Support max_single_primary_size in Resize Action and exposed in ILM

client/rest-high-level/src/main/java/org/elasticsearch/client/ilm/ShrinkAction.java

@@ -18,9 +18,12 @@
  */
 package org.elasticsearch.client.ilm;
 
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.ToXContentObject;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -31,31 +34,53 @@
 public class ShrinkAction implements LifecycleAction, ToXContentObject {
     public static final String NAME = "shrink";
     private static final ParseField NUMBER_OF_SHARDS_FIELD = new ParseField("number_of_shards");
+    private static final ParseField MAX_SINGLE_PRIMARY_SIZE = new ParseField("max_single_primary_size");
 
     private static final ConstructingObjectParser<ShrinkAction, Void> PARSER =
-        new ConstructingObjectParser<>(NAME, true, a -> new ShrinkAction((Integer) a[0]));
+        new ConstructingObjectParser<>(NAME, true, a -> new ShrinkAction((Integer) a[0], (ByteSizeValue) a[1]));
 
     static {
-        PARSER.declareInt(ConstructingObjectParser.constructorArg(), NUMBER_OF_SHARDS_FIELD);
+        PARSER.declareInt(ConstructingObjectParser.optionalConstructorArg(), NUMBER_OF_SHARDS_FIELD);
+        PARSER.declareField(ConstructingObjectParser.optionalConstructorArg(),
+            (p, c) -> ByteSizeValue.parseBytesSizeValue(p.text(), MAX_SINGLE_PRIMARY_SIZE.getPreferredName()),
+            MAX_SINGLE_PRIMARY_SIZE, ObjectParser.ValueType.STRING);
     }
 
-    private int numberOfShards;
+    private Integer numberOfShards;
+    private ByteSizeValue maxSinglePrimarySize;
 
     public static ShrinkAction parse(XContentParser parser) throws IOException {
         return PARSER.parse(parser, null);
     }
 
-    public ShrinkAction(int numberOfShards) {
-        if (numberOfShards <= 0) {
-            throw new IllegalArgumentException("[" + NUMBER_OF_SHARDS_FIELD.getPreferredName() + "] must be greater than 0");
+    public ShrinkAction(@Nullable Integer numberOfShards, ByteSizeValue maxSinglePrimarySize) {
+        if (numberOfShards != null && maxSinglePrimarySize != null) {
+            throw new IllegalArgumentException("Cannot set both [number_of_shards] and [max_single_primary_size]");
+        }
+        if (numberOfShards == null && maxSinglePrimarySize == null) {
+            throw new IllegalArgumentException("Either [number_of_shards] or [max_single_primary_size] must be set");
+        }
+        if (maxSinglePrimarySize != null) {
+            if (maxSinglePrimarySize.getBytes() <= 0) {
+                throw new IllegalArgumentException("[max_single_primary_size] must be greater than 0");
+            }
+            this.maxSinglePrimarySize = maxSinglePrimarySize;
+        } else {
+            if (numberOfShards <= 0) {
+                throw new IllegalArgumentException("[" + NUMBER_OF_SHARDS_FIELD.getPreferredName() + "] must be greater than 0");
+            }
+            this.numberOfShards = numberOfShards;
         }
-        this.numberOfShards = numberOfShards;
     }
 
-    int getNumberOfShards() {
+    Integer getNumberOfShards() {
         return numberOfShards;
     }
 
+    ByteSizeValue getMaxSinglePrimarySize() {
+        return maxSinglePrimarySize;
+    }
+
     @Override
     public String getName() {
         return NAME;
@@ -64,7 +89,12 @@ public String getName() {
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject();
-        builder.field(NUMBER_OF_SHARDS_FIELD.getPreferredName(), numberOfShards);
+        if (numberOfShards != null) {
+            builder.field(NUMBER_OF_SHARDS_FIELD.getPreferredName(), numberOfShards);
+        }
+        if (maxSinglePrimarySize != null) {
+            builder.field(MAX_SINGLE_PRIMARY_SIZE.getPreferredName(), maxSinglePrimarySize);
+        }
         builder.endObject();
         return builder;
     }
@@ -74,12 +104,14 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         ShrinkAction that = (ShrinkAction) o;
-        return Objects.equals(numberOfShards, that.numberOfShards);
+
+        return Objects.equals(numberOfShards, that.numberOfShards) &&
+            Objects.equals(maxSinglePrimarySize, that.maxSinglePrimarySize);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(numberOfShards);
+        return Objects.hash(numberOfShards, maxSinglePrimarySize);
     }
 
     @Override

client/rest-high-level/src/main/java/org/elasticsearch/client/indices/ResizeRequest.java

