KAFKA-18404: Remove partitionMaxBytes usage from DelayedShareFetch

core/src/main/java/kafka/server/share/DelayedShareFetch.java

@@ -27,6 +27,7 @@
 import org.apache.kafka.server.purgatory.DelayedOperation;
 import org.apache.kafka.server.share.SharePartitionKey;
 import org.apache.kafka.server.share.fetch.DelayedShareFetchGroupKey;
+import org.apache.kafka.server.share.fetch.PartitionMaxBytesStrategy;
 import org.apache.kafka.server.share.fetch.ShareFetch;
 import org.apache.kafka.server.storage.log.FetchIsolation;
 import org.apache.kafka.server.storage.log.FetchPartitionData;
@@ -60,24 +61,35 @@ public class DelayedShareFetch extends DelayedOperation {
     private final ShareFetch shareFetch;
     private final ReplicaManager replicaManager;
     private final BiConsumer<SharePartitionKey, Throwable> exceptionHandler;
+    private final PartitionMaxBytesStrategy partitionMaxBytesStrategy;
     // The topic partitions that need to be completed for the share fetch request are given by sharePartitions.
     // sharePartitions is a subset of shareFetchData. The order of insertion/deletion of entries in sharePartitions is important.
     private final LinkedHashMap<TopicIdPartition, SharePartition> sharePartitions;
-    private LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> partitionsAcquired;
+    private LinkedHashMap<TopicIdPartition, Long> partitionsAcquired;
     private LinkedHashMap<TopicIdPartition, LogReadResult> partitionsAlreadyFetched;
 
     DelayedShareFetch(
             ShareFetch shareFetch,
             ReplicaManager replicaManager,
             BiConsumer<SharePartitionKey, Throwable> exceptionHandler,
             LinkedHashMap<TopicIdPartition, SharePartition> sharePartitions) {
+        this(shareFetch, replicaManager, exceptionHandler, sharePartitions, PartitionMaxBytesStrategy.type(PartitionMaxBytesStrategy.StrategyType.UNIFORM));
+    }
+
+    DelayedShareFetch(
+        ShareFetch shareFetch,
+        ReplicaManager replicaManager,
+        BiConsumer<SharePartitionKey, Throwable> exceptionHandler,
+        LinkedHashMap<TopicIdPartition, SharePartition> sharePartitions,
+        PartitionMaxBytesStrategy partitionMaxBytesStrategy) {
         super(shareFetch.fetchParams().maxWaitMs, Optional.empty());
         this.shareFetch = shareFetch;
         this.replicaManager = replicaManager;
         this.partitionsAcquired = new LinkedHashMap<>();
         this.partitionsAlreadyFetched = new LinkedHashMap<>();
         this.exceptionHandler = exceptionHandler;
         this.sharePartitions = sharePartitions;
+        this.partitionMaxBytesStrategy = partitionMaxBytesStrategy;
     }
 
     @Override
@@ -99,7 +111,7 @@ public void onComplete() {
             partitionsAcquired.keySet());
 
         try {
-            LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData;
+            LinkedHashMap<TopicIdPartition, Long> topicPartitionData;
             // tryComplete did not invoke forceComplete, so we need to check if we have any partitions to fetch.
             if (partitionsAcquired.isEmpty())
                 topicPartitionData = acquirablePartitions();
@@ -121,11 +133,13 @@ public void onComplete() {
         }
     }
 
-    private void completeShareFetchRequest(LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData) {
+    private void completeShareFetchRequest(LinkedHashMap<TopicIdPartition, Long> topicPartitionData) {
         try {
             LinkedHashMap<TopicIdPartition, LogReadResult> responseData;
             if (partitionsAlreadyFetched.isEmpty())
-                responseData = readFromLog(topicPartitionData);
+                responseData = readFromLog(
+                    topicPartitionData,
+                    partitionMaxBytesStrategy.maxBytes(shareFetch.fetchParams().maxBytes, topicPartitionData.keySet(), topicPartitionData.size()));
             else
                 // There shouldn't be a case when we have a partitionsAlreadyFetched value here and this variable is getting
                 // updated in a different tryComplete thread.
@@ -158,7 +172,7 @@ private void completeShareFetchRequest(LinkedHashMap<TopicIdPartition, FetchRequ
      */
     @Override
     public boolean tryComplete() {
-        LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData = acquirablePartitions();
+        LinkedHashMap<TopicIdPartition, Long> topicPartitionData = acquirablePartitions();
 
