Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Message archiving for FIFO topic owners

Message archiving provides the ability to archive a single copy of all messages published to your topic. You can store published messages within your topic by enabling the message archive policy on the topic, which enables message archiving for all subscriptions linked to that topic. Messages can be archived for a minimum of one day to a maximum of 365 days.

Additional charges apply when setting an archive policy. For pricing information, see Amazon SNS pricing.

Create a message archive policy using the Amazon Web Services Management Console

To view, edit, and deactivate a message archiving topic policy

Create a message archive policy using the API

To create a message archive policy using the API, you need to add the attribute ArchivePolicy to your topic. You can set an ArchivePolicy using the API actions CreateTopic and SetTopicAttributes. ArchivePolicy has a single value, MessageRetentionPeriod, which represents the number of days Amazon SNS retains messages. To activate message archiving for your topic, set the MessageRetentionPeriod to an integer value greater than zero. For example, to retain messages in your archive for 30 days, set the ArchivePolicy to:

{
    "ArchivePolicy": {
        "MessageRetentionPeriod": "30"
    }
}

To disable message archiving for your topic, and clear the archive, unset the ArchivePolicy, as follows:

{}

Create a message archive policy using the SDK

To use an Amazon SDK, you must configure it with your credentials. For more information, see Shared config and credentials files in the Amazon SDKs and Tools Reference Guide.

The following code example shows how to set the ArchivePolicy for an Amazon SNS topic to retain all messages published to the topic for 30 days.

// Specify the ARN of the Amazon SNS topic to set the ArchivePolicy for.
String topicArn =
    "arn:aws-cn:sns:us-east-2:123456789012:MyArchiveTopic.fifo";

// Set the MessageRetentionPeriod to 30 days for the ArchivePolicy.
String archivePolicy =
    "{\"MessageRetentionPeriod\":\"30\"}";

// Set the ArchivePolicy for the Amazon SNS topic
SetTopicAttributesRequest request = new SetTopicAttributesRequest()
    .withTopicArn(topicArn)
    .withAttributeName("ArchivePolicy")
    .withAttributeValue(archivePolicy);
sns.setTopicAttributes(request);

Create a message archive policy using Amazon CloudFormation

To create an archive policy using Amazon CloudFormation see AWS::SNS::Topic in the Amazon CloudFormation User Guide.

Grant access to an encrypted archive

Before a subscriber can begin replaying messages from an encrypted topic, you must complete the following steps. Because past messages are replayed, Amazon SNS needs to be provisioned Decrypt access to the KMS key that was used to encrypt the messages in the archive.

Grant decrypt permissions to Amazon SNS

In order for Amazon SNS to access encrypted messages from within your topic’s archive and replay them to subscribed endpoints, you must enable the Amazon SNS service principle to decrypt these messages.

The following is an example policy that is required to allow the Amazon SNS service principal to decrypt stored messages during a replay of historical messages from within your topic.

{
    "Sid": "Allow SNS to decrypt archived messages",
    "Effect": "Allow",
    "Principal": {
        "Service": "sns.amazonaws.com"
    },
    "Action": [
        "kms:Decrypt",
        "kms:GenerateDataKey"
    ],
    "Resource": "*"
}

Monitor message archive metrics using Amazon CloudWatch

You can monitor archived messages using Amazon CloudWatch using the following metrics. To be notified of anomalies in your workloads and help avoid impact, you can configure Amazon CloudWatch alarms on these metrics. For more details, see Logging and monitoring in Amazon SNS.

The GetTopicAttributes API has a BeginningArchiveTime property, which represents the oldest timestamp at which a subscriber can start a replay. The following represents a sample response for this API action:

{
 "ArchivePolicy": {
    "MessageRetentionPeriod": "<integer>"
  },
  "BeginningArchiveTime": "<timestamp>",
  ...
}