diff --git a/BUILD b/BUILD
index 4750354..4070a77 100644
--- a/BUILD
+++ b/BUILD
@@ -21,10 +21,10 @@
 ELASTICSEARCH_DEPS = [
     "@docker-java-api//jar",
     "@docker-java-transport//jar",
+    "@docker-java-transport-zerodep//jar",
     "@duct-tape//jar",
     "@httpasyncclient//jar",
     "@jackson-annotations//jar",
-    "@jackson-core//jar",
     "@jna//jar",
     "@testcontainers-elasticsearch//jar",
     "@testcontainers//jar",
@@ -73,6 +73,7 @@
     tags = [
         "docker",
         "elastic",
+        "exclusive",
     ],
     deps = ELASTICSEARCH_DEPS + PLUGIN_TEST_DEPS + [
         QUERY_TESTS_DEP % name,
diff --git a/README.md b/README.md
index 6565f33..41d4279 100644
--- a/README.md
+++ b/README.md
@@ -3,9 +3,13 @@
 Indexing backend libModule for [Gerrit Code Review](https://gerritcodereview.com)
 based on [ElasticSearch](https://www.elastic.co/elasticsearch/).
 
-This module was original part of Gerrit core and then extracted into a separate
+This module was originally part of Gerrit core and then extracted into a separate
 component from v3.5.0-rc3 as part of [Change-Id: Ib7b5167ce](https://gerrit-review.googlesource.com/c/gerrit/+/323676).
 
+Note that, ElasticSearch source code is no longer Apache 2.0-licensed for versions
+7.11 and newer. See ElasticSearch [2021 license change](https://www.elastic.co/pricing/faq/licensing)
+for more information.
+
 ## How to build
 
 This libModule is built like a Gerrit in-tree plugin, using Bazelisk. See the
@@ -13,32 +17,13 @@
 
 ## Setup
 
-* Install index-elasticsearch module
+See the [setup instructions](src/main/resources/Documentation/setup.md) for how to install the
+index-elasticsearch module.
 
-Install the index-elasticsearch.jar into the `$GERRIT_SITE/lib` directory.
-
-Add the index-elasticsearch module to `$GERRIT_SITE/etc/gerrit.config` as follows:
-
-```ini
-[gerrit]
-  installIndexModule = com.google.gerrit.elasticsearch.ElasticIndexModule
-```
-
-When installing the module on Gerrit replicas, use following example:
-
-```ini
-[gerrit]
-  installIndexModule = com.google.gerrit.elasticsearch.ReplicaElasticIndexModule
-```
-
-For further information and supported options, refer to [config](src/main/resources/Documentation/config.md)
+For further information and supported options, refer to the [config](src/main/resources/Documentation/config.md)
 documentation.
 
 ## Integration test
 
-Gerrit acceptance tests allow the execution with an alternate implementation of
-the indexing backend using the `GERRIT_INDEX_MODULE` environment variable.
-
-```sh
-bazel test --test_env=GERRIT_INDEX_MODULE=com.google.gerrit.elasticsearch.ElasticIndexModule //...
-```
+This libModule runs tests like a Gerrit in-tree plugin, using Bazelisk. See the
+[test instructions](src/main/resources/Documentation/build.md#Integration-test) for more details.
diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index fc1420c..7ab2c29 100644
--- a/external_plugin_deps.bzl
+++ b/external_plugin_deps.bzl
@@ -1,30 +1,26 @@
 load("//tools/bzl:maven_jar.bzl", "maven_jar")
 
-TESTCONTAINERS_VERSION = "1.15.3"
-
-# Ensure artifacts compatibility by selecting them from the Bill Of Materials
-# https://search.maven.org/artifact/net.openhft/chronicle-bom/2.20.191/pom
 def external_plugin_deps():
     maven_jar(
+        name = "jackson-core",
+        artifact = "com.fasterxml.jackson.core:jackson-core:2.11.3",
+        sha1 = "c2351800432bdbdd8284c3f5a7f0782a352aa84a",
+    )
+
+    # Ensure artifacts compatibility by selecting them from the Bill Of Materials
+    # https://search.maven.org/artifact/org.testcontainers/testcontainers/1.17.5/pom
+    TESTCONTAINERS_VERSION = "1.17.5"
+
+    maven_jar(
         name = "testcontainers",
         artifact = "org.testcontainers:testcontainers:" + TESTCONTAINERS_VERSION,
-        sha1 = "95c6cfde71c2209f0c29cb14e432471e0b111880",
-    )
-
-    # When upgrading elasticsearch-rest-client, also upgrade httpcore-nio
-    # and httpasyncclient as necessary in tools/nongoogle.bzl. Consider
-    # also the other org.apache.httpcomponents dependencies in
-    # WORKSPACE.
-    maven_jar(
-        name = "elasticsearch-rest-client",
-        artifact = "org.elasticsearch.client:elasticsearch-rest-client:7.8.1",
-        sha1 = "59feefe006a96a39f83b0dfb6780847e06c1d0a8",
+        sha1 = "7c5ad975fb789ecd09b1ee5f72907f48a300bc61",
     )
 
     maven_jar(
         name = "testcontainers-elasticsearch",
         artifact = "org.testcontainers:elasticsearch:" + TESTCONTAINERS_VERSION,
-        sha1 = "595e3a50f59cd3c1d281ca6c1bc4037e277a1353",
+        sha1 = "060895f2fc6640ab4a6c383bc98c5c39ef644fbb",
     )
 
     maven_jar(
@@ -33,30 +29,49 @@
         sha1 = "92edc22a9ab2f3e17c9bf700aaee377d50e8b530",
     )
 
-    maven_jar(
-        name = "visible-assertions",
-        artifact = "org.rnorth.visible-assertions:visible-assertions:2.1.2",
-        sha1 = "20d31a578030ec8e941888537267d3123c2ad1c1",
-    )
-
-    maven_jar(
-        name = "jna",
-        artifact = "net.java.dev.jna:jna:5.5.0",
-        sha1 = "0e0845217c4907822403912ad6828d8e0b256208",
-    )
-
-    DOCKER_JAVA_VERS = "3.2.8"
+    DOCKER_JAVA_VERS = "3.2.13"
 
     maven_jar(
         name = "docker-java-api",
         artifact = "com.github.docker-java:docker-java-api:" + DOCKER_JAVA_VERS,
-        sha1 = "4ac22a72d546a9f3523cd4b5fabffa77c4a6ec7c",
+        sha1 = "5817ef8f770cb7e740d590090bf352df9491f3c1",
     )
 
     maven_jar(
         name = "docker-java-transport",
         artifact = "com.github.docker-java:docker-java-transport:" + DOCKER_JAVA_VERS,
-        sha1 = "c3b5598c67d0a5e2e780bf48f520da26b9915eab",
+        sha1 = "e9d308d1822181a9d48c99739f5eca014ec89199",
+    )
+
+    maven_jar(
+        name = "docker-java-transport-zerodep",
+        artifact = "com.github.docker-java:docker-java-transport-zerodep:" + DOCKER_JAVA_VERS,
+        sha1 = "4cbc2c09d6c264767a39624066987ed4a152bc68",
+    )
+
+    # Match version used in docker-java-transport
+    # https://search.maven.org/artifact/com.github.docker-java/docker-java-transport/3.2.12/pom
+    maven_jar(
+        name = "jna",
+        artifact = "net.java.dev.jna:jna:5.8.0",
+        sha1 = "3551d8d827e54858214107541d3aff9c615cb615",
+    )
+
+    # Match jackson.version from docker-java
+    # https://search.maven.org/artifact/com.github.docker-java/docker-java-parent/3.2.12/pom
+    maven_jar(
+        name = "jackson-annotations",
+        artifact = "com.fasterxml.jackson.core:jackson-annotations:2.10.3",
+        sha1 = "0f63b3b1da563767d04d2e4d3fc1ae0cdeffebe7",
+    )
+
+    # When upgrading elasticsearch-rest-client, also upgrade httpcore-nio
+    # and httpasyncclient as necessary. Consider also the other
+    # org.apache.httpcomponents dependencies in core.
+    maven_jar(
+        name = "elasticsearch-rest-client",
+        artifact = "org.elasticsearch.client:elasticsearch-rest-client:8.3.2",
+        sha1 = "bb5cb3dbd82ea75a6d49b9011ca5b1d125b30f00",
     )
 