         try {
             if (!topicPartitionData.isEmpty()) {
@@ -167,7 +181,7 @@ public boolean tryComplete() {
                 // those topic partitions.
                 LinkedHashMap<TopicIdPartition, LogReadResult> replicaManagerReadResponse = maybeReadFromLog(topicPartitionData);
                 maybeUpdateFetchOffsetMetadata(topicPartitionData, replicaManagerReadResponse);
-                if (anyPartitionHasLogReadError(replicaManagerReadResponse) || isMinBytesSatisfied(topicPartitionData)) {
+                if (anyPartitionHasLogReadError(replicaManagerReadResponse) || isMinBytesSatisfied(topicPartitionData, partitionMaxBytesStrategy.maxBytes(shareFetch.fetchParams().maxBytes, topicPartitionData.keySet(), topicPartitionData.size()))) {
                     partitionsAcquired = topicPartitionData;
                     partitionsAlreadyFetched = replicaManagerReadResponse;
                     boolean completedByMe = forceComplete();
@@ -202,28 +216,18 @@ public boolean tryComplete() {
      * Prepare fetch request structure for partitions in the share fetch request for which we can acquire records.
      */
     // Visible for testing
-    LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> acquirablePartitions() {
+    LinkedHashMap<TopicIdPartition, Long> acquirablePartitions() {
         // Initialize the topic partitions for which the fetch should be attempted.
-        LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData = new LinkedHashMap<>();
+        LinkedHashMap<TopicIdPartition, Long> topicPartitionData = new LinkedHashMap<>();
 
         sharePartitions.forEach((topicIdPartition, sharePartition) -> {
-            int partitionMaxBytes = shareFetch.partitionMaxBytes().getOrDefault(topicIdPartition, 0);
             // Add the share partition to the list of partitions to be fetched only if we can
             // acquire the fetch lock on it.
             if (sharePartition.maybeAcquireFetchLock()) {
                 try {
                     // If the share partition is already at capacity, we should not attempt to fetch.
                     if (sharePartition.canAcquireRecords()) {
-                        topicPartitionData.put(
-                            topicIdPartition,
-                            new FetchRequest.PartitionData(
-                                topicIdPartition.topicId(),
-                                sharePartition.nextFetchOffset(),
-                                0,
-                                partitionMaxBytes,
-                                Optional.empty()
-                            )
-                        );
+                        topicPartitionData.put(topicIdPartition, sharePartition.nextFetchOffset());
                     } else {
                         sharePartition.releaseFetchLock();
                         log.trace("Record lock partition limit exceeded for SharePartition {}, " +
@@ -239,24 +243,28 @@ LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> acquirablePartitions
         return topicPartitionData;
     }
 
-    private LinkedHashMap<TopicIdPartition, LogReadResult> maybeReadFromLog(LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData) {
-        LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> partitionsNotMatchingFetchOffsetMetadata = new LinkedHashMap<>();
-        topicPartitionData.forEach((topicIdPartition, partitionData) -> {
+    private LinkedHashMap<TopicIdPartition, LogReadResult> maybeReadFromLog(LinkedHashMap<TopicIdPartition, Long> topicPartitionData) {
+        LinkedHashMap<TopicIdPartition, Long> partitionsNotMatchingFetchOffsetMetadata = new LinkedHashMap<>();
+        topicPartitionData.forEach((topicIdPartition, fetchOffset) -> {
             SharePartition sharePartition = sharePartitions.get(topicIdPartition);
-            if (sharePartition.fetchOffsetMetadata(partitionData.fetchOffset).isEmpty()) {
-                partitionsNotMatchingFetchOffsetMetadata.put(topicIdPartition, partitionData);
+            if (sharePartition.fetchOffsetMetadata(fetchOffset).isEmpty()) {
+                partitionsNotMatchingFetchOffsetMetadata.put(topicIdPartition, fetchOffset);
             }
         });
         if (partitionsNotMatchingFetchOffsetMetadata.isEmpty()) {
             return new LinkedHashMap<>();
         }
         // We fetch data from replica manager corresponding to the topic partitions that have missing fetch offset metadata.
-        return readFromLog(partitionsNotMatchingFetchOffsetMetadata);
+        // Although we are fetching partition max bytes for partitionsNotMatchingFetchOffsetMetadata,
+        // we will take acquired partitions size = topicPartitionData.size() because we do not want to let the
+        // leftover partitions to starve which will be fetched later.
+        return readFromLog(
+            partitionsNotMatchingFetchOffsetMetadata,
+            partitionMaxBytesStrategy.maxBytes(shareFetch.fetchParams().maxBytes, partitionsNotMatchingFetchOffsetMetadata.keySet(), topicPartitionData.size()));
     }
 
