[Distribute] Add elastic-grpc server.

Signed-off-by: JunqiHu <silenceki@hotmail.com>

configure.py

@@ -1433,6 +1433,9 @@ def main():
   set_build_var(environ_cp, 'TF_NEED_STAR', 'STAR', 'with_star_support',
                 True, 'star')
 
+  set_build_var(environ_cp, 'TF_NEED_ELASTIC', 'ELASTIC TRAINING', 'with_elastic_support',
+                True, 'elastic')
+
   set_build_var(environ_cp, 'TF_ENABLE_PMEM', 'PMEM', 'with_pmem_support',
                 False, 'pmem')
 

tensorflow/BUILD

@@ -434,6 +434,12 @@ config_setting(
     visibility = ["//visibility:public"],
 )
 
+config_setting(
+    name = "with_elastic_support",
+    values = {"define": "with_elastic_support=true"},
+    visibility = ["//visibility:public"],
+)
+
 config_setting(
     name = "with_pmem_support",
     values = {"define": "with_pmem_support=true"},

tensorflow/contrib/elastic_grpc_server/BUILD

@@ -0,0 +1,70 @@
+licenses(["notice"])  # Apache 2.0
+
+exports_files(["LICENSE"])
+
+package(default_visibility = [
+    "//tensorflow:internal",
+])
+
+load(
+    "//tensorflow:tensorflow.bzl", "tf_cc_test",
+)
+
+cc_library(
+    name = "elastic_grpc_server_lib",
+    srcs = select({"//tensorflow:with_elastic_support": ["elastic_service.cc",
+                                                     "elastic_grpc_server_lib.cc"],
+		   "//conditions:default": []}),
+    hdrs = ["elastic_service.h",
+            "elastic_grpc_server_lib.h"],
+    linkstatic = 1,  # Seems to be needed since alwayslink is broken in bazel
+    deps = [
+        "//tensorflow/core:elastic_service_proto_cc",
+        "//tensorflow/core/distributed_runtime/rpc:grpc_server_lib",
+        "//tensorflow/core/distributed_runtime/rpc:async_service_interface",
+        "//tensorflow/core/distributed_runtime/rpc:grpc_channel",
+        "//tensorflow/core/distributed_runtime/rpc:grpc_master_service",
+        "//tensorflow/core/distributed_runtime/rpc:grpc_worker_cache",
+        "//tensorflow/core/distributed_runtime/rpc:grpc_worker_service",
+        "//tensorflow/core/distributed_runtime/rpc:rpc_rendezvous_mgr",
+        "//tensorflow:grpc",
+        "//tensorflow:grpc++",
+        "//tensorflow/core:core_cpu",
+        "//tensorflow/core:core_cpu_internal",
+        "//tensorflow/core:framework",
+        "//tensorflow/core:framework_internal",
+        "//tensorflow/core:lib",
+        "//tensorflow/core/common_runtime/eager:context",
+        "//tensorflow/core/distributed_runtime:collective_param_resolver_distributed",
+        "//tensorflow/core/distributed_runtime:device_resolver_distributed",
+        "//tensorflow/core/distributed_runtime:graph_mgr",
+        "//tensorflow/core/distributed_runtime:local_master",
+        "//tensorflow/core/distributed_runtime:master",
+        "//tensorflow/core/distributed_runtime:master_env",
+        "//tensorflow/core/distributed_runtime:master_session",
+        "//tensorflow/core/distributed_runtime:rpc_collective_executor_mgr",
+        "//tensorflow/core/distributed_runtime:server_lib",
+        "//tensorflow/core/distributed_runtime:session_mgr",
+        "//tensorflow/core/distributed_runtime:worker_cache_wrapper",
+        "//tensorflow/core/distributed_runtime:worker_env",
+        "//tensorflow/core/distributed_runtime:worker_resource",
+        "//tensorflow/core/distributed_runtime/rpc/eager:grpc_eager_service_impl",
+    ],
+    alwayslink = 1,
+)
+
+tf_cc_test(
+    name = "elastic_grpc_test",
+    size = "small",
+    srcs = ["elastic_grpc_server_lib_test.cc"],
+    deps = [
+        ":elastic_grpc_server_lib",
+        "//tensorflow/core/distributed_runtime/rpc:grpc_util",
+        "//tensorflow:grpc",
+        "//tensorflow:grpc++",
+        "//tensorflow/core:test",
+        "//tensorflow/core:test_main",
+        "//tensorflow/core:worker_proto_cc",
+    ],
+    linkstatic = 1, 
+)