[experiments] Add a placeholder experiment to test rollout monitoring (#31110)

src/core/lib/experiments/experiments.cc

@@ -46,6 +46,8 @@ const char* const description_new_hpack_huffman_decoder =
     "implementation.";
 const char* const description_event_engine_client =
     "Use EventEngine clients instead of iomgr's grpc_tcp_client";
+const char* const description_monitoring_experiment =
+    "Placeholder experiment to prove/disprove our monitoring is working";
 #ifdef NDEBUG
 const bool kDefaultForDebugOnly = false;
 #else
@@ -70,6 +72,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"new_hpack_huffman_decoder", description_new_hpack_huffman_decoder,
      kDefaultForDebugOnly},
     {"event_engine_client", description_event_engine_client, false},
+    {"monitoring_experiment", description_monitoring_experiment, true},
 };
 
 }  // namespace grpc_core

src/core/lib/experiments/experiments.h

@@ -41,6 +41,7 @@ inline bool IsUnconstrainedMaxQuotaBufferSizeEnabled() {
 }
 inline bool IsNewHpackHuffmanDecoderEnabled() { return IsExperimentEnabled(8); }
 inline bool IsEventEngineClientEnabled() { return IsExperimentEnabled(9); }
+inline bool IsMonitoringExperimentEnabled() { return IsExperimentEnabled(10); }
 
 struct ExperimentMetadata {
   const char* name;
@@ -48,7 +49,7 @@ struct ExperimentMetadata {
   bool default_value;
 };
 
-constexpr const size_t kNumExperiments = 10;
+constexpr const size_t kNumExperiments = 11;
 extern const ExperimentMetadata g_experiment_metadata[kNumExperiments];
 
 }  // namespace grpc_core

src/core/lib/experiments/experiments.yaml

@@ -112,3 +112,10 @@
   expiry: 2023/01/13
   owner: hork@google.com
   test_tags: ["event_engine_client_test"]
+- name: monitoring_experiment
+  description:
+    Placeholder experiment to prove/disprove our monitoring is working
+  default: true
+  expiry: 2022/10/01
+  owner: ctiller@google.com
+  test_tags: []