-    private void maybeUpdateFetchOffsetMetadata(
-        LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData,
-        LinkedHashMap<TopicIdPartition, LogReadResult> replicaManagerReadResponseData) {
+    private void maybeUpdateFetchOffsetMetadata(LinkedHashMap<TopicIdPartition, Long> topicPartitionData,
+                                                LinkedHashMap<TopicIdPartition, LogReadResult> replicaManagerReadResponseData) {
         for (Map.Entry<TopicIdPartition, LogReadResult> entry : replicaManagerReadResponseData.entrySet()) {
             TopicIdPartition topicIdPartition = entry.getKey();
             SharePartition sharePartition = sharePartitions.get(topicIdPartition);
@@ -267,17 +275,18 @@ private void maybeUpdateFetchOffsetMetadata(
                 continue;
             }
             sharePartition.updateFetchOffsetMetadata(
-                topicPartitionData.get(topicIdPartition).fetchOffset,
+                topicPartitionData.get(topicIdPartition),
                 replicaManagerLogReadResult.info().fetchOffsetMetadata);
         }
     }
 
     // minByes estimation currently assumes the common case where all fetched data is acquirable.
-    private boolean isMinBytesSatisfied(LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData) {
+    private boolean isMinBytesSatisfied(LinkedHashMap<TopicIdPartition, Long> topicPartitionData,
+                                        LinkedHashMap<TopicIdPartition, Integer> partitionMaxBytes) {
         long accumulatedSize = 0;
-        for (Map.Entry<TopicIdPartition, FetchRequest.PartitionData> entry : topicPartitionData.entrySet()) {
+        for (Map.Entry<TopicIdPartition, Long> entry : topicPartitionData.entrySet()) {
             TopicIdPartition topicIdPartition = entry.getKey();
-            FetchRequest.PartitionData partitionData = entry.getValue();
+            long fetchOffset = entry.getValue();
 
             LogOffsetMetadata endOffsetMetadata;
             try {
@@ -294,7 +303,7 @@ private boolean isMinBytesSatisfied(LinkedHashMap<TopicIdPartition, FetchRequest
 
             SharePartition sharePartition = sharePartitions.get(topicIdPartition);
 
-            Optional<LogOffsetMetadata> optionalFetchOffsetMetadata = sharePartition.fetchOffsetMetadata(partitionData.fetchOffset);
+            Optional<LogOffsetMetadata> optionalFetchOffsetMetadata = sharePartition.fetchOffsetMetadata(fetchOffset);
             if (optionalFetchOffsetMetadata.isEmpty() || optionalFetchOffsetMetadata.get() == LogOffsetMetadata.UNKNOWN_OFFSET_METADATA)
                 continue;
             LogOffsetMetadata fetchOffsetMetadata = optionalFetchOffsetMetadata.get();
@@ -312,7 +321,7 @@ private boolean isMinBytesSatisfied(LinkedHashMap<TopicIdPartition, FetchRequest
                     return true;
                 } else if (fetchOffsetMetadata.onSameSegment(endOffsetMetadata)) {
                     // we take the partition fetch size as upper bound when accumulating the bytes.
-                    long bytesAvailable = Math.min(endOffsetMetadata.positionDiff(fetchOffsetMetadata), partitionData.maxBytes);
+                    long bytesAvailable = Math.min(endOffsetMetadata.positionDiff(fetchOffsetMetadata), partitionMaxBytes.get(topicIdPartition));
                     accumulatedSize += bytesAvailable;
                 }
             }
@@ -335,13 +344,25 @@ else if (isolationType == FetchIsolation.HIGH_WATERMARK)
 
