From 269e2d898b76b5c9c58232c35bee805ceacc2ead Mon Sep 17 00:00:00 2001
From: ClarkChen <clark@hokplay.com>
Date: Thu, 27 Feb 2025 16:05:24 +0800
Subject: [PATCH] KAFKA-18849 Add "strict min ISR" to the docs of
 "min.insync.replicas" (#19016)

KIP-966 adds strict min ISR rule, so this PR improves the docs of min.insync.replicas to include that change.

Reviewers: Ismael Juma <ismael@juma.me.uk>, Chia-Ping Tsai <chia7712@gmail.com>
---
 .../org/apache/kafka/common/config/TopicConfig.java | 13 +++++++------
 .../kafka/server/config/ServerLogConfigs.java       | 10 +---------
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/clients/src/main/java/org/apache/kafka/common/config/TopicConfig.java b/clients/src/main/java/org/apache/kafka/common/config/TopicConfig.java
index fb51d254cdd..10d6024163b 100755
--- a/clients/src/main/java/org/apache/kafka/common/config/TopicConfig.java
+++ b/clients/src/main/java/org/apache/kafka/common/config/TopicConfig.java
@@ -173,12 +173,13 @@ public class TopicConfig {
     public static final String MIN_IN_SYNC_REPLICAS_DOC = "When a producer sets acks to \"all\" (or \"-1\"), " +
         "this configuration specifies the minimum number of replicas that must acknowledge " +
         "a write for the write to be considered successful. If this minimum cannot be met, " +
-        "then the producer will raise an exception (either NotEnoughReplicas or " +
-        "NotEnoughReplicasAfterAppend).<br>When used together, <code>min.insync.replicas</code> and <code>acks</code> " +
-        "allow you to enforce greater durability guarantees. A typical scenario would be to " +
-        "create a topic with a replication factor of 3, set <code>min.insync.replicas</code> to 2, and " +
-        "produce with <code>acks</code> of \"all\". This will ensure that the producer raises an exception " +
-        "if a majority of replicas do not receive a write.";
+        "then the producer will raise an exception (either <code>NotEnoughReplicas</code> or <code>NotEnoughReplicasAfterAppend</code>).<br> " +
+        "Regardless of the <code>acks</code> setting, the messages will not be visible to the consumers until " +
+        "they are replicated to all in-sync replicas and the <code>min.insync.replicas</code> condition is met.<br> " +
+        "When used together, <code>min.insync.replicas</code> and <code>acks</code> allow you to enforce greater durability guarantees. " +
+        "A typical scenario would be to create a topic with a replication factor of 3, " +
+        "set <code>min.insync.replicas</code> to 2, and produce with <code>acks</code> of \"all\". " +
+        "This will ensure that a majority of replicas must persist a write before it's considered successful by the producer and it's visible to consumers.";
 
     public static final String COMPRESSION_TYPE_CONFIG = "compression.type";
     public static final String COMPRESSION_TYPE_DOC = "Specify the final compression type for a given topic. " +
diff --git a/server-common/src/main/java/org/apache/kafka/server/config/ServerLogConfigs.java b/server-common/src/main/java/org/apache/kafka/server/config/ServerLogConfigs.java
index fa7ed93850f..ac11be948ad 100644
--- a/server-common/src/main/java/org/apache/kafka/server/config/ServerLogConfigs.java
+++ b/server-common/src/main/java/org/apache/kafka/server/config/ServerLogConfigs.java
@@ -135,15 +135,7 @@ public class ServerLogConfigs {
 
     public static final String MIN_IN_SYNC_REPLICAS_CONFIG = ServerTopicConfigSynonyms.serverSynonym(TopicConfig.MIN_IN_SYNC_REPLICAS_CONFIG);
     public static final int MIN_IN_SYNC_REPLICAS_DEFAULT = 1;
-    public static final String MIN_IN_SYNC_REPLICAS_DOC = "When a producer sets acks to \"all\" (or \"-1\"), " +
-            "<code>min.insync.replicas</code> specifies the minimum number of replicas that must acknowledge " +
-            "a write for the write to be considered successful. If this minimum cannot be met, " +
-            "then the producer will raise an exception (either <code>NotEnoughReplicas</code> or " +
-            "<code>NotEnoughReplicasAfterAppend</code>).<br>When used together, <code>min.insync.replicas</code> and acks " +
-            "allow you to enforce greater durability guarantees. A typical scenario would be to " +
-            "create a topic with a replication factor of 3, set <code>min.insync.replicas</code> to 2, and " +
-            "produce with acks of \"all\". This will ensure that the producer raises an exception " +
-            "if a majority of replicas do not receive a write.";
+    public static final String MIN_IN_SYNC_REPLICAS_DOC = TopicConfig.MIN_IN_SYNC_REPLICAS_DOC;
 
     public static final String CREATE_TOPIC_POLICY_CLASS_NAME_CONFIG = "create.topic.policy.class.name";
     public static final String CREATE_TOPIC_POLICY_CLASS_NAME_DOC = "The create topic policy class that should be used for validation. The class should " +