Remove upper limit for chunking settings (elastic#133718)

kderusso · JeremyDahlgren · commit 525417ae7dbe · 2025-08-29T12:20:39.000-04:00
diff --git a/docs/changelog/133718.yaml b/docs/changelog/133718.yaml
@@ -0,0 +1,5 @@
+pr: 133718
+summary: Remove upper limit for chunking settings
+area: Machine Learning
+type: enhancement
+issues: []
diff --git a/server/src/main/java/org/elasticsearch/inference/ChunkingSettings.java b/server/src/main/java/org/elasticsearch/inference/ChunkingSettings.java
@@ -15,7 +15,13 @@
 import java.util.Map;
 
 public interface ChunkingSettings extends ToXContentObject, VersionedNamedWriteable {
+
     ChunkingStrategy getChunkingStrategy();
 
     Map<String, Object> asMap();
+
+    /**
+     * @return The max chunk size specified, or null if not specified
+     */
+    Integer maxChunkSize();
 }
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/NoneChunkingSettings.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/NoneChunkingSettings.java
@@ -37,6 +37,11 @@ public ChunkingStrategy getChunkingStrategy() {
         return STRATEGY;
     }
 
+    @Override
+    public Integer maxChunkSize() {
+        return null;
+    }
+
     @Override
     public String getWriteableName() {
         return NAME;
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/RecursiveChunker.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/RecursiveChunker.java
@@ -41,7 +41,7 @@ public List<ChunkOffset> chunk(String input, ChunkingSettings chunkingSettings)
                 input,
                 new ChunkOffset(0, input.length()),
                 recursiveChunkingSettings.getSeparators(),
-                recursiveChunkingSettings.getMaxChunkSize(),
+                recursiveChunkingSettings.maxChunkSize(),
                 0
             );
         } else {
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/RecursiveChunkingSettings.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/RecursiveChunkingSettings.java
@@ -31,7 +31,6 @@ public class RecursiveChunkingSettings implements ChunkingSettings {
     public static final String NAME = "RecursiveChunkingSettings";
     private static final ChunkingStrategy STRATEGY = ChunkingStrategy.RECURSIVE;
     private static final int MAX_CHUNK_SIZE_LOWER_LIMIT = 10;
-    private static final int MAX_CHUNK_SIZE_UPPER_LIMIT = 300;
 
     private static final Set<String> VALID_KEYS = Set.of(
         ChunkingSettingsOptions.STRATEGY.toString(),
@@ -63,11 +62,10 @@ public static RecursiveChunkingSettings fromMap(Map<String, Object> map) {
             );
         }
 
-        Integer maxChunkSize = ServiceUtils.extractRequiredPositiveIntegerBetween(
+        Integer maxChunkSize = ServiceUtils.extractRequiredPositiveIntegerGreaterThanOrEqualToMin(
             map,
             ChunkingSettingsOptions.MAX_CHUNK_SIZE.toString(),
             MAX_CHUNK_SIZE_LOWER_LIMIT,
-            MAX_CHUNK_SIZE_UPPER_LIMIT,
             ModelConfigurations.CHUNKING_SETTINGS,
             validationException
         );
@@ -105,7 +103,8 @@ public static RecursiveChunkingSettings fromMap(Map<String, Object> map) {
         return new RecursiveChunkingSettings(maxChunkSize, separators);
     }
 
-    public int getMaxChunkSize() {
+    @Override
+    public Integer maxChunkSize() {
         return maxChunkSize;
     }
 
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/SentenceBoundaryChunkingSettings.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/SentenceBoundaryChunkingSettings.java
@@ -31,7 +31,6 @@ public class SentenceBoundaryChunkingSettings implements ChunkingSettings {
     public static final String NAME = "SentenceBoundaryChunkingSettings";
     private static final ChunkingStrategy STRATEGY = ChunkingStrategy.SENTENCE;
     private static final int MAX_CHUNK_SIZE_LOWER_LIMIT = 20;
-    private static final int MAX_CHUNK_SIZE_UPPER_LIMIT = 300;
     private static final Set<String> VALID_KEYS = Set.of(
         ChunkingSettingsOptions.STRATEGY.toString(),
         ChunkingSettingsOptions.MAX_CHUNK_SIZE.toString(),
@@ -55,6 +54,11 @@ public SentenceBoundaryChunkingSettings(StreamInput in) throws IOException {
         }
     }
 
+    @Override
+    public Integer maxChunkSize() {
+        return maxChunkSize;
+    }
+
     @Override
     public Map<String, Object> asMap() {
         return Map.of(
@@ -77,11 +81,10 @@ public static SentenceBoundaryChunkingSettings fromMap(Map<String, Object> map)
             );
         }
 
