Allow the user to provide a custome trace log file identifier that will be used as the prefix of all trace log files created at the client side.

fdbclient/NativeAPI.actor.cpp

@@ -792,7 +792,9 @@ Database Database::createDatabase( Reference<ClusterConnectionFile> connFile, in
 			auto publicIP = determinePublicIPAutomatically( connFile->getConnectionString() );
 			selectTraceFormatter(networkOptions.traceFormat);
 			selectTraceClockSource(networkOptions.traceClockSource);
-			openTraceFile(NetworkAddress(publicIP, ::getpid()), networkOptions.traceRollSize, networkOptions.traceMaxLogsSize, networkOptions.traceDirectory.get(), "trace", networkOptions.traceLogGroup);
+			openTraceFile(NetworkAddress(publicIP, ::getpid()), networkOptions.traceRollSize,
+			              networkOptions.traceMaxLogsSize, networkOptions.traceDirectory.get(), "trace",
+			              networkOptions.traceLogGroup, networkOptions.traceFileIdentifier);
 
 			TraceEvent("ClientStart")
 				.detail("SourceVersion", getSourceVersion())
@@ -874,7 +876,11 @@ void setNetworkOption(FDBNetworkOptions::Option option, Optional<StringRef> valu
 				throw invalid_option_value();
 			}
 			break;
-		case FDBNetworkOptions::KNOB: {
+	    case FDBNetworkOptions::TRACE_FILE_IDENTIFIER:
+		    validateOptionValue(value, true);
+		    networkOptions.traceFileIdentifier = value.get().toString();
+		    break;
+	    case FDBNetworkOptions::KNOB: {
 			validateOptionValue(value, true);
 
 			std::string optionValue = value.get().toString();

fdbclient/NativeAPI.actor.h

@@ -58,6 +58,7 @@ struct NetworkOptions {
 	std::string traceLogGroup;
 	std::string traceFormat;
 	std::string traceClockSource;
+	std::string traceFileIdentifier;
 	Optional<bool> logClientInfo;
 	Reference<ReferencedObject<Standalone<VectorRef<ClientVersionRef>>>> supportedVersions;
 	bool slowTaskProfilingEnabled;

fdbclient/vexillographer/fdb.options

@@ -54,6 +54,9 @@ description is not currently required but encouraged.
     <Option name="trace_clock_source" code="35"
             paramType="String" paramDescription="Trace clock source"
             description="Select clock source for trace files. now (the default) or realtime are supported." />
+    <Option name="trace_file_identifier" code="36"
+            paramType="String" paramDescription="The identifier that will be part of all trace file names"
+            description="Once provided, all trace log file names will use this string as the prefix." />
     <Option name="knob" code="40"
             paramType="String" paramDescription="knob_name=knob_value"
             description="Set internal tuning or debugging knobs"/>

flow/Trace.cpp

@@ -711,7 +711,8 @@ void flushTraceFileVoid() {
 	}
 }
 
-void openTraceFile(const NetworkAddress& na, uint64_t rollsize, uint64_t maxLogsSize, std::string directory, std::string baseOfBase, std::string logGroup) {
+void openTraceFile(const NetworkAddress& na, uint64_t rollsize, uint64_t maxLogsSize, std::string directory,
+                   std::string baseOfBase, std::string logGroup, std::string identifier) {
 	if(g_traceLog.isOpen())
 		return;
 
@@ -723,7 +724,12 @@ void openTraceFile(const NetworkAddress& na, uint64_t rollsize, uint64_t maxLogs
 
 	std::string ip = na.ip.toString();
 	std::replace(ip.begin(), ip.end(), ':', '_'); // For IPv6, Windows doesn't accept ':' in filenames.
-	std::string baseName = format("%s.%s.%d", baseOfBase.c_str(), ip.c_str(), na.port);
+	std::string baseName;
+	if (identifier.size() > 0) {
+		baseName = format("%s.%s.%s.%d", identifier, baseOfBase.c_str(), ip.c_str(), na.port);
+	} else {
+		baseName = format("%s.%s.%d", baseOfBase.c_str(), ip.c_str(), na.port);
+	}
 	g_traceLog.open( directory, baseName, logGroup, format("%lld", time(NULL)), rollsize, maxLogsSize, !g_network->isSimulated() ? na : Optional<NetworkAddress>());
 
 	uncancellable(recurring(&flushTraceFile, FLOW_KNOBS->TRACE_FLUSH_INTERVAL, TaskPriority::FlushTrace));

flow/Trace.h

@@ -587,7 +587,8 @@ struct EventCacheHolder : public ReferenceCounted<EventCacheHolder> {
 #endif
 
 struct NetworkAddress;
-void openTraceFile(const NetworkAddress& na, uint64_t rollsize, uint64_t maxLogsSize, std::string directory = ".", std::string baseOfBase = "trace", std::string logGroup = "default");
+void openTraceFile(const NetworkAddress& na, uint64_t rollsize, uint64_t maxLogsSize, std::string directory = ".",
+                   std::string baseOfBase = "trace", std::string logGroup = "default", std::string identifier = "");
 void initTraceEventMetrics();
 void closeTraceFile();
 bool traceFileIsOpen();