I have a question regarded the threaded publishing that is mentioned in the 6.7 upgrade documentation. It mentions that in previous releases you could launch multiple Editions simultaneously to process concurrently. Is this referring to editions that publish to different sites. Will this be changed in 6.7? So you can only publish 1 edition at a time regardless of what site it publishes to?
Previously, each Edition spawned a single thread, and it was possible to launch multiple Editions simultaneously to process concurrently. In the new mechanism, each Edition spawns multiple threads, but the currently-running Edition consumes all threads. Editions generally run sequentially, but each Edition is assigned a priority. If an Edition with a higher-priority is launched, Rhythmyx stops processing of the Edition that is currently running and processes the newly-launched Edition. When processing of the high-priority Edition is complete, processing of the original Edition resumes.
In 6.6+, you can publish multiple editions at the same time, irrespective of which site they publish to.
However, the behavior is a bit different than it was in 6.5 and earlier. Each item that is published is dumped into a queue. If you have an edition that publishes 1000 pages, there will be 1000 items in the queue. There are multiple worker threads (the number is configurable) that take items out of the queue and deliver (publish) them.
At any time, any other edition may run that adds more items to the queue. There is no exclusion on site id, as there was in 6.5 and earlier.
In addition, there are multiple priority levels, so that an edition can be marked with a higher priority. The higher priority items go to the front of the queue and get published first.
While this scenario does not contain any exclusivity mechanism, in practice the items from a single edition will dominate the front of the queue, and all of the worker threads will be working on items from the same edition most of the time.
Finally, there is also “transactional” behavior in 6.6+. When an edition is published, the items are written to a temporary file store on the server. When the last item has been published, ALL of the items are copied from the temporary storage to the website definition. This greatly reduces the time that the website is in an inconsistent state.
This transactional behavior is used by the Filesystem, FTP and SFTP publishers.