     # elasticsearch-rest-client explicitly depends on this version
@@ -72,21 +87,3 @@
         artifact = "org.apache.httpcomponents:httpcore-nio:4.4.12",
         sha1 = "84cd29eca842f31db02987cfedea245af020198b",
     )
-
-    maven_jar(
-        name = "jackson-core",
-        artifact = "com.fasterxml.jackson.core:jackson-core:2.11.3",
-        sha1 = "c2351800432bdbdd8284c3f5a7f0782a352aa84a",
-    )
-
-    maven_jar(
-        name = "jackson-annotations",
-        artifact = "com.fasterxml.jackson.core:jackson-annotations:2.10.3",
-        sha1 = "0f63b3b1da563767d04d2e4d3fc1ae0cdeffebe7",
-    )
-
-    maven_jar(
-        name = "httpasyncclient",
-        artifact = "org.apache.httpcomponents:httpasyncclient:4.1.4",
-        sha1 = "f3a3240681faae3fa46b573a4c7e50cec9db0d86",
-    )
diff --git a/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index 90ce18b..fce86b9 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -19,6 +19,7 @@
 import static com.google.gson.FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -29,7 +30,7 @@
 import com.google.common.io.BaseEncoding;
 import com.google.common.io.CharStreams;
 import com.google.gerrit.common.Nullable;
-import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
+import com.google.gerrit.elasticsearch.ElasticMapping.Mapping;
 import com.google.gerrit.elasticsearch.builders.QueryBuilder;
 import com.google.gerrit.elasticsearch.builders.SearchSourceBuilder;
 import com.google.gerrit.elasticsearch.bulk.DeleteRequest;
@@ -42,6 +43,7 @@
 import com.google.gerrit.index.Schema;
 import com.google.gerrit.index.query.DataSource;
 import com.google.gerrit.index.query.FieldBundle;
+import com.google.gerrit.index.query.HasCardinality;
 import com.google.gerrit.index.query.ListResultSet;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
@@ -49,6 +51,7 @@
 import com.google.gerrit.proto.Protos;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.index.IndexUtils;
+import com.google.gerrit.server.index.options.AutoFlush;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonArray;
@@ -64,7 +67,6 @@
 import java.net.URLEncoder;
 import java.sql.Timestamp;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -75,6 +77,7 @@
 import org.apache.http.client.methods.HttpPost;
 import org.apache.http.entity.ContentType;
 import org.apache.http.nio.entity.NStringEntity;
+import org.apache.http.util.EntityUtils;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
 
@@ -129,6 +132,7 @@
   private final Schema<V> schema;
   private final SitePaths sitePaths;
   private final String indexNameRaw;
+  private final Map<String, String> refreshParam;
 
   protected final ElasticRestClientProvider client;
   protected final String indexName;
@@ -140,7 +144,8 @@
       SitePaths sitePaths,
       Schema<V> schema,
       ElasticRestClientProvider client,
-      String indexName) {
+      String indexName,
+      AutoFlush autoFlush) {
     this.config = config;
     this.sitePaths = sitePaths;
     this.schema = schema;
@@ -149,6 +154,10 @@
     this.indexName = config.getIndexName(indexName, schema.getVersion());
     this.indexNameRaw = indexName;
     this.client = client;
+    this.refreshParam =
+        Map.of(
+            "refresh",
+            autoFlush == AutoFlush.ENABLED ? Boolean.TRUE.toString() : Boolean.FALSE.toString());
   }
 
   @Override
@@ -174,7 +183,7 @@
   @Override
   public void delete(K id) {
     String uri = getURI(BULK);
-    Response response = postRequest(uri, getDeleteActions(id), getRefreshParam());
+    Response response = postRequestWithRefreshParam(uri, getDeleteActions(id));
     int statusCode = response.getStatusLine().getStatusCode();
     if (statusCode != HttpStatus.SC_OK) {
       throw new StorageException(
@@ -217,14 +226,14 @@
 
   protected abstract String getId(V v);
 
-  protected String getMappingsForSingleType(MappingProperties properties) {
-    return getMappingsFor(properties);
+  protected String getMappingsForSingleType(Mapping mapping) {
+    return getMappingsFor(mapping);
   }
 
-  protected String getMappingsFor(MappingProperties properties) {
+  protected String getMappingsFor(Mapping mapping) {
     JsonObject mappings = new JsonObject();
 
-    mappings.add(MAPPINGS, gson.toJsonTree(properties));
+    mappings.add(MAPPINGS, gson.toJsonTree(mapping));
     return gson.toJson(mappings);
   }
 
@@ -265,6 +274,20 @@
     return new FieldBundle(rawFields);
   }
 
+  protected boolean hasErrors(Response response) {
+    try {
+      String contentType = response.getEntity().getContentType().getValue();
+      Preconditions.checkState(
+          contentType.equals(ContentType.APPLICATION_JSON.toString()),
+          String.format("Expected %s, but was: %s", ContentType.APPLICATION_JSON, contentType));
+      String responseStr = EntityUtils.toString(response.getEntity());
+      JsonObject responseJson = (JsonObject) new JsonParser().parse(responseStr);
+      return responseJson.get("errors").getAsBoolean();
+    } catch (IOException e) {
+      throw new StorageException(e);
+    }
+  }
+
   protected String toAction(String type, String id, String action) {
     JsonObject properties = new JsonObject();
     properties.addProperty("_id", id);
@@ -282,12 +305,6 @@
     array.add(arrayElement);
   }
 
-  protected Map<String, String> getRefreshParam() {
-    Map<String, String> params = new HashMap<>();
-    params.put("refresh", "true");
-    return params;
-  }
-
   protected String getSearch(SearchSourceBuilder searchSource, JsonArray sortArray) {
     JsonObject search = new JsonParser().parse(searchSource.toString()).getAsJsonObject();
     search.add("sort", sortArray);
@@ -311,12 +328,8 @@
     }
   }
 
-  protected Response postRequest(String uri, Object payload) {
-    return performRequest("POST", uri, payload);
-  }
-
-  protected Response postRequest(String uri, Object payload, Map<String, String> params) {
-    return performRequest("POST", uri, payload, params);
+  protected Response postRequestWithRefreshParam(String uri, Object payload) {
+    return performRequest("POST", uri, payload, refreshParam);
   }
 
   private String concatJsonString(String target, String addition) {
@@ -350,23 +363,32 @@
 
   protected class ElasticQuerySource implements DataSource<V> {
     private final QueryOptions opts;
+    private final Predicate<V> predicate;
     private final String search;
 
     ElasticQuerySource(Predicate<V> p, QueryOptions opts, JsonArray sortArray)
         throws QueryParseException {
       this.opts = opts;
+      this.predicate = p;
       QueryBuilder qb = queryBuilder.toQueryBuilder(p);
       SearchSourceBuilder searchSource =
           new SearchSourceBuilder(client.adapter())
               .query(qb)
-              .from(opts.start())
-              .size(opts.limit())
-              .fields(Lists.newArrayList(opts.fields()));
+              .size(opts.pageSize())
+              .fields(Lists.newArrayList(opts.fields()))
+              .trackTotalHits(false);
+      searchSource =
+          opts.searchAfter() != null
+              ? searchSource.searchAfter((JsonArray) opts.searchAfter())
+              : searchSource.from(opts.start());
       search = getSearch(searchSource, sortArray);
     }
 
     @Override
     public int getCardinality() {
+      if (predicate instanceof HasCardinality) {
+        return ((HasCardinality) predicate).getCardinality();
+      }
       return 10;
     }
 
