HWKMETRICS-99: modification request from initial PR.

hawkular · May 22, 2015 · ef8689f · ef8689f
1 parent 6763aa6
commit ef8689f
Show file tree

Hide file tree

Showing 6 changed files with 75 additions and 52 deletions.
diff --git a/...etrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/HawkularMetricsRestApp.java b/...etrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/HawkularMetricsRestApp.java
@@ -16,11 +16,9 @@
  */
 package org.hawkular.metrics.api.jaxrs;
 
-import javax.inject.Inject;
 import javax.ws.rs.ApplicationPath;
 import javax.ws.rs.core.Application;
 
-import org.hawkular.metrics.core.api.MetricsService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -33,13 +31,8 @@ public class HawkularMetricsRestApp extends Application {
 
     private static final Logger logger = LoggerFactory.getLogger(HawkularMetricsRestApp.class);
 
-    @Inject
-    private MetricsService metricsService;
-
     public HawkularMetricsRestApp() {
-
         logger.info("Hawkular Metrics starting ..");
-
     }
 
 }
diff --git a/...etrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/MetricsServiceProducer.java b/...etrics-api-jaxrs/src/main/java/org/hawkular/metrics/api/jaxrs/MetricsServiceProducer.java
@@ -20,16 +20,15 @@
 import static org.hawkular.metrics.api.jaxrs.config.ConfigurationKey.CASSANDRA_KEYSPACE;
 import static org.hawkular.metrics.api.jaxrs.config.ConfigurationKey.CASSANDRA_NODES;
 
+import com.datastax.driver.core.Session;
+import com.google.common.util.concurrent.FutureCallback;
 import java.util.HashMap;
 import java.util.Map;
-
 import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
 import javax.enterprise.context.ApplicationScoped;
 import javax.enterprise.inject.Produces;
 import javax.inject.Inject;
-
-import com.datastax.driver.core.Session;
-import com.google.common.util.concurrent.FutureCallback;
 import org.hawkular.metrics.api.jaxrs.config.Configurable;
 import org.hawkular.metrics.api.jaxrs.config.ConfigurationProperty;
 import org.hawkular.metrics.api.jaxrs.util.Eager;
@@ -62,41 +61,42 @@ public class MetricsServiceProducer {
     @ConfigurationProperty(CASSANDRA_KEYSPACE)
     private String keyspace;
 
+    @Produces
     private MetricsService metricsService;
 
+    private CassandraSession cassandraSession;
+
     @PostConstruct
     void init() {
         LOG.info("Initializing metrics service");
-        getMetricsService();
+        metricsService = new MetricsServiceCassandra();
+        Map<String, String> options = new HashMap<>();
+        options.put("cqlport", cqlPort);
+        options.put("nodes", nodes);
+        options.put("keyspace", keyspace);
+
+        CassandraSession.Builder cassandraSessionBuilder = new CassandraSession.Builder();
+        cassandraSessionBuilder.withOptions(options);
+
+        cassandraSessionBuilder.withInitializationCallback(new FutureCallback<Session>() {
+            @Override
+            public void onSuccess(Session session) {
+                metricsService.startUp(session);
+            }
+
+            @Override
+            public void onFailure(Throwable t) {
+                LOG.error("An error occurred trying to connect to the Cassandra cluster.", t);
+                metricsService.setState(MetricsService.State.FAILED);
+            }
+        });
+
+        cassandraSession = cassandraSessionBuilder.build();
     }
 
-    @Produces
-    public MetricsService getMetricsService() {
-        if (metricsService == null) {
-            metricsService = new MetricsServiceCassandra();
-            Map<String, String> options = new HashMap<>();
-            options.put("cqlport", cqlPort);
-            options.put("nodes", nodes);
-            options.put("keyspace", keyspace);
-
-            CassandraSession.Builder cassandraSessionBuilder = new CassandraSession.Builder();
-            cassandraSessionBuilder.withOptions(options);
-
-            cassandraSessionBuilder.withInitializationCallback(new FutureCallback<Session>() {
-                @Override
-                public void onSuccess(Session session) {
-                    metricsService.startUp(session);
-                }
-
-                @Override
-                public void onFailure(Throwable t) {
-                    throw new RuntimeException("Error trying to get the Cassandra Session", t);
-                }
-            });
-
-            cassandraSessionBuilder.build();
-        }
-
-        return metricsService;
+    @PreDestroy
+    void destroy() {
+        metricsService.shutdown();
+        cassandraSession.shutdown();
     }
 }
diff --git a/...s/filter/CassandraAvailabilityFilter.java → ...xrs/filter/MetricsServiceStateFilter.java b/...s/filter/CassandraAvailabilityFilter.java → ...xrs/filter/MetricsServiceStateFilter.java
@@ -32,24 +32,39 @@
  * Created by mwringe on 20/05/15.
  */
 @Provider
-public class CassandraAvailabilityFilter implements ContainerRequestFilter {
+public class MetricsServiceStateFilter implements ContainerRequestFilter {
 
