Merge remote-tracking branch 'remotes/origin/master' into mqttTopics

.gitignore

@@ -2,6 +2,9 @@
 deps/
 install/
 
+## Ignore DCDB generated documentation
+doc/html
+
 ## Ignore object files and other binaries
 *.o
 *.so

Makefile

@@ -61,7 +61,7 @@ PUBHEADERS = pusherpqueue.h dcdbdaemon.h
 FULL_CC = $(shell which $(CC))
 FULL_CXX = $(shell which $(CXX))
 
-.PHONY : info all clean cleanall distclean check-cross-compile deps depsinstall $(SUB_DIRS)
+.PHONY : info all clean cleanall cleandoc distclean check-cross-compile deps depsinstall $(SUB_DIRS) doc
 
 info:
 	@echo ""
@@ -97,8 +97,12 @@ clean:
 cleandeps:
 	@$(foreach f,$(DISTFILESPATHS),echo "Cleaning $(f)..." && rm -rf $(DCDBDEPSPATH)/$(f) && echo;)
 	@$(foreach f,cpp-netlib,echo "Cleaning $(f)..." && rm -rf $(DCDBDEPSPATH)/$(f)_build && echo;)
+	
+cleandoc:
+	@echo "Cleaning doc/html..."
+	@rm -rf doc/html
 
-cleanall: clean cleandeps
+cleanall: clean cleandeps cleandoc
 
 distclean: clean
 	@echo "Wiping dependencies..."
@@ -110,10 +114,15 @@ mrproper: distclean
 	@echo ""
 	@echo "Wiping installation directory..."
 	@rm -rf $(DCDBDEPLOYPATH)
+	
+doc:
+	@echo "Generating doxygen HTML documentation..."
+	@cd doc/ && doxygen Doxyfile
+	@echo "Generated docs into doc/html"
 
-all: check-cross-compile deps $(foreach s,$(SUB_DIRS),$(s)-build) 
+all: check-cross-compile deps $(foreach s,$(SUB_DIRS),$(s)-build) doc
 
-install: depsinstall $(SUB_DIRS)
+install: depsinstall $(SUB_DIRS) doc
 	@cd common/include && install $(PUBHEADERS) $(DCDBDEPLOYPATH)/include/dcdb && cd ..
 	@echo DONE
 

analytics/AnalyticsManager.cpp

@@ -48,6 +48,8 @@ bool AnalyticsManager::load(const string& path, const string& globalFile, const
 
     if (_configPath != "" && _configPath[_configPath.length()-1] != '/')
         _configPath.append("/");
+    else if(_configPath.empty())
+        _configPath = "./";
 
     try {
         boost::property_tree::read_info(_configPath + globalFile, cfg);
@@ -66,92 +68,130 @@ bool AnalyticsManager::load(const string& path, const string& globalFile, const
     BOOST_FOREACH(boost::property_tree::iptree::value_type &plugin, cfg.get_child("analyzerPlugins")) {
         if (boost::iequals(plugin.first, "analyzerPlugin")) {
             if (!plugin.second.empty()) {
-                LOG(info) << "Loading analyzer plugin \"" << plugin.second.data() << "\"...";
-                std::string pluginConfig; //path to config file for plugin
-                std::string pluginLib = "libdcdbanalyzer_" + plugin.second.data();
-#if __APPLE__
-                pluginLib+= ".dylib";
-#else
-                pluginLib+= ".so";
-#endif
+                string pluginConfig="", pluginPath="";
                 BOOST_FOREACH(boost::property_tree::iptree::value_type &val, plugin.second) {
                     if (boost::iequals(val.first, "path")) {
-                        std::string iPath = val.second.data();
-                        // If path not specified we will look up in the default lib-directories (usr/lib and friends)
-                        if (iPath != "") {
-                            if (iPath[iPath.length()-1] != '/')
-                                iPath.append("/");
-                            pluginLib = iPath + pluginLib;
-                        }
+                        pluginPath = val.second.data();
                     } else if (boost::iequals(val.first, "config")) {
                         pluginConfig = val.second.data();
-                        // If config-path not specified we will look for pluginName.conf in the global conf directory
-                        if (pluginConfig == "")
-                            pluginConfig = _configPath + plugin.second.data() + ".conf";
                     } else {
                         LOG(warning) << "  Value \"" << val.first << "\" not recognized. Omitting";
                     }
                 }
-                // Open dl-code based on http://tldp.org/HOWTO/C++-dlopen/thesolution.html
-                if (FILE *file = fopen(pluginConfig.c_str(), "r")) {
-                    fclose(file);
-                    an_dl_t dynLib;
-                    dynLib.id = plugin.second.data();
-                    dynLib.DL = NULL;
-                    dynLib.configurator = NULL;
-
-                    // If plugin.conf exists, open libdcdbanalyzer_pluginName.so and read config
-                    LOG(info) << pluginConfig << " found";
-                    dynLib.DL = dlopen(pluginLib.c_str(), RTLD_NOW);
-                    if(!dynLib.DL) {
-                        LOG(error) << "Cannot load " << dynLib.id << "-library: " << dlerror();
-                        return false;
-                    }
-                    dlerror();
-
-                    // Set dynLib an_dl_t struct, load create and destroy symbols
-                    dynLib.create = (an_create_t*) dlsym(dynLib.DL, "create");
-                    const char* dlsym_error = dlerror();
-                    if (dlsym_error) {
-                        LOG(error) << "Cannot load symbol create for " << dynLib.id << ": " << dlsym_error;
-                        return false;
-                    }
+                if(!loadPlugin(plugin.second.data(), pluginPath, pluginConfig))
+                    return false;
+            }
+        }
+    }
+    _status = LOADED;
+    return true;
+}
 
