[Breaking] Switch from rabit to the collective communicator

demo/nvflare/custom/trainer.py

@@ -52,15 +52,15 @@ def execute(self, task_name: str, shareable: Shareable, fl_ctx: FLContext,
     def _do_training(self, fl_ctx: FLContext):
         client_name = fl_ctx.get_prop(FLContextKey.CLIENT_NAME)
         rank = int(client_name.split('-')[1]) - 1
-        rabit_env = [
-            f'federated_server_address={self._server_address}',
-            f'federated_world_size={self._world_size}',
-            f'federated_rank={rank}',
-            f'federated_server_cert={self._server_cert_path}',
-            f'federated_client_key={self._client_key_path}',
-            f'federated_client_cert={self._client_cert_path}'
-        ]
-        with xgb.rabit.RabitContext([e.encode() for e in rabit_env]):
+        communicator_env = {
+            'federated_server_address': self._server_address,
+            'federated_world_size': self._world_size,
+            'federated_rank': rank,
+            'federated_server_cert': self._server_cert_path,
+            'federated_client_key': self._client_key_path,
+            'federated_client_cert': self._client_cert_path
+        }
+        with xgb.collective.CommunicatorContext(**communicator_env):
             # Load file, file will not be sharded in federated mode.
             dtrain = xgb.DMatrix('agaricus.txt.train')
             dtest = xgb.DMatrix('agaricus.txt.test')
@@ -86,4 +86,4 @@ def _do_training(self, fl_ctx: FLContext):
             run_number = fl_ctx.get_prop(FLContextKey.CURRENT_RUN)
             run_dir = workspace.get_run_dir(run_number)
             bst.save_model(os.path.join(run_dir, "test.model.json"))
-            xgb.rabit.tracker_print("Finished training\n")
+            xgb.collective.communicator_print("Finished training\n")

jvm-packages/xgboost4j-flink/src/main/scala/ml/dmlc/xgboost4j/scala/flink/XGBoost.scala

@@ -19,7 +19,7 @@ package ml.dmlc.xgboost4j.scala.flink
 import scala.collection.JavaConverters.asScalaIteratorConverter
 
 import ml.dmlc.xgboost4j.LabeledPoint
-import ml.dmlc.xgboost4j.java.{Rabit, RabitTracker}
+import ml.dmlc.xgboost4j.java.{Communicator, RabitTracker}
 import ml.dmlc.xgboost4j.scala.{DMatrix, XGBoost => XGBoostScala}
 
 import org.apache.commons.logging.LogFactory
@@ -46,7 +46,7 @@ object XGBoost {
                      collector: Collector[XGBoostModel]): Unit = {
       workerEnvs.put("DMLC_TASK_ID", String.valueOf(this.getRuntimeContext.getIndexOfThisSubtask))
       logger.info("start with env" + workerEnvs.toString)
-      Rabit.init(workerEnvs)
+      Communicator.init(workerEnvs)
       val mapper = (x: LabeledVector) => {
         val (index, value) = x.vector.toSeq.unzip
         LabeledPoint(x.label.toFloat, x.vector.size, index.toArray, value.map(_.toFloat).toArray)
@@ -59,7 +59,7 @@ object XGBoost {
           .map(_.toString.toInt).getOrElse(0)
       val booster = XGBoostScala.train(trainMat, paramMap, round, watches,
         earlyStoppingRound = numEarlyStoppingRounds)
-      Rabit.shutdown()
+      Communicator.shutdown()
       collector.collect(new XGBoostModel(booster))
     }
   }

jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/PreXGBoost.scala

@@ -22,7 +22,7 @@ import java.util.ServiceLoader
 import scala.collection.JavaConverters._
 import scala.collection.{AbstractIterator, Iterator, mutable}
 
-import ml.dmlc.xgboost4j.java.Rabit
+import ml.dmlc.xgboost4j.java.Communicator
 import ml.dmlc.xgboost4j.scala.{Booster, DMatrix}
 import ml.dmlc.xgboost4j.scala.spark.util.DataUtils.PackedParams
 import ml.dmlc.xgboost4j.scala.spark.params.XGBoostEstimatorCommon
@@ -266,7 +266,7 @@ object PreXGBoost extends PreXGBoostProvider {
           if (batchCnt == 0) {
             val rabitEnv = Array(
               "DMLC_TASK_ID" -> TaskContext.getPartitionId().toString).toMap
-            Rabit.init(rabitEnv.asJava)
+            Communicator.init(rabitEnv.asJava)
           }
 
           val features = batchRow.iterator.map(row => row.getAs[Vector](featuresCol))
@@ -298,7 +298,7 @@ object PreXGBoost extends PreXGBoostProvider {
         override def next(): Row = {
           val ret = batchIterImpl.next()
           if (!batchIterImpl.hasNext) {
-            Rabit.shutdown()
+            Communicator.shutdown()
           }
           ret
         }

jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/XGBoost.scala

@@ -22,7 +22,7 @@ import scala.collection.mutable
 import scala.util.Random
 import scala.collection.JavaConverters._
 
-import ml.dmlc.xgboost4j.java.{IRabitTracker, Rabit, XGBoostError, RabitTracker => PyRabitTracker}
+import ml.dmlc.xgboost4j.java.{Communicator, IRabitTracker, XGBoostError, RabitTracker => PyRabitTracker}
 import ml.dmlc.xgboost4j.scala.rabit.RabitTracker
 import ml.dmlc.xgboost4j.scala.spark.params.LearningTaskParams
 import ml.dmlc.xgboost4j.scala.ExternalCheckpointManager
@@ -303,7 +303,7 @@ object XGBoost extends Serializable {
     val makeCheckpoint = xgbExecutionParam.checkpointParam.isDefined && taskId.toInt == 0
 
     try {
-      Rabit.init(rabitEnv)
+      Communicator.init(rabitEnv)
 
       watches = buildWatchesAndCheck(buildWatches)
 
@@ -342,7 +342,7 @@ object XGBoost extends Serializable {
         logger.error(s"XGBooster worker $taskId has failed $attempt times due to ", xgbException)
         throw xgbException
     } finally {
-      Rabit.shutdown()
+      Communicator.shutdown()
       if (watches != null) watches.delete()
     }
   }