DynamoDB custom metrics generator.

README.md

@@ -63,6 +63,10 @@ resource.
 
 **CloudFormation** custom resource handler for setting log retention for **CloudWatch** log groups.
 
+## [Lambda-Metrics DynamoDb](https://rafalwrzeszcz-wrzasqpl.github.io/pl.wrzasq.lambda/lambda-metrics/lambda-metrics-dynamodb/)
+
+**CloudWatch** custom metrics for **DynamoDb**.
+
 # Resources
 
 -   [GitHub page with API documentation](https://rafalwrzeszcz-wrzasqpl.github.io/pl.wrzasq.lambda)

lambda-metrics/lambda-metrics-dynamodb/pom.xml

@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+# This file is part of the pl.wrzasq.lambda.
+#
+# @license http://mit-license.org/ The MIT license
+# @copyright 2019 © by Rafał Wrzeszcz - Wrzasq.pl.
+-->
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="
+        http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd
+">
+    <modelVersion>4.0.0</modelVersion>
+
+    <!-- core project settings -->
+    <artifactId>lambda-metrics-dynamodb</artifactId>
+    <packaging>jar</packaging>
+    <parent>
+        <groupId>pl.wrzasq.lambda</groupId>
+        <artifactId>lambda-metrics</artifactId>
+        <version>1.0.31-SNAPSHOT</version>
+        <relativePath>../</relativePath>
+    </parent>
+
+    <!-- project meta info -->
+    <name>WrzasqPl CloudWatch DynamoDb metrics</name>
+    <url>https://rafalwrzeszcz-wrzasqpl.github.io/pl.wrzasq.lambda/lambda-metrics/lambda-metrics-dynamodb/</url>
+    <description>DynamoDb additional CloudWatch metrics.</description>
+    <inceptionYear>2019</inceptionYear>
+
+    <!-- plugins configuration -->
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <configuration>
+                    <usedDependencies>
+                        <usedDependency>com.amazonaws:aws-xray-recorder-sdk-aws-sdk</usedDependency>
+                        <usedDependency>com.amazonaws:aws-xray-recorder-sdk-aws-sdk-instrumentor</usedDependency>
+                        <usedDependency>io.symphonia:lambda-logging</usedDependency>
+                    </usedDependencies>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <!-- project dependencies -->
+    <dependencies>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>lambda-json</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk-cloudwatch</artifactId>
+            <version>1.11.588</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk-dynamodb</artifactId>
+            <version>1.11.588</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-xray-recorder-sdk-aws-sdk</artifactId>
+            <version>2.2.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-xray-recorder-sdk-aws-sdk-instrumentor</artifactId>
+            <version>2.2.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.9.9.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>io.symphonia</groupId>
+            <artifactId>lambda-logging</artifactId>
+            <version>1.0.3</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>1.7.26</version>
+        </dependency>
+    </dependencies>
+</project>

lambda-metrics/lambda-metrics-dynamodb/src/main/checkstyle/java.header

@@ -0,0 +1,8 @@
+^/\*$
+^ \* This file is part of the pl\.wrzasq\.lambda\.$
+^ \*$
+^ \* @license http://mit-license\.org/ The MIT license$
+^ \* @copyright \d{4}[0-9, -]* © by Rafał Wrzeszcz - Wrzasq\.pl\.$
+^ \*/$
+
+^package pl\.wrzasq\.lambda\.metrics\.dynamodb(\..+)?;$

lambda-metrics/lambda-metrics-dynamodb/src/main/java/pl/wrzasq/lambda/metrics/dynamodb/Handler.java

@@ -0,0 +1,81 @@
+/*
+ * This file is part of the pl.wrzasq.lambda.
+ *
+ * @license http://mit-license.org/ The MIT license
+ * @copyright 2019 © by Rafał Wrzeszcz - Wrzasq.pl.
+ */
+
+package pl.wrzasq.lambda.metrics.dynamodb;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import com.amazonaws.services.cloudwatch.AmazonCloudWatchClientBuilder;
+import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.AllArgsConstructor;
+import pl.wrzasq.lambda.json.ObjectMapperFactory;
+import pl.wrzasq.lambda.metrics.dynamodb.model.TableMetricRequest;
+import pl.wrzasq.lambda.metrics.dynamodb.service.CloudWatchDynamoDbMetricGenerator;
+
+/**
+ * CloudWatch Events request handler.
+ *
+ * <p>Required environment variables:</p>
+ *
+ * <dl>
+ *     <dt><tt>METRICS_NAMESPACE</tt></dt>
+ *     <dd>Namespace to use for CloudWatch metrics.</dd>
+ * </dl>
+ *
+ * <p>Recommended memory: 256MB.</p>
+ */
+@AllArgsConstructor
+public class Handler {
+    /**
+     * Metrics namespace to use.
+     */
+    private static final String METRICS_NAMESPACE = System.getenv("METRICS_NAMESPACE");
+
+    /**
+     * JSON handler.
+     */
+    private ObjectMapper objectMapper;
+
+    /**
+     * DynamoDB metrics generator.
+     */
+    private CloudWatchDynamoDbMetricGenerator metricGenerator;
+
+    /**
+     * Default constructure.
+     */
+    public Handler() {
+        this(
+            ObjectMapperFactory.createObjectMapper(),
+            new CloudWatchDynamoDbMetricGenerator(
+                AmazonDynamoDBClientBuilder.standard().build(),
+                AmazonCloudWatchClientBuilder.standard().build(),
+                Handler.METRICS_NAMESPACE
+            )
+        );
+    }
+
+    /**
+     * Handles invocation.
+     *
+     * @param inputStream Request input.
+     * @param outputStream Output stream.
+     * @throws IOException When JSON loading/dumping fails.
+     */
+    public void handle(InputStream inputStream, OutputStream outputStream) throws IOException {
+        try {
+            TableMetricRequest request = this.objectMapper.readValue(inputStream, TableMetricRequest.class);
+
+            this.metricGenerator.generateMetrics(request.getTableName());
+        } finally {
+            outputStream.close();
+        }
+    }
+}

lambda-metrics/lambda-metrics-dynamodb/src/main/java/pl/wrzasq/lambda/metrics/dynamodb/model/TableMetricRequest.java