-                    dynLib.destroy = (an_destroy_t*) dlsym(dynLib.DL, "destroy");
-                    dlsym_error = dlerror();
-                    if (dlsym_error) {
-                        LOG(error) << "Cannot load symbol destroy for " << dynLib.id << ": " << dlsym_error;
-                        return false;
-                    }
+bool AnalyticsManager::loadPlugin(const string& name, const string& pluginPath, const string& config) {
+    LOG(info) << "Loading analyzer plugin \"" << name << "\"...";
+    std::string pluginConfig; //path to config file for plugin
+    std::string pluginLib = "libdcdbanalyzer_" + name;
+#if __APPLE__
+    pluginLib+= ".dylib";
+#else
+    pluginLib+= ".so";
+#endif
+    
+    std::string iPath = pluginPath;
+    // If path not specified we will look up in the default lib-directories (usr/lib and friends)
+    if (iPath != "") {
+        if (iPath[iPath.length()-1] != '/')
+            iPath.append("/");
+        pluginLib = iPath + pluginLib;
+    }
+    
+    pluginConfig = config;
+    // If config-path not specified we will look for pluginName.conf in the global conf directory
+    if (pluginConfig == "")
+        pluginConfig = _configPath + name + ".conf";
+        
+    // Open dl-code based on http://tldp.org/HOWTO/C++-dlopen/thesolution.html
+    if (FILE *file = fopen(pluginConfig.c_str(), "r")) {
+        fclose(file);
+        an_dl_t dynLib;
+        dynLib.id = name;
+        dynLib.DL = NULL;
+        dynLib.configurator = NULL;
+
+        // If plugin.conf exists, open libdcdbanalyzer_pluginName.so and read config
+        LOG(info) << pluginConfig << " found";
+        dynLib.DL = dlopen(pluginLib.c_str(), RTLD_NOW);
+        if(!dynLib.DL) {
+            LOG(error) << "Cannot load " << dynLib.id << "-library: " << dlerror();
+            return false;
+        }
+        dlerror();
+
+        // Set dynLib an_dl_t struct, load create and destroy symbols
+        dynLib.create = (an_create_t*) dlsym(dynLib.DL, "create");
+        const char* dlsym_error = dlerror();
+        if (dlsym_error) {
+            LOG(error) << "Cannot load symbol create for " << dynLib.id << ": " << dlsym_error;
+            return false;
+        }
 
-                    dynLib.configurator = dynLib.create();
-                    dynLib.configurator->setGlobalSettings(_pluginSettings);
-                    // Read the analyzer plugin configuration
-                    if (!(dynLib.configurator->readConfig(pluginConfig))) {
-                        LOG(error) << "Plugin \"" << dynLib.id << "\" could not read configuration!";
-                        return false;
-                    }
+        dynLib.destroy = (an_destroy_t*) dlsym(dynLib.DL, "destroy");
+        dlsym_error = dlerror();
+        if (dlsym_error) {
+            LOG(error) << "Cannot load symbol destroy for " << dynLib.id << ": " << dlsym_error;
+            return false;
+        }
 
