increase keepaliveTime variance

CHANGES

@@ -1,5 +1,9 @@
 HikariCP Changes
 
+Changes in 6.2.2
+
+ * increase keepaliveTime variance from 10% to 20%
+
 Changes in 6.2.1
 
  * change default keepaliveTime to 2 minutes

src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -493,8 +493,8 @@ public final class HikariPool extends PoolBase implements HikariPoolMXBean, IBag
 
          final long keepaliveTime = config.getKeepaliveTime();
          if (keepaliveTime > 0) {
-            // variance up to 10% of the heartbeat time
-            final var variance = ThreadLocalRandom.current().nextLong(keepaliveTime / 10);
+            // variance up to 20% of the heartbeat time
+            final var variance = ThreadLocalRandom.current().nextLong(keepaliveTime / 5);
             final var heartbeatTime = keepaliveTime - variance;
             poolEntry.setKeepalive(houseKeepingExecutorService.scheduleWithFixedDelay(new KeepaliveTask(poolEntry), heartbeatTime, heartbeatTime, MILLISECONDS));
          }