diff --git a/cartographer/cloud/client/map_builder_stub.cc b/cartographer/cloud/client/map_builder_stub.cc
index 73c82dc..b29d836 100644
--- a/cartographer/cloud/client/map_builder_stub.cc
+++ b/cartographer/cloud/client/map_builder_stub.cc
@@ -32,13 +32,22 @@ namespace cloud {
 namespace {
 
 using common::make_unique;
+constexpr int kConnectionTimeoutInSecond = 10;
 
 }  // namespace
 
 MapBuilderStub::MapBuilderStub(const std::string& server_address)
     : client_channel_(::grpc::CreateChannel(
           server_address, ::grpc::InsecureChannelCredentials())),
-      pose_graph_stub_(make_unique<PoseGraphStub>(client_channel_)) {}
+      pose_graph_stub_(make_unique<PoseGraphStub>(client_channel_)) {
+  LOG(INFO) << "Connecting to SLAM process at " << server_address;
+  std::chrono::system_clock::time_point deadline(
+      std::chrono::system_clock::now() +
+      std::chrono::seconds(kConnectionTimeoutInSecond));
+  if (!client_channel_->WaitForConnected(deadline)) {
+    LOG(FATAL) << "Failed to connect to " << server_address;
+  }
+}
 
 int MapBuilderStub::AddTrajectoryBuilder(
     const std::set<SensorId>& expected_sensor_ids,
diff --git a/cartographer/cloud/internal/local_trajectory_uploader.cc b/cartographer/cloud/internal/local_trajectory_uploader.cc
index fb31caf..a9b61a9 100644
--- a/cartographer/cloud/internal/local_trajectory_uploader.cc
+++ b/cartographer/cloud/internal/local_trajectory_uploader.cc
@@ -40,13 +40,12 @@ namespace {
 
 using common::make_unique;
 
+constexpr int kConnectionTimeoutInSecond = 10;
 const common::Duration kPopTimeout = common::FromMilliseconds(100);
 
 class LocalTrajectoryUploader : public LocalTrajectoryUploaderInterface {
  public:
-  LocalTrajectoryUploader(const std::string &uplink_server_address)
-      : client_channel_(::grpc::CreateChannel(
-            uplink_server_address, ::grpc::InsecureChannelCredentials())) {}
+  LocalTrajectoryUploader(const std::string &uplink_server_address);
   ~LocalTrajectoryUploader();
 
   // Starts the upload thread.
@@ -96,6 +95,19 @@ class LocalTrajectoryUploader : public LocalTrajectoryUploaderInterface {
       add_landmark_client_;
 };
 
+LocalTrajectoryUploader::LocalTrajectoryUploader(
+    const std::string &uplink_server_address)
+    : client_channel_(::grpc::CreateChannel(
+          uplink_server_address, ::grpc::InsecureChannelCredentials())) {
+  std::chrono::system_clock::time_point deadline(
+      std::chrono::system_clock::now() +
+      std::chrono::seconds(kConnectionTimeoutInSecond));
+  LOG(INFO) << "Connecting to uplink " << uplink_server_address;
+  if (!client_channel_->WaitForConnected(deadline)) {
+    LOG(FATAL) << "Failed to connect to " << uplink_server_address;
+  }
+}
+
 LocalTrajectoryUploader::~LocalTrajectoryUploader() {
   if (add_imu_client_) {
     CHECK(add_imu_client_->StreamWritesDone());