-                    // Returning an empty vector may indicate problems with the config file
-                    if(dynLib.configurator->getAnalyzers().size() == 0) {
-                        LOG(warning) << "Plugin \"" << dynLib.id << "\" created no analyzers!";
-                    } else if(!checkTopics(dynLib)) {
-                        LOG(error) << "Problematic MQTT topics or sensor names, please check your config files!";
-                        return false;
-                    }
-                    //save dl-struct
-                    _plugins.push_back(dynLib);
-                    LOG(info) << "Plugin \"" << dynLib.id << "\" loaded!";
-                } else {
-                    LOG(info) << pluginConfig << " not found. Omitting";
-                }
-            }
+        dynLib.configurator = dynLib.create();
+        dynLib.configurator->setGlobalSettings(_pluginSettings);
+        // Read the analyzer plugin configuration
+        if (!(dynLib.configurator->readConfig(pluginConfig))) {
+            LOG(error) << "Plugin \"" << dynLib.id << "\" could not read configuration!";
+            return false;
+        }
+
+        // Returning an empty vector may indicate problems with the config file
+        if(dynLib.configurator->getAnalyzers().size() == 0) {
+            LOG(warning) << "Plugin \"" << dynLib.id << "\" created no analyzers!";
+        } else if(!checkTopics(dynLib)) {
+            LOG(error) << "Problematic MQTT topics or sensor names, please check your config files!";
+            return false;
         }
+        //save dl-struct
+        _plugins.push_back(dynLib);
+        LOG(info) << "Plugin \"" << dynLib.id << "\" loaded!";
+    } else {
+        LOG(info) << pluginConfig << " not found. Omitting";
+        return false;
     }
-    _status = LOADED;
     return true;
 }
 
+void AnalyticsManager::unloadPlugin(const string& id) {
+    for (auto it = _plugins.begin(); it != _plugins.end(); ++it) {
+        if(it->id == id || id == "") {
+            for (const auto& a : it->configurator->getAnalyzers())
+                a->stop();
+
+            removeTopics(*it);
+
+            if (it->configurator)
+                it->destroy(it->configurator);
+            
+            if (it->DL)
+                dlclose(it->DL);
+
+            if (id != "") {
+                _plugins.erase(it);
+                return;
+            }
+        }
+    }
+
+    if (id == "")
+        _plugins.clear();
+}
+
 bool AnalyticsManager::init(boost::asio::io_service& io, const string& plugin) {
     if(_status != LOADED) {
         LOG(error) << "Cannot init, AnalyticsManager is not loaded!";
@@ -280,7 +320,6 @@ void AnalyticsManager::addRestEndpoints(RESTHttpsServer* restServer) {
 
     restServer->addEndpoint("/analytics/start",    {http::verb::put, stdBind(PUT_analytics_start)});
     restServer->addEndpoint("/analytics/stop",     {http::verb::put, stdBind(PUT_analytics_stop)});
-    restServer->addEndpoint("/analytics/reload",   {http::verb::put, stdBind(PUT_analytics_reload)});
     restServer->addEndpoint("/analytics/compute",  {http::verb::put, stdBind(PUT_analytics_compute)});
     restServer->addEndpoint("/analytics/analyzer", {http::verb::put, stdBind(PUT_analytics_analyzer)});
 }
@@ -498,36 +537,6 @@ void AnalyticsManager::PUT_analytics_stop(endpointArgs) {
     }
 }
 
-void AnalyticsManager::PUT_analytics_reload(endpointArgs) {
-    if (!managerLoaded(res)) {
-        return;
-    }
-    /*
-     * This endpoint must either be overwritten (by adding a custom
-     * "analyzer/reload" endpoint) or must not be used. A reload requires
-     * an external io_service object and can therefore not be conducted by the
-     * AnalyticsManager itself.
-     */
-
-    res.body() = "Sorry! It seems like this endpoint was not properly implemented.\n";
-    res.result(http::status::not_implemented);
-
-    /*
-    const std::string plugin   = getQuery("plugin", queries);
-
-    if (!reload(_io, plugin)) {
-        res.body() = "Plugin not found or reload failed, please check the config files and MQTT topics!\n";
-        res.result(http::status::not_found);
-    } else if (!start(plugin)){
-        res.body() = "Plugin cannot be restarted!\n";
-        res.result(http::status::internal_server_error);
-    } else {
-        res.body() = "Plugin " + plugin + ": Sensors reloaded";
-        res.result(http::status::ok);
-    }
-    */
-}
-
 void AnalyticsManager::PUT_analytics_compute(endpointArgs) {
     if (!managerLoaded(res)) {
         return;

analytics/AnalyticsManager.h

@@ -137,6 +137,23 @@ public:
     */
     bool stop(const string& plugin="", const string& analyzer="");
 
