Add a metric for diagram generations in the thread pool

pom.xml

@@ -130,18 +130,17 @@
             <groupId>org.springdoc</groupId>
             <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
 
         <!-- Runtime dependencies -->
         <dependency>
             <groupId>com.powsybl</groupId>
             <artifactId>powsybl-config-classic</artifactId>
             <scope>runtime</scope>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-actuator</artifactId>
-            <scope>runtime</scope>
-        </dependency>
         <dependency>
             <groupId>io.micrometer</groupId>
             <artifactId>micrometer-registry-prometheus</artifactId>

src/main/java/com/powsybl/sld/server/DiagramGenerationObserver.java

@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2024, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package com.powsybl.sld.server;
+
+import io.micrometer.core.instrument.Gauge;
+import io.micrometer.core.instrument.MeterRegistry;
+import lombok.NonNull;
+import org.springframework.stereotype.Service;
+
+import java.util.concurrent.ThreadPoolExecutor;
+
+/**
+ * @author Slimane Amar <slimane.amar at rte-france.com>
+ */
+@Service
+public class DiagramGenerationObserver {
+    private static final String OBSERVATION_PREFIX = "app.diagram.";
+    private static final String TASK_TYPE_TAG_NAME = "type";
+    private static final String TASK_TYPE_TAG_VALUE_CURRENT = "current";
+    private static final String TASK_TYPE_TAG_VALUE_PENDING = "pending";
+    private static final String TASK_POOL_METER_NAME_PREFIX = OBSERVATION_PREFIX + "tasks.pool.";
+
+    private final MeterRegistry meterRegistry;
+
+    public DiagramGenerationObserver(@NonNull MeterRegistry meterRegistry) {
+        this.meterRegistry = meterRegistry;
+    }
+
+    public void createThreadPoolMetric(ThreadPoolExecutor threadPoolExecutor) {
+        Gauge.builder(TASK_POOL_METER_NAME_PREFIX + TASK_TYPE_TAG_VALUE_CURRENT, threadPoolExecutor, ThreadPoolExecutor::getActiveCount)
+            .description("The number of active diagram generation tasks in the thread pool")
+            .tag(TASK_TYPE_TAG_NAME, TASK_TYPE_TAG_VALUE_CURRENT)
+            .register(meterRegistry);
+        Gauge.builder(TASK_POOL_METER_NAME_PREFIX + TASK_TYPE_TAG_VALUE_PENDING, threadPoolExecutor, executor -> executor.getQueue().size())
+            .description("The number of pending diagram generation tasks in the thread pool")
+            .tag(TASK_TYPE_TAG_NAME, TASK_TYPE_TAG_VALUE_PENDING)
+            .register(meterRegistry);
+    }
+}

src/main/java/com/powsybl/sld/server/NetworkAreaDiagramService.java

@@ -6,7 +6,10 @@
  */
 package com.powsybl.sld.server;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.util.RawValue;
+import com.powsybl.commons.PowsyblException;
 import com.powsybl.iidm.network.Network;
 import com.powsybl.iidm.network.Substation;
 import com.powsybl.iidm.network.VoltageLevel;
@@ -28,7 +31,6 @@
 import com.powsybl.sld.server.dto.VoltageLevelInfos;
 import com.powsybl.sld.server.utils.DiagramUtils;
 import com.powsybl.sld.server.utils.GeoDataUtils;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Service;
@@ -46,15 +48,49 @@
 @ComponentScan(basePackageClasses = {NetworkStoreService.class})
 @Service
 class NetworkAreaDiagramService {
-    @Autowired
-    private NetworkStoreService networkStoreService;
-
-    @Autowired
-    private GeoDataService geoDataService;
-
     private static final int SCALING_FACTOR = 450000;
     private static final double RADIUS_FACTOR = 300;
 
