executor creation failed should not make the worker restart
fix for SPARK-1027

change TestClient & Worker to Some("xxx")

kill manager if it is started

remove unnecessary .get when fetch "SPARK_HOME" values
fixed job name and usage information for the JavaSparkPi example
Depend on Commons Math explicitly instead of accidentally getting it from Hadoop (which stops working in 2.2.x) and also use the newer commons-math3
Merge pull request #492 from skicavs/master

fixed job name and usage information for the JavaSparkPi example
Also add graphx commons-math3 dependeny in sbt build
Merge pull request #495 from srowen/GraphXCommonsMathDependency

Fix graphx Commons Math dependency

`graphx` depends on Commons Math (2.x) in `SVDPlusPlus.scala`. However the module doesn't declare this dependency. It happens to work because it is included by Hadoop artifacts. But, I can tell you this isn't true as of a month or so ago. Building versus recent Hadoop would fail. (That's how we noticed.)

The simple fix is to declare the dependency, as it should be. But it's also worth noting that `commons-math` is the old-ish 2.x line, while `commons-math3` is where newer 3.x releases are. Drop-in replacement, but different artifact and package name. Changing this only usage to `commons-math3` works, tests pass, and isn't surprising that it does, so is probably also worth changing. (A comment in some test code also references `commons-math3`, FWIW.)

It does raise another question though: `mllib` looks like it uses the `jblas` `DoubleMatrix` for general purpose vector/matrix stuff. Should `graphx` really use Commons Math for this? Beyond the tiny scope here but worth asking.
refactor sparkHome to val

clean code
Fix bug in worker clean-up in UI

Introduced in d5a96fec. This should be picked into 0.8 and 0.9 as well.
Merge pull request #447 from CodingCat/SPARK-1027

fix for SPARK-1027

fix for SPARK-1027  (https://spark-project.atlassian.net/browse/SPARK-1027)

FIXES

1. change sparkhome from String to Option(String) in ApplicationDesc

2. remove sparkhome parameter in LaunchExecutor message

3. adjust involved files
Merge pull request #496 from pwendell/master

Fix bug in worker clean-up in UI

Introduced in d5a96fec (/cc @aarondav).

This should be picked into 0.8 and 0.9 as well. The bug causes old (zombie) workers on a node to not disappear immediately from the UI when a new one registers.