diff --git a/spring-cloud-aws-sqs/pom.xml b/spring-cloud-aws-sqs/pom.xml
index e8d139b0e..1c690abab 100644
--- a/spring-cloud-aws-sqs/pom.xml
+++ b/spring-cloud-aws-sqs/pom.xml
@@ -13,6 +13,10 @@
Spring Cloud AWS SQS
Spring Cloud AWS Simple Queue Service
+
+ 3.17.0
+
+
software.amazon.awssdk
@@ -34,6 +38,11 @@
org.springframework.retry
spring-retry
+
+ org.apache.commons
+ commons-lang3
+ ${apache-commons-lang3.version}
+
com.fasterxml.jackson.core
jackson-databind
diff --git a/spring-cloud-aws-sqs/src/main/java/io/awspring/cloud/sqs/listener/RateLimitSemaphoreBackPressureHandler.java b/spring-cloud-aws-sqs/src/main/java/io/awspring/cloud/sqs/listener/RateLimitSemaphoreBackPressureHandler.java
new file mode 100644
index 000000000..e10b63eee
--- /dev/null
+++ b/spring-cloud-aws-sqs/src/main/java/io/awspring/cloud/sqs/listener/RateLimitSemaphoreBackPressureHandler.java
@@ -0,0 +1,283 @@
+/*
+ * Copyright 2013-2022 the original author or authors.
+ *
+ * Licensed 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
+ *
+ * https://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 io.awspring.cloud.sqs.listener;
+
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.apache.commons.lang3.concurrent.TimedSemaphore;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.util.Assert;
+
+/**
+ * {@link BackPressureHandler} implementation that uses a {@link Semaphore} for handling backpressure.
+ *
+ * @author Jeroen Vandevelde
+ * @see io.awspring.cloud.sqs.listener.source.PollingMessageSource
+ * @since 3.0
+ */
+public class RateLimitSemaphoreBackPressureHandler
+ implements BatchAwareBackPressureHandler, IdentifiableContainerComponent {
+
+ private static final Logger logger = LoggerFactory.getLogger(RateLimitSemaphoreBackPressureHandler.class);
+
+ private final Semaphore semaphore;
+ private final TimedSemaphore timedSemaphore;
+
+ private final int batchSize;
+
+ private final int totalPermits;
+
+ private final Duration acquireTimeout;
+
+ private final BackPressureMode backPressureConfiguration;
+
+ private volatile CurrentThroughputMode currentThroughputMode;
+
+ private final AtomicBoolean hasAcquiredFullPermits = new AtomicBoolean(false);
+
+ private String id;
+
+ private RateLimitSemaphoreBackPressureHandler(Builder builder) {
+ this.batchSize = builder.batchSize;
+ this.totalPermits = builder.totalPermits;
+ this.acquireTimeout = builder.acquireTimeout;
+ this.backPressureConfiguration = builder.backPressureMode;
+ this.semaphore = new Semaphore(totalPermits);
+ this.timedSemaphore = new TimedSemaphore(1, TimeUnit.SECONDS, 10);
+ this.currentThroughputMode = BackPressureMode.FIXED_HIGH_THROUGHPUT.equals(backPressureConfiguration)
+ ? CurrentThroughputMode.HIGH
+ : CurrentThroughputMode.LOW;
+ logger.debug("SemaphoreBackPressureHandler created with configuration {} and {} total permits",
+ backPressureConfiguration, totalPermits);
+ }
+
+ public static Builder builder() {
+ return new Builder();
+ }
+
+ @Override
+ public void setId(String id) {
+ this.id = id;
+ }
+
+ @Override
+ public String getId() {
+ return this.id;
+ }
+
+ @Override
+ public int request(int amount) throws InterruptedException {
+ if (timedSemaphore.getAvailablePermits() >= amount) {
+ for (int i = 0; i < amount; i++) {
+ boolean acquired = timedSemaphore.tryAcquire();
+ if (!acquired) {
+ return i;
+ }
+ }
+ return amount;
+ }
+ else if (timedSemaphore.getAvailablePermits() > 0) {
+ for (int i = 0; i < timedSemaphore.getAvailablePermits(); i++) {
+ boolean acquired = timedSemaphore.tryAcquire();
+ if (!acquired) {
+ return i;
+ }
+ }
+ return amount;
+ }
+ else {
+ return 0;
+ }
+ }
+
+ // @formatter:off
+ @Override
+ public int requestBatch() throws InterruptedException {
+ return CurrentThroughputMode.LOW.equals(this.currentThroughputMode)
+ ? requestInLowThroughputMode()
+ : requestInHighThroughputMode();
+ }
+
+ private int requestInHighThroughputMode() throws InterruptedException {
+ return tryAcquire(this.batchSize, CurrentThroughputMode.HIGH)
+ ? this.batchSize
+ : tryAcquirePartial();
+ }
+ // @formatter:on
+
+ private int tryAcquirePartial() throws InterruptedException {
+ int availablePermits = this.timedSemaphore.getAvailablePermits();
+ if (availablePermits == 0 || BackPressureMode.ALWAYS_POLL_MAX_MESSAGES.equals(this.backPressureConfiguration)) {
+ return 0;
+ }
+ int permitsToRequest = Math.min(availablePermits, this.batchSize);
+ CurrentThroughputMode currentThroughputModeNow = this.currentThroughputMode;
+ logger.trace("Trying to acquire partial batch of {} permits from {} available for {} in TM {}",
+ permitsToRequest, availablePermits, this.id, currentThroughputModeNow);
+ boolean hasAcquiredPartial = tryAcquire(permitsToRequest, currentThroughputModeNow);
+ return hasAcquiredPartial ? permitsToRequest : 0;
+ }
+
+ private int requestInLowThroughputMode() throws InterruptedException {
