diff --git a/pom.xml b/pom.xml
index cd4bf4af60842b4de22ceec8f3919ef3c52e38bd..6b0b7678e986f97a45a9a6255e2d67582ea9edd2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,8 +62,8 @@
 		<suggest.version>2.0.0</suggest.version>
 
 		<!-- Elasticsearch -->
-		<elasticsearch.version>2.0.0</elasticsearch.version>
-		<cluster.runner.version>2.0.0.0</cluster.runner.version>
+		<elasticsearch.version>2.1.0</elasticsearch.version>
+		<cluster.runner.version>2.1.0.0-SNAPSHOT</cluster.runner.version>
 
 		<!-- Tomcat -->
 		<tomcat.boot.version>0.3.8-RC9</tomcat.boot.version>
@@ -278,18 +278,18 @@
 					<tasks>
 						<mkdir dir="${basedir}/target/plugins" />
 						<get dest="${basedir}/target/plugins">
-							<url url="${maven.release.repo.url}/org/codelibs/elasticsearch-analysis-kuromoji-neologd/2.0.0/elasticsearch-analysis-kuromoji-neologd-2.0.0.zip" />
-							<url url="${maven.release.repo.url}/org/codelibs/elasticsearch-analysis-synonym/2.0.0/elasticsearch-analysis-synonym-2.0.0.zip" />
-							<url url="${maven.release.repo.url}/org/codelibs/elasticsearch-configsync/2.0.0/elasticsearch-configsync-2.0.0.zip" />
-							<url url="${maven.release.repo.url}/org/codelibs/elasticsearch-langfield/2.0.0/elasticsearch-langfield-2.0.0.zip" />
+							<url url="${maven.snapshot.repo.url}/org/codelibs/elasticsearch-analysis-kuromoji-neologd/2.1.0-SNAPSHOT/elasticsearch-analysis-kuromoji-neologd-2.1.0-20151127.223316-1.zip" />
+							<url url="${maven.snapshot.repo.url}/org/codelibs/elasticsearch-analysis-synonym/2.1.0-SNAPSHOT/elasticsearch-analysis-synonym-2.1.0-20151127.081411-1.zip" />
+							<url url="${maven.snapshot.repo.url}/org/codelibs/elasticsearch-configsync/2.1.0-SNAPSHOT/elasticsearch-configsync-2.1.0-20151127.054727-1.zip" />
+							<url url="${maven.snapshot.repo.url}/org/codelibs/elasticsearch-langfield/2.1.0-SNAPSHOT/elasticsearch-langfield-2.1.0-20151129.210553-1.zip" />
 							<url url="http://maven.codelibs.org/archive/elasticsearch/plugin/kopf/elasticsearch-kopf-2.0.0.0.zip" />
 						</get>
 						<delete dir="${basedir}/plugins" />
 						<mkdir dir="${basedir}/plugins" />
-						<unzip dest="${basedir}/plugins/analysis-kuromoji-neologd" src="${basedir}/target/plugins/elasticsearch-analysis-kuromoji-neologd-2.0.0.zip" />
-						<unzip dest="${basedir}/plugins/analysis-synonym" src="${basedir}/target/plugins/elasticsearch-analysis-synonym-2.0.0.zip" />
-						<unzip dest="${basedir}/plugins/configsync" src="${basedir}/target/plugins/elasticsearch-configsync-2.0.0.zip" />
-						<unzip dest="${basedir}/plugins/langfield" src="${basedir}/target/plugins/elasticsearch-langfield-2.0.0.zip" />
+						<unzip dest="${basedir}/plugins/analysis-kuromoji-neologd" src="${basedir}/target/plugins/elasticsearch-analysis-kuromoji-neologd-2.1.0-20151127.223316-1.zip" />
+						<unzip dest="${basedir}/plugins/analysis-synonym" src="${basedir}/target/plugins/elasticsearch-analysis-synonym-2.1.0-20151127.081411-1.zip" />
+						<unzip dest="${basedir}/plugins/configsync" src="${basedir}/target/plugins/elasticsearch-configsync-2.1.0-20151127.054727-1.zip" />
+						<unzip dest="${basedir}/plugins/langfield" src="${basedir}/target/plugins/elasticsearch-langfield-2.1.0-20151129.210553-1.zip" />
 						<unzip dest="${basedir}/plugins/kopf" src="${basedir}/target/plugins/elasticsearch-kopf-2.0.0.0.zip" />
 					</tasks>
 				</configuration>
diff --git a/src/main/java/org/codelibs/fess/es/client/FessEsClient.java b/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
index df091013ef2284e1dbcc3449ac4b4d440950b109..2c9fd3769bc8c6e83ee508d9c137564f419eb8bd 100644
--- a/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
+++ b/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
@@ -68,7 +68,6 @@ import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
 import org.elasticsearch.action.admin.indices.flush.FlushResponse;
 import org.elasticsearch.action.admin.indices.mapping.get.GetMappingsResponse;
 import org.elasticsearch.action.admin.indices.mapping.put.PutMappingResponse;
-import org.elasticsearch.action.admin.indices.optimize.OptimizeResponse;
 import org.elasticsearch.action.admin.indices.refresh.RefreshResponse;
 import org.elasticsearch.action.bulk.BulkItemResponse;
 import org.elasticsearch.action.bulk.BulkItemResponse.Failure;
@@ -715,23 +714,6 @@ public class FessEsClient implements Client {
 
     }
 
-    public void optimize(final String index) {
-        client.admin().indices().prepareOptimize(index).execute(new ActionListener<OptimizeResponse>() {
-
-            @Override
-            public void onResponse(final OptimizeResponse response) {
-                if (logger.isDebugEnabled()) {
-                    logger.debug("Optimzed " + index + ".");
-                }
-            }
-
-            @Override
-            public void onFailure(final Throwable e) {
-                logger.error("Failed to optimze " + index + ".", e);
-            }
-        });
-    }
-
     public PingResponse ping() {
         try {
             final ClusterHealthResponse response = client.admin().cluster().prepareHealth().execute().actionGet();