-    private static final String NO_CASSANDRA_SESSION_MSG = "Service unavailable while initializing.";
+    private static final String STARTING = "Service unavailable while initializing.";
+    private static final String FAILED = "Internal server error.";
+    private static final String STOPPED = "The service is no longer running.";
 
     @Inject
     private MetricsService metricsService;
 
 
     @Override
     public void filter(ContainerRequestContext containerRequestContext) throws IOException {
-        if (!metricsService.isStarted()) {
+        if (metricsService.getState() == MetricsService.State.STARTING) {
             // Fail since the Cassandra cluster is not yet up yet.
             Response response = Response.status(Response.Status.SERVICE_UNAVAILABLE)
                     .type(APPLICATION_JSON_TYPE)
-                    .entity(new ApiError(NO_CASSANDRA_SESSION_MSG))
+                    .entity(new ApiError(STARTING))
+                    .build();
+            containerRequestContext.abortWith(response);
+        } else if (metricsService.getState() == MetricsService.State.FAILED) {
+            // Fail since an error has occured trying to start the Metrics service
+            Response response = Response.status(Response.Status.INTERNAL_SERVER_ERROR)
+                    .type(APPLICATION_JSON_TYPE)
+                    .entity(new ApiError(FAILED))
+                    .build();
+            containerRequestContext.abortWith(response);
+        } else if (metricsService.getState() == MetricsService.State.STOPPED ||
+                metricsService.getState() == MetricsService.State.STOPPING ) {
+            Response response = Response.status(Response.Status.SERVICE_UNAVAILABLE)
+                    .type(APPLICATION_JSON_TYPE)
+                    .entity(new ApiError(STOPPED))
                     .build();
             containerRequestContext.abortWith(response);
         }
-
     }
 }
diff --git a/core/metrics-core-api/src/main/java/org/hawkular/metrics/core/api/MetricsService.java b/core/metrics-core-api/src/main/java/org/hawkular/metrics/core/api/MetricsService.java
@@ -32,6 +32,11 @@
  */
 public interface MetricsService {
 
+    public enum State {
+        STARTING, STARTED, STOPPING, STOPPED, FAILED
+    }
+
+
     // For now we will use a default or fake tenant id until we get APIs in place for
     // creating tenants.
     String DEFAULT_TENANT_ID = "test";
@@ -42,7 +47,9 @@ public interface MetricsService {
      */
     void startUp(Session session);
 
-    boolean isStarted();
+    State getState();
+
+    void setState(State state);
 
     void shutdown();
 

diff --git a/...cs-core-impl/src/main/java/org/hawkular/metrics/core/impl/cassandra/CassandraSession.java b/...cs-core-impl/src/main/java/org/hawkular/metrics/core/impl/cassandra/CassandraSession.java
@@ -109,8 +109,9 @@ public Builder withInitializationCallback(FutureCallback<Session> callback) {
             return this;
         }
 
-        public void build() {
+        public CassandraSession build() {
             CassandraSession cassandraSession = new CassandraSession(options, callback);
+            return cassandraSession;
         }
     }
 

diff --git a/...-impl/src/main/java/org/hawkular/metrics/core/impl/cassandra/MetricsServiceCassandra.java b/...-impl/src/main/java/org/hawkular/metrics/core/impl/cassandra/MetricsServiceCassandra.java
@@ -87,6 +87,8 @@ public class MetricsServiceCassandra implements MetricsService {
 
     public static final int DEFAULT_TTL = Duration.standardDays(7).toStandardSeconds().getSeconds();
 
+    public volatile State state;
+
     private static class DataRetentionKey {
         private final String tenantId;
         private final MetricId metricId;
@@ -140,26 +142,30 @@ public int hashCode() {
     private final ListeningExecutorService metricsTasks = MoreExecutors
         .listeningDecorator(Executors.newFixedThreadPool(4, new MetricsThreadFactory()));
 
-    private boolean started = false;
-
     /**
      * Note that while user specifies the durations in hours, we store them in seconds.
      */
     private final Map<DataRetentionKey, Integer> dataRetentions = new ConcurrentHashMap<>();
 
     public MetricsServiceCassandra() {
+        this.state = State.STARTING;
     }
 
     @Override
     public void startUp(Session s) {
         this.dataAccess = new DataAccessImpl(s);
         loadDataRetentions();
-        started = true;
+        state = State.STARTED;
+    }
+
+    @Override
+    public State getState() {
+        return state;
     }
 
     @Override
-    public boolean isStarted() {
-        return started;
+    public void setState(State state) {
+        this.state = state;
     }
 
     void loadDataRetentions() {
@@ -251,6 +257,7 @@ public void onFailure(Throwable t) {
 
     @Override
     public void shutdown() {
+        state = State.STOPPED;
     }
 
     /**