From 715e4db0c538add15fd3bc0da278f7c97bb518ef Mon Sep 17 00:00:00 2001
From: Nikita Koksharov <nkoksharov@redisson.pro>
Date: Mon, 13 Dec 2021 12:50:01 +0300
Subject: [PATCH] Fixed - master node shouldn't be initialized as slave in
 single mode. #4011

---
 .../cluster/ClusterConnectionManager.java     |  7 +++++-
 .../MasterSlaveConnectionManager.java         |  2 +-
 .../redisson/connection/MasterSlaveEntry.java | 24 +++++++------------
 3 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/redisson/src/main/java/org/redisson/cluster/ClusterConnectionManager.java b/redisson/src/main/java/org/redisson/cluster/ClusterConnectionManager.java
index c193ceaae..06d73aab7 100644
--- a/redisson/src/main/java/org/redisson/cluster/ClusterConnectionManager.java
+++ b/redisson/src/main/java/org/redisson/cluster/ClusterConnectionManager.java
@@ -311,7 +311,12 @@ public class ClusterConnectionManager extends MasterSlaveConnectionManager {
                 }
 
                 if (!config.checkSkipSlavesInit()) {
-                    List<RFuture<Void>> fs = entry.initSlaveBalancer(partition.getFailedSlaveAddresses(), masterClient, configEndpointHostName);
+                    List<RFuture<Void>> fs = entry.initSlaveBalancer(partition.getFailedSlaveAddresses(), configEndpointHostName);
+                    if (fs.isEmpty()) {
+                        result.trySuccess(null);
+                        return;
+                    }
+
                     AtomicInteger counter = new AtomicInteger(fs.size());
                     AtomicInteger errorCounter = new AtomicInteger(fs.size());
                     for (RFuture<Void> future : fs) {
diff --git a/redisson/src/main/java/org/redisson/connection/MasterSlaveConnectionManager.java b/redisson/src/main/java/org/redisson/connection/MasterSlaveConnectionManager.java
index 67232cffd..73653a8c2 100644
--- a/redisson/src/main/java/org/redisson/connection/MasterSlaveConnectionManager.java
+++ b/redisson/src/main/java/org/redisson/connection/MasterSlaveConnectionManager.java
@@ -337,7 +337,7 @@ public class MasterSlaveConnectionManager implements ConnectionManager {
             masterFuture.syncUninterruptibly();
 
             if (!config.checkSkipSlavesInit()) {
-                List<RFuture<Void>> fs = masterSlaveEntry.initSlaveBalancer(getDisconnectedNodes(), masterFuture.getNow());
+                List<RFuture<Void>> fs = masterSlaveEntry.initSlaveBalancer(getDisconnectedNodes());
                 for (RFuture<Void> future : fs) {
                     future.syncUninterruptibly();
                 }
diff --git a/redisson/src/main/java/org/redisson/connection/MasterSlaveEntry.java b/redisson/src/main/java/org/redisson/connection/MasterSlaveEntry.java
index 810b5bed7..fa8f41898 100644
--- a/redisson/src/main/java/org/redisson/connection/MasterSlaveEntry.java
+++ b/redisson/src/main/java/org/redisson/connection/MasterSlaveEntry.java
@@ -79,21 +79,15 @@ public class MasterSlaveEntry {
         return config;
     }
 
-    public List<RFuture<Void>> initSlaveBalancer(Collection<RedisURI> disconnectedNodes, RedisClient master) {
-        return initSlaveBalancer(disconnectedNodes, master, null);
+    public List<RFuture<Void>> initSlaveBalancer(Collection<RedisURI> disconnectedNodes) {
+        return initSlaveBalancer(disconnectedNodes, null);
     }
 
-    public List<RFuture<Void>> initSlaveBalancer(Collection<RedisURI> disconnectedNodes, RedisClient master, String slaveSSLHostname) {
-        boolean freezeMasterAsSlave = !config.getSlaveAddresses().isEmpty()
-                && !config.checkSkipSlavesInit()
-                && disconnectedNodes.size() < config.getSlaveAddresses().size();
-
-        List<RFuture<Void>> result = new LinkedList<RFuture<Void>>();
-        RFuture<Void> f = addSlave(master.getAddr(), master.getConfig().getAddress(), freezeMasterAsSlave, NodeType.MASTER, master.getConfig().getSslHostname());
-        result.add(f);
+    public List<RFuture<Void>> initSlaveBalancer(Collection<RedisURI> disconnectedNodes, String slaveSSLHostname) {
+        List<RFuture<Void>> result = new ArrayList<>(config.getSlaveAddresses().size());
         for (String address : config.getSlaveAddresses()) {
             RedisURI uri = new RedisURI(address);
-            f = addSlave(uri, disconnectedNodes.contains(uri), NodeType.SLAVE, slaveSSLHostname);
+            RFuture<Void> f = addSlave(uri, disconnectedNodes.contains(uri), NodeType.SLAVE, slaveSSLHostname);
             result.add(f);
         }
         return result;
@@ -139,7 +133,7 @@ public class MasterSlaveEntry {
             List<CompletableFuture<Void>> futures = new ArrayList<>();
             if (!config.checkSkipSlavesInit() && !slaveBalancer.contains(client.getAddr())) {
                 RFuture<Void> masterAsSlaveFuture = addSlave(client.getAddr(), client.getConfig().getAddress(),
-                                                    false, NodeType.MASTER, client.getConfig().getSslHostname());
+                                                    true, NodeType.MASTER, client.getConfig().getSslHostname());
                 futures.add(masterAsSlaveFuture.toCompletableFuture());
             }
 
@@ -477,10 +471,10 @@ public class MasterSlaveEntry {
             // freeze in slaveBalancer
             slaveDown(oldMaster.getClient().getAddr(), FreezeReason.MANAGER);
 
-            // more than one slave available, so master can be removed from slaves
+            // check if at least one slave is available, use master as slave if false
             if (!config.checkSkipSlavesInit()
-                    && slaveBalancer.getAvailableClients() > 1) {
-                slaveDown(newMasterClient.getAddr(), FreezeReason.SYSTEM);
+                    && slaveBalancer.getAvailableClients() == 0) {
+                slaveUp(newMasterClient.getAddr(), FreezeReason.SYSTEM);
             }
             oldMaster.shutdownAsync();
             log.info("master {} has changed to {}", oldMaster.getClient().getAddr(), masterEntry.getClient().getAddr());