bit more documentation

documentation/sphinx/source/mr-status-json-schemas.rst.inc

@@ -120,7 +120,7 @@
                      "counter":0,
                      "roughness":0.0
                   },
-                  "grv_latency_statistics":{
+                  "grv_latency_statistics":{ // GRV Latency metrics are grouped according to priority (currently batch or default).
                      "default":{
                          "count":0,
                          "min":0.0,

fdbserver/GrvProxyServer.actor.cpp

@@ -77,6 +77,7 @@ struct GrvProxyStats {
 		       (FLOW_KNOBS->BASIC_LOAD_BALANCE_UPDATE_RATE - (lastBucketBegin + bucketInterval - now()));
 	}
 
+	// Current stats maintained for a given grv proxy server
 	explicit GrvProxyStats(UID id)
 	  : cc("GrvProxyStats", id.toString()), recentRequests(0), lastBucketBegin(now()),
 	    bucketInterval(FLOW_KNOBS->BASIC_LOAD_BALANCE_UPDATE_RATE / FLOW_KNOBS->BASIC_LOAD_BALANCE_BUCKETS),
@@ -513,6 +514,9 @@ ACTOR Future<GetReadVersionReply> getLiveCommittedVersion(SpanID parentSpan,
 	return rep;
 }
 
+// Returns the current read version (or minimum known committed verison if requested),
+// to each request in the provided list. Also check if the request should be throttled.
+// Update GRV statistics according to the request's priority.
 ACTOR Future<Void> sendGrvReplies(Future<GetReadVersionReply> replyFuture,
                                   std::vector<GetReadVersionRequest> requests,
                                   GrvProxyStats* stats,

fdbserver/Status.actor.cpp

@@ -624,6 +624,8 @@ struct RolesInfo {
 
 		return roles.insert(std::make_pair(iface.address(), obj))->second;
 	}
+
+	// Returns a json object encoding a snapshot of grv proxy statistics
 	JsonBuilderObject& addRole(std::string const& role, GrvProxyInterface& iface, EventMap const& metrics) {
 		JsonBuilderObject obj;
 		obj["id"] = iface.id().shortString();
@@ -1844,6 +1846,7 @@ ACTOR static Future<vector<std::pair<TLogInterface, EventMap>>> getTLogsAndMetri
 	return results;
 }
 
+// Returns list of tuples of grv proxy interfaces and their latency metrics
 ACTOR static Future<vector<std::pair<CommitProxyInterface, EventMap>>> getCommitProxiesAndMetrics(
     Reference<AsyncVar<ServerDBInfo>> db,
     std::unordered_map<NetworkAddress, WorkerInterface> address_workers) {