diff --git a/MetricUpdater.cpp b/MetricUpdater.cpp
index 5b7c16b..4874ace 100644
--- a/MetricUpdater.cpp
+++ b/MetricUpdater.cpp
@@ -147,6 +147,42 @@ void MetricUpdater::UpdateMetricValue(
}
}
+// --------------------------------------------------------------------------
+// Application lifcycle
+// --------------------------------------------------------------------------
+//
+// When the lifecycle message is received, the state is just recorded in the
+// state variable.
+
+void MetricUpdater::LifecycleHandler(
+ const ApplicationLifecycle & TheState,
+ const Address TheLifecycleTopic )
+{
+ Theron::ConsoleOutput Output;
+
+ ApplicationState = TheState;
+
+ Output << "Application state updated: " << std::endl
+ << TheState.dump(2) << std::endl;
+}
+
+// The message handler used the conversion operator to read out the state
+// carried in the message. It is based on having a static map from the textual
+// representation of the state to the enumeration.
+
+MetricUpdater::ApplicationLifecycle::operator State() const
+{
+ static std::map< std::string_view, State > LifecycleStates{
+ {"NEW", State::New},
+ {"READY", State::Ready},
+ {"DEPLOYING", State::Deploying},
+ {"RUNNING", State::Running},
+ {"FAILED", State::Failed}
+ };
+
+ return LifecycleStates.at( this->at("state").get< std::string >() );
+}
+
// --------------------------------------------------------------------------
// SLO Violation Events
// --------------------------------------------------------------------------
@@ -174,7 +210,7 @@ void MetricUpdater::SLOViolationHandler(
Output << "Metric Updater: SLO violation received " << std::endl
<< SeverityMessage.dump(2) << std::endl;
- if( !ReconfigurationInProgress &&
+ if(( ApplicationState == ApplicationLifecycle::State::Running ) &&
( AllMetricValuesSet ||
(!MetricValues.empty() &&
std::ranges::none_of( std::views::values( MetricValues ),
@@ -183,41 +219,17 @@ void MetricUpdater::SLOViolationHandler(
Send( Solver::ApplicationExecutionContext(
SeverityMessage.at(
MetricValueUpdate::Keys::TimePoint ).get< Solver::TimePointType >(),
- MetricValues, true
+ MetricValues, true
), TheSolverManager );
- AllMetricValuesSet = true;
- ReconfigurationInProgress = true;
+ AllMetricValuesSet = true;
+ ApplicationState = ApplicationLifecycle::State::Deploying;
}
else
Output << "... failed to forward the application execution context (size: "
<< MetricValues.size() << ")" << std::endl;
}
-// --------------------------------------------------------------------------
-// Reconfigured application
-// --------------------------------------------------------------------------
-//
-// When the reconfiguration message is received it is an indication tha the
-// Optimiser Controller has reconfigured the application and that the
-// application is running in the new configuration found by the solver.
-// It is the event that is important m not the content of the message, and
-// it is therefore only used to reset the ongoing reconfiguration flag.
-
-void MetricUpdater::ReconfigurationDone(
- const ReconfigurationMessage & TheReconfiguraton,
- const Address TheReconfigurationTopic )
-{
- Theron::ConsoleOutput Output;
-
- ReconfigurationInProgress = false;
-
- Output << "Reconfiguration ongoing flag reset after receiving the following "
- << "message indicating that the previous reconfiguration was"
- << "completed: " << std::endl
- << TheReconfiguraton.dump(2) << std::endl;
-}
-
// --------------------------------------------------------------------------
// Constructor and destructor
// --------------------------------------------------------------------------
@@ -239,13 +251,13 @@ MetricUpdater::MetricUpdater( const std::string UpdaterName,
StandardFallbackHandler( Actor::GetAddress().AsString() ),
NetworkingActor( Actor::GetAddress().AsString() ),
MetricValues(), ValidityTime(0), AllMetricValuesSet(false),
- TheSolverManager( ManagerOfSolvers ),
- ReconfigurationInProgress( false )
+ ApplicationState( ApplicationLifecycle::State::New ),
+ TheSolverManager( ManagerOfSolvers )
{
RegisterHandler( this, &MetricUpdater::AddMetricSubscription );
RegisterHandler( this, &MetricUpdater::UpdateMetricValue );
RegisterHandler( this, &MetricUpdater::SLOViolationHandler );
- RegisterHandler( this, &MetricUpdater::ReconfigurationDone );
+ RegisterHandler( this, &MetricUpdater::LifecycleHandler );
Send( Theron::AMQ::NetworkLayer::TopicSubscription(
Theron::AMQ::NetworkLayer::TopicSubscription::Action::Subscription,
@@ -254,7 +266,7 @@ MetricUpdater::MetricUpdater( const std::string UpdaterName,
Send( Theron::AMQ::NetworkLayer::TopicSubscription(
Theron::AMQ::NetworkLayer::TopicSubscription::Action::Subscription,
- ReconfigurationMessage::AMQTopic ),
+ ApplicationLifecycle::AMQTopic ),
GetSessionLayerAddress() );
Send( Theron::AMQ::NetworkLayer::TopicSubscription(
@@ -279,7 +291,7 @@ MetricUpdater::~MetricUpdater()
Send( Theron::AMQ::NetworkLayer::TopicSubscription(
Theron::AMQ::NetworkLayer::TopicSubscription::Action::CloseSubscription,
- ReconfigurationMessage::AMQTopic ),
+ ApplicationLifecycle::AMQTopic ),
GetSessionLayerAddress() );
Send( Theron::AMQ::NetworkLayer::TopicSubscription(
diff --git a/MetricUpdater.hpp b/MetricUpdater.hpp
index 281500b..1d2d855 100644
--- a/MetricUpdater.hpp
+++ b/MetricUpdater.hpp
@@ -225,6 +225,74 @@ private:
void UpdateMetricValue( const MetricValueUpdate & TheMetricValue,
const Address TheMetricTopic );
+ // --------------------------------------------------------------------------
+ // Application lifecycle
+ // --------------------------------------------------------------------------
+ //
+ // There is a message from the Optimiser Controller when the status of the
+ // application changes. The state communicated in this message shows the
+ // current state of the application and decides how the Solver will act to
+ // SLO Violations detected.
