Using aws cloudwatch with queue

Question

Pulumi · Accepted Answer

When integrating AWS CloudWatch with Amazon Simple Queue Service (SQS), the primary goal is to monitor the activity of the queue and set alarms based on certain thresholds or conditions. You can use CloudWatch to collect and track metrics, collect and monitor log files, set alarms, and automatically react to changes in your AWS resources.

AWS CloudWatch can be used to monitor SQS metrics like the number of messages sent or received, the number of messages deleted, or the number of messages available, among others. To create a CloudWatch alarm that triggers whenever certain thresholds are met for these metrics, you can use Pulumi's `aws.cloudwatch.MetricAlarm` resource.

The following Pulumi TypeScript program creates an AWS SQS queue and sets up a CloudWatch alarm to monitor the number of messages visible in the queue:

```typescript
import * as aws from "@pulumi/aws";

// Create an AWS SQS queue.
const queue = new aws.sqs.Queue("myQueue", {
    // Set queue attributes as needed, for example enabling long polling
    receiveMessageWaitTimeSeconds: 20,
});

// Create a CloudWatch metric alarm for monitoring the SQS queue.
const queueAlarm = new aws.cloudwatch.MetricAlarm("myQueueAlarm", {
    // Alarm when the number of messages visible in the queue is greater than 100
    metricQuery: {
        id: "m1",
        returnData: true,
        metric: {
            namespace: "AWS/SQS",
            metricName: "ApproximateNumberOfMessagesVisible",
            dimensions: {
                QueueName: queue.name, // Reference the queue name
            },
            // Use 'Sum' to calculate the sum of the occurrences of the monitored event
            stat: "Sum",
            period: 300, // Period to sample the metric, in seconds (5 minutes here)
        },
    },
    evaluationPeriods: 1, // The number of periods to evaluate for the alarm
    threshold: 100, // The value against which the specified statistic is compared
    comparisonOperator: "GreaterThanOrEqualToThreshold", // Trigger the alarm when the threshold is breached
    alarmDescription: "Alarm when queue message count exceeds 100",
});

export const queueUrl = queue.id; // Export the URL of the created SQS queue.
export const queueArn = queue.arn; // Export the ARN (Amazon Resource Name) of the SQS queue.
export const queueAlarmName = queueAlarm.name; // Export the name of the created alarm.
```

In this program, we perform the following steps:

1. Import the `aws` module from the Pulumi AWS package.
2. Create an SQS queue named "myQueue" with an attribute to enable long polling that can help reduce costs by limiting the number of empty responses when there are no messages available to return in reply to a `ReceiveMessage` request and eliminating false empty responses by querying the queue fewer times.
3. Define a CloudWatch metric alarm named "myQueueAlarm" with a `metricQuery` that references the `ApproximateNumberOfMessagesVisible` metric from the `AWS/SQS` namespace. We use this metric to monitor the number of messages available for retrieval from the queue.
4. Configure the alarm to evaluate the metric sum over a period of 300 seconds (5 minutes).
5. Set the alarm threshold as 100, so if the number of messages visible is greater than or equal to this number, the alarm transitions to the `ALARM` state.
6. Set the `comparisonOperator` to `GreaterThanOrEqualToThreshold`, which triggers the alarm when the metric value is greater than or equal to the threshold.
7. Set an alarm description for clarity.
8. Export values such as the queue URL, queue ARN, and the alarm name so that they can be accessed outside of Pulumi, such as in the Pulumi console or the AWS console.

With this setup, CloudWatch provides monitoring for the SQS queue, and you can set up notifications or other automated actions based on the state of the alarm. For example, you could create an AWS SNS topic and subscribe to it to receive notifications when the alarm state changes.

Please ensure that you have installed the Pulumi CLI, configured your AWS credentials, and have initialized a Pulumi project before running this code.