-        Integer maxChunkSize = ServiceUtils.extractRequiredPositiveIntegerBetween(
+        Integer maxChunkSize = ServiceUtils.extractRequiredPositiveIntegerGreaterThanOrEqualToMin(
             map,
             ChunkingSettingsOptions.MAX_CHUNK_SIZE.toString(),
             MAX_CHUNK_SIZE_LOWER_LIMIT,
-            MAX_CHUNK_SIZE_UPPER_LIMIT,
             ModelConfigurations.CHUNKING_SETTINGS,
             validationException
         );
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/WordBoundaryChunkingSettings.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/chunking/WordBoundaryChunkingSettings.java
@@ -30,7 +30,6 @@ public class WordBoundaryChunkingSettings implements ChunkingSettings {
     public static final String NAME = "WordBoundaryChunkingSettings";
     private static final ChunkingStrategy STRATEGY = ChunkingStrategy.WORD;
     private static final int MAX_CHUNK_SIZE_LOWER_LIMIT = 10;
-    private static final int MAX_CHUNK_SIZE_UPPER_LIMIT = 300;
     private static final Set<String> VALID_KEYS = Set.of(
         ChunkingSettingsOptions.STRATEGY.toString(),
         ChunkingSettingsOptions.MAX_CHUNK_SIZE.toString(),
@@ -61,7 +60,8 @@ public Map<String, Object> asMap() {
         );
     }
 
-    public int maxChunkSize() {
+    @Override
+    public Integer maxChunkSize() {
         return maxChunkSize;
     }
 
@@ -79,11 +79,10 @@ public static WordBoundaryChunkingSettings fromMap(Map<String, Object> map) {
             );
         }
 
-        Integer maxChunkSize = ServiceUtils.extractRequiredPositiveIntegerBetween(
+        Integer maxChunkSize = ServiceUtils.extractRequiredPositiveIntegerGreaterThanOrEqualToMin(
             map,
             ChunkingSettingsOptions.MAX_CHUNK_SIZE.toString(),
             MAX_CHUNK_SIZE_LOWER_LIMIT,
-            MAX_CHUNK_SIZE_UPPER_LIMIT,
             ModelConfigurations.CHUNKING_SETTINGS,
             validationException
         );
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/ServiceUtils.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/ServiceUtils.java
@@ -749,6 +749,25 @@ public static Integer extractRequiredPositiveIntegerLessThanOrEqualToMax(
         return field;
     }
 
+    public static Integer extractRequiredPositiveIntegerGreaterThanOrEqualToMin(
+        Map<String, Object> map,
+        String settingName,
+        int minValue,
+        String scope,
+        ValidationException validationException
+    ) {
+        Integer field = extractRequiredPositiveInteger(map, settingName, scope, validationException);
+
+        if (field != null && field < minValue) {
+            validationException.addValidationError(
+                ServiceUtils.mustBeGreaterThanOrEqualNumberErrorMessage(settingName, scope, field, minValue)
+            );
+            return null;
+        }
+
+        return field;
+    }
+
     public static Integer extractRequiredPositiveIntegerBetween(
         Map<String, Object> map,
         String settingName,
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElserInternalModel.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElserInternalModel.java
@@ -12,6 +12,9 @@
 
 public class ElserInternalModel extends ElasticsearchInternalModel {
 
+    // Ensure that inference endpoints based on ELSER don't go past its truncation window of 512 tokens
+    public static final int ELSER_MAX_WINDOW_SIZE = 300;
+
     public ElserInternalModel(
         String inferenceEntityId,
         TaskType taskType,
@@ -21,6 +24,14 @@ public ElserInternalModel(
         ChunkingSettings chunkingSettings
     ) {
         super(inferenceEntityId, taskType, service, serviceSettings, taskSettings, chunkingSettings);
+        if (chunkingSettings != null && chunkingSettings.maxChunkSize() != null) {
+            if (chunkingSettings.maxChunkSize() > ELSER_MAX_WINDOW_SIZE) throw new IllegalArgumentException(
+                "ELSER based models do not support chunk sizes larger than "
+                    + ELSER_MAX_WINDOW_SIZE
+                    + ". Requested chunk size: "
+                    + chunkingSettings.maxChunkSize()
+            );
+        }
     }
 
