Monitoring AWS DataSync activity with Amazon CloudWatch - AWS DataSync

Monitoring AWS DataSync activity with Amazon CloudWatch

You can monitor AWS DataSync using Amazon CloudWatch, which collects and processes raw data from DataSync into readable, near real-time metrics. These statistics are retained for a period of 15 months.

By default, DataSync metrics data is automatically sent to CloudWatch in 5-minute intervals. For more information, see What is Amazon CloudWatch? in the Amazon CloudWatch User Guide.

Amazon CloudWatch metrics for DataSync

Amazon CloudWatch provides metrics that you can use to get information about DataSync performance and troubleshoot issues. You can see CloudWatch metrics for DataSync by use the following tools:

  • CloudWatch console

  • CloudWatch CLI

  • CloudWatch API

  • DataSync console (task execution page)

For information, see Using Amazon CloudWatch metrics in the Amazon CloudWatch User Guide.

DataSync metrics use the AWS/DataSync namespace and provide metrics for the following dimensions:

  • AgentId – The unique ID of the agent.

  • TaskId – The unique ID of the task. It takes the form of task-01234567890abcdef.

The AWS/DataSync namespace includes the following metrics.

Metric Description


The physical number of bytes transferred over the network after compression was applied. In most cases, this number is less than BytesTransferred unless the data isn't compressible.

Unit: Bytes


The total number of bytes of data that are prepared at the destination location.

Unit: Bytes


The total number of bytes of data that are prepared at the source location.

Unit: Bytes


The total number of bytes that are involved in the transfer. For the number of bytes sent over the network, see BytesCompressed.

Unit: Bytes


The total number of bytes of data that are verified at the destination location.

Unit: Bytes


The total number of bytes of data that are verified at the source location.

Units: Bytes


The total logical size of all files that have been transferred to the destination location.

Unit: Bytes


The total number of files that are prepared at the destination location.

Unit: Count


The total number of files that are prepared at the source location.

Unit: Count


The actual number of files or metadata that were transferred over the network. This value is calculated and updated on an ongoing basis during the TRANSFERRING phase. It's updated periodically when each file is read from the source location and sent over the network.

If failures occur during a transfer, this value can be less than EstimatedFilesToTransfer. This value can also be greater than EstimatedFilesTransferred in some cases. This element is implementation-specific for some location types, so don't use it as an indicator for a correct file number or to monitor your task execution.

Unit: Count


The total number of files that are verified at the destination location.

Unit: Count


The total number of files that are verified at the source location.

Unit: Count

Amazon EventBridge events for DataSync

Amazon EventBridge events describe changes in DataSync resources. You can set up rules to match these events and route them to one or more target functions or streams. Events are emitted on a best-effort basis.

DataSync transfer events

The following EventBridge events are available for DataSync transfers.

Agent state changes
Event Description
Online The agent is configured properly and is available to use. This status is the normal running status for an agent.
Offline The agent's VM is turned off or the agent is in an unhealthy state and has been out of contact with the service for 5 minutes or longer. When the issue that caused the unhealthy state is resolved, the agent returns to ONLINE status.
Location state changes
Event Description
Adding DataSync is adding a location.
Available The location is created and is available to use.
Task state changes
Event Description
Available The task was created and is ready to start.
Running The task is in progress and functioning properly.
Unavailable The task isn't configured properly and can't be used. You may see this when an agent associated with the task goes offline.
Queued Another task is running and using the same agent. DataSync runs tasks in series (first in, first out).
Task execution state changes
Event Description
Queueing DataSync is waiting for another task that's using the same agent to finish.
Launching DataSync is initializing the task execution.
Preparing DataSync is determining which files need to be transferred.
Transferring DataSync is performing the actual transfer of your data.
Verifying DataSync performs a full data and metadata integrity verification to ensure that the data in your destination is an exact copy of your source.
Success The transfer is successful.
Error The transfer failed.

DataSync Discovery events

The following EventBridge events are available for DataSync Discovery.

Storage system state changes
Event Description
Storage System Connectivity Status Change The connection between your DataSync agent and on-premises storage system changed. For details, see your CloudWatch logs.
Discovery job state changes
Event Description
Discovery Job State Change The status of your discovery job changed. For more information, see discovery job statuses.
Discovery Job Expiration Soon Your discovery job expires soon. This includes any information the discovery job collected about your on-premises storage system. Before the job expires, you can export collected data by using the DescribeStorageSystemResources and DescribeStorageSystemResourceMetrics operations.

