Refactor: umbp metadata store

.dockerignore

@@ -1,6 +1,7 @@
 # Keep build outputs, VCS data, and caches out of the docker build context.
 build/
 .git/
+.rocprofv3/
 **/__pycache__/
 **/*.egg-info/
 **/*.pyc

src/umbp/CMakeLists.txt

@@ -308,10 +308,7 @@ add_library(
   ${UMBP_GRPC_SRCS}
   ${UMBP_PEER_PROTO_SRCS}
   ${UMBP_PEER_GRPC_SRCS}
-  distributed/master/global_block_index.cpp
-  distributed/master/external_kv_block_index.cpp
-  distributed/master/client_registry.cpp
-  distributed/master/external_kv_hit_index.cpp
+  distributed/master/in_memory_master_metadata_store.cpp
   distributed/master/master_server.cpp
   distributed/master/master_client.cpp
   distributed/master/rpc_latency_timer.cpp
@@ -382,4 +379,6 @@ endif()
 target_link_libraries(umbp_client PRIVATE umbp_common ${_PROTOBUF_LIBS}
                                           ${_GRPCPP_LIB})
 
-add_subdirectory(tests)
+# UMBP unit tests live under tests/cpp/umbp (built when BUILD_TESTS=ON); they
+# were previously duplicated here under src/umbp/tests with a second GoogleTest
+# fetch.

src/umbp/distributed/bin/client_main.cpp

@@ -99,6 +99,11 @@ int main(int argc, char** argv) {
     return 1;
   }
 
+  // This demo drives MasterClient directly (it does not go through PoolClient,
+  // which is what normally honors config.auto_heartbeat on Init). Start the
+  // heartbeat thread so the master's reaper does not expire us.
+  client.StartHeartbeat();
+
   constexpr auto kOperationInterval = std::chrono::seconds(3);
   uint64_t iteration = 0;