     @Override
diff --git a/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/MultilingualE5SmallModel.java b/x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/MultilingualE5SmallModel.java
@@ -12,6 +12,9 @@
 
 public class MultilingualE5SmallModel extends ElasticsearchInternalModel {
 
+    // Ensure that inference endpoints based on E5 small don't go past its window size
+    public static final int E5_SMALL_MAX_WINDOW_SIZE = 300;
+
     public MultilingualE5SmallModel(
         String inferenceEntityId,
         TaskType taskType,
@@ -20,6 +23,15 @@ public MultilingualE5SmallModel(
         ChunkingSettings chunkingSettings
     ) {
         super(inferenceEntityId, taskType, service, serviceSettings, chunkingSettings);
+        if (chunkingSettings != null && chunkingSettings.maxChunkSize() != null) {
+            if (chunkingSettings.maxChunkSize() > E5_SMALL_MAX_WINDOW_SIZE) throw new IllegalArgumentException(
+                serviceSettings.modelId()
+                    + " does not support chunk sizes larger than "
+                    + E5_SMALL_MAX_WINDOW_SIZE
+                    + ". Requested chunk size: "
+                    + chunkingSettings.maxChunkSize()
+            );
+        }
     }
 
     @Override
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/chunking/RecursiveChunkingSettingsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/chunking/RecursiveChunkingSettingsTests.java
@@ -28,7 +28,7 @@ public void testFromMapValidSettingsWithSeparators() {
 
         RecursiveChunkingSettings settings = RecursiveChunkingSettings.fromMap(validSettings);
 
-        assertEquals(maxChunkSize, settings.getMaxChunkSize());
+        assertEquals(maxChunkSize, (int) settings.maxChunkSize());
         assertEquals(separators, settings.getSeparators());
     }
 
@@ -39,7 +39,7 @@ public void testFromMapValidSettingsWithSeparatorGroup() {
 
         RecursiveChunkingSettings settings = RecursiveChunkingSettings.fromMap(validSettings);
 
-        assertEquals(maxChunkSize, settings.getMaxChunkSize());
+        assertEquals(maxChunkSize, (int) settings.maxChunkSize());
         assertEquals(separatorGroup.getSeparators(), settings.getSeparators());
     }
 
@@ -49,12 +49,6 @@ public void testFromMapMaxChunkSizeTooSmall() {
         assertThrows(ValidationException.class, () -> RecursiveChunkingSettings.fromMap(invalidSettings));
     }
 
-    public void testFromMapMaxChunkSizeTooLarge() {
-        Map<String, Object> invalidSettings = buildChunkingSettingsMap(randomIntBetween(301, 500), Optional.empty(), Optional.empty());
-
-        assertThrows(ValidationException.class, () -> RecursiveChunkingSettings.fromMap(invalidSettings));
-    }
-
     public void testFromMapInvalidSeparatorGroup() {
         Map<String, Object> invalidSettings = buildChunkingSettingsMap(randomIntBetween(10, 300), Optional.of("invalid"), Optional.empty());
 
@@ -116,7 +110,7 @@ protected RecursiveChunkingSettings createTestInstance() {
 
     @Override
     protected RecursiveChunkingSettings mutateInstance(RecursiveChunkingSettings instance) throws IOException {
-        int maxChunkSize = randomValueOtherThan(instance.getMaxChunkSize(), () -> randomIntBetween(10, 300));
+        int maxChunkSize = randomValueOtherThan(instance.maxChunkSize(), () -> randomIntBetween(10, 300));
         List<String> separators = instance.getSeparators();
         separators.add(randomAlphaOfLength(1));
         return new RecursiveChunkingSettings(maxChunkSize, separators);
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/ServiceUtilsTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/ServiceUtilsTests.java
@@ -40,6 +40,7 @@
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractOptionalTimeValue;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractRequiredMap;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractRequiredPositiveInteger;
+import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractRequiredPositiveIntegerGreaterThanOrEqualToMin;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractRequiredPositiveIntegerLessThanOrEqualToMax;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractRequiredSecureString;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.extractRequiredString;
@@ -656,6 +657,69 @@ public void testExtractRequiredPositiveIntegerLessThanOrEqualToMax_AddsErrorWhen
         assertThat(validation.validationErrors().get(1), is("[scope] does not contain the required setting [not_key]"));
     }
 
