This is an automated email from the ASF dual-hosted git repository.
tabish pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/activemq-artemis.git
The following commit(s) were added to refs/heads/main by this push:
new 3cf670d8d3 ARTEMIS-5467 high CPU usage in OutboundStore.generateMqttId
3cf670d8d3 is described below
commit 3cf670d8d3cff7e13d91d52553b0f388ff3490f9
Author: Justin Bertram <[email protected]>
AuthorDate: Tue May 13 11:32:18 2025 -0500
ARTEMIS-5467 high CPU usage in OutboundStore.generateMqttId
---
.../artemis/core/protocol/mqtt/MQTTBundle.java | 3 +
.../core/protocol/mqtt/MQTTSessionState.java | 25 +++++---
.../core/protocol/mqtt/MQTTSessionStateTest.java | 66 ++++++++++++++++++++++
3 files changed, 87 insertions(+), 7 deletions(-)
diff --git
a/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTBundle.java
b/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTBundle.java
index 10bed9c38d..42e5d472e5 100644
---
a/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTBundle.java
+++
b/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTBundle.java
@@ -30,4 +30,7 @@ public interface MQTTBundle {
@Message(id = 850000, value = "Unable to store MQTT state within given
timeout: {}ms")
IllegalStateException unableToStoreMqttState(long timeout);
+
+ @Message(id = 850001, value = "Unable to generate MQTT packet ID. All valid
values between 1 and 65535 are in use. IDs will become available as messages
are acknowledged by the client that has received them.")
+ IllegalStateException unableToGenerateID();
}
diff --git
a/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionState.java
b/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionState.java
index 1535c7792a..6d7a53daf0 100644
---
a/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionState.java
+++
b/artemis-protocols/artemis-mqtt-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionState.java
@@ -16,6 +16,7 @@
*/
package org.apache.activemq.artemis.core.protocol.mqtt;
+import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
@@ -40,7 +41,6 @@ import
org.apache.activemq.artemis.core.message.impl.CoreMessage;
import org.apache.activemq.artemis.core.settings.impl.Match;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
-import java.lang.invoke.MethodHandles;
public class MQTTSessionState {
@@ -450,7 +450,9 @@ public class MQTTSessionState {
private final Object dataStoreLock = new Object();
- private int currentId = 0;
+ private final int INITIAL_ID = 0;
+
+ private int currentId = INITIAL_ID;
private Pair<Long, Long> generateKey(long messageId, long consumerID) {
return new Pair<>(messageId, consumerID);
@@ -460,13 +462,22 @@ public class MQTTSessionState {
synchronized (dataStoreLock) {
Integer id = artemisToMqttMessageMap.get(generateKey(messageId,
consumerId));
if (id == null) {
+ final int start = currentId;
do {
- if (currentId == MQTTUtil.TWO_BYTE_INT_MAX) {
- currentId = 0;
+ // wrap around to the start if we reach the max
+ if (++currentId > MQTTUtil.TWO_BYTE_INT_MAX) {
+ currentId = INITIAL_ID;
+ }
+ // check to see if we looped all the way back around to
where we started
+ if (start == currentId) {
+ // this detects an edge case where the same ID is acked &
then generated again
+ if (currentId != INITIAL_ID &&
!mqttToServerIds.containsKey(currentId)) {
+ break;
+ }
+ throw MQTTBundle.BUNDLE.unableToGenerateID();
}
- ++currentId;
}
- while (mqttToServerIds.containsKey(currentId));
+ while (mqttToServerIds.containsKey(currentId) || currentId ==
INITIAL_ID);
id = currentId;
}
return id;
@@ -515,7 +526,7 @@ public class MQTTSessionState {
synchronized (dataStoreLock) {
artemisToMqttMessageMap.clear();
mqttToServerIds.clear();
- currentId = 0;
+ currentId = INITIAL_ID;
}
}
}
diff --git
a/artemis-protocols/artemis-mqtt-protocol/src/test/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionStateTest.java
b/artemis-protocols/artemis-mqtt-protocol/src/test/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionStateTest.java
new file mode 100644
index 0000000000..7e37bd3e9a
--- /dev/null
+++
b/artemis-protocols/artemis-mqtt-protocol/src/test/java/org/apache/activemq/artemis/core/protocol/mqtt/MQTTSessionStateTest.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.activemq.artemis.core.protocol.mqtt;
+
+import org.apache.activemq.artemis.utils.RandomUtil;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class MQTTSessionStateTest {
+
+ @Test
+ public void testGenerateMqttIdOrder() {
+ MQTTSessionState mqttSessionState = new
MQTTSessionState(RandomUtil.randomUUIDString());
+ for (int i = 1; i <= MQTTUtil.TWO_BYTE_INT_MAX; i++) {
+ assertEquals(i,
mqttSessionState.getOutboundStore().generateMqttId(RandomUtil.randomLong(),
RandomUtil.randomLong()));
+ mqttSessionState.getOutboundStore().publish(i,
RandomUtil.randomLong(), RandomUtil.randomLong());
+ }
+ }
+
+ @Test
+ public void testGenerateMqttIdWithRandomAcks() {
+ MQTTSessionState mqttSessionState =
createMqttSessionStateWithFullOutboundStore();
+ for (int i = 0; i < 10_000; i++) {
+ int random = RandomUtil.randomInterval(1, MQTTUtil.TWO_BYTE_INT_MAX);
+ // acknowledge a random ID
+ mqttSessionState.getOutboundStore().publishAckd(random);
+ // the ID that was acked is now the only one available so ensure
generator finds it
+ assertEquals(random,
mqttSessionState.getOutboundStore().generateMqttId(RandomUtil.randomLong(),
RandomUtil.randomLong()));
+ // "publish" a new message with the ID to ensure the store is full
for the next loop
+ mqttSessionState.getOutboundStore().publish(random,
RandomUtil.randomLong(), RandomUtil.randomLong());
+ }
+ }
+
+ @Test
+ public void testGenerateMqttIdExhausted() {
+ MQTTSessionState mqttSessionState =
createMqttSessionStateWithFullOutboundStore();
+ // ensure we throw an exception when we try generate a new ID once the
store is full
+ assertThrows(IllegalStateException.class, () ->
mqttSessionState.getOutboundStore().generateMqttId(RandomUtil.randomLong(),
RandomUtil.randomLong()));
+ }
+
+ private static MQTTSessionState
createMqttSessionStateWithFullOutboundStore() {
+ MQTTSessionState mqttSessionState = new
MQTTSessionState(RandomUtil.randomUUIDString());
+ for (int i = 1; i <= MQTTUtil.TWO_BYTE_INT_MAX; i++) {
+ mqttSessionState.getOutboundStore().publish(i,
RandomUtil.randomLong(), RandomUtil.randomLong());
+ }
+ return mqttSessionState;
+ }
+}
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
For further information, visit: https://activemq.apache.org/contact
