Enhancing the REST template with HttpClient5

for better performance and allowing users to configure timeouts as per their requirements

Issue-ID: CPS-1994
Change-Id: I9fa94fb3923a50e33b3850ec0f190a51e278698f
Signed-off-by: waqas.ikram <waqas.ikram@est.tech>

2 files changed, 97 insertions, 8 deletions

diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/HttpClientConfiguration.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/HttpClientConfiguration.java
new file mode 100644
index 0000000000..aaa4f1e5bb
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/HttpClientConfiguration.java
@@ -0,0 +1,57 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2023 Nordix Foundation.
+ * ================================================================================
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.ncmp.api.impl.config;
+
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.convert.DurationUnit;
+
+@Getter
+@Setter
+@ConfigurationProperties(prefix = "httpclient5", ignoreUnknownFields = true)
+public class HttpClientConfiguration {
+
+    /**
+     * The maximum time to establish a connection.
+     */
+    @DurationUnit(ChronoUnit.SECONDS)
+    private Duration connectionTimeoutInSeconds = Duration.ofSeconds(180);
+
+    /**
+     * The maximum number of open connections per route.
+     */
+    private int maximumConnectionsPerRoute = 50;
+
+    /**
+     * The maximum total number of open connections.
+     */
+    private int maximumConnectionsTotal = maximumConnectionsPerRoute * 2;
+
+    /**
+     * The duration after which idle connections are evicted.
+     */
+    @DurationUnit(ChronoUnit.SECONDS)
+    private Duration idleConnectionEvictionThresholdInSeconds = Duration.ofSeconds(5);
+
+}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/NcmpConfiguration.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/NcmpConfiguration.java
index ffecf9c7f1..4460094f54 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/NcmpConfiguration.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/config/NcmpConfiguration.java
@@ -1,6 +1,6 @@
 /*
  * ============LICENSE_START=======================================================
- *  Copyright (C) 2021-2022 Nordix Foundation
+ *  Copyright (C) 2021-2023 Nordix Foundation
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -20,29 +20,36 @@
 
 package org.onap.cps.ncmp.api.impl.config;
 
-import java.time.Duration;
 import java.util.Arrays;
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
+import org.apache.hc.client5.http.config.ConnectionConfig;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClients;
+import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManager;
+import org.apache.hc.client5.http.impl.io.PoolingHttpClientConnectionManagerBuilder;
+import org.apache.hc.core5.util.TimeValue;
+import org.apache.hc.core5.util.Timeout;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Scope;
 import org.springframework.http.MediaType;
+import org.springframework.http.client.ClientHttpRequestFactory;
+import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.stereotype.Component;
 import org.springframework.web.client.RestTemplate;
 
 @Configuration
+@EnableConfigurationProperties(HttpClientConfiguration.class)
 @RequiredArgsConstructor(access = AccessLevel.PROTECTED)
 public class NcmpConfiguration {
 
-    private static final Duration CONNECTION_TIMEOUT_MILLISECONDS = Duration.ofMillis(180000);
-    private static final Duration READ_TIMEOUT_MILLISECONDS = Duration.ofMillis(180000);
-
     @Getter
     @Component
     public static class DmiProperties {
@@ -60,13 +67,38 @@ public class NcmpConfiguration {
      * Rest template bean.
      *
      * @param restTemplateBuilder the rest template builder
+     * @param httpClientConfiguration the http client configuration
      * @return rest template instance
      */
     @Bean
     @Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)
-    public static RestTemplate restTemplate(final RestTemplateBuilder restTemplateBuilder) {
-        final RestTemplate restTemplate = restTemplateBuilder.setConnectTimeout(CONNECTION_TIMEOUT_MILLISECONDS)
-                .setReadTimeout(READ_TIMEOUT_MILLISECONDS).build();
+    public static RestTemplate restTemplate(final RestTemplateBuilder restTemplateBuilder, 
+                                            final HttpClientConfiguration httpClientConfiguration) {
+        
+        final ConnectionConfig connectionConfig = ConnectionConfig.copy(ConnectionConfig.DEFAULT)
+                .setConnectTimeout(Timeout.of(httpClientConfiguration.getConnectionTimeoutInSeconds()))
+                .build();
+        
+        final PoolingHttpClientConnectionManager connectionManager = PoolingHttpClientConnectionManagerBuilder.create()
+                .setDefaultConnectionConfig(connectionConfig)
+                .setMaxConnTotal(httpClientConfiguration.getMaximumConnectionsTotal())
+                .setMaxConnPerRoute(httpClientConfiguration.getMaximumConnectionsPerRoute())
+                .build();
+        
+        final CloseableHttpClient httpClient = HttpClients.custom()
+                .setConnectionManager(connectionManager)
+                .evictExpiredConnections()
+                .evictIdleConnections(
+                        TimeValue.of(httpClientConfiguration.getIdleConnectionEvictionThresholdInSeconds()))
+                .build();
+        
+        final ClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(httpClient);
+        
+        final RestTemplate restTemplate = restTemplateBuilder
+                .requestFactory(() -> requestFactory)
+                .setConnectTimeout(httpClientConfiguration.getConnectionTimeoutInSeconds())
+                .build();
+        
         setRestTemplateMessageConverters(restTemplate);
         return restTemplate;
     }