ARTEMIS-4873: tweak example to avoid potential NPE from race between …

…creating new backlog and replenishing credit Also swap startup/shutdown order to reduce reconnect logging
apache · Jul 26, 2024 · bc86b5d · bc86b5d
1 parent c5d2ab6
commit bc86b5d
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Showing 2 changed files with 21 additions and 19 deletions.
diff --git a/examples/features/broker-connection/amqp-federation-queue-pull-messages/pom.xml b/examples/features/broker-connection/amqp-federation-queue-pull-messages/pom.xml
@@ -76,37 +76,37 @@ under the License.
                      <javaOptions>-Djava.net.preferIPv4Stack=true</javaOptions>
                   </configuration>
                </execution>
-               <!-- we first start broker 1, to avoid reconnecting statements -->
+               <!-- we first start broker 2, to avoid reconnecting statements -->
                <execution>
-                  <id>start1</id>
+                  <id>start2</id>
                   <goals>
                      <goal>cli</goal>
                   </goals>
                   <configuration>
                      <ignore>${noServer}</ignore>
                      <spawn>true</spawn>
-                     <location>${basedir}/target/server1</location>
-                     <testURI>tcp://localhost:5660</testURI>
+                     <location>${basedir}/target/server2</location>
+                     <testURI>tcp://localhost:5770</testURI>
                      <args>
                         <param>run</param>
                      </args>
-                     <name>server1</name>
+                     <name>server2</name>
                   </configuration>
                </execution>
                <execution>
-                  <id>start2</id>
+                  <id>start1</id>
                   <goals>
                      <goal>cli</goal>
                   </goals>
                   <configuration>
                      <spawn>true</spawn>
                      <ignore>${noServer}</ignore>
-                     <location>${basedir}/target/server2</location>
-                     <testURI>tcp://localhost:5770</testURI>
+                     <location>${basedir}/target/server1</location>
+                     <testURI>tcp://localhost:5660</testURI>
                      <args>
                         <param>run</param>
                      </args>
-                     <name>server2</name>
+                     <name>server1</name>
                   </configuration>
                </execution>
                <execution>
@@ -121,23 +121,23 @@ under the License.
                   </configuration>
                </execution>
                <execution>
-                  <id>stop2</id>
+                  <id>stop1</id>
                   <goals>
                      <goal>stop</goal>
                   </goals>
                   <configuration>
                      <ignore>${noServer}</ignore>
-                     <location>${basedir}/target/server2</location>
+                     <location>${basedir}/target/server1</location>
                   </configuration>
                </execution>
                <execution>
-                  <id>stop1</id>
+                  <id>stop2</id>
                   <goals>
                      <goal>stop</goal>
                   </goals>
                   <configuration>
                      <ignore>${noServer}</ignore>
-                     <location>${basedir}/target/server1</location>
+                     <location>${basedir}/target/server2</location>
                   </configuration>
                </execution>
             </executions>

diff --git a/...ssages/src/main/java/org/apache/activemq/artemis/jms/example/BrokerFederationExample.java b/...ssages/src/main/java/org/apache/activemq/artemis/jms/example/BrokerFederationExample.java
@@ -72,12 +72,8 @@ public static void main(final String[] args) throws Exception {
       System.out.println("Consumer on server 2 received message: " + receivedFromC2.getText());
       System.out.println("Consumer on server 2 received message: " + receivedFromC3.getText());
 
-      final TextMessage receivedFromC1 = (TextMessage) consumerOn1.receive(10_000);
-
-      System.out.println("Consumer on server 1 received message: " + receivedFromC1.getText());
-
-      // Now create local backlog on server 1 which should prevent any messages being federated
-      // from server 2 and the local consumer on server 2 should be able to receive them
+      // Now create more local backlog on server 1 which should prevent more messages being federated
+      // from server 2 and the local consumer on server 2 should be able to receive them all
 
       final TextMessage messageSent4 = sessionOnServer1.createTextMessage("message #4");
       final TextMessage messageSent5 = sessionOnServer1.createTextMessage("message #5");
@@ -87,6 +83,12 @@ public static void main(final String[] args) throws Exception {
       producerOn1.send(messageSent5);
       producerOn1.send(messageSent6);
 
+      // Consume the first message from server1 (federated from server2 on first send)
+
+      final TextMessage receivedFromC1 = (TextMessage) consumerOn1.receive(10_000);
+
+      System.out.println("Consumer on server 1 received message: " + receivedFromC1.getText());
+
       // These should stay local to server 2 and be consumed when pulled by the consumer on 2
 
       final TextMessage messageSent7 = sessionOnServer2.createTextMessage("message #7");