How CloudTrail works
You automatically have access to the CloudTrail Event history when you create your Amazon Web Services account. The Event history provides a viewable, searchable, downloadable, and immutable record of the past 90 days of recorded management events in an Amazon Web Services Region.
For an ongoing record of events in your Amazon Web Services account past 90 days, create a trail.
CloudTrail Event history
You can easily view the last 90 days of management events in the CloudTrail console by going
to the Event history page. You can also view the event history by
running the aws cloudtrail
lookup-events command, or the LookupEvents API operation. You can search events in
Event history by filtering for events on a single attribute.
For more information, see Working with CloudTrail Event history.
The Event history is not connected to any trails that exist in your account and is not affected by configuration changes you make to your trails.
There are no CloudTrail charges for viewing the Event
history page or running the lookup-events command.
CloudTrail trails
A trail is a configuration that enables delivery of events to an Amazon S3 bucket that you specify. You can also deliver and analyze events in a trail with Amazon CloudWatch Logs and Amazon EventBridge.
Trails can log CloudTrail management events, data events, and Insights events.
You can create two types of trails for an Amazon Web Services account: multi-Region trails and single-Region trails.
- Multi-Region trails
-
When you create a multi-Region trail, CloudTrail records events in all Amazon Web Services Regions in the Amazon partition in which you are working and delivers the CloudTrail event log files to an S3 bucket that you specify. If an Amazon Web Services Region is added after you create a multi-Region trail, that new Region is automatically included, and events in that Region are logged. Creating a multi-Region trail is a recommended best practice since you capture activity in all Regions in your account. All trails you create using the CloudTrail console are multi-Region. You can convert a single-Region trail to a multi-Region trail by using the Amazon CLI. For more information, see Creating a trail in the console and Converting a trail that applies to one Region to apply to all Regions.
- Single-Region trails
-
When you create a single-Region trail, CloudTrail records the events in that Region only. It then delivers the CloudTrail event log files to an Amazon S3 bucket that you specify. You can only create a single-Region trail by using the Amazon CLI. If you create additional single trails, you can have those trails deliver CloudTrail event log files to the same S3 bucket or to separate buckets. This is the default option when you create a trail using the Amazon CLI or the CloudTrail API. For more information, see Creating, updating, and managing trails with the Amazon Command Line Interface.
Note
For both types of trails, you can specify an Amazon S3 bucket from any Region.
If you have created an organization in Amazon Organizations, you can create an organization trail that logs all events for all Amazon accounts in that organization. Organization trails can apply to all Amazon Regions, or the current Region. Organization trails must be created using the management account or delegated administrator account, and when specified as applying to an organization, are automatically applied to all member accounts in the organization. Member accounts can see the organization trail, but cannot modify or delete it. By default, member accounts do not have access to the log files for an organization trail in the Amazon S3 bucket.
By default, when you create a trail in the CloudTrail console, your event log files are encrypted with a KMS key. If you choose not to enable SSE-KMS encryption, your event logs are encrypted using Amazon S3 server-side encryption (SSE). You can store your log files in your bucket for as long as you want. You can also define Amazon S3 lifecycle rules to archive or delete log files automatically. If you want notifications about log file delivery and validation, you can set up Amazon SNS notifications.
CloudTrail publishes log files multiple times an hour, about every 5 minutes. These log files contain API calls from services in the account that support CloudTrail. For more information, see CloudTrail supported services and integrations.
Note
CloudTrail typically delivers logs within an average of about 5 minutes of an API call. This time is not guaranteed.
If you misconfigure your trail (for example, the S3 bucket is unreachable), CloudTrail will attempt to redeliver the log files to your S3 bucket for 30 days, and these attempted-to-deliver events will be subject to standard CloudTrail charges. To avoid charges on a misconfigured trail, you need to delete the trail.
CloudTrail captures actions made directly by the user or on behalf of the user by an
Amazon service. For example, an Amazon CloudFormation CreateStack call can result in
additional API calls to Amazon EC2, Amazon RDS, Amazon EBS, or other services as required by the
Amazon CloudFormation template. This behavior is normal and expected. You can identify if the action
was taken by an Amazon service with the invokedby field in the CloudTrail
event.