     }
 
-    private LinkedHashMap<TopicIdPartition, LogReadResult> readFromLog(LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData) {
+    private LinkedHashMap<TopicIdPartition, LogReadResult> readFromLog(LinkedHashMap<TopicIdPartition, Long> topicPartitionFetchOffsets,
+                                                                       LinkedHashMap<TopicIdPartition, Integer> partitionMaxBytes) {
         // Filter if there already exists any erroneous topic partition.
-        Set<TopicIdPartition> partitionsToFetch = shareFetch.filterErroneousTopicPartitions(topicPartitionData.keySet());
+        Set<TopicIdPartition> partitionsToFetch = shareFetch.filterErroneousTopicPartitions(topicPartitionFetchOffsets.keySet());
         if (partitionsToFetch.isEmpty()) {
             return new LinkedHashMap<>();
         }
 
+        LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData = new LinkedHashMap<>();
+
+        topicPartitionFetchOffsets.forEach((topicIdPartition, fetchOffset) -> topicPartitionData.put(topicIdPartition,
+            new FetchRequest.PartitionData(
+                topicIdPartition.topicId(),
+                fetchOffset,
+                0,
+                partitionMaxBytes.get(topicIdPartition),
+                Optional.empty())
+        ));
+
         Seq<Tuple2<TopicIdPartition, LogReadResult>> responseLogResult = replicaManager.readFromLog(
             shareFetch.fetchParams(),
             CollectionConverters.asScala(
@@ -390,18 +411,21 @@ private void handleFetchException(
     }
 
     // Visible for testing.
-    LinkedHashMap<TopicIdPartition, LogReadResult> combineLogReadResponse(LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> topicPartitionData,
-                                                                LinkedHashMap<TopicIdPartition, LogReadResult> existingFetchedData) {
-        LinkedHashMap<TopicIdPartition, FetchRequest.PartitionData> missingLogReadTopicPartitions = new LinkedHashMap<>();
-        topicPartitionData.forEach((topicIdPartition, partitionData) -> {
+    LinkedHashMap<TopicIdPartition, LogReadResult> combineLogReadResponse(LinkedHashMap<TopicIdPartition, Long> topicPartitionData,
+                                                                          LinkedHashMap<TopicIdPartition, LogReadResult> existingFetchedData) {
+        LinkedHashMap<TopicIdPartition, Long> missingLogReadTopicPartitions = new LinkedHashMap<>();
+        topicPartitionData.forEach((topicIdPartition, fetchOffset) -> {
             if (!existingFetchedData.containsKey(topicIdPartition)) {
-                missingLogReadTopicPartitions.put(topicIdPartition, partitionData);
+                missingLogReadTopicPartitions.put(topicIdPartition, fetchOffset);
             }
         });
         if (missingLogReadTopicPartitions.isEmpty()) {
             return existingFetchedData;
         }
-        LinkedHashMap<TopicIdPartition, LogReadResult> missingTopicPartitionsLogReadResponse = readFromLog(missingLogReadTopicPartitions);
+
+        LinkedHashMap<TopicIdPartition, LogReadResult> missingTopicPartitionsLogReadResponse = readFromLog(
+            missingLogReadTopicPartitions,
+            partitionMaxBytesStrategy.maxBytes(shareFetch.fetchParams().maxBytes, missingLogReadTopicPartitions.keySet(), topicPartitionData.size()));
         missingTopicPartitionsLogReadResponse.putAll(existingFetchedData);
         return missingTopicPartitionsLogReadResponse;
     }

