Allow to configure and disable the size of lookahead for detecting fi…

…xed delays in messages (apache#17907)

(cherry picked from commit 5582674)
(cherry picked from commit 0705547)

conf/broker.conf

@@ -550,6 +550,12 @@ isDelayedDeliveryDeliverAtTimeStrict=false
 # fixed delays in messages in a different way.
 delayedDeliveryFixedDelayDetectionLookahead=50000
 
+# Size of the lookahead window to use when detecting if all the messages in the topic
+# have a fixed delay.
+# Default is 50,000. Setting the lookahead window to 0 will disable the logic to handle
+# fixed delays in messages in a different way.
+delayedDeliveryFixedDelayDetectionLookahead=50000
+
 # Whether to enable acknowledge of batch local index.
 acknowledgmentAtBatchIndexLevelEnabled=false
 

pulsar-broker-common/src/main/java/org/apache/pulsar/broker/ServiceConfiguration.java

@@ -329,6 +329,12 @@ public class ServiceConfiguration implements PulsarConfiguration {
             + "logic to handle fixed delays in messages in a different way.")
     private long delayedDeliveryFixedDelayDetectionLookahead = 50_000;
 
+    @FieldContext(category = CATEGORY_SERVER, doc = "Size of the lookahead window to use "
+            + "when detecting if all the messages in the topic have a fixed delay. "
+            + "Default is 50,000. Setting the lookahead window to 0 will disable the "
+            + "logic to handle fixed delays in messages in a different way.")
+    private long delayedDeliveryFixedDelayDetectionLookahead = 50_000;
+
     @FieldContext(category = CATEGORY_SERVER, doc = "Whether to enable the acknowledge of batch local index")
     private boolean acknowledgmentAtBatchIndexLevelEnabled = false;