@@ -383,6 +405,7 @@
     private <T> ResultSet<T> readImpl(Function<JsonObject, T> mapper) {
       try {
         String uri = getURI(SEARCH);
+        JsonArray searchAfter = null;
         Response response =
             performRequest(HttpPost.METHOD_NAME, uri, search, Collections.emptyMap());
         StatusLine statusLine = response.getStatusLine();
@@ -393,16 +416,27 @@
           if (obj.get("hits") != null) {
             JsonArray json = obj.getAsJsonArray("hits");
             ImmutableList.Builder<T> results = ImmutableList.builderWithExpectedSize(json.size());
+            JsonObject hit = null;
             for (int i = 0; i < json.size(); i++) {
-              T mapperResult = mapper.apply(json.get(i).getAsJsonObject());
+              hit = json.get(i).getAsJsonObject();
+              T mapperResult = mapper.apply(hit);
               if (mapperResult != null) {
                 results.add(mapperResult);
               }
             }
-            return new ListResultSet<>(results.build());
+            if (hit != null && hit.get("sort") != null) {
+              searchAfter = hit.getAsJsonArray("sort");
+            }
+            JsonArray finalSearchAfter = searchAfter;
+            return new ListResultSet<T>(results.build()) {
+              @Override
+              public Object searchAfter() {
+                return finalSearchAfter;
+              }
+            };
           }
         } else {
-          logger.atSevere().log(statusLine.getReasonPhrase());
+          logger.atSevere().log("%s", statusLine.getReasonPhrase());
         }
         return new ListResultSet<>(ImmutableList.of());
       } catch (IOException e) {
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
index 8967789..1e94148 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticAccountIndex.java
@@ -15,7 +15,7 @@
 package com.google.gerrit.elasticsearch;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
+import com.google.gerrit.elasticsearch.ElasticMapping.Mapping;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
 import com.google.gerrit.elasticsearch.bulk.UpdateRequest;
@@ -32,6 +32,7 @@
 import com.google.gerrit.server.index.IndexUtils;
 import com.google.gerrit.server.index.account.AccountField;
 import com.google.gerrit.server.index.account.AccountIndex;
+import com.google.gerrit.server.index.options.AutoFlush;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
@@ -45,7 +46,7 @@
 public class ElasticAccountIndex extends AbstractElasticIndex<Account.Id, AccountState>
     implements AccountIndex {
   static class AccountMapping {
-    final MappingProperties accounts;
+    final Mapping accounts;
 
     AccountMapping(Schema<AccountState> schema, ElasticQueryAdapter adapter) {
       this.accounts = ElasticMapping.createMapping(schema, adapter);
@@ -64,8 +65,9 @@
       SitePaths sitePaths,
       Provider<AccountCache> accountCache,
       ElasticRestClientProvider client,
+      AutoFlush autoFlush,
       @Assisted Schema<AccountState> schema) {
-    super(cfg, sitePaths, schema, client, ACCOUNTS);
+    super(cfg, sitePaths, schema, client, ACCOUNTS, autoFlush);
     this.accountCache = accountCache;
     this.mapping = new AccountMapping(schema, client.adapter());
     this.schema = schema;
@@ -78,9 +80,9 @@
             .add(new UpdateRequest<>(schema, as, ImmutableSet.of()));
 
     String uri = getURI(BULK);
-    Response response = postRequest(uri, bulk, getRefreshParam());
+    Response response = postRequestWithRefreshParam(uri, bulk);
     int statusCode = response.getStatusLine().getStatusCode();
-    if (statusCode != HttpStatus.SC_OK) {
+    if (hasErrors(response) || statusCode != HttpStatus.SC_OK) {
       throw new StorageException(
           String.format(
               "Failed to replace account %s in index %s: %s",
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
index 7d4e0c7..8504e16 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
@@ -17,7 +17,7 @@
 import static java.util.Objects.requireNonNull;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
+import com.google.gerrit.elasticsearch.ElasticMapping.Mapping;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
 import com.google.gerrit.elasticsearch.bulk.UpdateRequest;
@@ -37,6 +37,7 @@
 import com.google.gerrit.server.index.IndexUtils;
 import com.google.gerrit.server.index.change.ChangeField;
 import com.google.gerrit.server.index.change.ChangeIndex;
+import com.google.gerrit.server.index.options.AutoFlush;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
@@ -52,12 +53,12 @@
 class ElasticChangeIndex extends AbstractElasticIndex<Change.Id, ChangeData>
     implements ChangeIndex {
   static class ChangeMapping {
-    final MappingProperties changes;
-    final MappingProperties openChanges;
-    final MappingProperties closedChanges;
+    final Mapping changes;
+    final Mapping openChanges;
+    final Mapping closedChanges;
 
     ChangeMapping(Schema<ChangeData> schema, ElasticQueryAdapter adapter) {
-      MappingProperties mapping = ElasticMapping.createMapping(schema, adapter);
+      Mapping mapping = ElasticMapping.createMapping(schema, adapter);
       this.changes = mapping;
       this.openChanges = mapping;
       this.closedChanges = mapping;
@@ -79,8 +80,9 @@
       SitePaths sitePaths,
       ElasticRestClientProvider clientBuilder,
       @GerritServerConfig Config gerritConfig,
+      AutoFlush autoFlush,
       @Assisted Schema<ChangeData> schema) {
-    super(cfg, sitePaths, schema, clientBuilder, CHANGES);
+    super(cfg, sitePaths, schema, clientBuilder, CHANGES, autoFlush);
     this.changeDataFactory = changeDataFactory;
     this.schema = schema;
     this.mapping = new ChangeMapping(schema, client.adapter());
@@ -98,9 +100,9 @@
         new IndexRequest(getId(cd), indexName).add(new UpdateRequest<>(schema, cd, skipFields));
 
     String uri = getURI(BULK);
-    Response response = postRequest(uri, bulk, getRefreshParam());
+    Response response = postRequestWithRefreshParam(uri, bulk);
     int statusCode = response.getStatusLine().getStatusCode();
-    if (statusCode != HttpStatus.SC_OK) {
+    if (hasErrors(response) || statusCode != HttpStatus.SC_OK) {
       throw new StorageException(
           String.format(
               "Failed to replace change %s in index %s: %s", cd.getId(), indexName, statusCode));
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java
index e544d9f..2a5fcde 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java
@@ -43,9 +43,11 @@
   static final String KEY_NUMBER_OF_SHARDS = "numberOfShards";
   static final String KEY_NUMBER_OF_REPLICAS = "numberOfReplicas";
   static final String KEY_MAX_RESULT_WINDOW = "maxResultWindow";
+  static final String KEY_CODEC = "codec";
   static final String KEY_CONNECT_TIMEOUT = "connectTimeout";
   static final String KEY_SOCKET_TIMEOUT = "socketTimeout";
 
+  static final String DEFAULT_CODEC = "default";
   static final String DEFAULT_PORT = "9200";
   static final String DEFAULT_USERNAME = "elastic";
   static final int DEFAULT_NUMBER_OF_SHARDS = 1;
@@ -62,6 +64,7 @@
   final int numberOfShards;
   final int numberOfReplicas;
   final int maxResultWindow;
+  final String codec;
   final int connectTimeout;
   final int socketTimeout;
   final String prefix;
@@ -82,6 +85,7 @@
         cfg.getInt(SECTION_ELASTICSEARCH, null, KEY_NUMBER_OF_REPLICAS, DEFAULT_NUMBER_OF_REPLICAS);
     this.maxResultWindow =
         cfg.getInt(SECTION_ELASTICSEARCH, null, KEY_MAX_RESULT_WINDOW, DEFAULT_MAX_RESULT_WINDOW);
+    this.codec = firstNonNull(cfg.getString(SECTION_ELASTICSEARCH, null, KEY_CODEC), DEFAULT_CODEC);
     this.connectTimeout =
         (int)
             cfg.getTimeUnit(
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
index 781ed43..e0b337e 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticGroupIndex.java
@@ -15,7 +15,7 @@
 package com.google.gerrit.elasticsearch;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
+import com.google.gerrit.elasticsearch.ElasticMapping.Mapping;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
 import com.google.gerrit.elasticsearch.bulk.UpdateRequest;
@@ -32,6 +32,7 @@
 import com.google.gerrit.server.index.IndexUtils;
 import com.google.gerrit.server.index.group.GroupField;
 import com.google.gerrit.server.index.group.GroupIndex;
+import com.google.gerrit.server.index.options.AutoFlush;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
@@ -45,7 +46,7 @@
 public class ElasticGroupIndex extends AbstractElasticIndex<AccountGroup.UUID, InternalGroup>
     implements GroupIndex {
   static class GroupMapping {
-    final MappingProperties groups;
+    final Mapping groups;
 
     GroupMapping(Schema<InternalGroup> schema, ElasticQueryAdapter adapter) {
       this.groups = ElasticMapping.createMapping(schema, adapter);
@@ -64,8 +65,9 @@
       SitePaths sitePaths,
       Provider<GroupCache> groupCache,
       ElasticRestClientProvider client,
+      AutoFlush autoFlush,
       @Assisted Schema<InternalGroup> schema) {
-    super(cfg, sitePaths, schema, client, GROUPS);
+    super(cfg, sitePaths, schema, client, GROUPS, autoFlush);
     this.groupCache = groupCache;
     this.mapping = new GroupMapping(schema, client.adapter());
     this.schema = schema;
@@ -78,9 +80,9 @@
             .add(new UpdateRequest<>(schema, group, ImmutableSet.of()));
 