+
+ class ApplicationLifecycle
+ : public Theron::AMQ::JSONTopicMessage
+ {
+ public:
+
+ // The topic for the reconfiguration finished messages is defined by the
+ // optimiser as the sender.
+
+ static constexpr std::string_view AMQTopic
+ = "eu.nebulouscloud.optimiser.controller.app_state";
+
+ // The state of the application goes from the the initial creation of
+ // the cluster to deployments covering reconfigurations. Note that there is
+ // no state indicating that the application has terminated.
+
+ enum class State
+ {
+ New, // Waiting for the utility evaluator
+ Ready, // The application is ready for deployment
+ Deploying, // The application is being deployed or redeployed
+ Running, // The application is running
+ Failed // The application is in an invalid state
+ };
+
+ // An arriving lifecycle message indicates a change in state and it is
+ // therefore a way to set a state variable directly from the message by
+ // a cast operator
+
+ operator State() const;
+
+ // Constructors and destructor
+
+ ApplicationLifecycle( void )
+ : JSONTopicMessage( AMQTopic )
+ {}
+
+ ApplicationLifecycle( const ApplicationLifecycle & Other )
+ : JSONTopicMessage( Other )
+ {}
+
+ virtual ~ApplicationLifecycle() = default;
+ };
+
+ // After starting a reconfiguration with an SLO Violation, one should not
+ // initiate another reconfiguration because the state may the possibly be
+ // inconsistent with the SLO Violation Detector belieivng that the old
+ // configuration is still in effect while the new configuration is being
+ // enacted. The application lifecycle state must therefore be marked as
+ // running before the another SLO Violation will trigger the next
+ // reconfiguration
+
+ ApplicationLifecycle::State ApplicationState;
+
+ // The handler for the lifecycle message simply updates this variable by
+ // setting it to the state received in the lifecycle message.
+
+ void LifecycleHandler( const ApplicationLifecycle & TheState,
+ const Address TheLifecycleTopic );
+
// --------------------------------------------------------------------------
// SLO violations
// --------------------------------------------------------------------------
@@ -295,54 +363,6 @@ private:
const Address TheSolverManager;
- // After the sending of the application's excution context, one should not
- // initiate another reconfiguration because the state may the possibly be
- // inconsistent with the SLO Violation Detector belieivng that the old
- // configuration is still in effect while the new configuration is being
- // enacted. It is therefore a flag that will be set by the SLO Violation
- // handler indicating that a reconfiguration is ongoing.
-
- bool ReconfigurationInProgress;
-
- // When a reconfiguration has been enacted by the Optimiser Controller and
- // a new configuration is confirmed to be running on the new platofrm, it
- // will send a message to inform all other components that the
- // reconfiguration has happened. The event is just the reception of the
- // message and its content will not be processed, so there are no keys for
- // the JSON map received.
-
- class ReconfigurationMessage
- : public Theron::AMQ::JSONTopicMessage
- {
- public:
-
- // The topic for the reconfiguration finished messages is defined by the
- // optimiser as the sender.
-
- static constexpr std::string_view AMQTopic
- = "eu.nebulouscloud.optimiser.controller.reconfiguration";
-
- // Constructors
-
- ReconfigurationMessage( void )
- : JSONTopicMessage( AMQTopic )
- {}
-
- ReconfigurationMessage( const ReconfigurationMessage & Other )
- : JSONTopicMessage( Other )
- {}
-
- virtual ~ReconfigurationMessage() = default;
- };
-
- // The handler for this message will actually not use its contents, but only
- // note that the reconfiguration has been completed to reset the
- // reconfiguration in progress flag allowing future SLO Violation Events to
- // triger new reconfigurations.
-
- void ReconfigurationDone( const ReconfigurationMessage & TheReconfiguraton,
- const Address TheReconfigurationTopic );
-
// --------------------------------------------------------------------------
// Constructor and destructor
// --------------------------------------------------------------------------