Merge pull request #875 from tqchen/master

Fix model save problem in YARN

README.md

@@ -7,38 +7,30 @@
 [![PyPI version](https://badge.fury.io/py/xgboost.svg)](https://pypi.python.org/pypi/xgboost/)
 [![Gitter chat for developers at https://gitter.im/dmlc/xgboost](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/dmlc/xgboost?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
-|[Documentation](https://xgboost.readthedocs.org)| [Resources](demo/README.md) | [Installation](https://xgboost.readthedocs.org/en/latest/build.html)|
+[Documentation](https://xgboost.readthedocs.org) |
+[Resources](demo/README.md) |
+[Installation](https://xgboost.readthedocs.org/en/latest/build.html) |
 [Release Notes](NEWS.md)|
+[RoadMap](https://github.com/dmlc/xgboost/issues/873)
 
-XGBoost is an optimized distributed gradient boosting library designed to be highly *efficient*, *flexible* and *portable*.
+XGBoost is an optimized distributed gradient boosting library designed to be highly ***efficient***, ***flexible*** and ***portable***.
 It implements machine learning algorithms under the [Gradient Boosting](https://en.wikipedia.org/wiki/Gradient_boosting) framework.
 XGBoost provides a parallel tree boosting(also known as GBDT, GBM) that solve many data science problems in a fast and accurate way.
 The same code runs on major distributed environment(Hadoop, SGE, MPI) and can solve problems beyond billions of examples.
-XGBoost is part of [DMLC](http://dmlc.github.io/) projects.
 
 What's New
 ----------
 * [XGBoost brick](NEWS.md) Release
 
-Features
+Ask a Question
---------
+--------------
-* Easily accessible through CLI, [python](https://github.com/dmlc/xgboost/blob/master/demo/guide-python/basic_walkthrough.py),
-  [R](https://github.com/dmlc/xgboost/blob/master/R-package/demo/basic_walkthrough.R),
-  [Julia](https://github.com/antinucleon/XGBoost.jl/blob/master/demo/basic_walkthrough.jl)
-* Its fast! Benchmark numbers comparing xgboost, H20, Spark, R - [benchm-ml numbers](https://github.com/szilard/benchm-ml)
-* Memory efficient - Handles sparse matrices, supports external memory
-* Accurate prediction, and used extensively by data scientists and kagglers - [highlight links](https://github.com/dmlc/xgboost/blob/master/doc/README.md#highlight-links)
-* Distributed version runs on Hadoop (YARN), MPI, SGE etc., scales to billions of examples.
-
-Bug Reporting
--------------
 * For reporting bugs please use the [xgboost/issues](https://github.com/dmlc/xgboost/issues) page.
-* For generic questions or to share your experience using xgboost please use the [XGBoost User Group](https://groups.google.com/forum/#!forum/xgboost-user/)
+* For generic questions for to share your experience using xgboost please use the [XGBoost User Group](https://groups.google.com/forum/#!forum/xgboost-user/)
 
 Contributing to XGBoost
 -----------------------
 XGBoost has been developed and used by a group of active community members. Everyone is more than welcome to contribute. It is a way to make the project better and more accessible to more users.
-* Check out [Feature Wish List](https://github.com/dmlc/xgboost/labels/Wish-List) to see what can be improved, or open an issue if you want something.
+* Check out [call for contributions](https://github.com/dmlc/xgboost/issues?q=is%3Aissue+is%3Aclosed+label%3Acall-for-contribution) and [Roadmap](https://github.com/dmlc/xgboost/issues/873) to see what can be improved, or open an issue if you want something.
 * Contribute to the [documents and examples](https://github.com/dmlc/xgboost/blob/master/doc/) to share your experience with other users.
 * Please add your name to [CONTRIBUTORS.md](CONTRIBUTORS.md) and after your patch has been merged.
   - Please also update [NEWS.md](NEWS.md) on changes and improvements in API and docs.

src/cli_main.cc

@@ -213,7 +213,9 @@ void CLITrain(const CLIParam& param) {
         LOG(CONSOLE) << res;
       }
     }
-    if (param.save_period != 0 && (i + 1) % param.save_period == 0) {
+    if (param.save_period != 0 &&
+        (i + 1) % param.save_period == 0 &&
+        rabit::GetRank() == 0) {
       std::ostringstream os;
       os << param.model_dir << '/'
          << std::setfill('0') << std::setw(4)
@@ -233,7 +235,8 @@ void CLITrain(const CLIParam& param) {
   }
   // always save final round
   if ((param.save_period == 0 || param.num_round % param.save_period != 0) &&
-      param.model_out != "NONE") {
+      param.model_out != "NONE" &&
+      rabit::GetRank() == 0) {
     std::ostringstream os;
     if (param.model_out == "NULL") {
       os << param.model_dir << '/'