Skip to content
Snippets Groups Projects
user avatar
Grace authored
By using the dynamic allocation, sometimes it occurs false killing for those busy executors. Some executors with assignments will be killed because of being idle for enough time (say 60 seconds). The root cause is that the Task-Launch listener event is asynchronized.

For example, some executors are under assigning tasks, but not sending out the listener notification yet. Meanwhile, the dynamic allocation's executor idle time is up (e.g., 60 seconds). It will trigger killExecutor event at the same time.
 1. the timer expiration starts before the listener event arrives.
 2. Then, the task is going to run on top of that killed/killing executor. It will lead to task failure finally.

Here is the proposal to fix it. We can add the force control for killExecutor. If the force control is not set (i.e., false), we'd better to check if the executor under killing is idle or busy. If the current executor has some assignment, we should not kill that executor and return back false (to indicate killing failure). In dynamic allocation, we'd better to turn off force killing (i.e., force = false), we will meet killing failure if tries to kill a busy executor. And then, the executor timer won't be invalid. Later on, the task assignment event arrives, we can remove the idle timer accordingly. So that we can avoid false killing for those busy executors in dynamic allocation.

For the rest of usages, the end users can decide if to use force killing or not by themselves.  If to turn on that option, the killExecutor will do the action without any status checking.

Author: Grace <jie.huang@intel.com>
Author: Andrew Or <andrew@databricks.com>
Author: Jie Huang <jie.huang@intel.com>

Closes #7888 from GraceH/forcekill.
965245d0
History

Apache Spark

Spark is a fast and general cluster computing system for Big Data. It provides high-level APIs in Scala, Java, Python, and R, and an optimized engine that supports general computation graphs for data analysis. It also supports a rich set of higher-level tools including Spark SQL for SQL and DataFrames, MLlib for machine learning, GraphX for graph processing, and Spark Streaming for stream processing.

http://spark.apache.org/

Online Documentation

You can find the latest Spark documentation, including a programming guide, on the project web page and project wiki. This README file only contains basic setup instructions.

Building Spark

Spark is built using Apache Maven. To build Spark and its example programs, run:

build/mvn -DskipTests clean package

(You do not need to do this if you downloaded a pre-built package.) More detailed documentation is available from the project site, at "Building Spark".

Interactive Scala Shell

The easiest way to start using Spark is through the Scala shell:

./bin/spark-shell

Try the following command, which should return 1000:

scala> sc.parallelize(1 to 1000).count()

Interactive Python Shell

Alternatively, if you prefer Python, you can use the Python shell:

./bin/pyspark

And run the following command, which should also return 1000:

>>> sc.parallelize(range(1000)).count()

Example Programs

Spark also comes with several sample programs in the examples directory. To run one of them, use ./bin/run-example <class> [params]. For example:

./bin/run-example SparkPi

will run the Pi example locally.

You can set the MASTER environment variable when running examples to submit examples to a cluster. This can be a mesos:// or spark:// URL, "yarn" to run on YARN, and "local" to run locally with one thread, or "local[N]" to run locally with N threads. You can also use an abbreviated class name if the class is in the examples package. For instance:

MASTER=spark://host:7077 ./bin/run-example SparkPi

Many of the example programs print usage help if no params are given.

Running Tests

Testing first requires building Spark. Once Spark is built, tests can be run using:

./dev/run-tests

Please see the guidance on how to run tests for a module, or individual tests.

A Note About Hadoop Versions

Spark uses the Hadoop core library to talk to HDFS and other Hadoop-supported storage systems. Because the protocols have changed in different versions of Hadoop, you must build Spark against the same version that your cluster runs.

Please refer to the build documentation at "Specifying the Hadoop Version" for detailed guidance on building for a particular distribution of Hadoop, including building for particular Hive and Hive Thriftserver distributions.

Configuration

Please refer to the Configuration Guide in the online documentation for an overview on how to configure Spark.