@@ -24,6 +24,7 @@
 import org.elasticsearch.client.Validatable;
 import org.elasticsearch.client.ValidationException;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.ToXContentObject;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 
@@ -45,6 +46,7 @@ public class ResizeRequest extends TimedRequest implements Validatable, ToXConte
     private final String targetIndex;
     private Settings settings = Settings.EMPTY;
     private Set<Alias> aliases = new HashSet<>();
+    private ByteSizeValue maxSinglePrimarySize;
 
     /**
      * Creates a new resize request
@@ -87,6 +89,20 @@ public Set<Alias> getAliases() {
         return Collections.unmodifiableSet(this.aliases);
     }
 
+    /**
+     * Sets the max single primary shard size of the target index
+     */
+    public void setMaxSinglePrimarySize(ByteSizeValue maxSinglePrimarySize) {
+        this.maxSinglePrimarySize = maxSinglePrimarySize;
+    }
+
+    /**
+     * Return the max single primary shard size of the target index
+     */
+    public ByteSizeValue getMaxSinglePrimarySize() {
+        return maxSinglePrimarySize;
+    }
+
     @Override
     public Optional<ValidationException> validate() {
         ValidationException validationException = new ValidationException();

client/rest-high-level/src/test/java/org/elasticsearch/client/IndexLifecycleIT.java

@@ -156,7 +156,7 @@ public void testExplainLifecycle() throws Exception {
         Map<String, LifecycleAction> warmActions = new HashMap<>();
         warmActions.put(UnfollowAction.NAME, new UnfollowAction());
         warmActions.put(AllocateAction.NAME, new AllocateAction(null, null, null, Collections.singletonMap("_name", "node-1")));
-        warmActions.put(ShrinkAction.NAME, new ShrinkAction(1));
+        warmActions.put(ShrinkAction.NAME, new ShrinkAction(1, null));
         warmActions.put(ForceMergeAction.NAME, new ForceMergeAction(1000));
         lifecyclePhases.put("warm", new Phase("warm", TimeValue.timeValueSeconds(1000), warmActions));
 

client/rest-high-level/src/test/java/org/elasticsearch/client/IndicesRequestConvertersTests.java

@@ -62,6 +62,7 @@
 import org.elasticsearch.common.CheckedFunction;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.util.CollectionUtils;
 import org.elasticsearch.common.xcontent.XContentType;
@@ -655,6 +656,9 @@ private void resizeTest(ResizeType resizeType, CheckedFunction<ResizeRequest, Re
         if (resizeType == ResizeType.SPLIT) {
             resizeRequest.setSettings(Settings.builder().put("index.number_of_shards", 2).build());
         }
+        if (resizeType == ResizeType.SHRINK) {
+            resizeRequest.setMaxSinglePrimarySize(new ByteSizeValue(randomIntBetween(1, 100)));
+        }
 
         Request request = function.apply(resizeRequest);
         Assert.assertEquals(HttpPut.METHOD_NAME, request.getMethod());

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/ILMDocumentationIT.java

@@ -264,7 +264,7 @@ public void testGetLifecyclePolicy() throws IOException, InterruptedException {
             PutLifecyclePolicyRequest putRequest = new PutLifecyclePolicyRequest(myPolicyAsPut);
 
             Map<String, Phase> otherPolicyPhases = new HashMap<>(phases);
-            Map<String, LifecycleAction> warmActions = Collections.singletonMap(ShrinkAction.NAME, new ShrinkAction(1));
+            Map<String, LifecycleAction> warmActions = Collections.singletonMap(ShrinkAction.NAME, new ShrinkAction(1, null));
             otherPolicyPhases.put("warm", new Phase("warm", new TimeValue(30, TimeUnit.DAYS), warmActions));
             otherPolicyAsPut = new LifecyclePolicy("other_policy", otherPolicyPhases);
 
@@ -614,7 +614,7 @@ public void testRetryPolicy() throws Exception {
         {
             Map<String, Phase> phases = new HashMap<>();
             Map<String, LifecycleAction> warmActions = new HashMap<>();
-            warmActions.put(ShrinkAction.NAME, new ShrinkAction(3));
+            warmActions.put(ShrinkAction.NAME, new ShrinkAction(3, null));
             phases.put("warm", new Phase("warm", TimeValue.ZERO, warmActions));
 
             LifecyclePolicy policy = new LifecyclePolicy("my_policy",

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/IndicesClientDocumentationIT.java