+ // Although LTM can be set / unset by many processes, only the MessageSource thread gets here,
+ // so no actual concurrency
+ logger.debug("Trying to acquire full permits for {}. Permits left: {}", this.id,
+ this.timedSemaphore.getAvailablePermits());
+ boolean hasAcquired = tryAcquire(this.totalPermits, CurrentThroughputMode.LOW);
+ if (hasAcquired) {
+ logger.debug("Acquired full permits for {}. Permits left: {}", this.id,
+ this.timedSemaphore.getAvailablePermits());
+ // We've acquired all permits - there's no other process currently processing messages
+ if (!this.hasAcquiredFullPermits.compareAndSet(false, true)) {
+ logger.warn("hasAcquiredFullPermits was already true. Permits left: {}",
+ this.timedSemaphore.getAvailablePermits());
+ }
+ return this.batchSize;
+ }
+ else {
+ return 0;
+ }
+ }
+
+ private boolean tryAcquire(int amount, CurrentThroughputMode currentThroughputModeNow) throws InterruptedException {
+ logger.trace("Acquiring {} permits for {} in TM {}", amount, this.id, this.currentThroughputMode);
+
+ for (int i = 0; i < amount; i++) {
+ if (!this.timedSemaphore.tryAcquire()) {
+ logger.trace("Not able to acquire {} permits in {} milliseconds for {} in TM {}. Permits left: {}",
+ amount, this.acquireTimeout.toMillis(), this.id, currentThroughputModeNow,
+ this.timedSemaphore.getAvailablePermits());
+ return false;
+ }
+ }
+
+ logger.trace("{} permits acquired for {} in TM {}. Permits left: {}", amount, this.id, currentThroughputModeNow,
+ this.timedSemaphore.getAvailablePermits());
+ return true;
+ }
+
+ @Override
+ public void releaseBatch() {
+ maybeSwitchToLowThroughputMode();
+ // TODO is this still needed with a timed one
+ // int permitsToRelease = getPermitsToRelease(this.batchSize);
+ // this.semaphore.release(permitsToRelease);
+ // logger.trace("Released {} permits for {}. Permits left: {}", permitsToRelease, this.id,
+ // this.timedSemaphore.getAvailablePermits());
+ }
+
+ @Override
+ public int getBatchSize() {
+ return this.batchSize;
+ }
+
+ private void maybeSwitchToLowThroughputMode() {
+ if (!BackPressureMode.FIXED_HIGH_THROUGHPUT.equals(this.backPressureConfiguration)
+ && CurrentThroughputMode.HIGH.equals(this.currentThroughputMode)) {
+ logger.debug("Entire batch of permits released for {}, setting TM LOW. Permits left: {}", this.id,
+ this.timedSemaphore.getAvailablePermits());
+ this.currentThroughputMode = CurrentThroughputMode.LOW;
+ }
+ }
+
+ @Override
+ public void release(int amount) {
+ // logger.trace("Releasing {} permits for {}. Permits left: {}", amount, this.id,
+ // this.timedSemaphore.getAvailablePermits());
+ // maybeSwitchToHighThroughputMode(amount);
+ // int permitsToRelease = getPermitsToRelease(amount);
+ // this.semaphore.release(permitsToRelease);
+ // logger.trace("Released {} permits for {}. Permits left: {}", permitsToRelease, this.id,
+ // this.timedSemaphore.getAvailablePermits());
+
+ // TODO figure out how to deal with release capabilities
+ }
+
+ private int getPermitsToRelease(int amount) {
+ return this.hasAcquiredFullPermits.compareAndSet(true, false)
+ // The first process that gets here should release all permits except for inflight messages
+ // We can have only one batch of messages at this point since we have all permits
+ ? this.totalPermits - (this.batchSize - amount)
+ : amount;
+ }
+
+ private void maybeSwitchToHighThroughputMode(int amount) {
+ if (CurrentThroughputMode.LOW.equals(this.currentThroughputMode)) {
+ logger.debug("{} unused permit(s), setting TM HIGH for {}. Permits left: {}", amount, this.id,
+ this.timedSemaphore.getAvailablePermits());
+ this.currentThroughputMode = CurrentThroughputMode.HIGH;
+ }
+ }
+
+ @Override
+ public boolean drain(Duration timeout) {
+ // TODO figure out a different way to make certain all the messages have been processed
+ timedSemaphore.shutdown();
+ return true;
+ }
+
+ private enum CurrentThroughputMode {
+
+ HIGH,
+
+ LOW;
+
+ }
+
+ public static class Builder {
+
+ private int batchSize;
+
+ private int totalPermits;
+
+ private Duration acquireTimeout;
+
+ private BackPressureMode backPressureMode;
+
+ public Builder batchSize(int batchSize) {
+ this.batchSize = batchSize;
+ return this;
+ }
+
+ public Builder totalPermits(int totalPermits) {
+ this.totalPermits = totalPermits;
+ return this;
+ }
+
+ public Builder acquireTimeout(Duration acquireTimeout) {
+ this.acquireTimeout = acquireTimeout;
+ return this;
+ }
+
+ public Builder throughputConfiguration(BackPressureMode backPressureConfiguration) {
+ this.backPressureMode = backPressureConfiguration;
+ return this;
+ }
+
+ public RateLimitSemaphoreBackPressureHandler build() {
+ Assert.noNullElements(
+ Arrays.asList(this.batchSize, this.totalPermits, this.acquireTimeout, this.backPressureMode),
+ "Missing configuration");
+ return new RateLimitSemaphoreBackPressureHandler(this);
+ }
+
+ }
+
+}