Asynchronous process
When there is a lot of data to process some services don’t return the results directly but start an asynchronous process (or thread). The thread writes results to a log which can be accessed at another time.
When a service starts a thread it returns a HTTP code 202 Accepted instead of 200 OK.
XML returned
When a thread is started, the service output includes the following thread XML:
<thread id="[thread id]"
name="[thread name]"
username="[username of user starting thread]"
groupid="[ID of group if applicable or -1]"
status="[initialised|
inprogress|
error|
warning|
cancelled|
failed|
complete]">
[<message>[explanation or error]</message>]
[thread specific XML]
</thread>
For example:
<thread id="349f4fbcd872d514751f7809acf4d888"
name="Moving thread for group test-local5"
username="jjones"
groupid="240"
status="initialised">
<message>Finding URIs</message>
</thread>
Thread services
Various services can be used to:
- list current threads
- check a thread’s progress
- get a thread's logs
- cancel a thread
See the Thread category under Services for more details.
Services that have a group in their URL are generally used by group contributors or managers while the others are used by system administrators.