     String uri = getURI(BULK);
-    Response response = postRequest(uri, bulk, getRefreshParam());
+    Response response = postRequestWithRefreshParam(uri, bulk);
     int statusCode = response.getStatusLine().getStatusCode();
-    if (statusCode != HttpStatus.SC_OK) {
+    if (hasErrors(response) || statusCode != HttpStatus.SC_OK) {
       throw new StorageException(
           String.format(
               "Failed to replace group %s in index %s: %s",
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexModule.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexModule.java
index 671e9f4..b1bb7b1 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexModule.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexModule.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.elasticsearch;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.index.project.ProjectIndex;
 import com.google.gerrit.server.ModuleImpl;
@@ -22,6 +23,7 @@
 import com.google.gerrit.server.index.account.AccountIndex;
 import com.google.gerrit.server.index.change.ChangeIndex;
 import com.google.gerrit.server.index.group.GroupIndex;
+import com.google.gerrit.server.index.options.AutoFlush;
 import com.google.inject.Inject;
 import java.util.Map;
 
@@ -29,22 +31,28 @@
 public class ElasticIndexModule extends AbstractIndexModule {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  private final AutoFlush autoFlush;
+
+  @VisibleForTesting
   public static ElasticIndexModule singleVersionWithExplicitVersions(
       Map<String, Integer> versions, int threads, boolean slave) {
-    return new ElasticIndexModule(versions, threads, slave);
+    return new ElasticIndexModule(versions, threads, slave, AutoFlush.ENABLED);
   }
 
-  public static ElasticIndexModule latestVersion(boolean slave) {
-    return new ElasticIndexModule(null, 0, slave);
-  }
-
-  protected ElasticIndexModule(Map<String, Integer> singleVersions, int threads, boolean slave) {
-    super(singleVersions, threads, slave);
+  public static ElasticIndexModule singleVersionWithExplicitVersions(
+      Map<String, Integer> versions, int threads, boolean slave, AutoFlush autoFlush) {
+    return new ElasticIndexModule(versions, threads, slave, autoFlush);
   }
 
   @Inject
   public ElasticIndexModule() {
-    this(null, 0, false);
+    this(null, 0, false, AutoFlush.ENABLED);
+  }
+
+  protected ElasticIndexModule(
+      Map<String, Integer> singleVersions, int threads, boolean slave, AutoFlush autoFlush) {
+    super(singleVersions, threads, slave);
+    this.autoFlush = autoFlush;
   }
 
   @Override
@@ -52,6 +60,7 @@
     logger.atInfo().log("Gerrit index backend set to ElasticSearch");
     super.configure();
     install(ElasticRestClientProvider.module());
+    bind(AutoFlush.class).toInstance(autoFlush);
   }
 
   @Override
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java
index 100022a..4217f45 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticIndexVersionDiscovery.java
@@ -49,7 +49,7 @@
           String.format(
               "Failed to discover index versions for %s: %d: %s",
               name, statusLine.getStatusCode(), statusLine.getReasonPhrase());
-      logger.atSevere().log(message);
+      logger.atSevere().log("%s", message);
       throw new IOException(message);
     }
 
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticMapping.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticMapping.java
index edd05c9..1668450 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticMapping.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticMapping.java
@@ -18,14 +18,15 @@
 import com.google.gerrit.index.FieldDef;
 import com.google.gerrit.index.FieldType;
 import com.google.gerrit.index.Schema;
+import com.google.gson.annotations.SerializedName;
 import java.util.Map;
 
 class ElasticMapping {
 
   protected static final String TIMESTAMP_FIELD_TYPE = "date";
-  protected static final String TIMESTAMP_FIELD_FORMAT = "dateOptionalTime";
+  protected static final String TIMESTAMP_FIELD_FORMAT = "date_optional_time";
 
-  static MappingProperties createMapping(Schema<?> schema, ElasticQueryAdapter adapter) {
+  static Mapping createMapping(Schema<?> schema, ElasticQueryAdapter adapter) {
     ElasticMapping.Builder mapping = new ElasticMapping.Builder(adapter);
     for (FieldDef<?, ?> field : schema.getFields().values()) {
       String name = field.getName();
@@ -46,6 +47,11 @@
         throw new IllegalStateException("Unsupported field type: " + fieldType.getName());
       }
     }
+    mapping.addSourceIncludes(
+        schema.getFields().values().stream()
+            .filter(f -> f.isStored())
+            .map(f -> f.getName())
+            .toArray(String[]::new));
     return mapping.build();
   }
 
@@ -53,15 +59,18 @@
     private final ElasticQueryAdapter adapter;
     private final ImmutableMap.Builder<String, FieldProperties> fields =
         new ImmutableMap.Builder<>();
+    private final ImmutableMap.Builder<String, String[]> sourceIncludes =
+        new ImmutableMap.Builder<>();
 
     Builder(ElasticQueryAdapter adapter) {
       this.adapter = adapter;
     }
 
-    MappingProperties build() {
-      MappingProperties properties = new MappingProperties();
-      properties.properties = fields.build();
-      return properties;
+    Mapping build() {
+      Mapping mapping = new Mapping();
+      mapping.properties = fields.build();
+      mapping.source = sourceIncludes.build();
+      return mapping;
     }
 
     Builder addExactField(String name) {
@@ -99,13 +108,21 @@
       return this;
     }
 
+    Builder addSourceIncludes(String[] includes) {
+      sourceIncludes.put("includes", includes);
+      return this;
+    }
+
     Builder add(String name, String type) {
       fields.put(name, new FieldProperties(type));
       return this;
     }
   }
 
-  static class MappingProperties {
+  static class Mapping {
+    @SerializedName("_source")
+    Map<String, String[]> source;
+
     Map<String, FieldProperties> properties;
   }
 
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java
index b8bfc38..4703f1f 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticProjectIndex.java
@@ -15,7 +15,7 @@
 package com.google.gerrit.elasticsearch;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.gerrit.elasticsearch.ElasticMapping.MappingProperties;
+import com.google.gerrit.elasticsearch.ElasticMapping.Mapping;
 import com.google.gerrit.elasticsearch.bulk.BulkRequest;
 import com.google.gerrit.elasticsearch.bulk.IndexRequest;
 import com.google.gerrit.elasticsearch.bulk.UpdateRequest;
@@ -31,6 +31,7 @@
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.index.IndexUtils;
+import com.google.gerrit.server.index.options.AutoFlush;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
 import com.google.gson.JsonArray;
@@ -47,7 +48,7 @@
 public class ElasticProjectIndex extends AbstractElasticIndex<Project.NameKey, ProjectData>
     implements ProjectIndex {
   static class ProjectMapping {
-    MappingProperties projects;
+    Mapping projects;
 
     ProjectMapping(Schema<ProjectData> schema, ElasticQueryAdapter adapter) {
       this.projects = ElasticMapping.createMapping(schema, adapter);
@@ -66,8 +67,9 @@
       SitePaths sitePaths,
       Provider<ProjectCache> projectCache,
       ElasticRestClientProvider client,
+      AutoFlush autoFlush,
       @Assisted Schema<ProjectData> schema) {
-    super(cfg, sitePaths, schema, client, PROJECTS);
+    super(cfg, sitePaths, schema, client, PROJECTS, autoFlush);
     this.projectCache = projectCache;
     this.schema = schema;
     this.mapping = new ProjectMapping(schema, client.adapter());
@@ -80,9 +82,9 @@
             .add(new UpdateRequest<>(schema, projectState, ImmutableSet.of()));
 
     String uri = getURI(BULK);
-    Response response = postRequest(uri, bulk, getRefreshParam());
+    Response response = postRequestWithRefreshParam(uri, bulk);
     int statusCode = response.getStatusLine().getStatusCode();
-    if (statusCode != HttpStatus.SC_OK) {
+    if (hasErrors(response) || statusCode != HttpStatus.SC_OK) {
       throw new StorageException(
           String.format(
               "Failed to replace project %s in index %s: %s",
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java
index 9fc070a..3580089 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java
@@ -51,7 +51,7 @@
   private <T> BoolQueryBuilder and(Predicate<T> p) throws QueryParseException {
     BoolQueryBuilder b = QueryBuilders.boolQuery();
     for (Predicate<T> c : p.getChildren()) {
-      b.must(toQueryBuilder(c));
+      b.filter(toQueryBuilder(c));
     }
     return b;
   }
@@ -72,7 +72,7 @@
 
