Adding support for ignore_unavailable in search request

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Tiered Caching] Make took time caching policy setting dynamic ([#13063](https://github.com/opensearch-project/OpenSearch/pull/13063))
 - Derived fields support to derive field values at query time without indexing ([#12569](https://github.com/opensearch-project/OpenSearch/pull/12569))
 - Detect breaking changes on pull requests ([#9044](https://github.com/opensearch-project/OpenSearch/pull/9044))
+- Adding support for ignore_unavailable in search request ([#13209](https://github.com/opensearch-project/OpenSearch/pull/13209))
 - Add cluster primary balance contraint for rebalancing with buffer ([#12656](https://github.com/opensearch-project/OpenSearch/pull/12656))
 - [Remote Store] Make translog transfer timeout configurable ([#12704](https://github.com/opensearch-project/OpenSearch/pull/12704))
 - Reject Resize index requests (i.e, split, shrink and clone), While DocRep to SegRep migration is in progress.([#12686](https://github.com/opensearch-project/OpenSearch/pull/12686))

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

@@ -470,6 +470,9 @@ static void addSearchRequestParams(Params params, SearchRequest searchRequest) {
         if (searchRequest.allowPartialSearchResults() != null) {
             params.withAllowPartialResults(searchRequest.allowPartialSearchResults());
         }
+        if (searchRequest.ignoreUnavailable() != null) {
+            params.withIgnoreUnavailable(searchRequest.ignoreUnavailable());
+        }
         params.withBatchedReduceSize(searchRequest.getBatchedReduceSize());
         if (searchRequest.scroll() != null) {
             params.putParam("scroll", searchRequest.scroll().keepAlive());

server/src/main/java/org/opensearch/action/search/AbstractSearchAsyncAction.java

@@ -425,8 +425,10 @@ public final void executeNextPhase(SearchPhase currentPhase, SearchPhase nextPha
                             currentPhase.getName()
                         );
                     }
-                    onPhaseFailure(currentPhase, "Partial shards failure (" + discrepancy + " shards unavailable)", null);
-                    return;
+                    if (!request.ignoreUnavailable()) {
+                        onPhaseFailure(currentPhase, "Partial shards failure (" + discrepancy + " shards unavailable)", null);
+                        return;
+                    }
                 }
             }
             if (logger.isTraceEnabled()) {

server/src/main/java/org/opensearch/action/search/SearchRequest.java

@@ -102,6 +102,8 @@ public class SearchRequest extends ActionRequest implements IndicesRequest.Repla
 
     private Boolean allowPartialSearchResults;
 
+    private Boolean ignoreUnavailable;
+
     private Scroll scroll;
 
     private int batchedReduceSize = DEFAULT_BATCHED_REDUCE_SIZE;
@@ -198,6 +200,7 @@ private SearchRequest(
         boolean finalReduce
     ) {
         this.allowPartialSearchResults = searchRequest.allowPartialSearchResults;
+        this.ignoreUnavailable = searchRequest.ignoreUnavailable;
         this.batchedReduceSize = searchRequest.batchedReduceSize;
         this.ccsMinimizeRoundtrips = searchRequest.ccsMinimizeRoundtrips;
         this.indices = indices;
@@ -246,6 +249,9 @@ public SearchRequest(StreamInput in) throws IOException {
         maxConcurrentShardRequests = in.readVInt();
         preFilterShardSize = in.readOptionalVInt();
         allowPartialSearchResults = in.readOptionalBoolean();
+        if (in.getVersion().onOrAfter(Version.V_2_14_0)) {
+            ignoreUnavailable = in.readOptionalBoolean();
+        }
         localClusterAlias = in.readOptionalString();
         if (localClusterAlias != null) {
             absoluteStartMillis = in.readVLong();
@@ -283,6 +289,9 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeVInt(maxConcurrentShardRequests);
         out.writeOptionalVInt(preFilterShardSize);
         out.writeOptionalBoolean(allowPartialSearchResults);
+        if (out.getVersion().onOrAfter(Version.V_2_14_0)) {
+            out.writeOptionalBoolean(ignoreUnavailable);
+        }
         out.writeOptionalString(localClusterAlias);
         if (localClusterAlias != null) {
             out.writeVLong(absoluteStartMillis);
@@ -567,6 +576,20 @@ public Boolean allowPartialSearchResults() {
         return this.allowPartialSearchResults;
     }
 
