
Read a directory of text files from HDFS, a local file system (available on all nodes), or any Hadoop-supported file system URI. Each file is read as a single record and returned in a key-value pair, where the key is the path of each file, the value is the content of each file.
For example, if you have the following files:
hdfs://a-hdfs-path/part-00000 hdfs://a-hdfs-path/part-00001 ... hdfs://a-hdfs-path/part-nnnnn
Do val rdd = sparkContext.wholeTextFile("hdfs://a-hdfs-path")
,
then rdd
contains
(a-hdfs-path/part-00000, its content) (a-hdfs-path/part-00001, its content) ... (a-hdfs-path/part-nnnnn, its content)
A suggestion value of the minimal splitting number for input data.
Small files are preferred, large file is also allowable, but may cause bad performance.
Clear the job's list of files added by addFile
so that they do not get downloaded to
any new nodes.
Clear the job's list of files added by addFile
so that they do not get downloaded to
any new nodes.
(Since version 1.0.0) adding files no longer creates local copies that need to be deleted
Clear the job's list of JARs added by addJar
so that they do not get downloaded to
any new nodes.
Clear the job's list of JARs added by addJar
so that they do not get downloaded to
any new nodes.
(Since version 1.0.0) adding jars no longer creates local copies that need to be deleted
Default min number of partitions for Hadoop RDDs when not given by user
Default min number of partitions for Hadoop RDDs when not given by user
(Since version 1.0.0) use defaultMinPartitions
(Since version 1.0.0) Properties no longer need to be explicitly initialized.
Set a human readable description of the current job.
Set a human readable description of the current job.
(Since version 0.8.1) use setJobGroup
Main entry point for Spark functionality. A SparkContext represents the connection to a Spark cluster, and can be used to create RDDs, accumulators and broadcast variables on that cluster.