     // Lucene does not support negation, start with all and subtract.
     BoolQueryBuilder q = QueryBuilders.boolQuery();
-    q.must(QueryBuilders.matchAllQuery());
+    q.filter(QueryBuilders.matchAllQuery());
     q.mustNot(toQueryBuilder(n));
     return q;
   }
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticSetting.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticSetting.java
index 7ec0566..0059574 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticSetting.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticSetting.java
@@ -15,6 +15,7 @@
 package com.google.gerrit.elasticsearch;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.gson.annotations.SerializedName;
 import java.util.Map;
 
 class ElasticSetting {
@@ -36,6 +37,7 @@
       properties.numberOfShards = config.getNumberOfShards();
       properties.numberOfReplicas = config.numberOfReplicas;
       properties.maxResultWindow = config.maxResultWindow;
+      properties.codec = config.codec;
       return properties;
     }
 
@@ -73,6 +75,9 @@
   }
 
   static class SettingProperties {
+    @SerializedName("index.codec")
+    String codec;
+
     Map<String, FieldProperties> analysis;
     Integer numberOfShards;
     Integer numberOfReplicas;
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java b/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java
index b5bf44b..dffdf3e 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java
@@ -18,9 +18,7 @@
 import java.util.regex.Pattern;
 
 public enum ElasticVersion {
-  V7_6("7.6.*"),
-  V7_7("7.7.*"),
-  V7_8("7.8.*");
+  V7_16("7.16.*");
 
   private final String version;
   private final Pattern pattern;
diff --git a/src/main/java/com/google/gerrit/elasticsearch/PrimaryElasticIndexModule.java b/src/main/java/com/google/gerrit/elasticsearch/PrimaryElasticIndexModule.java
index 8500844..823c657 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/PrimaryElasticIndexModule.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/PrimaryElasticIndexModule.java
@@ -16,11 +16,12 @@
 
 import com.google.gerrit.server.ModuleImpl;
 import com.google.gerrit.server.index.AbstractIndexModule;
+import com.google.gerrit.server.index.options.AutoFlush;
 
 @ModuleImpl(name = AbstractIndexModule.INDEX_MODULE)
 public class PrimaryElasticIndexModule extends ElasticIndexModule {
 
   public PrimaryElasticIndexModule() {
-    super(null, 0, false);
+    super(null, 0, false, AutoFlush.ENABLED);
   }
 }
diff --git a/src/main/java/com/google/gerrit/elasticsearch/ReplicaElasticIndexModule.java b/src/main/java/com/google/gerrit/elasticsearch/ReplicaElasticIndexModule.java
index 8845cbe..86ccac6 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/ReplicaElasticIndexModule.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/ReplicaElasticIndexModule.java
@@ -16,11 +16,12 @@
 
 import com.google.gerrit.server.ModuleImpl;
 import com.google.gerrit.server.index.AbstractIndexModule;
+import com.google.gerrit.server.index.options.AutoFlush;
 
 @ModuleImpl(name = AbstractIndexModule.INDEX_MODULE)
 public class ReplicaElasticIndexModule extends ElasticIndexModule {
 
   public ReplicaElasticIndexModule() {
-    super(null, 0, true);
+    super(null, 0, true, AutoFlush.ENABLED);
   }
 }
diff --git a/src/main/java/com/google/gerrit/elasticsearch/builders/BoolQueryBuilder.java b/src/main/java/com/google/gerrit/elasticsearch/builders/BoolQueryBuilder.java
index a204919..741aec7 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/builders/BoolQueryBuilder.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/builders/BoolQueryBuilder.java
@@ -42,6 +42,15 @@
   }
 
   /**
+   * Adds a query that <b>must</b> appear in the matching documents and will not contribute to
+   * scoring.
+   */
+  public BoolQueryBuilder filter(QueryBuilder queryBuilder) {
+    filterClauses.add(queryBuilder);
+    return this;
+  }
+
+  /**
    * Adds a query that <b>must not</b> appear in the matching documents and will not contribute to
    * scoring.
    */
diff --git a/src/main/java/com/google/gerrit/elasticsearch/builders/SearchAfterBuilder.java b/src/main/java/com/google/gerrit/elasticsearch/builders/SearchAfterBuilder.java
new file mode 100644
index 0000000..0951217
--- /dev/null
+++ b/src/main/java/com/google/gerrit/elasticsearch/builders/SearchAfterBuilder.java
@@ -0,0 +1,45 @@
+// Copyright (C) 2022 The Android Open Source Project, 2009-2015 Elasticsearch
+//
+// Licensed 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 com.google.gerrit.elasticsearch.builders;
+
+import com.google.gson.JsonArray;
+import com.google.gson.JsonPrimitive;
+import java.io.IOException;
+
+/**
+ * A trimmed down and modified version of org.elasticsearch.search.searchafter.SearchAfterBuilder.
+ */
+public final class SearchAfterBuilder {
+  private JsonArray sortValues;
+
+  public SearchAfterBuilder(JsonArray sortValues) {
+    this.sortValues = sortValues;
+  }
+
+  public void innerToXContent(XContentBuilder builder) throws IOException {
+    builder.startArray("search_after");
+    for (int i = 0; i < sortValues.size(); i++) {
+      JsonPrimitive value = sortValues.get(i).getAsJsonPrimitive();
+      if (value.isNumber()) {
+        builder.value(value.getAsLong());
+      } else if (value.isBoolean()) {
+        builder.value(value.getAsBoolean());
+      } else {
+        builder.value(value.getAsString());
+      }
+    }
+    builder.endArray();
+  }
+}
diff --git a/src/main/java/com/google/gerrit/elasticsearch/builders/SearchSourceBuilder.java b/src/main/java/com/google/gerrit/elasticsearch/builders/SearchSourceBuilder.java
index 35cbea9..7e4ea93 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/builders/SearchSourceBuilder.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/builders/SearchSourceBuilder.java
@@ -15,6 +15,7 @@
 package com.google.gerrit.elasticsearch.builders;
 
 import com.google.gerrit.elasticsearch.ElasticQueryAdapter;
+import com.google.gson.JsonArray;
 import java.io.IOException;
 import java.util.List;
 
@@ -28,10 +29,14 @@
 
   private QuerySourceBuilder querySourceBuilder;
 
+  private SearchAfterBuilder searchAfterBuilder;
+
   private int from = -1;
 
   private int size = -1;
 
+  private boolean trackTotalHits = true;
+
   private List<String> fieldNames;
 
   /** Constructs a new search source builder. */
@@ -53,12 +58,22 @@
     return this;
   }
 
+  public SearchSourceBuilder searchAfter(JsonArray sortValues) {
+    this.searchAfterBuilder = new SearchAfterBuilder(sortValues);
+    return this;
+  }
+
   /** The number of search hits to return. Defaults to <tt>10</tt>. */
   public SearchSourceBuilder size(int size) {
     this.size = size;
     return this;
   }
 
+  public SearchSourceBuilder trackTotalHits(boolean track) {
+    this.trackTotalHits = track;
+    return this;
+  }
+
   /**
    * Sets the fields to load and return as part of the search request. If none are specified, the
    * source of the document will be returned.
@@ -93,6 +108,10 @@
       builder.field("size", size);
     }
 
