lwc-events: make refresh frequency configurable (#1659)

Add config setting for the config refresh frequency.

atlas-lwc-events/src/main/resources/reference.conf

@@ -5,6 +5,12 @@ atlas.lwc.events {
   config-uri = ${atlas.lwc.events.base-uri}"/expressions"
   eval-uri = ${atlas.lwc.events.base-uri}"/evaluate"
 
+  // Frequency for refreshing configs
+  config-refresh-frequency = 10s
+
+  // Frequency for sending heartbeats
+  heartbeat-frequency = 2s
+
   // Max buffer size before events will start getting dropped. Used to avoid OOM.
   buffer-size = 1000000
 

atlas-lwc-events/src/main/scala/com/netflix/atlas/lwc/events/RemoteLwcEventClient.scala

@@ -43,6 +43,9 @@ class RemoteLwcEventClient(registry: Registry, config: Config)
   private val configUri = URI.create(scopedConfig.getString("config-uri"))
   private val evalUri = URI.create(scopedConfig.getString("eval-uri"))
 
+  private val configRefreshFrequency = scopedConfig.getDuration("config-refresh-frequency")
+  private val heartbeatFrequency = scopedConfig.getDuration("heartbeat-frequency")
+
   private val bufferSize = scopedConfig.getInt("buffer-size")
   private val flushSize = scopedConfig.getInt("flush-size")
   private val batchSize = scopedConfig.getInt("batch-size")
@@ -66,12 +69,12 @@ class RemoteLwcEventClient(registry: Registry, config: Config)
       scheduler = new Scheduler(registry, "LwcEventClient", 2)
 
       val refreshOptions = new Scheduler.Options()
-        .withFrequency(Scheduler.Policy.FIXED_DELAY, Duration.ofSeconds(10))
+        .withFrequency(Scheduler.Policy.FIXED_DELAY, configRefreshFrequency)
         .withStopOnFailure(false)
       scheduler.schedule(refreshOptions, () => refreshConfigs())
 
       val heartbeatOptions = new Scheduler.Options()
-        .withFrequency(Scheduler.Policy.FIXED_DELAY, Duration.ofSeconds(2))
+        .withFrequency(Scheduler.Policy.FIXED_DELAY, heartbeatFrequency)
         .withStopOnFailure(false)
       scheduler.schedule(heartbeatOptions, () => sendHeartbeat())