Using  setservicedata as an example, describe the possible effects of concurrency on Grid service operations, and the 
need to document these to enable consistency of results for clients.

The assumption behind servicedata is that 'set' may be assumed to behave naturally if there are no concurrent client 
requests.  It may be assumed that the implementation will not itself - as a result of internal timer events, for example
 - create conflicting 'set' events (exceptions should be documented). Set operations may delay the application of the 
new setting for some time period, and the use of a sequence of 'set' events is not guaranteed to be executed in order of
 submission. Again, exceptions should be documented. Advice on the correct approaches to the 'single client' restriction
, and references to approaches for handling concurrency should be given.

Grid services may define their own operations for setting of service data, but developers should be aware of the need to
 clearly define the semantics. .