+    static final String SVG_TAG = "svg";
+    static final String METADATA = "metadata";
+    static final String ADDITIONAL_METADATA = "additionalMetadata";
+
+    private final NetworkStoreService networkStoreService;
+    private final GeoDataService geoDataService;
+    private final NetworkAreaExecutionService diagramExecutionService;
+
+    private final ObjectMapper objectMapper;
+
+    public NetworkAreaDiagramService(NetworkStoreService networkStoreService, GeoDataService geoDataService,
+                                     NetworkAreaExecutionService diagramExecutionService, ObjectMapper objectMapper) {
+        this.networkStoreService = networkStoreService;
+        this.geoDataService = geoDataService;
+        this.diagramExecutionService = diagramExecutionService;
+        this.objectMapper = objectMapper;
+    }
+
+    public String getNetworkAreaDiagramSvgAsync(UUID networkUuid, String variantId, List<String> voltageLevelsIds, int depth, boolean withGeoData) {
+        return diagramExecutionService
+            .supplyAsync(() -> getNetworkAreaDiagramSvg(networkUuid, variantId, voltageLevelsIds, depth, withGeoData))
+            .join();
+    }
+
+    private String getNetworkAreaDiagramSvg(UUID networkUuid, String variantId, List<String> voltageLevelsIds, int depth, boolean withGeoData) {
+        try {
+            SvgAndMetadata svgAndMetadata = generateNetworkAreaDiagramSvg(networkUuid, variantId, voltageLevelsIds, depth, withGeoData);
+            String svg = svgAndMetadata.getSvg();
+            String metadata = svgAndMetadata.getMetadata();
+            Object additionalMetadata = svgAndMetadata.getAdditionalMetadata();
+            return objectMapper.writeValueAsString(
+                objectMapper.createObjectNode()
+                    .put(SVG_TAG, svg)
+                    .putRawValue(METADATA, new RawValue(metadata))
+                    .putPOJO(ADDITIONAL_METADATA, additionalMetadata));
+        } catch (JsonProcessingException e) {
+            throw new PowsyblException("Failed to parse JSON response", e);
+        }
+    }
+
     public SvgAndMetadata generateNetworkAreaDiagramSvg(UUID networkUuid, String variantId, List<String> voltageLevelsIds, int depth, boolean withGeoData) {
         Network network = DiagramUtils.getNetwork(networkUuid, variantId, networkStoreService, PreloadingStrategy.COLLECTION);
         List<String> existingVLIds = voltageLevelsIds.stream().filter(vl -> network.getVoltageLevel(vl) != null).toList();

src/main/java/com/powsybl/sld/server/NetworkAreaExecutionService.java

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) 2024, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+package com.powsybl.sld.server;
+
+import jakarta.annotation.PreDestroy;
+import lombok.NonNull;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+import java.util.concurrent.*;
+import java.util.function.Supplier;
+
+/**
+ * @author Slimane Amar <slimane.amar at rte-france.com>
+ */
+@Service
+public class NetworkAreaExecutionService {
+
+    private ThreadPoolExecutor executorService;
+
+    public NetworkAreaExecutionService(@Value("${max-concurrent-nad-generations}") int maxConcurrentNadGenerations,
+                                       @NonNull DiagramGenerationObserver diagramGenerationObserver) {
+        executorService = (ThreadPoolExecutor) Executors.newFixedThreadPool(maxConcurrentNadGenerations);
+        diagramGenerationObserver.createThreadPoolMetric(executorService);
+    }
+
+    @PreDestroy
+    private void preDestroy() {
+        executorService.shutdown();
+    }
+
+    public <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier) {
+        return CompletableFuture.supplyAsync(supplier, executorService);
+    }
+}

src/main/java/com/powsybl/sld/server/SingleLineDiagramController.java

@@ -9,20 +9,16 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.util.RawValue;
-import com.powsybl.commons.PowsyblException;
 import com.powsybl.sld.server.dto.SvgAndMetadata;
-import com.powsybl.sld.server.utils.SldDisplayMode;
 import com.powsybl.sld.server.utils.SingleLineDiagramParameters;
+import com.powsybl.sld.server.utils.SldDisplayMode;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import io.swagger.v3.oas.annotations.tags.Tag;
-import jakarta.annotation.PreDestroy;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -31,11 +27,8 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.UUID;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
 
+import static com.powsybl.sld.server.NetworkAreaDiagramService.*;
 import static com.powsybl.ws.commons.LogUtils.sanitizeParam;
 
 /**
@@ -53,21 +46,16 @@ public class SingleLineDiagramController {
 
     static final String IMAGE_SVG_PLUS_XML = "image/svg+xml";
     static final String HORIZONTAL = "horizontal";
-    static final String SVG_TAG = "svg";
-    static final String METADATA = "metadata";
-    static final String ADDITIONAL_METADATA = "additionalMetadata";
 