core/src/test/java/kafka/server/share/SharePartitionManagerTest.java

@@ -64,6 +64,7 @@
 import org.apache.kafka.server.share.context.ShareSessionContext;
 import org.apache.kafka.server.share.fetch.DelayedShareFetchGroupKey;
 import org.apache.kafka.server.share.fetch.DelayedShareFetchKey;
+import org.apache.kafka.server.share.fetch.PartitionMaxBytesStrategy;
 import org.apache.kafka.server.share.fetch.ShareAcquiredRecords;
 import org.apache.kafka.server.share.fetch.ShareFetch;
 import org.apache.kafka.server.share.persister.NoOpShareStatePersister;
@@ -1711,6 +1712,7 @@ public void testAcknowledgeCompletesDelayedShareFetchRequest() {
             .withShareFetchData(shareFetch)
             .withReplicaManager(mockReplicaManager)
             .withSharePartitions(sharePartitions)
+            .withPartitionMaxBytesStrategy(PartitionMaxBytesStrategy.type(PartitionMaxBytesStrategy.StrategyType.UNIFORM))
             .build();
 
         delayedShareFetchPurgatory.tryCompleteElseWatch(delayedShareFetch, delayedShareFetchWatchKeys);
@@ -1912,6 +1914,7 @@ public void testReleaseSessionCompletesDelayedShareFetchRequest() {
             .withShareFetchData(shareFetch)
             .withReplicaManager(mockReplicaManager)
             .withSharePartitions(sharePartitions)
+            .withPartitionMaxBytesStrategy(PartitionMaxBytesStrategy.type(PartitionMaxBytesStrategy.StrategyType.UNIFORM))
             .build();
 
         delayedShareFetchPurgatory.tryCompleteElseWatch(delayedShareFetch, delayedShareFetchWatchKeys);

core/src/test/java/kafka/test/api/ShareConsumerTest.java

@@ -902,7 +902,7 @@ public void testFetchRecordLargerThanMaxPartitionFetchBytes(String persister) th
             shareConsumer.subscribe(Collections.singleton(tp.topic()));
 
             ConsumerRecords<byte[], byte[]> records = shareConsumer.poll(Duration.ofMillis(5000));
-            assertEquals(1, records.count());
+            assertEquals(2, records.count());
         }
     }
 

core/src/test/scala/unit/kafka/server/ShareFetchAcknowledgeRequestTest.scala

@@ -1310,7 +1310,7 @@ class ShareFetchAcknowledgeRequestTest(cluster: ClusterInstance) extends GroupCo
       ),
     )
   )
-  def testShareFetchBrokerRespectsPartitionsSizeLimit(): Unit = {
+  def testShareFetchBrokerDoesNotRespectPartitionsSizeLimit(): Unit = {
     val groupId: String = "group"
     val memberId = Uuid.randomUuid()
 
@@ -1350,10 +1350,10 @@ class ShareFetchAcknowledgeRequestTest(cluster: ClusterInstance) extends GroupCo
       .setPartitionIndex(partition)
       .setErrorCode(Errors.NONE.code())
       .setAcknowledgeErrorCode(Errors.NONE.code())
-      .setAcquiredRecords(expectedAcquiredRecords(Collections.singletonList(0), Collections.singletonList(11), Collections.singletonList(1)))
+      .setAcquiredRecords(expectedAcquiredRecords(Collections.singletonList(0), Collections.singletonList(12), Collections.singletonList(1)))
     // The first 10 records will be consumed as it is. For the last 3 records, each of size MAX_PARTITION_BYTES/3,
-    // only 2 of then will be consumed (offsets 10 and 11) because the inclusion of the third last record will exceed
-    // the max partition bytes limit
+    // all 3 of then will be consumed (offsets 10, 11 and 12) because even though the inclusion of the third last record will exceed
+    // the max partition bytes limit. We should only consider the request level maxBytes as the hard limit.
 
     val partitionData = shareFetchResponseData.responses().get(0).partitions().get(0)
     compareFetchResponsePartitions(expectedPartitionData, partitionData)
@@ -1412,15 +1412,15 @@ class ShareFetchAcknowledgeRequestTest(cluster: ClusterInstance) extends GroupCo
     // mocking the behaviour of multiple share consumers from the same share group
     val metadata1: ShareRequestMetadata = new ShareRequestMetadata(memberId1, ShareRequestMetadata.INITIAL_EPOCH)
     val acknowledgementsMap1: Map[TopicIdPartition, util.List[ShareFetchRequestData.AcknowledgementBatch]] = Map.empty
-    val shareFetchRequest1 = createShareFetchRequest(groupId, metadata1, MAX_PARTITION_BYTES, send, Seq.empty, acknowledgementsMap1)
+    val shareFetchRequest1 = createShareFetchRequest(groupId, metadata1, MAX_PARTITION_BYTES, send, Seq.empty, acknowledgementsMap1, minBytes = 100, maxBytes = 1500)
 
