Happy Holidays from Twin Oaks Computing!
755 Maleta Lane, Suite 203
Castle Rock, CO 80108
December Newsletter 2012
Welcome to the Twin Oaks Computing, Inc Newsletter!
Our monthly newsletter brings you news and information about Twin Oaks Computing and our CoreDX DDS middleware. Be sure to "like", "follow" and "friend" us on our Social Networking sites for fun facts, free giveaways, and stories about Communications Middleware, Technology, and Twin Oaks Computing.
Twin Oaks Computing Announces Royalty Free Deployments
Twin Oaks Computing is thrilled to announce we are now offering unlimited royalty free runtime deployments for your CoreDX DDS enabled applications and systems. This translates into several benefits for your organization.
DDS licensing doesn't have to be complicated. In addition to free deployments, we offer very simple licensing for binary and source code packages. Coupled with Free Evaluations and Free Licenses for University or IR&D projects, CoreDX DDS is easily accessible.
For more information about CoreDX DDS Royalty Free Deployments, click here...
Office Holiday Closure
Please note: Our offices will be closed Saturday, December 22nd thru Tuesday, January 2nd to allow our employees time with their families during the Holidays. We will re-open on Wednesday, January 3rd. We pride ourselves on our superior customer service, and ask that if you anticipate the need for technical support during this time to schedule an appointment in the next few weeks. This will allow time for us to adequately address your request.
All of us at Twin Oaks Computing wish everyone a safe and Happy Holiday season.
Congratulations to our recent winner!
Steve Dynes won a flash drive in our Facebook Flash Drive Giveaway contest. For your chance to win, "like" us on Facebook.
Frequently Asked Question: Using keys in data types
Question: I have found that I need to make every member of my data types a key, in order to not lose any data samples. If I remove the key definitions, my subscribing applications lose a lot of samples. Why does a key definition affect data delivery?
Answer: The use of keys in your application data types does (indirectly) affect data delivery because of the way CoreDX DDS handles instances. Each unique key value will have its own instance. If there are no keys on a data type, it will have only 1 instance.
Data samples are collected and grouped within instances. For example, with a History.kind = KEEP_LAST and a History.Depth = 1, DDS will keep one sample for each instance in the system. If you have only 1 instance, only one sample will be kept in the DataWriter and DataReader caches (newer samples will push out the older samples, possibly before they read by the application). If you have multiple instances, multiple samples will be kept (one for each instance). If your entire data structure is a key, then every unique sample will be its own instance, and nothing will be dropped.
That being said, you do not need to have instances in order to avoid lost samples. You can instead use a QoS configuration:
With this QoS configuration, no samples will ever be overwritten (because of KEEP_ALL) and you will be limited to a fixed number of samples for each instance (max_samples_per_instance). If samples accumulate at the DataReader up to the limits configured in its Resource Limits QoS policy, the DataReader will stop accepting new samples. With the same QoS on the DataWriter, the DataWriter will also start accumulating samples up to the limits configured in its Resource Limits QoS policy. Any new writes() performed by the application will either block the application or return an error (as configured in the Reliability QoS policy on the DataWriter).
Click here to learn more
More Upcoming Events
December 22, 2012 - January 2, 2013 Twin Oaks Computing Holiday Office Closure
January 24, 2013 Real Time Embedded Computing Conference, Santa Clara, CA, USA. Read more...
March 18-21, 2013 OMG Technical Meeting, Reston, VA, USA. Read more...
June 18, 2013 Real Time Embedded Computing Conference, Denver, CO, USA. Read more...
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