+    /**
+     * @brief             Loads a plugin dynamically
+     * 
+     * @param name        Name of the plugin
+     * @param pluginPath  Path to the plugin library
+     * @param config      Path to the configuration file
+     * @return            True if successful, false otherwise
+     */
+    bool loadPlugin(const string& name, const string& pluginPath, const string& config);
+
+    /**
+     * @brief             Unloads a currently loaded plugin
+     * 
+     * @param id          Name of the plugin to be unloaded
+     */
+    void unloadPlugin(const string& id);
+
     /**
     * @brief            Get the vector of currently loaded plugins
     *
@@ -182,6 +199,11 @@ public:
                                     "                           Stop all or only a specific analytics plugin or\n"
                                     "                           stop only a specific analyzer within a plugin.\n"
                                     "       /reload?[plugin]    Reload all or only a specific analytics plugin.\n"
+                                    "       /load?plugin;[path];[config]\n"
+                                    "                           Load a new plugin. Optionally specify path to the\n"
+                                    "                           shared library and/or the config file for the \n"
+                                    "                           plugin.\n"
+                                    "       /unload?plugin      Unload a plugin.\n"
                                     "       /compute?plugin;analyzer;[unit];[json]\n"
                                     "                           Query the specified analyzer for a unit. Default\n"
                                     "                           unit is the root.\n"

collectagent/CARestAPI.cpp

@@ -24,8 +24,9 @@ CARestAPI::CARestAPI(serverSettings_t settings,
 
     _analyticsController->getManager()->addRestEndpoints(this);
 
-    //Overwrite analytic's reload endpoint because we need to stop analyticscontroller beforehand
     addEndpoint("/analytics/reload", {http::verb::put, stdBind(PUT_analytics_reload)});
+    addEndpoint("/analytics/load", {http::verb::put, stdBind(PUT_analytics_load)});
+    addEndpoint("/analytics/unload", {http::verb::put, stdBind(PUT_analytics_unload)});
 }
 
 void CARestAPI::GET_help(endpointArgs) {
@@ -59,7 +60,6 @@ void CARestAPI::GET_average(endpointArgs) {
     //try getting the latest value
     try {
         int64_t val = _sensorCache->getSensor(sensor, (uint64_t) time * 1000000000);
-
         res.body() = "collectagent::" + sensor + " Average of last " +
                      std::to_string(time) + " seconds is " + std::to_string(val);
         res.result(http::status::ok);
@@ -105,3 +105,45 @@ void CARestAPI::PUT_analytics_reload(endpointArgs) {
 
     _analyticsController->resume();
 }
+
+void CARestAPI::PUT_analytics_load(endpointArgs) {
+    const std::string plugin = getQuery("plugin", queries);
+    const std::string path   = getQuery("path", queries);
+    const std::string config = getQuery("config", queries);
+
+    if (!hasPlugin(plugin, res)) {
+        return;
+    }
+
+    // Wait until controller is paused in order to reload plugins
+    _analyticsController->halt(true);
+
+    if(_analyticsController->getManager()->loadPlugin(plugin, path, config)) {
+        res.body() = "Analytics plugin " + plugin + " successfully loaded!\n";
+        res.result(http::status::ok);
+
+        _analyticsController->getManager()->init(_analyticsController->getIoService(), plugin);
+    } else {
+        res.body() = "Failed to load analytics plugin " + plugin + "!\n";
+        res.result(http::status::internal_server_error);
+    }
+
+    _analyticsController->resume();
+}
+
+void CARestAPI::PUT_analytics_unload(endpointArgs) {
+    const std::string plugin = getQuery("plugin", queries);
+
+    if (!hasPlugin(plugin, res)) {
+        return;
+    }
+
+    // Wait until controller is paused in order to reload plugins
+    _analyticsController->halt(true);
+
+    _analyticsController->getManager()->unloadPlugin(plugin);
+    res.body() = "Analytics plugin " + plugin + " unloaded.\n";
+    res.result(http::status::ok);
+
+    _analyticsController->resume();
+}

collectagent/CARestAPI.h

@@ -79,6 +79,39 @@ private:
      */
     void PUT_analytics_reload(endpointArgs);
 
