Rocksdb metrics in status json (apple#11321)

Author: neethuhaneesha

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

@@ -176,6 +176,17 @@
                      "unknown"
                      ]}
                   },
+                  "rocksdb_metrics":{
+                     "block_cache_hits":12341234,
+                     "block_cache_misses":12341234,
+                     "pending_compaction_bytes":12341234,
+                     "memtable_bytes":12341234,
+                     "sst_reader_bytes":12341234,
+                     "block_cache_usage":12341234,
+                     "block_cache_limit":12341234,
+                     "throttled_commits":12341234,
+                     "write_stall_microseconds":12341234
+                  },
                   "data_version":12341234,
                   "durable_version":12341234,
                   "data_lag": {

fdbclient/Schemas.cpp

@@ -162,6 +162,17 @@ const KeyRef JSONSchemas::statusSchema = R"statusSchema(
                      "unknown"
                      ]}
                   },
+                  "rocksdb_metrics":{
+                     "block_cache_hits":12341234,
+                     "block_cache_misses":12341234,
+                     "pending_compaction_bytes":12341234,
+                     "memtable_bytes":12341234,
+                     "sst_reader_bytes":12341234,
+                     "block_cache_usage":12341234,
+                     "block_cache_limit":12341234,
+                     "throttled_commits":12341234,
+                     "write_stall_microseconds":12341234
+                  },
                   "data_version":12341234,
                   "durable_version":12341234,
                   "data_lag": {

fdbserver/KeyValueStoreRocksDB.actor.cpp

@@ -1078,12 +1078,15 @@ ACTOR Future<Void> rocksDBMetricLogger(UID id,
 		{ "NumTimesReadIteratorsReused", 0 },
 	};
 
+	state std::string rocksdbMetricsTrackingKey = id.toString() + "/RocksDBMetrics";
 	loop {
 		wait(delay(SERVER_KNOBS->ROCKSDB_METRICS_DELAY));
 		if (sharedState->isClosing()) {
 			break;
 		}
 		TraceEvent e("RocksDBMetrics", id);
+		e.trackLatest(rocksdbMetricsTrackingKey);
+
 		uint64_t stat;
 		for (auto& [name, ticker, cum] : tickerStats) {
 			stat = statistics->getTickerCount(ticker);

fdbserver/Status.actor.cpp

@@ -615,6 +615,24 @@ struct RolesInfo {
 				}
 			}
 
+			TraceEventFields const& rocksdbMetrics = metrics.at("RocksDBMetrics");
+			if (rocksdbMetrics.size()) {
+				JsonBuilderObject rocksdbMetricsObj;
+				rocksdbMetricsObj.setKeyRawNumber("block_cache_hits", rocksdbMetrics.getValue("BlockCacheHits"));
+				rocksdbMetricsObj.setKeyRawNumber("block_cache_misses", rocksdbMetrics.getValue("BlockCacheMisses"));
+				rocksdbMetricsObj.setKeyRawNumber("pending_compaction_bytes",
+				                                  rocksdbMetrics.getValue("EstPendCompactBytes"));
+				rocksdbMetricsObj.setKeyRawNumber("memtable_bytes", rocksdbMetrics.getValue("AllMemtablesBytes"));
+				rocksdbMetricsObj.setKeyRawNumber("sst_reader_bytes",
+				                                  rocksdbMetrics.getValue("EstimateSstReaderBytes"));
+				rocksdbMetricsObj.setKeyRawNumber("block_cache_usage", rocksdbMetrics.getValue("BlockCacheUsage"));
+				rocksdbMetricsObj.setKey("block_cache_limit", SERVER_KNOBS->ROCKSDB_BLOCK_CACHE_SIZE);
+				rocksdbMetricsObj.setKeyRawNumber("throttled_commits", rocksdbMetrics.getValue("CommitDelayed"));
+				rocksdbMetricsObj.setKeyRawNumber("write_stall_microseconds", rocksdbMetrics.getValue("StallMicros"));
+
+				obj["rocksdb_metrics"] = std::move(rocksdbMetricsObj);
+			}
+
 		} catch (AttributeNotFoundError& e) {
 			TraceEvent(SevWarnAlways, "StorageServerStatusJson").detail("MissingAttribute", e.getMissingAttribute());
 		}
@@ -1976,11 +1994,8 @@ static Future<std::vector<std::pair<iface, EventMap>>> getServerMetrics(
 
 namespace {
 
-const std::vector<std::string> STORAGE_SERVER_METRICS_LIST{ "StorageMetrics",
-	                                                        "ReadLatencyMetrics",
-	                                                        "ReadLatencyBands",
-	                                                        "BusiestReadTag",
-	                                                        "BusiestWriteTag" };
+const std::vector<std::string> STORAGE_SERVER_METRICS_LIST{ "StorageMetrics", "ReadLatencyMetrics", "ReadLatencyBands",
+	                                                        "BusiestReadTag", "BusiestWriteTag",    "RocksDBMetrics" };
 
 } // namespace