Cisco Systems 5.2.x manual Resumption of Interrupted and Paused File Transfers, File Size, 19-5

Chapter 19 Content Distribution and Delivery

Concepts

Resumption of Interrupted and Paused File Transfers

File transfer resumption in DMS-CD helps to compensate for bandwidth throttling and other constraints that might limit how many assets you can provision at a time. Such constraints commonly include a limited number of nighttime hours when deployments are certain not to disrupt the digital signage messages or Cisco Cast programs that your organization shows to its targeted audiences.

Values that you define at Deployment Manager > Deployment Preferences determine in part how DMS-CD responds to any incomplete file transfers, but its response also considers the size of individual files within a deployment package. Finally, a DMP might generate a queue for itself if it is the target of multiple deployments, because a DMP can receive data from only one deployment package at a time.

Outages and Other Disruptions

When the scheduled delivery of a deployment package is interrupted — by a power failure or a network outage, for example — while you are provisioning assets, the file transfer process might resume automatically at a later time.

•When sufficient time remains during the same deployment window that was interrupted, your file transfer resumes after your retry interval has elapsed.

Tip You set this interval in the “Deployment retry time (in seconds)” field.

•When the interruption extends past the end of the scheduled deployment window and the deployment is scheduled to recur, file transfer resumes automatically the next time that the deployment is scheduled to run.

•When the interruption extends past the end of the scheduled deployment window but you did not schedule the deployment to recur, file transfer stops without success and does not recur.

Likewise, the maximum number of times that DMS-CD tries to provision assets for an interrupted deployment package is constrained by the “Deployment retry count” value.

File Size

When your deployment is scheduled to recur, DMS-CD will either pause or stop the transfer of assets whose transfer did not finish during the deployment window. DMS-CD uses file size to determine whether an incomplete file is paused or stopped:

•Transfer is stopped for any partially transferred file whose size is less than 6 MB, no matter how much of it was transferred. Transfer of a 100 KB file, for example, must start over again from the first byte when the deployment recurs.

•Transfer is paused for any partially transferred file whose size is greater than 6 MB, no matter how little of it was transferred. A file whose size is 1.6 GB, for example, is paused when none of your DMPs can download more than 200 MB per day.

Tip	• Calculations of this kind can help you to estimate how far in advance you should schedule the first instance of a
	recurring deployment. When you know already, for example, that one-fifth of the data within a deployment package can
	transfer to DMP local storage during the deployment window that you reserved, then you know also that the deployment must
	recur on at least 5 separate days or your DMPs will not receive their assets in time.
	• We recommend that your deployments recur once each day.
	• When a deployment is scheduled to recur at any other interval than once per day — such as once per week — then this is the
	interval after which any paused transfer will resume.

	User Guide for Cisco Digital Media Manager 5.2.x
OL-15762-03		19-5