Can I use a remote network call in a synchronous custom process?
November 2012 and newer releases, Process Designer, Custom Processes
When researching converting an external event to a custom process please note: external events that call out over the network are poor candidates for migrations to synchronous custom processes. The reason for this is that changes in network environments can cause timeouts which if they occur repeated will cause a cascading failure. Repeated failures will cause the SPM to be automatically disabled.
A typical example of a cascading failure of this type is an object event handler attached to the creation of an incident. This handler will be called during techmail each time an incident is created. There is a processing limit of 5 seconds for this operation, if the network response has not been returned in the allotted time it is possible that the failure of the object event handler will impact the running of mail processor and ultimately techmail -s, if the failure were not noticed quickly techmail -s could be placed in no-utils. This would have a significant business impact for most users.
It is possible to convert some of these types of external events to asynchronous processes, but the user must not have a need for "real-time" processing as there is no guarantee on the immediacy of the processing of the request.
For further information refer to: