[improve] [doc] Add compatibility reminders for retry queues

docs/concepts-messaging.md

@@ -244,6 +244,11 @@ The default retry letter topic uses this format:
 <topicname>-<subscriptionname>-RETRY
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default retry letter topic uses the format of `<subscriptionname>-RETRY`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical retry letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-RETRY`.
+- It is not recommended to use `<subscriptionname>-RETRY` because if multiple topics under the same namespace have the same subscription, then retry message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the retry letter topic.
 
 ```java
@@ -321,6 +326,10 @@ The default dead letter topic uses this format:
 ```
 <topicname>-<subscriptionname>-DLQ
 ```
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default dead letter topic uses the format of `<subscriptionname>-DLQ`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical dead letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-DLQ`.
+- It is not recommended to use `<subscriptionname>-DLQ` because if multiple topics under the same namespace have the same subscription, then dead message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
 
 Use the Java client to specify the name of the dead letter topic.
 

versioned_docs/version-2.10.x/concepts-messaging.md

@@ -377,6 +377,11 @@ The default retry letter topic uses this format:
 
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default retry letter topic uses the format of `<subscriptionname>-RETRY`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical retry letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-RETRY`.
+- It is not recommended to use `<subscriptionname>-RETRY` because if multiple topics under the same namespace have the same subscription, then retry message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the retry letter topic.
 
 ```java
@@ -466,6 +471,11 @@ The default dead letter topic uses this format:
 
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default dead letter topic uses the format of `<subscriptionname>-DLQ`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical dead letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-DLQ`.
+- It is not recommended to use `<subscriptionname>-DLQ` because if multiple topics under the same namespace have the same subscription, then dead message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the dead letter topic.
 
 ```java

versioned_docs/version-2.11.x/concepts-messaging.md

@@ -393,6 +393,11 @@ The default retry letter topic uses this format:
 <topicname>-<subscriptionname>-RETRY
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default retry letter topic uses the format of `<subscriptionname>-RETRY`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical retry letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-RETRY`.
+- It is not recommended to use `<subscriptionname>-RETRY` because if multiple topics under the same namespace have the same subscription, then retry message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the retry letter topic.
 
 ```java
@@ -471,6 +476,11 @@ The default dead letter topic uses this format:
 <topicname>-<subscriptionname>-DLQ
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default dead letter topic uses the format of `<subscriptionname>-DLQ`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical dead letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-DLQ`.
+- It is not recommended to use `<subscriptionname>-DLQ` because if multiple topics under the same namespace have the same subscription, then dead message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the dead letter topic.
 
 ```java

versioned_docs/version-2.8.x/concepts-messaging.md

@@ -231,6 +231,10 @@ The default dead letter topic uses this format:
 
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default dead letter topic uses the format of `<subscriptionname>-DLQ`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical dead letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-DLQ`.
+- It is not recommended to use `<subscriptionname>-DLQ` because if multiple topics under the same namespace have the same subscription, then dead message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
 
 If you want to specify the name of the dead letter topic, use this Java client example:
 

versioned_docs/version-2.9.x/concepts-messaging.md

@@ -253,6 +253,11 @@ The default dead letter topic uses this format:
 
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default dead letter topic uses the format of `<subscriptionname>-DLQ`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical dead letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-DLQ`.
+- It is not recommended to use `<subscriptionname>-DLQ` because if multiple topics under the same namespace have the same subscription, then dead message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 If you want to specify the name of the dead letter topic, use this Java client example:
 
 ```java

versioned_docs/version-3.0.x/concepts-messaging.md

@@ -244,6 +244,11 @@ The default retry letter topic uses this format:
 <topicname>-<subscriptionname>-RETRY
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default retry letter topic uses the format of `<subscriptionname>-RETRY`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical retry letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-RETRY`.
+- It is not recommended to use `<subscriptionname>-RETRY` because if multiple topics under the same namespace have the same subscription, then retry message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the retry letter topic.
 
 ```java
@@ -322,6 +327,11 @@ The default dead letter topic uses this format:
 <topicname>-<subscriptionname>-DLQ
 ```
 
+:::note
+- For Pulsar 2.6.x and 2.7.x, the default dead letter topic uses the format of `<subscriptionname>-DLQ`. If you upgrade from 2.6.x~2.7.x to 2.8.x or later, you need to delete historical dead letter topics and retry letter partitioned topics. Otherwise, Pulsar continues to use original topics, which are formatted with `<subscriptionname>-DLQ`.
+- It is not recommended to use `<subscriptionname>-DLQ` because if multiple topics under the same namespace have the same subscription, then dead message topic names for multiple topics might be the same, which will result in mutual consumptions.
+:::
+
 Use the Java client to specify the name of the dead letter topic.
 
 ```java