Add ?wait_for_active_shards=default

Today you cannot explicitly indicate that an operation should use the
usual behaviour of waiting for active shards according to the underlying
index setting. This is a problem for the close index API which has a
default of `none` in 7.x for BWC reasons (see elastic#33888), but the usual
behaviour in 8.0: you cannot today opt-in to the 8.0 behaviour with this
parameter.

This commit adds support for the literal value `default` for the
`wait_for_active_shards` query parameter.

Relates elastic#66419

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

@@ -1008,7 +1008,7 @@ Params withWaitForActiveShards(ActiveShardCount activeShardCount) {
         }
 
         Params withWaitForActiveShards(ActiveShardCount activeShardCount, ActiveShardCount defaultActiveShardCount) {
-            if (activeShardCount != null && activeShardCount != defaultActiveShardCount) {
+            if (activeShardCount != null) {
                 return putParam("wait_for_active_shards", activeShardCount.toString().toLowerCase(Locale.ROOT));
             }
             return this;

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

@@ -60,7 +60,7 @@ public void testPutFollow() throws Exception {
         Request result = CcrRequestConverters.putFollow(putFollowRequest);
         assertThat(result.getMethod(), equalTo(HttpPut.METHOD_NAME));
         assertThat(result.getEndpoint(), equalTo("/" + putFollowRequest.getFollowerIndex() + "/_ccr/follow"));
-        if (putFollowRequest.waitForActiveShards() != null && putFollowRequest.waitForActiveShards() != ActiveShardCount.DEFAULT) {
+        if (putFollowRequest.waitForActiveShards() != null) {
             String expectedValue = putFollowRequest.waitForActiveShards().toString().toLowerCase(Locale.ROOT);
             assertThat(result.getParameters().get("wait_for_active_shards"), equalTo(expectedValue));
         } else {

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

@@ -24,7 +24,6 @@
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterGetSettingsRequest;
 import org.elasticsearch.action.admin.cluster.settings.ClusterUpdateSettingsRequest;
-import org.elasticsearch.action.support.ActiveShardCount;
 import org.elasticsearch.action.support.master.AcknowledgedRequest;
 import org.elasticsearch.client.cluster.RemoteInfoRequest;
 import org.elasticsearch.cluster.health.ClusterHealthStatus;
@@ -104,7 +103,7 @@ public void testClusterHealth() {
             default:
                 throw new UnsupportedOperationException();
         }
-        RequestConvertersTests.setRandomWaitForActiveShards(healthRequest::waitForActiveShards, ActiveShardCount.NONE, expectedParams);
+        RequestConvertersTests.setRandomWaitForActiveShards(healthRequest::waitForActiveShards, expectedParams);
         if (ESTestCase.randomBoolean()) {
             ClusterHealthRequest.Level level = ESTestCase.randomFrom(ClusterHealthRequest.Level.values());
             healthRequest.level(level);

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

@@ -449,7 +449,7 @@ public void testReindex() throws IOException {
             expectedParams.put("slices", "1");
         }
         setRandomTimeout(reindexRequest::setTimeout, ReplicationRequest.DEFAULT_TIMEOUT, expectedParams);
-        setRandomWaitForActiveShards(reindexRequest::setWaitForActiveShards, ActiveShardCount.DEFAULT, expectedParams);
+        setRandomWaitForActiveShards(reindexRequest::setWaitForActiveShards, expectedParams);
         expectedParams.put("scroll", reindexRequest.getScrollTime().getStringRep());
         expectedParams.put("wait_for_completion", Boolean.TRUE.toString());
         Request request = RequestConverters.reindex(reindexRequest);
@@ -2053,24 +2053,19 @@ static void setRandomMasterTimeout(Consumer<TimeValue> setter, TimeValue default
     }
 
     static void setRandomWaitForActiveShards(Consumer<ActiveShardCount> setter, Map<String, String> expectedParams) {
-        setRandomWaitForActiveShards(setter, ActiveShardCount.DEFAULT, expectedParams);
-    }
-
-    static void setRandomWaitForActiveShards(Consumer<ActiveShardCount> setter, ActiveShardCount defaultActiveShardCount,
-                                             Map<String, String> expectedParams) {
         if (randomBoolean()) {
-            int waitForActiveShardsInt = randomIntBetween(-1, 5);
+            int waitForActiveShardsInt = randomIntBetween(-2, 5);
             String waitForActiveShardsString;
             if (waitForActiveShardsInt == -1) {
                 waitForActiveShardsString = "all";
+            } else if (waitForActiveShardsInt == -2) {
+                waitForActiveShardsString = "default";
             } else {
                 waitForActiveShardsString = String.valueOf(waitForActiveShardsInt);
             }
             ActiveShardCount activeShardCount = ActiveShardCount.parseString(waitForActiveShardsString);
             setter.accept(activeShardCount);
-            if (defaultActiveShardCount.equals(activeShardCount) == false) {
-                expectedParams.put("wait_for_active_shards", waitForActiveShardsString);
-            }
+            expectedParams.put("wait_for_active_shards", waitForActiveShardsString);
         }
     }
 

docs/reference/docs/index_.asciidoc

@@ -353,10 +353,10 @@ This default can be overridden in the index settings dynamically
 by setting `index.write.wait_for_active_shards`. To alter this behavior
 per operation, the `wait_for_active_shards` request parameter can be used.
 