+    if (!trackTotalHits) {
+      builder.field("track_total_hits", false);
+    }
+
     if (querySourceBuilder != null) {
       querySourceBuilder.innerToXContent(builder);
     }
@@ -108,5 +127,9 @@
         builder.endArray();
       }
     }
+
+    if (searchAfterBuilder != null) {
+      searchAfterBuilder.innerToXContent(builder);
+    }
   }
 }
diff --git a/src/main/java/com/google/gerrit/elasticsearch/builders/XContentBuilder.java b/src/main/java/com/google/gerrit/elasticsearch/builders/XContentBuilder.java
index 9c44583..853596d 100644
--- a/src/main/java/com/google/gerrit/elasticsearch/builders/XContentBuilder.java
+++ b/src/main/java/com/google/gerrit/elasticsearch/builders/XContentBuilder.java
@@ -152,6 +152,8 @@
       generator.writeString((String) value);
     } else if (type == Integer.class) {
       generator.writeNumber(((Integer) value));
+    } else if (type == Long.class) {
+      generator.writeNumber(((Long) value));
     } else if (type == byte[].class) {
       generator.writeBinary((byte[]) value);
     } else if (value instanceof Date) {
diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
new file mode 100644
index 0000000..59fe0a3
--- /dev/null
+++ b/src/main/resources/Documentation/about.md
@@ -0,0 +1,7 @@
+# Index backend for Gerrit, based on ElasticSearch
+
+Indexing backend libModule for [Gerrit Code Review](https://gerritcodereview.com)
+based on [ElasticSearch](https://www.elastic.co/elasticsearch/).
+
+This module was originally part of Gerrit core and then extracted into a separate
+component from v3.5.0-rc3 as part of [Change-Id: Ib7b5167ce](https://gerrit-review.googlesource.com/c/gerrit/+/323676).
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
index 1720f52..acb8d85 100644
--- a/src/main/resources/Documentation/build.md
+++ b/src/main/resources/Documentation/build.md
@@ -1,12 +1,17 @@
 # Build
 
-This plugin is built with Bazel in-tree build.
+This plugin is built with Bazel in-tree build. This plugin depends on the Elasticsearch Java Low
+Level REST Client (abbreviated as LLRC by the ES dev team) for integration with an Elasticsearch
+cluster. The LLRC is licensed as Apache v2 (even after ES itself has moved to SSPL) and is
+compatible with all ES versions. See the [LLRC
+docs](https://www.elastic.co/guide/en/elasticsearch/client/java-api-client/8.3/java-rest-low-usage-maven.html)
+for more information.
 
 ## Build in Gerrit tree
 
-Create a symbolic link of the repsotiory source to the Gerrit source
-tree /plugins/index-elasticsearch directory, and the external_plugin_deps.bzl
-dependencies linked to /plugins/external_plugin_deps.bzl.
+Create a symbolic link of the repository source to the Gerrit source
+tree plugins/index-elasticsearch directory, and the external_plugin_deps.bzl
+dependencies linked to plugins/external_plugin_deps.bzl.
 
 Example:
 
@@ -18,7 +23,7 @@
 ln -sf ../../external_plugin_deps.bzl .
 ```
 
-From the Gerrit source tree issue the command `bazelsk build plugins/index-elasticsearch`.
+From the Gerrit source tree issue the command `bazelisk build plugins/index-elasticsearch`.
 
 Example:
 
@@ -26,16 +31,29 @@
 bazelisk build plugins/index-elasticsearch
 ```
 
-The libModule jar file is created under `basel-bin/plugins/index-elasticsearch/index-elasticsearch.jar`
+The libModule jar file is created under `bazel-bin/plugins/index-elasticsearch/index-elasticsearch.jar`
 
-To execute the tests run `bazelisk test plugins/index-elasticsearch/...` from the Gerrit source tree.
+## Integration test
 
-Example:
+There are two different ways to run tests for this module. You can either run only the tests
+provided by the module or you can run all Gerrit core acceptance tests with the indexing backend set
+to this module.
+
+To run only the tests provided by this plugin:
 
 ```sh
 bazelisk test plugins/index-elasticsearch/...
 ```
 
+Gerrit acceptance tests allow the execution with an alternate implementation of
+the indexing backend using the `GERRIT_INDEX_MODULE` environment variable.
+
+```sh
+bazelisk test --test_env=GERRIT_INDEX_MODULE=com.google.gerrit.elasticsearch.ElasticIndexModule //...
+```
+
+## IDE setup
+
 This project can be imported into the Eclipse IDE.
 Add the plugin name to the `CUSTOM_PLUGINS` and to the
 `CUSTOM_PLUGINS_TEST_DEPS` set in Gerrit core in
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index 2164d22..927d229 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -1,104 +1,104 @@
-Configuration
-=============
+# Configuration
 
-[[index]]
-=== Section index
+## Section index
 
-[[index.maxLimit]]index.maxLimit::
-+
-Maximum limit to allow for search queries. Requesting results above this
-limit will truncate the list (but will still set `_more_changes` on
-result lists). Set to 0 for no limit.
-This value should not exceed the `index.max_result_window` value configured
-on the Elasticsearch server.
-If a value is not configured during site initialization, defaults to
-10000, which is the default value of `index.max_result_window` in Elasticsearch.
+### index.maxLimit
 
-[[elasticsearch]]
-=== Section elasticsearch
+Maximum limit to allow for search queries. Requesting results above this limit will truncate the
+list (but will still set `_more_changes` on result lists). Set to 0 for no limit. This value
+should not exceed the `index.max_result_window` value configured on the Elasticsearch server. If a
+value is not configured during site initialization, defaults to 10000, which is the default value
+of `index.max_result_window` in Elasticsearch.
 
-WARNING: Support for Elasticsearch is still experimental and is not recommended
-for production use. For compatibility information, please refer to the
-link:https://www.gerritcodereview.com/elasticsearch.html[project homepage,role=external,window=_blank].
+## Section elasticsearch
+
+WARNING: Support for Elasticsearch is still experimental and is not recommended for production
+use. For compatibility information, please refer to the [project homepage](https://www.gerritcodereview.com/elasticsearch.html).
 
 Note that when Gerrit is configured to use Elasticsearch, the Elasticsearch
 server(s) must be reachable during the site initialization.
 
-[[elasticsearch.prefix]]elasticsearch.prefix::
-+
-This setting can be used to prefix index names to allow multiple Gerrit
-instances in a single Elasticsearch cluster. Prefix `gerrit1_` would result in a
-change index named `gerrit1_changes_0001`.
-+
+### elasticsearch.prefix
+
+This setting can be used to prefix index names to allow multiple Gerrit instances in a single
+Elasticsearch cluster. Prefix `gerrit1_` would result in a change index named
+`gerrit1_changes_0001`.
+
 Not set by default.
 
-[[elasticsearch.server]]elasticsearch.server::
-+
-Elasticsearch server URI in the form `http[s]://hostname:port`. The `port` is
-optional and defaults to `9200` if not specified.
-+
-At least one server must be specified. May be specified multiple times to
-configure multiple Elasticsearch servers.
-+
+### elasticsearch.server
+
+Elasticsearch server URI in the form `http[s]://hostname:port`. The `port` is optional and defaults
+to `9200` if not specified.
+
+At least one server must be specified. May be specified multiple times to configure multiple
+Elasticsearch servers.
+
 Note that the site initialization program only allows to configure a single
 server. To configure multiple servers the `gerrit.config` file must be edited
 manually.
 
-[[elasticsearch.numberOfShards]]elasticsearch.numberOfShards::
-+
+### elasticsearch.numberOfShards
+
 Sets the number of shards to use per index. Refer to the
-link:https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#_static_index_settings[
-Elasticsearch documentation,role=external,window=_blank] for details.
-+
+[Elasticsearch documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#_static_index_settings) for details.
+
 Defaults to 1.
 
-[[elasticsearch.numberOfReplicas]]elasticsearch.numberOfReplicas::
-+
+### elasticsearch.numberOfReplicas
+
 Sets the number of replicas to use per index. Refer to the
-link:https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#dynamic-index-settings[
-Elasticsearch documentation,role=external,window=_blank] for details.
-+
+[Elasticsearch documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#dynamic-index-settings) for details.
+
 Defaults to 1.
 
-[[elasticsearch.maxResultWindow]]elasticsearch.maxResultWindow::
-+
+### elasticsearch.maxResultWindow
+
 Sets the maximum value of `from + size` for searches to use per index. Refer to the
-link:https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#dynamic-index-settings[
-Elasticsearch documentation,role=external,window=_blank] for details.
-+
+[Elasticsearch documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#dynamic-index-settings) for details.
+
 Defaults to 10000.
 
-[[elasticsearch.connectTimeout]]elasticsearch.connectTimeout::
-+
+### elasticsearch.connectTimeout
+
 Sets the timeout for connecting to elasticsearch.
-+
+
 Defaults to `1 second`.
 