+    /**
+     * Sets if this request should ignore unavailable shards. This option is superseded
+     * by allowPartialSearchResults (ignores any type of shard failures) instead of just
+     * unavailable shards. (If method is not called, will default to the cluster level setting).
+     */
+    public SearchRequest ignoreUnavailable(boolean ignoreUnavailable) {
+        this.ignoreUnavailable = ignoreUnavailable;
+        return this;
+    }
+
+    public Boolean ignoreUnavailable() {
+        return this.ignoreUnavailable;
+    }
+
     /**
      * Sets the number of shard results that should be reduced at once on the coordinating node. This value should be used as a protection
      * mechanism to reduce the memory overhead per search request if the potential number of shards in the request can be large.
@@ -747,6 +770,7 @@ public boolean equals(Object o) {
             && Objects.equals(preFilterShardSize, that.preFilterShardSize)
             && Objects.equals(indicesOptions, that.indicesOptions)
             && Objects.equals(allowPartialSearchResults, that.allowPartialSearchResults)
+            && Objects.equals(ignoreUnavailable, that.ignoreUnavailable)
             && Objects.equals(localClusterAlias, that.localClusterAlias)
             && absoluteStartMillis == that.absoluteStartMillis
             && ccsMinimizeRoundtrips == that.ccsMinimizeRoundtrips
@@ -770,6 +794,7 @@ public int hashCode() {
             maxConcurrentShardRequests,
             preFilterShardSize,
             allowPartialSearchResults,
+            ignoreUnavailable,
             localClusterAlias,
             absoluteStartMillis,
             ccsMinimizeRoundtrips,
@@ -805,6 +830,8 @@ public String toString() {
             + preFilterShardSize
             + ", allowPartialSearchResults="
             + allowPartialSearchResults
+            + ", ignoreUnavailable="
+            + ignoreUnavailable
             + ", localClusterAlias="
             + localClusterAlias
             + ", getOrCreateAbsoluteStartMillis="

server/src/main/java/org/opensearch/action/search/SearchRequestBuilder.java

@@ -571,6 +571,15 @@ public SearchRequestBuilder setAllowPartialSearchResults(boolean allowPartialSea
         return this;
     }
 
+    /**
+     * Sets if this request should ignore unavailable shards.  (If method is not called,
+     * will default to the cluster level setting).
+     */
+    public SearchRequestBuilder setIgnoreUnavailable(boolean ignoreUnavailable) {
+        request.ignoreUnavailable(ignoreUnavailable);
+        return this;
+    }
+
     /**
      * Should the query be profiled. Defaults to <code>false</code>
      */

server/src/main/java/org/opensearch/rest/action/search/RestSearchAction.java

@@ -183,6 +183,11 @@ public static void parseSearchRequest(
             searchRequest.allowPartialSearchResults(request.paramAsBoolean("allow_partial_search_results", null));
         }
 
+        if (request.hasParam("ignore_unavailable")) {
+            // only set if we have the parameter passed to override the cluster-level default
+            searchRequest.ignoreUnavailable(request.paramAsBoolean("ignore_unavailable", null));
+        }
+
         if (request.hasParam("phase_took")) {
             // only set if we have the parameter passed to override the cluster-level default
             // else phaseTook = null

test/framework/src/main/java/org/opensearch/search/RandomSearchRequestGenerator.java

@@ -101,6 +101,7 @@ private RandomSearchRequestGenerator() {}
     public static SearchRequest randomSearchRequest(Supplier<SearchSourceBuilder> randomSearchSourceBuilder) {
         SearchRequest searchRequest = new SearchRequest();
         searchRequest.allowPartialSearchResults(true);
+        searchRequest.ignoreUnavailable(randomBoolean());
         if (randomBoolean()) {
             searchRequest.setCcsMinimizeRoundtrips(randomBoolean());
         }