-Valid values are `all` or any positive integer up to the total number
-of configured copies per shard in the index (which is `number_of_replicas+1`).
-Specifying a negative value or a number greater than the number of
-shard copies will throw an error.
+Valid values are `all`, `default`, and any positive integer up to the total
+number of configured copies per shard in the index (which is
+`number_of_replicas+1`). Specifying a negative value or a number greater than
+the number of shard copies will throw an error.
 
 For example, suppose we have a cluster of three nodes, `A`, `B`, and `C` and
 we create an index `index` with the number of replicas set to 3 (resulting in

docs/reference/rest-api/common-parms.asciidoc

@@ -1073,9 +1073,10 @@ tag::wait_for_active_shards[]
 +
 --
 (Optional, string) The number of shard copies that must be active before
-proceeding with the operation. Set to `all` or any positive integer up
-to the total number of shards in the index (`number_of_replicas+1`).
-Default: 1, the primary shard.
+proceeding with the operation. Set to `all` to wait for all shard copies to be
+active, or `default` to use the value from the
+`index.write.wait_for_active_shards` setting from the underlying index, or an
+integer between `1` and `number_of_replicas+1`. Defaults to `default`.
 
 See <<index-wait-for-active-shards>>.
 --

rest-api-spec/src/main/resources/rest-api-spec/api/bulk.json

@@ -54,7 +54,7 @@
     "params":{
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the bulk operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the bulk operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "refresh":{
         "type":"enum",

rest-api-spec/src/main/resources/rest-api-spec/api/create.json

@@ -60,7 +60,7 @@
     "params":{
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the index operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the index operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "refresh":{
         "type":"enum",

rest-api-spec/src/main/resources/rest-api-spec/api/delete.json

@@ -57,7 +57,7 @@
     "params":{
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the delete operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the delete operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "refresh":{
         "type":"enum",

rest-api-spec/src/main/resources/rest-api-spec/api/delete_by_query.json

@@ -160,7 +160,7 @@
       },
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the delete by query operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the delete by query operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "scroll_size":{
         "type":"number",

rest-api-spec/src/main/resources/rest-api-spec/api/index.json

@@ -46,7 +46,7 @@
     "params":{
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the index operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before returning. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "op_type":{
         "type":"enum",

rest-api-spec/src/main/resources/rest-api-spec/api/reindex.json

@@ -32,7 +32,7 @@
       },
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the reindex operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the reindex operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "wait_for_completion":{
         "type":"boolean",

rest-api-spec/src/main/resources/rest-api-spec/api/update.json

@@ -58,7 +58,7 @@
     "params":{
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the update operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the update operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "_source":{
         "type":"list",

rest-api-spec/src/main/resources/rest-api-spec/api/update_by_query.json

@@ -168,7 +168,7 @@
       },
       "wait_for_active_shards":{
         "type":"string",
-        "description":"Sets the number of shard copies that must be active before proceeding with the update by query operation. Defaults to 1, meaning the primary shard only. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)"
+        "description":"Sets the number of shard copies that must be active before proceeding with the update by query operation. Defaults to `default` meaning to use the value of the `index.write.wait_for_active_shards` setting. Set to `all` for all shard copies, otherwise set to any non-negative value less than or equal to the total number of copies for the shard (number of replicas + 1)."
       },
       "scroll_size":{
         "type":"number",

server/src/main/java/org/elasticsearch/action/support/ActiveShardCount.java

@@ -106,7 +106,7 @@ public static ActiveShardCount readFrom(final StreamInput in) throws IOException
      * IllegalArgumentException.
      */
     public static ActiveShardCount parseString(final String str) {
-        if (str == null) {
+        if (str == null || str.equals("default")) {
             return ActiveShardCount.DEFAULT;
         } else if (str.equals("all")) {
             return ActiveShardCount.ALL;

server/src/test/java/org/elasticsearch/action/support/ActiveShardCountTests.java

@@ -60,6 +60,7 @@ public void testSerialization() throws IOException {
     public void testParseString() {
         assertSame(ActiveShardCount.parseString("all"), ActiveShardCount.ALL);
         assertSame(ActiveShardCount.parseString(null), ActiveShardCount.DEFAULT);
+        assertSame(ActiveShardCount.parseString("default"), ActiveShardCount.DEFAULT);
         assertSame(ActiveShardCount.parseString("0"), ActiveShardCount.NONE);
         int value = randomIntBetween(1, 50);
         assertEquals(ActiveShardCount.parseString(value + ""), ActiveShardCount.from(value));

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ccr/action/PutFollowAction.java

@@ -130,8 +130,7 @@ public ActiveShardCount waitForActiveShards() {
         /**
          * Sets the number of shard copies that should be active for follower index creation to
          * return. Defaults to {@link ActiveShardCount#NONE}, which will not wait for any shards
-         * to be active. Set this value to {@link ActiveShardCount#DEFAULT} to wait for the primary
-         * shard to be active. Set this value to {@link ActiveShardCount#ALL} to  wait for all shards
+         * to be active. Set this value to {@link ActiveShardCount#ALL} to  wait for all shards
          * (primary and all replicas) to be active before returning.
          *
          * @param waitForActiveShards number of active shard copies to wait on