-    private final ExecutorService executorService;
-
-    public SingleLineDiagramController(@Value("${max-concurrent-nad-generations}") int maxConcurrentNadGenerations) {
-        this.executorService = Executors.newFixedThreadPool(maxConcurrentNadGenerations);
-    }
+    private final SingleLineDiagramService singleLineDiagramService;
 
-    @Autowired
-    private SingleLineDiagramService singleLineDiagramService;
+    private final NetworkAreaDiagramService networkAreaDiagramService;
 
-    @Autowired
-    private NetworkAreaDiagramService networkAreaDiagramService;
+    public SingleLineDiagramController(SingleLineDiagramService singleLineDiagramService,
+                                       NetworkAreaDiagramService networkAreaDiagramService) {
+        this.singleLineDiagramService = singleLineDiagramService;
+        this.networkAreaDiagramService = networkAreaDiagramService;
+    }
 
     // voltage levels
     //
@@ -279,28 +267,10 @@ public ResponseEntity<Collection<String>> getAvailableSvgComponentLibraries() {
             @Parameter(description = "Voltage levels ids") @RequestParam(name = "voltageLevelsIds", required = false) List<String> voltageLevelsIds,
             @Parameter(description = "Variant Id") @RequestParam(name = "variantId", required = false) String variantId,
             @Parameter(description = "depth") @RequestParam(name = "depth", required = false) int depth,
-            @Parameter(description = "Initialize NAD with Geographical Data") @RequestParam(name = "withGeoData", defaultValue = "true") boolean withGeoData) throws InterruptedException, ExecutionException {
-        CompletableFuture<String> futureNAD = CompletableFuture.supplyAsync(() -> {
-            try {
-                LOGGER.debug("getNetworkAreaDiagramSvg request received with parameter networkUuid = {}, voltageLevelsIds = {}, depth = {}", networkUuid, sanitizeParam(voltageLevelsIds.toString()), depth);
-                SvgAndMetadata svgAndMetadata = networkAreaDiagramService.generateNetworkAreaDiagramSvg(networkUuid, variantId, voltageLevelsIds, depth, withGeoData);
-                String svg = svgAndMetadata.getSvg();
-                String metadata = svgAndMetadata.getMetadata();
-                Object additionalMetadata = svgAndMetadata.getAdditionalMetadata();
-                return OBJECT_MAPPER.writeValueAsString(
-                        OBJECT_MAPPER.createObjectNode()
-                                .put(SVG_TAG, svg)
-                                .putRawValue(METADATA, new RawValue(metadata))
-                                .putPOJO(ADDITIONAL_METADATA, additionalMetadata));
-            } catch (JsonProcessingException e) {
-                throw new PowsyblException("Failed to parse JSON response", e);
-            }
-        }, executorService);
-        return futureNAD.get();
-    }
-
-    @PreDestroy
-    private void preDestroy() {
-        executorService.shutdown();
+            @Parameter(description = "Initialize NAD with Geographical Data") @RequestParam(name = "withGeoData", defaultValue = "true") boolean withGeoData) {
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug("getNetworkAreaDiagramSvg request received with parameter networkUuid = {}, voltageLevelsIds = {}, depth = {}", networkUuid, sanitizeParam(voltageLevelsIds.toString()), depth);
+        }
+        return networkAreaDiagramService.getNetworkAreaDiagramSvgAsync(networkUuid, variantId, voltageLevelsIds, depth, withGeoData);
     }
 }

src/test/java/com/powsybl/sld/server/SingleLineDiagramTest.java

@@ -38,10 +38,10 @@
 import org.junit.jupiter.api.Test;
 import org.mockito.MockitoAnnotations;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.mock.mockito.MockBean;
 import org.springframework.http.MediaType;
-import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.MvcResult;
 
@@ -70,8 +70,8 @@
  * @author Abdelsalem Hedhili <abdelsalem.hedhili at rte-france.com>
  * @author Franck Lecuyer <franck.lecuyer at rte-france.com>
  */
-@WebMvcTest(SingleLineDiagramController.class)
-@ContextConfiguration(classes = {SingleLineDiagramApplication.class})
+@SpringBootTest
+@AutoConfigureMockMvc
 class SingleLineDiagramTest {
 
     @Autowired