-[[elasticsearch.socketTimeout]]elasticsearch.socketTimeout::
-+
+### elasticsearch.socketTimeout
+
 Sets the timeout for the underlying connection. For more information, refer to
-link:#httpd.idleTimeout[`httpd.idleTimeout`].
-+
+[`httpd.idleTimeout`](https://gerrit-documentation.storage.googleapis.com/Documentation/3.5.2/config-gerrit.html#httpd.idleTimeout).
+
 Defaults to `30 seconds`.
 
-==== Elasticsearch Security
+## Elasticsearch Security
 
-When security is enabled in Elasticsearch, the username and password must be provided.
-Note that the same username and password are used for all servers.
+When security is enabled in Elasticsearch, the username and password must be provided. Note that
+the same username and password are used for all servers.
 
 For further information about Elasticsearch security, please refer to
-link:https://www.elastic.co/guide/en/elasticsearch/reference/current/security-getting-started.html[the documentation,role=external,window=_blank].
-This is the current documentation link. Select another Elasticsearch version
-from the dropdown menu available on that page if need be.
+[the documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/security-getting-started.html). This is the current documentation link. Select another Elasticsearch version from the dropdown menu available on that page if need be.
 
-[[elasticsearch.username]]elasticsearch.username::
-+
+### elasticsearch.username
+
 Username used to connect to Elasticsearch.
-+
+
 If a password is set, defaults to `elastic`, otherwise not set by default.
 
-[[elasticsearch.password]]elasticsearch.password::
-+
+### elasticsearch.password
+
 Password used to connect to Elasticsearch.
-+
+
 Not set by default.
+
+### elasticsearch.codec
+
+Sets the codec to be used for the index data. For further information about supported codecs, please refer to the static index setting
+[index.codec](https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#index-codec).
+
+Defaults to `default`.
+
+[Back to @PLUGIN@ documentation index][index]
+
+[index]: index.html
diff --git a/src/main/resources/Documentation/setup.md b/src/main/resources/Documentation/setup.md
new file mode 100644
index 0000000..7877b29
--- /dev/null
+++ b/src/main/resources/Documentation/setup.md
@@ -0,0 +1,26 @@
+# Setup
+
+* Install index-elasticsearch module
+
+Install the index-elasticsearch.jar into the `$GERRIT_SITE/lib` directory.
+
+Add the index-elasticsearch module to `$GERRIT_SITE/etc/gerrit.config` as follows:
+
+```ini
+[gerrit]
+  installIndexModule = com.google.gerrit.elasticsearch.ElasticIndexModule
+```
+
+When installing the module on Gerrit replicas, use following example:
+
+```ini
+[gerrit]
+  installIndexModule = com.google.gerrit.elasticsearch.ReplicaElasticIndexModule
+```
+
+For further information and supported options, refer to [config](config.html)
+documentation.
+
+[Back to @PLUGIN@ documentation index][index]
+
+[index]: index.html
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticContainer.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticContainer.java
index 503852b..86b1bac 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticContainer.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticContainer.java
@@ -14,38 +14,41 @@
 
 package com.google.gerrit.elasticsearch;
 
+import com.google.common.flogger.FluentLogger;
 import org.apache.http.HttpHost;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.testcontainers.containers.ContainerLaunchException;
 import org.testcontainers.elasticsearch.ElasticsearchContainer;
 import org.testcontainers.utility.DockerImageName;
 
 /* Helper class for running ES integration tests in docker container */
 public class ElasticContainer extends ElasticsearchContainer {
+  private static FluentLogger logger = FluentLogger.forEnclosingClass();
   private static final int ELASTICSEARCH_DEFAULT_PORT = 9200;
 
   public static ElasticContainer createAndStart(ElasticVersion version) {
     ElasticContainer container = new ElasticContainer(version);
-    container.start();
+    try {
+      container.start();
+    } catch (ContainerLaunchException e) {
+      logger.atSevere().log(
+          "Failed to launch elastic container. Logs from container :\n%s", container.getLogs());
+      throw e;
+    }
     return container;
   }
 
   private static String getImageName(ElasticVersion version) {
     switch (version) {
-      case V7_6:
-        return "blacktop/elasticsearch:7.6.2";
-      case V7_7:
-        return "blacktop/elasticsearch:7.7.1";
-      case V7_8:
-        return "blacktop/elasticsearch:7.8.1";
+      case V7_16:
+        return "docker.elastic.co/elasticsearch/elasticsearch:7.16.2";
     }
     throw new IllegalStateException("No tests for version: " + version.name());
   }
 
   private ElasticContainer(ElasticVersion version) {
-    super(
-        DockerImageName.parse(getImageName(version))
-            .asCompatibleSubstituteFor("docker.elastic.co/elasticsearch/elasticsearch"));
+    super(DockerImageName.parse(getImageName(version)));
   }
 
   @Override
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticTestUtils.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticTestUtils.java
index c3ca595..f5ba9db 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticTestUtils.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticTestUtils.java
@@ -14,6 +14,8 @@
 
 package com.google.gerrit.elasticsearch;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+
 import com.google.gerrit.index.IndexDefinition;
 import com.google.gerrit.server.LibModuleType;
 import com.google.gerrit.testing.GerritTestName;
@@ -25,6 +27,9 @@
 import com.google.inject.TypeLiteral;
 import java.util.Collection;
 import java.util.UUID;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.client.protocol.HttpClientContext;
+import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
 import org.eclipse.jgit.lib.Config;
 
 public final class ElasticTestUtils {
@@ -81,6 +86,22 @@
     return Guice.createInjector(new InMemoryModule(elasticsearchConfig));
   }
 
+  public static void closeIndex(
+      CloseableHttpAsyncClient client, ElasticContainer container, GerritTestName testName)
+      throws Exception {
+    client
+        .execute(
+            new HttpPost(
+                String.format(
+                    "http://%s:%d/%s*/_close",
+                    container.getHttpHost().getHostName(),
+                    container.getHttpHost().getPort(),
+                    testName.getSanitizedMethodName())),
+            HttpClientContext.create(),
+            null)
+        .get(5, MINUTES);
+  }
+
   private ElasticTestUtils() {
     // hide default constructor
   }
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryAccountsTest.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryAccountsTest.java
index 4ee5a16..7f6a585 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryAccountsTest.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryAccountsTest.java
@@ -14,12 +14,19 @@
 
 package com.google.gerrit.elasticsearch;
 
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
+
+import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.server.query.account.AbstractQueryAccountsTest;
 import com.google.gerrit.testing.ConfigSuite;
 import com.google.inject.Injector;
+import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
+import org.apache.http.impl.nio.client.HttpAsyncClients;
 import org.eclipse.jgit.lib.Config;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.Test;
 
 public class ElasticV7QueryAccountsTest extends AbstractQueryAccountsTest {
   @ConfigSuite.Default
@@ -27,14 +34,21 @@
     return ElasticTestUtils.createConfig();
   }
 
+  @ConfigSuite.Config
+  public static Config searchAfterPaginationType() {
+    Config config = defaultConfig();
+    config.setString("index", null, "paginationType", "SEARCH_AFTER");
+    return config;
+  }
+
   private static ElasticContainer container;
+  private static CloseableHttpAsyncClient client;
 
   @BeforeClass
   public static void startIndexService() {
-    if (container == null) {
-      // Only start Elasticsearch once
-      container = ElasticContainer.createAndStart(ElasticVersion.V7_8);
-    }
+    container = ElasticContainer.createAndStart(ElasticVersion.V7_16);
+    client = HttpAsyncClients.createDefault();
+    client.start();
   }
 
   @AfterClass
@@ -54,4 +68,14 @@
   protected Injector createInjector() {
     return ElasticTestUtils.createInjector(config, testName, container);
   }
+
+  @Test
+  public void testErrorResponseFromAccountIndex() throws Exception {
+    gApi.accounts().self().index();
+
+    ElasticTestUtils.closeIndex(client, container, testName);
+    StorageException thrown =
+        assertThrows(StorageException.class, () -> gApi.accounts().self().index());
+    assertThat(thrown).hasMessageThat().contains("Failed to replace account");
+  }
 }
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryChangesTest.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryChangesTest.java
index d704e40..6d0602b 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryChangesTest.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryChangesTest.java
@@ -14,19 +14,20 @@
 
 package com.google.gerrit.elasticsearch;
 