     val metadata2: ShareRequestMetadata = new ShareRequestMetadata(memberId2, ShareRequestMetadata.INITIAL_EPOCH)
     val acknowledgementsMap2: Map[TopicIdPartition, util.List[ShareFetchRequestData.AcknowledgementBatch]] = Map.empty
-    val shareFetchRequest2 = createShareFetchRequest(groupId, metadata2, MAX_PARTITION_BYTES, send, Seq.empty, acknowledgementsMap2)
+    val shareFetchRequest2 = createShareFetchRequest(groupId, metadata2, MAX_PARTITION_BYTES, send, Seq.empty, acknowledgementsMap2, minBytes = 100, maxBytes = 1500)
 
     val metadata3: ShareRequestMetadata = new ShareRequestMetadata(memberId3, ShareRequestMetadata.INITIAL_EPOCH)
     val acknowledgementsMap3: Map[TopicIdPartition, util.List[ShareFetchRequestData.AcknowledgementBatch]] = Map.empty
-    val shareFetchRequest3 = createShareFetchRequest(groupId, metadata3, MAX_PARTITION_BYTES, send, Seq.empty, acknowledgementsMap3)
+    val shareFetchRequest3 = createShareFetchRequest(groupId, metadata3, MAX_PARTITION_BYTES, send, Seq.empty, acknowledgementsMap3, minBytes = 100, maxBytes = 1500)
 
     val shareFetchResponse1 = connectAndReceive[ShareFetchResponse](shareFetchRequest1)
     val shareFetchResponse2 = connectAndReceive[ShareFetchResponse](shareFetchRequest2)

share/src/main/java/org/apache/kafka/server/share/fetch/PartitionMaxBytesStrategy.java

@@ -0,0 +1,77 @@
+/*
+ * 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.kafka.server.share.fetch;
+
+import org.apache.kafka.common.TopicIdPartition;
+
+import java.util.LinkedHashMap;
+import java.util.Locale;
+import java.util.Set;
+
+/**
+ * This interface helps identify the max bytes for topic partitions in a share fetch request based on different strategy types.
+ */
+public interface PartitionMaxBytesStrategy {
+
+    enum StrategyType {
+        UNIFORM;
+
+        @Override
+        public String toString() {
+            return super.toString().toLowerCase(Locale.ROOT);
+        }
+    }
+
+    /**
+     * Returns the partition max bytes for a given partition based on the strategy type.
+     *
+     * @param requestMaxBytes - The total max bytes available for the share fetch request
+     * @param partitions - The topic partitions in the order for which we compute the partition max bytes.
+     * @param acquiredPartitionsSize - The total partitions that have been acquired.
+     * @return the partition max bytes for the topic partitions
+     */
+    LinkedHashMap<TopicIdPartition, Integer> maxBytes(int requestMaxBytes, Set<TopicIdPartition> partitions, int acquiredPartitionsSize);
+
+    static PartitionMaxBytesStrategy type(StrategyType type) {
+        if (type == null)
+            throw new IllegalArgumentException("Strategy type cannot be null");
+        return switch (type) {
+            case UNIFORM -> PartitionMaxBytesStrategy::uniformPartitionMaxBytes;
+        };
+    }
+
+
+    private static LinkedHashMap<TopicIdPartition, Integer> uniformPartitionMaxBytes(int requestMaxBytes, Set<TopicIdPartition> partitions, int acquiredPartitionsSize) {
+        checkValidArguments(requestMaxBytes, partitions, acquiredPartitionsSize);
+        LinkedHashMap<TopicIdPartition, Integer> partitionMaxBytes = new LinkedHashMap<>();
+        partitions.forEach(partition -> partitionMaxBytes.put(partition, requestMaxBytes / acquiredPartitionsSize));
+        return partitionMaxBytes;
+    }
+
+    // Visible for testing.
+    static void checkValidArguments(int requestMaxBytes, Set<TopicIdPartition> partitions, int acquiredPartitionsSize) {
+        if (partitions == null || partitions.isEmpty()) {
+            throw new IllegalArgumentException("Partitions to generate max bytes is null or empty");
+        }
+        if (requestMaxBytes <= 0) {
+            throw new IllegalArgumentException("Request max bytes must be greater than 0");
+        }
+        if (acquiredPartitionsSize <= 0) {
+            throw new IllegalArgumentException("Acquired partitions size must be greater than 0");
+        }
+    }
+}