+    public void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_ReturnsValueWhenValueIsEqualToMin() {
+        testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_Successful(5, 5);
+    }
+
+    public void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_ReturnsValueWhenValueIsGreaterThanToMin() {
+        testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_Successful(5, 6);
+    }
+
+    private void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_Successful(int minValue, int actualValue) {
+        var validation = new ValidationException();
+        validation.addValidationError("previous error");
+        Map<String, Object> map = modifiableMap(Map.of("key", actualValue));
+        var parsedInt = extractRequiredPositiveIntegerGreaterThanOrEqualToMin(map, "key", minValue, "scope", validation);
+
+        assertThat(validation.validationErrors(), hasSize(1));
+        assertNotNull(parsedInt);
+        assertThat(parsedInt, is(actualValue));
+        assertTrue(map.isEmpty());
+    }
+
+    public void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsErrorWhenValueIsLessThanMin() {
+        testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsError(
+            "key",
+            5,
+            4,
+            "[scope] Invalid value [4.0]. [key] must be a greater than or equal to [5.0]"
+        );
+    }
+
+    public void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsErrorWhenKeyIsMissing() {
+        testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsError(
+            "not_key",
+            5,
+            -1,
+            "[scope] does not contain the required setting [not_key]"
+        );
+    }
+
+    public void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsErrorOnNegativeValue() {
+        testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsError(
+            "key",
+            5,
+            -1,
+            "[scope] Invalid value [-1]. [key] must be a positive integer"
+        );
+    }
+
+    private void testExtractRequiredPositiveIntegerGreaterThanOrEqualToMin_AddsError(
+        String key,
+        int minValue,
+        int actualValue,
+        String error
+    ) {
+        var validation = new ValidationException();
+        validation.addValidationError("previous error");
+        Map<String, Object> map = modifiableMap(Map.of("key", actualValue));
+        var parsedInt = extractRequiredPositiveIntegerGreaterThanOrEqualToMin(map, key, minValue, "scope", validation);
+
+        assertThat(validation.validationErrors(), hasSize(2));
+        assertNull(parsedInt);
+        assertThat(validation.validationErrors().get(1), containsString(error));
+    }
+
     public void testExtractRequiredPositiveIntegerBetween_ReturnsValueWhenValueIsBetweenMinAndMax() {
         var minValue = randomNonNegativeInt();
         var maxValue = randomIntBetween(minValue + 2, minValue + 10);
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElserInternalModelTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElserInternalModelTests.java
@@ -14,6 +14,7 @@
 import org.elasticsearch.xpack.core.ml.inference.assignment.AssignmentStats;
 import org.elasticsearch.xpack.core.ml.inference.assignment.TrainedModelAssignment;
 import org.elasticsearch.xpack.core.ml.inference.assignment.TrainedModelAssignmentTests;
+import org.elasticsearch.xpack.inference.chunking.SentenceBoundaryChunkingSettings;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.mockito.Mockito.mock;
@@ -48,4 +49,23 @@ public void testUpdateNumAllocation() {
             equalTo(trainedModelAssignment.getAdaptiveAllocationsSettings())
         );
     }
+
+    public void testHugeChunkingSettings() {
+        Exception expectedException = expectThrows(
+            IllegalArgumentException.class,
+            () -> new ElserInternalModel(
+                "foo",
+                TaskType.SPARSE_EMBEDDING,
+                ElasticsearchInternalService.NAME,
+                new ElserInternalServiceSettings(new ElasticsearchInternalServiceSettings(null, 1, "elser", null, null)),
+                new ElserMlNodeTaskSettings(),
+                new SentenceBoundaryChunkingSettings(10000, 0)
+            )
+        );
+
+        assertThat(
+            expectedException.getMessage(),
+            equalTo("ELSER based models do not support chunk sizes larger than 300. Requested chunk size: 10000")
+        );
+    }
 }
diff --git a/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/elasticsearch/MultilingualE5SmallModelTests.java b/x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/services/elasticsearch/MultilingualE5SmallModelTests.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.inference.services.elasticsearch;
+
+import org.elasticsearch.inference.TaskType;
+import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.xpack.inference.chunking.SentenceBoundaryChunkingSettings;
+
+import static org.hamcrest.Matchers.containsString;
+
+public class MultilingualE5SmallModelTests extends ESTestCase {
+
+    public void testHugeChunkingSettings() {
+        Exception expectedException = expectThrows(
+            IllegalArgumentException.class,
+            () -> new MultilingualE5SmallModel(
+                "foo",
+                TaskType.TEXT_EMBEDDING,
+                ElasticsearchInternalService.NAME,
+                MultilingualE5SmallInternalServiceSettings.defaultEndpointSettings(randomBoolean()),
+                new SentenceBoundaryChunkingSettings(10000, 0)
+            )
+        );
+
+        assertThat(
+            expectedException.getMessage(),
+            containsString("does not support chunk sizes larger than 300. Requested chunk size: 10000")
+        );
+    }
+}

Original file line number	Diff line number	Diff line change
`@@ -41,7 +41,7 @@ public List<ChunkOffset> chunk(String input, ChunkingSettings chunkingSettings)`
`41`	`41`	`input,`
`42`	`42`	`new ChunkOffset(0, input.length()),`
`43`	`43`	`recursiveChunkingSettings.getSeparators(),`
`44`		`- recursiveChunkingSettings.getMaxChunkSize(),`
	`44`	`+ recursiveChunkingSettings.maxChunkSize(),`
`45`	`45`	`0`
`46`	`46`	`);`
`47`	`47`	`} else {`