Modify cloudwatch sink to use FixedThreadPool

data-prepper-plugins/cloudwatch-logs/src/main/java/org/opensearch/dataprepper/plugins/sink/cloudwatch_logs/CloudWatchLogsSink.java

@@ -74,7 +74,7 @@ public CloudWatchLogsSink(final PluginSetting pluginSetting,
             dlqPushHandler = new DlqPushHandler(pluginFactory, pluginSetting, pluginMetrics, cloudWatchLogsSinkConfig.getDlq(), region, role, "cloudWatchLogs");
         }
 
-        Executor executor = Executors.newCachedThreadPool();
+        Executor executor = Executors.newFixedThreadPool(cloudWatchLogsSinkConfig.getWorkers());
 
         CloudWatchLogsDispatcher cloudWatchLogsDispatcher = CloudWatchLogsDispatcher.builder()
                 .cloudWatchLogsClient(cloudWatchLogsClient)

data-prepper-plugins/cloudwatch-logs/src/main/java/org/opensearch/dataprepper/plugins/sink/cloudwatch_logs/config/CloudWatchLogsSinkConfig.java

@@ -17,6 +17,7 @@
 
 public class CloudWatchLogsSinkConfig {
     public static final int DEFAULT_RETRY_COUNT = 5;
+    public static final int DEFAULT_NUM_WORKERS = 10;
 
     @JsonProperty("aws")
     @Valid
@@ -43,6 +44,11 @@ public class CloudWatchLogsSinkConfig {
     @Max(15)
     private int maxRetries = DEFAULT_RETRY_COUNT;
 
+    @JsonProperty(value = "workers", defaultValue = "10")
+    @Min(1)
+    @Max(50)
+    private int workers = DEFAULT_NUM_WORKERS;
+
     public AwsConfig getAwsConfig() {
         return awsConfig;
     }
@@ -67,4 +73,8 @@ public int getMaxRetries() {
         return maxRetries;
     }
 
+    public int getWorkers() {
+        return workers;
+    }
+
 }

data-prepper-plugins/cloudwatch-logs/src/test/java/org/opensearch/dataprepper/plugins/sink/cloudwatch_logs/CloudWatchLogsSinkTest.java

@@ -67,6 +67,8 @@ void setUp() {
         when(mockCloudWatchLogsSinkConfig.getThresholdConfig()).thenReturn(thresholdConfig);
         when(mockCloudWatchLogsSinkConfig.getLogGroup()).thenReturn(TEST_LOG_GROUP);
         when(mockCloudWatchLogsSinkConfig.getLogStream()).thenReturn(TEST_LOG_STREAM);
+        when(mockCloudWatchLogsSinkConfig.getMaxRetries()).thenReturn(3);
+        when(mockCloudWatchLogsSinkConfig.getWorkers()).thenReturn(10);
 
         when(mockPluginSetting.getName()).thenReturn(TEST_PLUGIN_NAME);
         when(mockPluginSetting.getPipelineName()).thenReturn(TEST_PIPELINE_NAME);

data-prepper-plugins/cloudwatch-logs/src/test/java/org/opensearch/dataprepper/plugins/sink/cloudwatch_logs/config/CloudWatchLogsSinkConfigTest.java

@@ -13,6 +13,8 @@
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.notNullValue;
 
+import java.util.Random;
+
 class CloudWatchLogsSinkConfigTest {
     private CloudWatchLogsSinkConfig cloudWatchLogsSinkConfig;
     private AwsConfig awsConfig;
@@ -42,11 +44,23 @@ void GIVEN_new_sink_config_WHEN_get_log_group_called_SHOULD_return_null() {
         assertThat(new CloudWatchLogsSinkConfig().getLogGroup(), equalTo(null));
     }
 
+    @Test
+    void GIVEN_new_sink_config_WHEN_get_num_threads_called_SHOULD_return_default_value() {
+        assertThat(new CloudWatchLogsSinkConfig().getWorkers(), equalTo(CloudWatchLogsSinkConfig.DEFAULT_NUM_WORKERS));
+    }
+
     @Test
     void GIVEN_new_sink_config_WHEN_get_log_stream_called_SHOULD_return_null() {
         assertThat(new CloudWatchLogsSinkConfig().getLogStream(), equalTo(null));
     }
 
+    @Test
+    void GIVEN_num_threads_configured_SHOULD_return_the_configured_value() throws NoSuchFieldException, IllegalAccessException {
+        int testValue = (new Random()).nextInt();
+        ReflectivelySetField.setField(cloudWatchLogsSinkConfig.getClass(), cloudWatchLogsSinkConfig, "workers", testValue);
+        assertThat(cloudWatchLogsSinkConfig.getWorkers(), equalTo(testValue));
+    }
+
     @Test
     void GIVEN_empty_sink_config_WHEN_deserialized_from_json_SHOULD_return_valid_log_group_and_log_stream() throws NoSuchFieldException, IllegalAccessException {
         ReflectivelySetField.setField(cloudWatchLogsSinkConfig.getClass(), cloudWatchLogsSinkConfig, "logGroup", LOG_GROUP);