share/src/test/java/org/apache/kafka/server/share/fetch/PartitionMaxBytesStrategyTest.java

@@ -0,0 +1,90 @@
+/*
+ * 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.kafka.server.share.fetch;
+
+import org.apache.kafka.common.TopicIdPartition;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.Uuid;
+import org.apache.kafka.server.share.fetch.PartitionMaxBytesStrategy.StrategyType;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class PartitionMaxBytesStrategyTest {
+
+    @Test
+    public void testConstructor() {
+        assertThrows(IllegalArgumentException.class, () -> PartitionMaxBytesStrategy.type(null));
+        assertDoesNotThrow(() -> PartitionMaxBytesStrategy.type(StrategyType.UNIFORM));
+    }
+
+    @Test
+    public void testCheckValidArguments() {
+        TopicIdPartition topicIdPartition1 = new TopicIdPartition(Uuid.randomUuid(), new TopicPartition("topic1", 0));
+        TopicIdPartition topicIdPartition2 = new TopicIdPartition(Uuid.randomUuid(), new TopicPartition("topic1", 1));
+        TopicIdPartition topicIdPartition3 = new TopicIdPartition(Uuid.randomUuid(), new TopicPartition("topic2", 0));
+        Set<TopicIdPartition> partitions = new LinkedHashSet<>();
+        partitions.add(topicIdPartition1);
+        partitions.add(topicIdPartition2);
+        partitions.add(topicIdPartition3);
+
+        // acquired partitions size is 0.
+        assertThrows(IllegalArgumentException.class, () -> PartitionMaxBytesStrategy.checkValidArguments(
+            100, partitions, 0));
+        // empty partitions set.
+        assertThrows(IllegalArgumentException.class, () -> PartitionMaxBytesStrategy.checkValidArguments(
+            100, Collections.EMPTY_SET, 20));
+        // partitions is null.
+        assertThrows(IllegalArgumentException.class, () -> PartitionMaxBytesStrategy.checkValidArguments(
+            100, null, 20));
+        // request max bytes is 0.
+        assertThrows(IllegalArgumentException.class, () -> PartitionMaxBytesStrategy.checkValidArguments(
+            0, partitions, 20));
+
+        // Valid arguments.
+        assertDoesNotThrow(() -> PartitionMaxBytesStrategy.checkValidArguments(100, partitions, 20));
+    }
+
+    @Test
+    public void testUniformStrategy() {
+        PartitionMaxBytesStrategy partitionMaxBytesStrategy = PartitionMaxBytesStrategy.type(StrategyType.UNIFORM);
+        TopicIdPartition topicIdPartition1 = new TopicIdPartition(Uuid.randomUuid(), new TopicPartition("topic1", 0));
+        TopicIdPartition topicIdPartition2 = new TopicIdPartition(Uuid.randomUuid(), new TopicPartition("topic1", 1));
+        TopicIdPartition topicIdPartition3 = new TopicIdPartition(Uuid.randomUuid(), new TopicPartition("topic2", 0));
+        Set<TopicIdPartition> partitions = new LinkedHashSet<>();
+        partitions.add(topicIdPartition1);
+        partitions.add(topicIdPartition2);
+        partitions.add(topicIdPartition3);
+
+        LinkedHashMap<TopicIdPartition, Integer> result = partitionMaxBytesStrategy.maxBytes(
+            100, partitions, 3);
+        assertEquals(result.values().stream().toList(), List.of(33, 33, 33));
+
+        result = partitionMaxBytesStrategy.maxBytes(
+            100, partitions, 5);
+        assertEquals(result.values().stream().toList(), List.of(20, 20, 20));
+    }
+}