Allowing DataSync to upload logs to CloudWatch log groups

DataSync requires sufficient permissions to send logs to your CloudWatch log group. When you create a task using the console, DataSync can automatically create an IAM resource policy with the correct permissions for you.

The following example is a resource policy that grants these permissions.

{ "Statement": [ { "Sid": "DataSyncLogsToCloudWatchLogs", "Effect": "Allow", "Action": [ "logs:PutLogEvents", "logs:CreateLogStream" ], "Principal": { "Service": "" }, "Condition": { "ArnLike": { "aws:SourceArn": [ "arn:aws:datasync:region:account-id:task/*" ] }, "StringEquals": { "aws:SourceAccount": "account-id" } }, "Resource": "arn:aws:logs:region:account-id:log-group:*:*" } ], "Version": "2012-10-17" }

The policy uses condition statements to ensure that only DataSync tasks from the specified account have access to the specified CloudWatch log group. We recommend using the aws:SourceArn and aws:SourceAccount global condition context keys in these condition statements to protect against the confused deputy problem. For more information, see Cross-service confused deputy prevention.

To specify the DataSync task or tasks, replace region with the Region code for the AWS Region where the tasks are located and replace account-id with the AWS account ID of the account that contains the tasks. To specify the CloudWatch log group, replace the same values. You can also modify the Resource statement to target specific log groups. For more information about using SourceArn and SourceAccount, see Global condition keys in the IAM User Guide.

To apply the policy, save this policy statement to a file on your local computer. Then run the following AWS CLI command to apply the resource policy:

aws logs put-resource-policy --policy-name trustDataSync --policy-document file://full-path-to-policy-file

Run this command using the same AWS account and AWS Region were you activated your DataSync agent.

For information, see Working with log groups and log streams in the Amazon CloudWatch Logs User Guide.

Monitoring your DataSync task from the command line

You can track your DataSync tasks with the AWS Command Line Interface or the standard Unix watch utility.

Monitoring your task by using the AWS CLI

To monitor the status of your DataSync task with the CLI, use the describe-task-execution command.

aws datasync describe-task-execution \ --task-execution-arn 'arn:aws:datasync:region:account-id:task/task-id/execution/task-execution-id'

This command returns information about a task execution similar to that shown following.

{ "BytesCompressed": 0, "BytesTransferred": 0, "BytesWritten": 0, "EstimatedFilesToTransfer": 0, "EstimatedBytesToTransfer": 0, "FilesTransferred": 0, "Options": { "VerifyMode": "POINT_IN_TIME_CONSISTENT", "Atime": "BEST_EFFORT", "Mtime": "PRESERVE", "Uid": "INT_VALUE", "Gid": "INT_VALUE", "PreserveDevices": "NONE", "PosixPermissions": "PRESERVE", "PreserveDeletedFiles": "PRESERVE", "OverwriteMode": "NEVER", "TaskQueueing": "ENABLED" }, "Result": { "PrepareDuration": 4355, "PrepareStatus": "Ok", "TransferDuration": 5889, "TransferStatus": "Ok", "VerifyDuration": 4538, "VerifyStatus": "Pending" }, "StartTime": 1532658526.949, "Status": "VERIFYING", "TaskExecutionArn": "arn:aws:datasync:us-east-1:112233445566:task/task-08de6e6697796f026/execution/exec-04ce9d516d69bd52f" }

If the task execution succeeds, the value of Status changes to SUCCESS. If the describe-task-execution command fails, the result sends error codes that can help you troubleshoot issues. For information about the error codes, see TaskExecutionResultDetail in the DataSync API Reference.

Monitoring your task by using the watch utility

To monitor the progress of your task in real time from the command line, you can use the standard Unix watch utility. Task execution duration values are measured in milliseconds.

The watch utility doesn't recognize the DataSync alias. The following example shows how to invoke the CLI directly.

# pass '-n 1' to update every second and '-d' to highlight differences $ watch -n 1 -d \ "aws datasync describe-task-execution --task-execution-arn 'arn:aws:datasync:region:account-id:task/task-id/execution/task execution-id'"