Openstack-swift object updater
swift-object-updater [CONFIG] [-h|--help] [-v|--verbose] [-o|--once]
The object updater is responsible for updating object information in container listings. It will check to see if there are any locally queued updates on the filesystem of each devices, what is also known as async pending file(s), walk each one and update the container listing.
For example, suppose a container server is under load and a new object is put into the system. The object will be immediately available for reads as soon as the proxy server responds to the client with success. However, the object server has not been able to update the object listing in the container server. Therefore, the update would be queued locally for a later update. Container listings, therefore, may not immediately contain the object. This is where an eventual consistency window will most likely come in to play.
In practice, the consistency window is only as large as the frequency at which the updater runs and may not even be noticed as the proxy server will route listing requests to the first container server which responds. The server under load may not be the one that serves subsequent listing requests – one of the other two replicas may handle the listing.
The options are as follows:
More in depth documentation in regards to swift-object-updater and also about Openstack-Swift as a whole can be found at http://swift.openstack.org/index.html