From 33ff36cc42a083311065dee56adc1d72d6866f2d Mon Sep 17 00:00:00 2001
From: fibersel <0583463@gmail.com>
Date: Wed, 26 May 2021 23:04:57 +0300
Subject: [PATCH] Add a system property to set hostId if not yet initialized

patch by Abi Palagashvili; reviewed by Stefan Miklosovic and Paulo Motta for CASSANDRA-14582
---
 CHANGES.txt                                          | 1 +
 conf/jvm-server.options                              | 3 +++
 src/java/org/apache/cassandra/db/SystemKeyspace.java | 6 ++++--
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 185ec72cf9..71018a655c 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 4.1
+ * Add a system property to set hostId if not yet initialized (CASSANDRA-14582)
  * GossiperTest.testHasVersion3Nodes didn't take into account trunk version changes, fixed to rely on latest version (CASSANDRA-16651)
 Merged from 4.0:
  * Make JmxHistogram#getRecentValues() and JmxTimer#getRecentValues() thread-safe (CASSANDRA-16707)
diff --git a/conf/jvm-server.options b/conf/jvm-server.options
index 46967f4ad7..f7845d4113 100644
--- a/conf/jvm-server.options
+++ b/conf/jvm-server.options
@@ -22,6 +22,9 @@
 # and perhaps have affinity.
 #-Dcassandra.available_processors=number_of_processors
 
+# Specify host id for the first boot and persist it
+#-Dcassandra.host_id_first_boot=host_id
+
 # The directory location of the cassandra.yaml file.
 #-Dcassandra.config=directory
 
diff --git a/src/java/org/apache/cassandra/db/SystemKeyspace.java b/src/java/org/apache/cassandra/db/SystemKeyspace.java
index cbb708465c..4d2a567ca1 100644
--- a/src/java/org/apache/cassandra/db/SystemKeyspace.java
+++ b/src/java/org/apache/cassandra/db/SystemKeyspace.java
@@ -1126,13 +1126,15 @@ public final class SystemKeyspace
             return hostId;
 
         // ID not found, generate a new one, persist, and then return it.
-        hostId = UUID.randomUUID();
+        String hostString = System.getProperty("cassandra.host_id_first_boot", UUID.randomUUID().toString());
+        hostId = UUID.fromString(hostString);
         logger.warn("No host ID found, created {} (Note: This should happen exactly once per node).", hostId);
         return setLocalHostId(hostId);
     }
 
     /**
-     * Sets the local host ID explicitly.  Should only be called outside of SystemTable when replacing a node.
+     * Sets the local host ID explicitly. Should only be called outside of SystemTable when replacing a node.
+     * Used also in CASSANDRA-14582.
      */
     public static synchronized UUID setLocalHostId(UUID hostId)
     {