@@ -0,0 +1,21 @@
+/*
+ * This file is part of the pl.wrzasq.lambda.
+ *
+ * @license http://mit-license.org/ The MIT license
+ * @copyright 2019 © by Rafał Wrzeszcz - Wrzasq.pl.
+ */
+
+package pl.wrzasq.lambda.metrics.dynamodb.model;
+
+import lombok.Data;
+
+/**
+ * Request specifying subject table.
+ */
+@Data
+public class TableMetricRequest {
+    /**
+     * DynamoDb table name.
+     */
+    private String tableName;
+}

lambda-metrics/lambda-metrics-dynamodb/src/main/java/pl/wrzasq/lambda/metrics/dynamodb/service/CloudWatchDynamoDbMetricGenerator.java

@@ -0,0 +1,96 @@
+/*
+ * This file is part of the pl.wrzasq.lambda.
+ *
+ * @license http://mit-license.org/ The MIT license
+ * @copyright 2019 © by Rafał Wrzeszcz - Wrzasq.pl.
+ */
+
+package pl.wrzasq.lambda.metrics.dynamodb.service;
+
+import com.amazonaws.services.cloudwatch.AmazonCloudWatch;
+import com.amazonaws.services.cloudwatch.model.Dimension;
+import com.amazonaws.services.cloudwatch.model.MetricDatum;
+import com.amazonaws.services.cloudwatch.model.PutMetricDataRequest;
+import com.amazonaws.services.cloudwatch.model.StandardUnit;
+import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
+import com.amazonaws.services.dynamodbv2.model.TableDescription;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * CloudWatch metrics handler.
+ */
+public class CloudWatchDynamoDbMetricGenerator {
+    /**
+     * Logger.
+     */
+    private Logger logger = LoggerFactory.getLogger(CloudWatchDynamoDbMetricGenerator.class);
+
+    /**
+     * AWS DynamoDB client.
+     */
+    private AmazonDynamoDB dynamoDb;
+
+    /**
+     * AWS CloudWatch client.
+     */
+    private AmazonCloudWatch cloudWatch;
+
+    /**
+     * Metrics namespace to use.
+     */
+    private String namespace;
+
+    /**
+     * Initializes object.
+     *
+     * @param dynamoDb DynamoDB client.
+     * @param cloudWatch CloudWatch client.
+     * @param namespace Metrics namespace.
+     */
+    public CloudWatchDynamoDbMetricGenerator(AmazonDynamoDB dynamoDb, AmazonCloudWatch cloudWatch, String namespace) {
+        this.dynamoDb = dynamoDb;
+        this.cloudWatch = cloudWatch;
+        this.namespace = namespace;
+    }
+
+    /**
+     * Table metrics generator.
+     *
+     * @param tableName Table name.
+     */
+    public void generateMetrics(String tableName) {
+        this.logger.info("Generating metrics for table: {}.", tableName);
+
+        TableDescription table = this.dynamoDb.describeTable(tableName).getTable();
+
+        this.putSingleMetric(tableName, "ItemCount", table.getItemCount(), StandardUnit.None);
+        this.putSingleMetric(tableName, "TableSizeBytes", table.getTableSizeBytes(), StandardUnit.Bytes);
+    }
+
+    /**
+     * Saves single metric value in CloudWatch.
+     *
+     * @param tableName DynamoDB table name.
+     * @param metricName Metric name.
+     * @param value Metric value.
+     * @param unit Metric unit.
+     */
+    private void putSingleMetric(String tableName, String metricName, double value, StandardUnit unit) {
+        this.cloudWatch.putMetricData(
+            new PutMetricDataRequest()
+                .withNamespace(this.namespace)
+                .withMetricData(
+                    new MetricDatum()
+                        .withMetricName(metricName)
+                        .withValue(value)
+                        .withUnit(unit)
+                        .withDimensions(
+                            new Dimension()
+                                .withName("TableName")
+                                .withValue(tableName)
+                        )
+                )
+        );
+    }
+}

lambda-metrics/lambda-metrics-dynamodb/src/main/resources/logback.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+# This file is part of the pl.wrzasq.lambda.
+#
+# @license http://mit-license.org/ The MIT license
+# @copyright 2019 © by Rafał Wrzeszcz - Wrzasq.pl.
+-->
+<configuration scan="true">
+    <!-- stdout output -->
+    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger - %msg%n%ex{full}</pattern>
+        </encoder>
+    </appender>
+
+    <!-- our logger instances -->
+    <logger name="com.amazonaws">
+        <level value="INFO"/>
+        <appender-ref ref="CONSOLE"/>
+    </logger>
+    <logger name="com.sunrun.cfnresponse">
+        <level value="INFO"/>
+        <appender-ref ref="CONSOLE"/>
+    </logger>
+    <logger name="pl.wrzasq">
+        <level value="INFO"/>
+        <appender-ref ref="CONSOLE"/>
+    </logger>
+</configuration>