@@ -1609,11 +1609,19 @@ public void testShrinkIndex() throws Exception {
         request.setWaitForActiveShards(2); // <1>
         request.setWaitForActiveShards(ActiveShardCount.DEFAULT); // <2>
         // end::shrink-index-request-waitForActiveShards
-        // tag::shrink-index-request-settings
-        request.getTargetIndexRequest().settings(Settings.builder()
+        if (randomBoolean()) {
+            // tag::shrink-index-request-settings
+            request.getTargetIndexRequest().settings(Settings.builder()
                 .put("index.number_of_shards", 2) // <1>
                 .putNull("index.routing.allocation.require._name")); // <2>
-        // end::shrink-index-request-settings
+            // end::shrink-index-request-settings
+        } else {
+            request.getTargetIndexRequest().settings(Settings.builder()
+                .putNull("index.routing.allocation.require._name"));
+            // tag::shrink-index-request-maxSinglePrimarySize
+            request.setMaxSinglePrimarySize(new ByteSizeValue(50, ByteSizeUnit.GB)); // <1>
+            // end::shrink-index-request-maxSinglePrimarySize
+        }
         // tag::shrink-index-request-aliases
         request.getTargetIndexRequest().alias(new Alias("target_alias")); // <1>
         // end::shrink-index-request-aliases

client/rest-high-level/src/test/java/org/elasticsearch/client/ilm/ShrinkActionTests.java

@@ -18,6 +18,7 @@
  */
 package org.elasticsearch.client.ilm;
 
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.test.AbstractXContentTestCase;
 
@@ -38,7 +39,11 @@ protected ShrinkAction createTestInstance() {
     }
 
     static ShrinkAction randomInstance() {
-        return new ShrinkAction(randomIntBetween(1, 100));
+        if (randomBoolean()) {
+            return new ShrinkAction(randomIntBetween(1, 100), null);
+        } else {
+            return new ShrinkAction(null, new ByteSizeValue(randomIntBetween(1, 100)));
+        }
     }
 
     @Override
@@ -47,7 +52,17 @@ protected boolean supportsUnknownFields() {
     }
 
     public void testNonPositiveShardNumber() {
-        Exception e = expectThrows(Exception.class, () -> new ShrinkAction(randomIntBetween(-100, 0)));
+        Exception e = expectThrows(Exception.class, () -> new ShrinkAction(randomIntBetween(-100, 0), null));
         assertThat(e.getMessage(), equalTo("[number_of_shards] must be greater than 0"));
     }
+
+    public void testMaxSinglePrimarySize() {
+        ByteSizeValue maxSinglePrimarySize1 = new ByteSizeValue(10);
+        Exception e1 = expectThrows(Exception.class, () -> new ShrinkAction(randomIntBetween(1, 100), maxSinglePrimarySize1));
+        assertThat(e1.getMessage(), equalTo("Cannot set both [number_of_shards] and [max_single_primary_size]"));
+
+        ByteSizeValue maxSinglePrimarySize2 = new ByteSizeValue(0);
+        Exception e2 = expectThrows(Exception.class, () -> new org.elasticsearch.client.ilm.ShrinkAction(null, maxSinglePrimarySize2));
+        assertThat(e2.getMessage(), equalTo("[max_single_primary_size] must be greater than 0"));
+    }
 }

docs/java-rest/high-level/indices/shrink_index.asciidoc

@@ -54,6 +54,12 @@ include-tagged::{doc-tests-file}[{api}-request-settings]
 <1> The number of shards on the target of the shrink index request
 <2> Remove the allocation requirement copied from the source index
 
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-request-maxSinglePrimarySize]
+--------------------------------------------------
+<1> The max single primary shard size of the target index
+
 ["source","java",subs="attributes,callouts,macros"]
 --------------------------------------------------
 include-tagged::{doc-tests-file}[{api}-request-aliases]
@@ -75,5 +81,3 @@ include-tagged::{doc-tests-file}[{api}-response]
 <1> Indicates whether all of the nodes have acknowledged the request
 <2> Indicates whether the requisite number of shard copies were started for
 each shard in the index before timing out
-
-

docs/reference/ilm/actions/ilm-shrink.asciidoc

@@ -4,24 +4,24 @@
 
 Phases allowed: hot, warm.
 
-Sets an index to <<dynamic-index-settings, read-only>> 
-and shrinks it into a new index with fewer primary shards. 
-The name of the new index is of the form `shrink-<original-index-name>`. 
-For example, if the name of the source index is _logs_, 
+Sets an index to <<dynamic-index-settings, read-only>>
+and shrinks it into a new index with fewer primary shards.
+The name of the new index is of the form `shrink-<original-index-name>`.
+For example, if the name of the source index is _logs_,
 the name of the shrunken index is _shrink-logs_.
 