+import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.TruthJUnit.assume;
-import static java.util.concurrent.TimeUnit.MINUTES;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
 
 import com.google.gerrit.entities.Change;
+import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.server.change.ChangeInserter;
 import com.google.gerrit.server.index.change.ChangeField;
 import com.google.gerrit.server.query.change.AbstractQueryChangesTest;
 import com.google.gerrit.testing.ConfigSuite;
 import com.google.gerrit.testing.GerritTestName;
+import com.google.gerrit.testing.InMemoryRepositoryManager;
 import com.google.gerrit.testing.InMemoryRepositoryManager.Repo;
 import com.google.inject.Injector;
-import org.apache.http.client.methods.HttpPost;
-import org.apache.http.client.protocol.HttpClientContext;
 import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
 import org.apache.http.impl.nio.client.HttpAsyncClients;
 import org.eclipse.jgit.junit.TestRepository;
@@ -43,17 +44,21 @@
     return ElasticTestUtils.createConfig();
   }
 
+  @ConfigSuite.Config
+  public static Config searchAfterPaginationType() {
+    Config config = defaultConfig();
+    config.setString("index", null, "paginationType", "SEARCH_AFTER");
+    return config;
+  }
+
   private static ElasticContainer container;
   private static CloseableHttpAsyncClient client;
 
   @BeforeClass
   public static void startIndexService() {
-    if (container == null) {
-      // Only start Elasticsearch once
-      container = ElasticContainer.createAndStart(ElasticVersion.V7_8);
-      client = HttpAsyncClients.createDefault();
-      client.start();
-    }
+    container = ElasticContainer.createAndStart(ElasticVersion.V7_16);
+    client = HttpAsyncClients.createDefault();
+    client.start();
   }
 
   @AfterClass
@@ -69,17 +74,7 @@
   public void closeIndex() throws Exception {
     // Close the index after each test to prevent exceeding Elasticsearch's
     // shard limit (see Issue 10120).
-    client
-        .execute(
-            new HttpPost(
-                String.format(
-                    "http://%s:%d/%s*/_close",
-                    container.getHttpHost().getHostName(),
-                    container.getHttpHost().getPort(),
-                    testName.getSanitizedMethodName())),
-            HttpClientContext.create(),
-            null)
-        .get(5, MINUTES);
+    ElasticTestUtils.closeIndex(client, container, testName);
   }
 
   @Override
@@ -138,4 +133,16 @@
   protected Injector createInjector() {
     return ElasticTestUtils.createInjector(config, testName, container);
   }
+
+  @Test
+  public void testErrorResponseFromChangeIndex() throws Exception {
+    TestRepository<InMemoryRepositoryManager.Repo> repo = createProject("repo");
+    Change c = insert(repo, newChangeWithStatus(repo, Change.Status.NEW));
+    gApi.changes().id(c.getChangeId()).index();
+
+    ElasticTestUtils.closeIndex(client, container, testName);
+    StorageException thrown =
+        assertThrows(StorageException.class, () -> gApi.changes().id(c.getChangeId()).index());
+    assertThat(thrown).hasMessageThat().contains("Failed to reindex change");
+  }
 }
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryGroupsTest.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryGroupsTest.java
index 649c0bc..271ee19 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryGroupsTest.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryGroupsTest.java
@@ -14,12 +14,20 @@
 
 package com.google.gerrit.elasticsearch;
 
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
+
+import com.google.gerrit.exceptions.StorageException;
+import com.google.gerrit.extensions.api.groups.GroupApi;
 import com.google.gerrit.server.query.group.AbstractQueryGroupsTest;
 import com.google.gerrit.testing.ConfigSuite;
 import com.google.inject.Injector;
+import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
+import org.apache.http.impl.nio.client.HttpAsyncClients;
 import org.eclipse.jgit.lib.Config;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.Test;
 
 public class ElasticV7QueryGroupsTest extends AbstractQueryGroupsTest {
   @ConfigSuite.Default
@@ -27,14 +35,21 @@
     return ElasticTestUtils.createConfig();
   }
 
+  @ConfigSuite.Config
+  public static Config searchAfterPaginationType() {
+    Config config = defaultConfig();
+    config.setString("index", null, "paginationType", "SEARCH_AFTER");
+    return config;
+  }
+
   private static ElasticContainer container;
+  private static CloseableHttpAsyncClient client;
 
   @BeforeClass
   public static void startIndexService() {
-    if (container == null) {
-      // Only start Elasticsearch once
-      container = ElasticContainer.createAndStart(ElasticVersion.V7_8);
-    }
+    container = ElasticContainer.createAndStart(ElasticVersion.V7_16);
+    client = HttpAsyncClients.createDefault();
+    client.start();
   }
 
   @AfterClass
@@ -54,4 +69,14 @@
   protected Injector createInjector() {
     return ElasticTestUtils.createInjector(config, testName, container);
   }
+
+  @Test
+  public void testErrorResponseFromGroupIndex() throws Exception {
+    GroupApi group = gApi.groups().create("test");
+    group.index();
+
+    ElasticTestUtils.closeIndex(client, container, testName);
+    StorageException thrown = assertThrows(StorageException.class, () -> group.index());
+    assertThat(thrown).hasMessageThat().contains("Failed to replace group");
+  }
 }
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryProjectsTest.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryProjectsTest.java
index d3b3d44..38eef22 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryProjectsTest.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticV7QueryProjectsTest.java
@@ -14,12 +14,20 @@
 
 package com.google.gerrit.elasticsearch;
 
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
+
+import com.google.gerrit.exceptions.StorageException;
+import com.google.gerrit.extensions.api.projects.ProjectApi;
 import com.google.gerrit.server.query.project.AbstractQueryProjectsTest;
 import com.google.gerrit.testing.ConfigSuite;
 import com.google.inject.Injector;
+import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
+import org.apache.http.impl.nio.client.HttpAsyncClients;
 import org.eclipse.jgit.lib.Config;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.Test;
 
 public class ElasticV7QueryProjectsTest extends AbstractQueryProjectsTest {
   @ConfigSuite.Default
@@ -27,14 +35,21 @@
     return ElasticTestUtils.createConfig();
   }
 
+  @ConfigSuite.Config
+  public static Config searchAfterPaginationType() {
+    Config config = defaultConfig();
+    config.setString("index", null, "paginationType", "SEARCH_AFTER");
+    return config;
+  }
+
   private static ElasticContainer container;
+  private static CloseableHttpAsyncClient client;
 
   @BeforeClass
   public static void startIndexService() {
-    if (container == null) {
-      // Only start Elasticsearch once
-      container = ElasticContainer.createAndStart(ElasticVersion.V7_8);
-    }
+    container = ElasticContainer.createAndStart(ElasticVersion.V7_16);
+    client = HttpAsyncClients.createDefault();
+    client.start();
   }
 
   @AfterClass
@@ -54,4 +69,14 @@
   protected Injector createInjector() {
     return ElasticTestUtils.createInjector(config, testName, container);
   }
+
+  @Test
+  public void testErrorResponseFromProjectIndex() throws Exception {
+    ProjectApi project = gApi.projects().create("test");
+    project.index(false);
+
+    ElasticTestUtils.closeIndex(client, container, testName);
+    StorageException thrown = assertThrows(StorageException.class, () -> project.index(false));
+    assertThat(thrown).hasMessageThat().contains("Failed to replace project");
+  }
 }
diff --git a/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java b/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java
index 2ce3a2c..ea7782b 100644
--- a/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java
+++ b/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java
@@ -22,14 +22,8 @@
 public class ElasticVersionTest {
   @Test
   public void supportedVersion() throws Exception {
-    assertThat(ElasticVersion.forVersion("7.6.0")).isEqualTo(ElasticVersion.V7_6);
-    assertThat(ElasticVersion.forVersion("7.6.1")).isEqualTo(ElasticVersion.V7_6);
-
-    assertThat(ElasticVersion.forVersion("7.7.0")).isEqualTo(ElasticVersion.V7_7);
-    assertThat(ElasticVersion.forVersion("7.7.1")).isEqualTo(ElasticVersion.V7_7);
-
-    assertThat(ElasticVersion.forVersion("7.8.0")).isEqualTo(ElasticVersion.V7_8);
-    assertThat(ElasticVersion.forVersion("7.8.1")).isEqualTo(ElasticVersion.V7_8);
+    assertThat(ElasticVersion.forVersion("7.16.0")).isEqualTo(ElasticVersion.V7_16);
+    assertThat(ElasticVersion.forVersion("7.16.1")).isEqualTo(ElasticVersion.V7_16);
   }
 
   @Test