Receiving incremental updates

DV is able to add, modify and remove individual advertisements by sending mutations. When an advertiser selects an object to be published on a site, DV sends an add mutation. As soon as the object is changed, for instance when the price has been lowered, DV modifies the existing advertisement by sending an update mutation. And when the object has been sold (or the advertiser no longer wishes to advertise the object), DV sends a delete mutation.

As with receiving data in bulk, DV also offers several options for incremental updates:

• Delivery protocols
  Data can be transferred in various ways, for example:
  • DV can send the mutations using a REST service set up by the site;
  • DV can send the mutations using a SOAP service set up by the site;
  • DV can send the mutations via HTTP POST operations to the web server of the site
• Data formats
  DV supports all common file formats like XML, JSON, HTTP Form data, etc.
• Character encoding
  DV supports the most common character encodings like UTF-8 (with or without BOM), ISO 8859-1, ISO 8859-15 and Windows-1252.
• Maximum number of parallel requests
  By default, DV only sends one request at a time (sequential processing). DV can also multiple requests in parallel if the site supports this, which can be beneficial to prevent queues forming. DV will never send multiple requests for the same advertisement at the same time.
• Buffering
  If real-time processing of mutations is not possible, DV can also save up all mutations and send them all together with regular intervals. For example twice a day.