add a hidden /tasks actuator endpoint (for async)

Author: derlin

src/main/kotlin/ch/derlin/bbdata/AsyncConfig.kt

@@ -1,12 +1,17 @@
 package ch.derlin.bbdata
 
+import io.swagger.v3.oas.annotations.Hidden
+import io.swagger.v3.oas.annotations.Operation
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
 import org.springframework.aop.interceptor.AsyncUncaughtExceptionHandler
 import org.springframework.beans.factory.annotation.Value
+import org.springframework.boot.actuate.endpoint.annotation.ReadOperation
+import org.springframework.boot.actuate.endpoint.web.annotation.WebEndpoint
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty
 import org.springframework.boot.task.TaskExecutorCustomizer
 import org.springframework.context.annotation.Configuration
+import org.springframework.core.task.TaskExecutor
 import org.springframework.scheduling.annotation.AsyncConfigurer
 import org.springframework.scheduling.annotation.EnableAsync
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor
@@ -45,7 +50,7 @@ class AsyncExecutorCustomizer : TaskExecutorCustomizer {
     }
 }
 
-@ConditionalOnProperty("async.enabled", havingValue = "true", matchIfMissing = true)
+@ConditionalOnProperty(AsyncProperties.ENABLED, havingValue = "true", matchIfMissing = true)
 @EnableAsync
 @Configuration
 class AsyncConfig : AsyncConfigurer {
@@ -66,4 +71,29 @@ class AsyncExceptionHandler : AsyncUncaughtExceptionHandler {
         val niceParams = params.take(2).joinToString(",") { it.toString() }
         logger.error("in ${method.name} with ${params.size} params: $niceParams ...", throwable)
     }
+}
+
+@Component
+@ConditionalOnProperty(AsyncProperties.ENABLED, havingValue = "true", matchIfMissing = true)
+@WebEndpoint(id = "tasks")
+class AsyncMonitor(private val taskExecutor: TaskExecutor? = null) {
+    /** add an optional tasks actuator to monitor async executor (hidden) */
+
+    @ReadOperation
+    @Operation(description = "Actuator web endpoint 'tasks', monitor async tasks execution")
+    @Hidden
+    fun executorInfo(): Map<String, Any> {
+        // use linkedMap to preserve insertion order in output
+        val executorInfo = linkedMapOf<String, Any>()
+        val tasksInfo = linkedMapOf<String, Any>()
+        if (taskExecutor is ThreadPoolTaskExecutor)
+            taskExecutor.threadPoolExecutor.let {
+                executorInfo["pool-size"] = it.corePoolSize
+                executorInfo["active-count"] = it.activeCount
+                executorInfo["queue-size"] = it.queue.size
+                tasksInfo["task-count"] = it.taskCount
+                tasksInfo["completed-task-count"] = it.completedTaskCount
+            }
+        return linkedMapOf("executor" to executorInfo, "tasks" to tasksInfo)
+    }
 }

src/main/kotlin/ch/derlin/bbdata/CustomProperties.kt

@@ -35,6 +35,10 @@ class ScanExcludeProperties {
 class AsyncProperties {
     /** Whether or not to turn async on: see AsyncConfig */
     var enabled: Boolean = true
+
+    companion object {
+        const val ENABLED = "async.enabled"
+    }
 }
 
 @Configuration

src/main/resources/application.properties

@@ -87,21 +87,22 @@ spring.task.execution.pool.allow-core-thread-timeout=false
 ## Input/Output
 # make json the default
 spring.data.rest.defaultMediaType=application/json
-# pretty print output
+# pretty print output + keep map order
 spring.jackson.serialization.indent-output=true
+spring.jackson.serialization.order-map-entries-by-keys=true
 # dates (declared here only for swagger)
 spring.jackson.date-format=yyyy-MM-dd'T'HH:mm:ss
 # Pageable configuration
 spring.data.web.pageable.max-page-size=1000000
 spring.data.web.pageable.default-page-size=1000000
 
 ## Actuator (config)
-management.endpoints.web.exposure.include=info, health
+management.endpoints.web.exposure.include=info, health, metrics, tasks
 management.endpoint.health.show-components=always
 #management.server.port=8888
 management.endpoints.web.base-path=/
 
-## Documentation
+## Documentation
 # Paths: UI at /docs/api, yaml at /docs/api/bbdata{.yaml}
 springdoc.swagger-ui.path=/docs/api
 springdoc.api-docs.path=/docs/api/bbdata