Regularly trigger GC to improve accuracy of metrics

1 files changed, 13 insertions, 0 deletions

diff --git a/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java b/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java
index 7902a89b88e..96bbb6a4111 100644
--- a/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java
+++ b/jdisc_core/src/main/java/com/yahoo/jdisc/core/ActiveContainerDeactivationWatchdog.java
@@ -28,6 +28,7 @@ import static java.util.stream.Collectors.toList;
 class ActiveContainerDeactivationWatchdog implements ActiveContainerMetrics, AutoCloseable {
     static final Duration WATCHDOG_FREQUENCY = Duration.ofMinutes(20);
     static final Duration ACTIVE_CONTAINER_GRACE_PERIOD = Duration.ofHours(1);
+    static final Duration GC_TRIGGER_FREQUENCY = ACTIVE_CONTAINER_GRACE_PERIOD.minusMinutes(5);
 
     private static final Logger log = Logger.getLogger(ActiveContainerDeactivationWatchdog.class.getName());
 
@@ -58,6 +59,11 @@ class ActiveContainerDeactivationWatchdog implements ActiveContainerMetrics, Aut
                 WATCHDOG_FREQUENCY.getSeconds(),
                 WATCHDOG_FREQUENCY.getSeconds(),
                 TimeUnit.SECONDS);
+        this.scheduler.scheduleWithFixedDelay(
+                ActiveContainerDeactivationWatchdog::triggerGc,
+                GC_TRIGGER_FREQUENCY.getSeconds(),
+                GC_TRIGGER_FREQUENCY.getSeconds(),
+                TimeUnit.SECONDS);
     }
 
     void onContainerActivation(ActiveContainer nextContainer) {
@@ -101,6 +107,13 @@ class ActiveContainerDeactivationWatchdog implements ActiveContainerMetrics, Aut
         }
     }
 
+    private static void triggerGc() {
+        // ActiveContainer has a finalizer, so gc -> finalizer -> gc is required.
+        System.gc();
+        System.runFinalization();
+        System.gc();
+    }
+
     private List<DeactivatedContainer> getDeactivatedContainersSnapshot() {
         Instant now = clock.instant();
         synchronized (monitor) {