Retention
Retention is simply defined as how long the server keeps articles. Most users want retention to be long enough so that they don't need to access the server every day. Conversely, overly long retention can overwhelm users with slow computers or network connections by making the article lists inordinately large.
Retention is generally quoted separately for text and binary articles, though it may also vary between different groups within these categories. The times vary greatly according to the amount of storage available on the servers and continually increasing traffic. As of 2009, it is common for average news providers to have text retention of over 1000 days and binary retention of over 200 days. Large news providers offer text retention up to 2480 days and binary retention of 850 days or more. It's important to understand that retention time varies between different newsgroups within the text and binary categories.
It can be difficult for end users to accurately measure the retention of a server. One common method is to examine the oldest articles in a group and examine the Date: headers, but this is not always accurate. Some articles in a group may be retained for longer than others, articles from remote servers do not always arrive promptly, and at times the date headers are simply incorrect. A sampling of many or all articles, preferably in more than one newsgroup, is required to detect such anomalies.
News servers do not have unlimited storage, and due to this fact they can only hold posts for a short length of time before they must delete them in order to make room for new posts. This is a particular problem to binary newsgroups which transmit large volumes of articles.
For news servers provided by Internet Service Providers as part of a user's subscription package, typical retention rates are usually only 2–4 days. For premium news servers, this often rises to 6–12 months. Many commercial providers are now advancing to 520 or more days of retention.
Read more about this topic: News Server Operation
Famous quotes containing the word retention:
“Unless a group of workers know their work is under surveillance, that they are being rated as fairly as human beings, with the fallibility that goes with human judgment, can rate them, and that at least an attempt is made to measure their worth to an organization in relative terms, they are likely to sink back on length of service as the sole reason for retention and promotion.”
—Mary Barnett Gilson (1877–?)