Squashed 'subtree/rabit/' changes from d4ec037..28ca7be

28ca7be add linear readme
ca4b20f add linear readme
1133628 add linear readme
6a11676 update docs
a607047 Update build.sh
2c1cfd8 complete yarn
4f28e32 change formater
2fbda81 fix stdin input
3258bcf checkin yarn master
67ebf81 allow setup from env variables
9b6bf57 fix hdfs
395d5c2 add make system
88ce767 refactor io, initial hdfs file access need test
19be870 chgs
a1bd3c6 Merge branch 'master' of ssh://github.com/tqchen/rabit
1a573f9 introduce input split
29476f1 fix timer issue

git-subtree-dir: subtree/rabit
git-subtree-split: 28ca7becbd

src/allreduce_base.cc

@@ -29,11 +29,24 @@ AllreduceBase::AllreduceBase(void) {
   task_id = "NULL";
   err_link = NULL;
   this->SetParam("rabit_reduce_buffer", "256MB");
+  // setup possible enviroment variable of intrest
+  env_vars.push_back("rabit_task_id");
+  env_vars.push_back("rabit_num_trial");
+  env_vars.push_back("rabit_reduce_buffer");
+  env_vars.push_back("rabit_tracker_uri");  
+  env_vars.push_back("rabit_tracker_port");
 }
 
 // initialization function
 void AllreduceBase::Init(void) {
   // setup from enviroment variables
+  // handler to get variables from env
+  for (size_t i = 0; i < env_vars.size(); ++i) {
+    const char *value = getenv(env_vars[i].c_str());
+    if (value != NULL) {
+      this->SetParam(env_vars[i].c_str(), value);
+    }
+  }
   {
     // handling for hadoop
     const char *task_id = getenv("mapred_tip_id");

src/allreduce_base.h

@@ -413,6 +413,8 @@ class AllreduceBase : public IEngine {
   // pointer to links in the ring
   LinkRecord *ring_prev, *ring_next;
   //----- meta information-----
+  // list of enviroment variables that are of possible interest
+  std::vector<std::string> env_vars;
   // unique identifier of the possible job this process is doing
   // used to assign ranks, optional, default to NULL
   std::string task_id;

src/allreduce_robust.cc

@@ -27,7 +27,9 @@ AllreduceRobust::AllreduceRobust(void) {
   result_buffer_round = 1;
   global_lazycheck = NULL;
   use_local_model = -1;
-  recover_counter = 0;
+  recover_counter = 0;  
+  env_vars.push_back("rabit_global_replica");
+  env_vars.push_back("rabit_local_replica");
 }
 void AllreduceRobust::Init(void) {
   AllreduceBase::Init();