From f125c73559957f7eedb8432864c167551cb9c6da Mon Sep 17 00:00:00 2001
From: Patrik Nordwall <patrik.nordwall@gmail.com>
Date: Fri, 20 Sep 2024 11:54:29 +0200
Subject: [PATCH] unique heartbeat persistenceId

---
 .../persistence/r2dbc/query/scaladsl/R2dbcReadJournal.scala | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/core/src/main/scala/akka/persistence/r2dbc/query/scaladsl/R2dbcReadJournal.scala b/core/src/main/scala/akka/persistence/r2dbc/query/scaladsl/R2dbcReadJournal.scala
index 314e780c..32aa691f 100644
--- a/core/src/main/scala/akka/persistence/r2dbc/query/scaladsl/R2dbcReadJournal.scala
+++ b/core/src/main/scala/akka/persistence/r2dbc/query/scaladsl/R2dbcReadJournal.scala
@@ -7,6 +7,7 @@ package akka.persistence.r2dbc.query.scaladsl
 import java.time.Clock
 import java.time.Instant
 import java.time.{ Duration => JDuration }
+import java.util.UUID
 import java.util.concurrent.ConcurrentHashMap
 
 import scala.annotation.tailrec
@@ -113,6 +114,8 @@ final class R2dbcReadJournal(system: ExtendedActorSystem, config: Config, cfgPat
 
   // key is tuple of entity type and slice
   private val heartbeatPersistenceIds = new ConcurrentHashMap[(String, Int), String]()
+  private val heartbeatUuid = UUID.randomUUID().toString
+  log.debug("Using heartbeat UUID [{}]", heartbeatUuid)
 
   private def heartbeatPersistenceId(entityType: String, slice: Int): String = {
     val key = entityType -> slice
@@ -128,7 +131,8 @@ final class R2dbcReadJournal(system: ExtendedActorSystem, config: Config, cfgPat
 
   @tailrec private def generateHeartbeatPersistenceId(entityType: String, slice: Int, n: Int = 1): String = {
     if (n < 1000000) {
-      val pid = PersistenceId.concat(entityType, s"_ht-$n")
+      // including a uuid to make sure it is not the same as any persistence id of the application
+      val pid = PersistenceId.concat(entityType, s"_hb-$heartbeatUuid-$n")
       if (persistenceExt.sliceForPersistenceId(pid) == slice)
         pid
       else