+    /**
+     * PUT "/analytics/load"
+     *
+     * @brief Load and initialize an analytics plugin but do not start it yet.
+     *
+     * Queries  | key     | possible values      | explanation
+     * -------------------------------------------------------------------------
+     * Required | plugin  | name of the new      | specify the plugin
+     *          |         | plugin               |
+     * Optional | path    | file path            | specify a file path where to
+     *          |         |                      | search for the shared lib.
+     *          |         |                      | Defaults to (usr/lib etc.)
+     *          | config  | file path + name     | specify the config file for
+     *          |         |                      | the plugin. Defaults to
+     *          |         |                      | ./PLUGINNAME.conf
+     *          
+     */
+    void PUT_analytics_load(endpointArgs);
+
+    /**
+     * PUT "/analytics/unload"
+     *
+     * @brief Unload a specific analytics plugin.
+     *
+     *
+     * Queries  | key     | possible values      | explanation
+     * -------------------------------------------------------------------------
+     * Required |  -      |        -             |      -
+     * Optional | plugin  | all analyzer plugin  | unload only the specified
+     *          |         | names                | plugin
+     */
+    void PUT_analytics_unload(endpointArgs);
+
     SensorCache*         _sensorCache;
     AnalyticsController* _analyticsController;
 };

common/include/dcdbendian.h

@@ -71,9 +71,9 @@ public:
     }
     
     static inline uint16_t hostToBE(uint16_t x) {
-#if defined BOOST_ENDIAN_BIG_BYTE
+#if BOOST_ENDIAN_BIG_BYTE
         return x;
-#elif defined BOOST_ENDIAN_LITTLE_BYTE
+#elif BOOST_ENDIAN_LITTLE_BYTE
         return swap(x);
 #else
 #   error Endianess of host is undefined!
@@ -81,9 +81,9 @@ public:
     }
     
     static inline uint32_t hostToBE(uint32_t x) {
-#if defined BOOST_ENDIAN_BIG_BYTE
+#if BOOST_ENDIAN_BIG_BYTE
         return x;
-#elif defined BOOST_ENDIAN_LITTLE_BYTE
+#elif BOOST_ENDIAN_LITTLE_BYTE
         return swap(x);
 #else
 #   error Endianess of host is undefined!
@@ -91,9 +91,9 @@ public:
     }
     
     static inline uint64_t hostToBE(uint64_t x) {
-#if defined BOOST_ENDIAN_BIG_BYTE
+#if BOOST_ENDIAN_BIG_BYTE
         return x;
-#elif defined BOOST_ENDIAN_LITTLE_BYTE
+#elif BOOST_ENDIAN_LITTLE_BYTE
         return swap(x);
 #else
 #   error Endianess of host is undefined!
@@ -101,9 +101,9 @@ public:
     }
     
     static inline uint16_t hostToLE(uint16_t x) {
-#if defined BOOST_ENDIAN_BIG_BYTE
+#if BOOST_ENDIAN_BIG_BYTE
         return swap(x);
-#elif defined BOOST_ENDIAN_LITTLE_BYTE
+#elif BOOST_ENDIAN_LITTLE_BYTE
         return x;
 #else
 #   error Endianess of host is undefined!
@@ -111,9 +111,9 @@ public:
     }
 
     static inline uint32_t hostToLE(uint32_t x) {
-#if defined BOOST_ENDIAN_BIG_BYTE
+#if BOOST_ENDIAN_BIG_BYTE
         return swap(x);
-#elif defined BOOST_ENDIAN_LITTLE_BYTE
+#elif BOOST_ENDIAN_LITTLE_BYTE
         return x;
 #else
 #   error Endianess of host is undefined!
@@ -121,9 +121,9 @@ public:
     }
 
     static inline uint64_t hostToLE(uint64_t x) {
-#if defined BOOST_ENDIAN_BIG_BYTE
+#if BOOST_ENDIAN_BIG_BYTE
         return swap(x);
-#elif defined BOOST_ENDIAN_LITTLE_BYTE
+#elif BOOST_ENDIAN_LITTLE_BYTE
         return x;
 #else
 #   error Endianess of host is undefined!

