multiple instances for one service; deployment scripts generator

This PR is related to issues https://gitlab.mpi-sws.org/cld/tracing/hindsight-grpc/-/issues/7 and https://gitlab.mpi-sws.org/cld/tracing/hindsight-grpc/-/issues/15.

src/hindsightgrpc/server.cc

@@ -80,9 +80,16 @@ void set_opentelemetry_enabled(bool is_enabled) {
   opentelemetry_enabled = is_enabled;
 }
 
-ServerImpl::ServerImpl(ServiceConfig config, std::map<std::string,
-  AddressInfo> addresses, bool nocompute, std::map<int, float> triggers) : alive(true), clients(),
-  config(config), addresses(addresses), nocompute_(nocompute) {
+ServerImpl::ServerImpl(ServiceConfig config,
+                       std::map<std::string, AddressInfo> addresses,
+                       bool nocompute, std::map<int, float> triggers,
+                       int instance_id)
+    : alive(true),
+      clients(),
+      config(config),
+      addresses(addresses),
+      nocompute_(nocompute),
+      instance_id(instance_id) {
   for (auto &p : triggers) {
     // trigger probabilities are typically small (e.g. 0.1, 0.01) so
     // we don't use, e.g. rand() % p to decide to trigger. instead we
@@ -105,7 +112,7 @@ ServerImpl::~ServerImpl() {
 
 void ServerImpl::Run(int nhandlers) {
   AddressInfo info = addresses[config.Name()];
-  std::string server_address(info.deploy_addr + ":" + info.port);
+  std::string server_address(info.deploy_addr + ":" + info.ports[instance_id]);
 
   // Build the gRPC server
   ServerBuilder builder;
@@ -118,7 +125,7 @@ void ServerImpl::Run(int nhandlers) {
   std::cout << "Server listening on " << server_address << std::endl;
   std::cout << "Server config " << config << std::endl;
 
-  std::string local_address = info.breadcrumb;
+  std::string local_address = info.breadcrumbs[instance_id];
   std::cout << "Using " << local_address
             << " for local breadcrumb" << std::endl;
 
@@ -366,7 +373,14 @@ void Request::Proceed(bool ok) {
     std::vector<Outcall*> child_calls;
     for (auto& child : api_info.children) {
       if (rand() % 100 < child.probability) {
-        child_calls.push_back(&child);
+        if (child.subcalls.size() > 0) {
+          // randomly choosing an instance of the target services
+          assert(child.subcalls.size() != 1);
+          child_calls.push_back(
+              &child.subcalls[rand() % child.subcalls.size()]);
+        } else {
+          child_calls.push_back(&child);
+        }
       }
     }