The following table provides information about tasks you can perform on trails.
| Task | Description |
|---|---|
|
Configure your trails to log read-only, write-only, or all management events. |
|
|
You can use advanced event selectors to create fine-grained
selectors to log only those data events of interest. When you use
advanced event selectors, you can filter on the
|
|
|
Configure your trails to log Insights events to help you identify and respond to unusual activity associated with management API calls. Additional charges apply for Insights events. You will be charged
separately if you enable Insights for both trails and event data
stores. For more information, see Amazon CloudTrail Pricing |
|
|
After you enable CloudTrail Insights on a trail, you can view up to 90 days of Insights events by using the CloudTrail console or the Amazon CLI. |
|
|
After you enable CloudTrail Insights on a trail, you can download a CSV or JSON file containing up to the past 90 days of Insights events for your trail. |
|
|
Subscribe to a topic to receive notifications about log file delivery to your bucket. Amazon SNS can notify you in multiple ways, including programmatically with Amazon Simple Queue Service. NoteIf you want to receive SNS notifications about log file deliveries from all Regions, specify only one SNS topic for your trail. If you want to programmatically process all events, see Using the CloudTrail Processing Library. |
|
|
Find and download your log files from the S3 bucket. |
|
|
You can configure your trail to send events to CloudWatch Logs. You can then use CloudWatch Logs to monitor your account for specific API calls and events. NoteIf you configure a trail that applies to all Regions to send events to a CloudWatch Logs log group, CloudTrail sends events from all Regions to a single log group. |
|
|
Log file encryption provides an extra layer of security for your log files. |
|
|
Log file integrity validation helps you verify that log files have remained unchanged since CloudTrail delivered them. |
|
|
You can share log files between accounts. |
|
|
You can aggregate log files from multiple accounts to a single bucket. |
|
|
Analyze your CloudTrail output with a partner solution that integrates with CloudTrail. Partner solutions offer a broad set of capabilities, such as change tracking, troubleshooting, and security analysis. |
You can deliver one copy of your ongoing management events to your S3 bucket at no
charge from CloudTrail by creating a trail, however, there are Amazon S3 storage charges. For
more information about CloudTrail pricing, see Amazon CloudTrail Pricing
CloudTrail Insights events
Amazon CloudTrail Insights help Amazon users identify and respond to unusual activity associated with
API calls and API error rates by continuously analyzing CloudTrail management events. CloudTrail Insights
analyzes your normal patterns of API call volume and API error rates, also called the
baseline, and generates Insights events when the call volume or error
rates are outside normal patterns. Insights events on API call volume are generated for
write management APIs, and Insights events on API error rate are generated for
both read and write management APIs.
By default, CloudTrail trails and event data stores don't log Insights events. You must configure your trail or event data store to log Insights events. For more information, see Logging Insights events with the Amazon Web Services Management Console and Logging Insights events with the Amazon Command Line Interface.
Additional charges apply for Insights events. You will be charged separately if you enable
Insights for both trails and event data stores. For more information, see Amazon CloudTrail Pricing
Viewing Insights events for trails and event data stores
CloudTrail supports Insights events for both trails and event data stores, however, there are some differences in how you view and access Insights events.
Viewing Insights events for trails
If you have Insights events enabled on a trail, and CloudTrail detects unusual activity, Insights events are logged to a different folder or prefix in the destination S3 bucket for your trail. You can also see the type of insight and the incident time period when you view Insights events on the CloudTrail console. For more information, see Viewing CloudTrail Insights events for trails in the CloudTrail console.
After you enable CloudTrail Insights for the first time on a trail, it can take up to 36 hours for CloudTrail to deliver the first Insights event, if unusual activity is detected.
Viewing Insights events for event data stores
To log Insights events in CloudTrail Lake, you need a destination event data store that logs Insights events and a source event data store that enables Insights and logs management events. For more information, see Create an event data store for CloudTrail Insights events with the console.
After you enable CloudTrail Insights for the first time on the source event data store, it can take up to 7 days for CloudTrail to deliver the first Insights event to the destination event data store, if unusual activity is detected.
If you have CloudTrail Insights enabled on a source event data store and CloudTrail detects unusual activity, CloudTrail delivers Insights events to your destination event data store. You can then query your destination event data store to get information about your Insights events and can optionally save the query results to an S3 bucket. For more information, see Create or edit a query and View sample queries in the CloudTrail console.
You can view the Insights Events dashboard to visualize the Insights events in your destination event data store. For more information about Lake dashboards, see View CloudTrail Lake dashboards.
CloudTrail channels
CloudTrail supports service-linked channels.
- Service-linked channels
-
Amazon services can create a service-linked channel to receive CloudTrail events on your behalf. The Amazon service creating the service-linked channel configures advanced event selectors for the channel and specifies whether the channel applies to all Regions, or the current Region.
You can use the CloudTrail console or Amazon CLI to view information about any CloudTrail service-linked channels created by Amazon Web Services.