-The shrink action allocates all primary shards of the index to one node so it 
+The shrink action allocates all primary shards of the index to one node so it
 can call the <<indices-shrink-index,Shrink API>> to shrink the index.
-After shrinking, it swaps aliases that point to the original index to the new shrunken index. 
+After shrinking, it swaps aliases that point to the original index to the new shrunken index.
 
 To use the `shrink` action in the `hot` phase, the `rollover` action *must* be present.
 If no rollover action is configured, {ilm-init} will reject the policy.
 
 [IMPORTANT]
-If the shrink action is used on a <<ccr-put-follow,follower index>>, 
+If the shrink action is used on a <<ccr-put-follow,follower index>>,
 policy execution waits until the leader index rolls over (or is
-<<skipping-rollover, otherwise marked complete>>), 
-then converts the follower index into a regular index with the 
+<<skipping-rollover, otherwise marked complete>>),
+then converts the follower index into a regular index with the
 <<ilm-unfollow,unfollow>> action before performing the shrink operation.
 
 If the managed index is part of a <<data-streams, data stream>>,
@@ -40,14 +40,30 @@ managed indices.
 [[ilm-shrink-options]]
 ==== Shrink options
 `number_of_shards`::
-(Required, integer) 
-Number of shards to shrink to. 
-Must be a factor of the number of shards in the source index.
+(Optional, integer)
+Number of shards to shrink to.
+Must be a factor of the number of shards in the source index. This parameter conflicts with
+`max_single_primary_size`, only one of them may be set.
+
+`max_single_primary_size`::
+(Optional, <<byte-units, byte units>>)
+The max single primary shard size for the target index. Used to find the optimum number of shards for the target index.
+When this parameter is set, each shard's storage in the target index will not be greater than the parameter.
+The shards count of the target index will still be a factor of the source index's shards count, but if the parameter
+is less than the single shard size in the source index, the shards count for the target index will be equal to the source index's shards count.
+For example, when this parameter is set to 50gb, if the source index has 60 primary shards with totaling 100gb, then the
+target index will have 2 primary shards, with each shard size of 50gb; if the source index has 60 primary shards
+with totaling 1000gb, then the target index will have 20 primary shards; if the source index has 60 primary shards
+with totaling 4000gb, then the target index will still have 60 primary shards. This parameter conflicts
+with `number_of_shards` in the `settings`, only one of them may be set.
 
 
 [[ilm-shrink-ex]]
 ==== Example
-
+
+[[ilm-shrink-shards-ex]]
+===== Set the number of shards of the new shrunken index explicitly
+
 [source,console]
 --------------------------------------------------
 PUT _ilm/policy/my_policy
@@ -65,3 +81,25 @@ PUT _ilm/policy/my_policy
   }
 }
 --------------------------------------------------
+
+[[ilm-shrink-size-ex]]
+===== Calculate the number of shards of the new shrunken index based on the storage of the
+source index and the `max_single_primary_size` parameter
+
+[source,console]
+--------------------------------------------------
+PUT _ilm/policy/my_policy
+{
+  "policy": {
+    "phases": {
+      "warm": {
+        "actions": {
+          "shrink" : {
+            "max_single_primary_size": "50gb"
+          }
+        }
+      }
+    }
+  }
+}
+--------------------------------------------------

docs/reference/indices/shrink-index.asciidoc

@@ -56,7 +56,7 @@ PUT /my_source_index/_settings
 // TEST[s/^/PUT my_source_index\n{"settings":{"index.number_of_shards":2}}\n/]
 
 <1> Removes replica shards for the index.
-<2> Relocates the index's shards to the `shrink_node_name` node. 
+<2> Relocates the index's shards to the `shrink_node_name` node.
     See <<shard-allocation-filtering>>.
 <3> Prevents write operations to this index. Metadata changes, such as deleting
     the index, are still allowed.
@@ -230,3 +230,15 @@ include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=timeoutparms]
 include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=target-index-aliases]
 
 include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=target-index-settings]
+
+`max_single_primary_size`::
+(Optional, <<byte-units, byte units>>)
+The max single primary shard size for the target index. Used to find the optimum number of shards for the target index.
+When this parameter is set, each shard's storage in the target index will not be greater than the parameter.
+The shards count of the target index will still be a factor of the source index's shards count, but if the parameter
+is less than the single shard size in the source index, the shards count for the target index will be equal to the source index's shards count.
+For example, when this parameter is set to 50gb, if the source index has 60 primary shards with totaling 100gb, then the
+target index will have 2 primary shards, with each shard size of 50gb; if the source index has 60 primary shards
+with totaling 1000gb, then the target index will have 20 primary shards; if the source index has 60 primary shards
+with totaling 4000gb, then the target index will still have 60 primary shards. This parameter conflicts
+with `number_of_shards` in the `settings`, only one of them may be set.