common/include/sensorbase.h

@@ -64,7 +64,7 @@ public:
 		_readingQueue(nullptr),
 		_sinkFile(nullptr) {}
 
-	virtual ~SensorBase() {}
+	virtual ~SensorBase() { if(_sinkFile) _sinkFile->close(); }
 
 	SensorBase& operator=(const SensorBase& other) {
 		_name = other._name;

dcdbpusher/Configuration.cpp

@@ -44,6 +44,7 @@ bool Configuration::readPlugins(PluginManager& pluginManager) {
 		return false;
 	}
 
+	pluginManager.setCfgFilePath(_cfgFilePath);
 	//read plugins
 	BOOST_FOREACH(boost::property_tree::iptree::value_type &plugin, cfg.get_child("plugins")) {
 		if (boost::iequals(plugin.first, "plugin")) {
@@ -59,10 +60,6 @@ bool Configuration::readPlugins(PluginManager& pluginManager) {
 					    pluginPath = val.second.data();
 					} else if (boost::iequals(val.first, "config")) {
 						pluginConfig = val.second.data();
-						//if config-path not specified we will look for pluginName.conf in the dcdbpusher.conf directory
-						if (pluginConfig == "") {
-							pluginConfig = _cfgFilePath + plugin.second.data() + ".conf";
-						}
 					} else {
 						LOG(warning) << "  Value \"" << val.first << "\" not recognized. Omitting";
 					}

dcdbpusher/PluginManager.cpp

@@ -14,7 +14,8 @@
 using namespace std;
 
 PluginManager::PluginManager(const pluginSettings_t& pluginSettings) :
-    _pluginSettings(pluginSettings) {}
+    _pluginSettings(pluginSettings),
+    _cfgFilePath("./") {}
 
 PluginManager::~PluginManager() {
     unloadPlugin();
@@ -42,9 +43,9 @@ bool PluginManager::loadPlugin(const string& name,
         pluginLib = pluginPath + pluginLib;
     }
 
-    // build plugin config path
+    //if config-path not specified we will look for pluginName.conf in the dcdbpusher.conf directory
     if (config == "") {
-        pluginConfig = "./" + name + ".conf";
+        pluginConfig = _cfgFilePath + name + ".conf";
     } else {
         pluginConfig = config;
     }

dcdbpusher/PluginManager.h

@@ -156,6 +156,13 @@ public:
     pusherPluginStorage_t& getPlugins() {
         return _plugins;
     }
+    
+    /**
+     * @brief   Sets the internal path to be used when loading plugins by default
+     * 
+     * @param p The string to be used as path 
+     */
+    void setCfgFilePath(const std::string& p) { _cfgFilePath = p; }
 
 private:
 
@@ -180,6 +187,7 @@ private:
     pusherPluginStorage_t _plugins; /**< Storage to hold all loaded plugins */
     pluginSettings_t _pluginSettings; /**< Default plugin settings to use when
                                            loading a new plugin */
+    std::string _cfgFilePath;
     logger_t lg;
 };
 

dcdbpusher/RestAPI.cpp

@@ -41,8 +41,9 @@ RestAPI::RestAPI(serverSettings_t settings,
 
     _manager->addRestEndpoints(this);
 
-    //Overwrite analytic's reload endpoint because we need to stop MQTTPusher beforehand
     addEndpoint("/analytics/reload", {http::verb::put, stdBind(PUT_analytics_reload)});
+    addEndpoint("/analytics/load", {http::verb::put, stdBind(PUT_analytics_load)});
+    addEndpoint("/analytics/unload", {http::verb::put, stdBind(PUT_analytics_unload)});
 }
 
 void RestAPI::GET_help(endpointArgs) {
@@ -198,7 +199,7 @@ void RestAPI::PUT_load(endpointArgs) {
     //before modifying the plugin we need to ensure that we have exclusive access
     //therefore pause the only other concurrent user (MQTTPusher)
     if (!_mqttPusher->halt()) {
-        res.body() = "Could not reload plugin (Timeout while waiting).\n";
+        res.body() = "Could not load plugin (Timeout while waiting).\n";