IBM BPM, V8.0.1, All platforms > Authoring services in Integration Designer > Services and service-related functions > Access external services with adapters > Configure and using adapters > IBM WebSphere Adapters > FTP > Overview of IBM WebSphere Adapter for FTP > Technical overview > Inbound processing
Event store
The event store (event persistence table) is a persistent cache where events are saved until the adapter can process them. The adapter uses event persistence tables to track the inbound requests as they make their way through the system. Each time a file is created in the event directory, the adapter tracks the activity as an event, and updates the status of the event in the event persistence table. The status of each event is continually updated by the adapter for recovery purposes until the events are delivered to a configured export.
If the adapter detects that there is no event persistence table, it automatically creates one when the module is deployed to the runtime environment. Each event persistence table created by the adapter is associated with a specific inbound module. The adapter does not support multiple adapter modules pointing to the same event persistence table.
When the adapter polls the FTP server, it creates an entry in the event persistence table for each event that matches the search criteria specified in the activation specification properties. The adapter records the status of each new entry as NEW. When the adapter sends the event to the function selector for data transformation, it deletes the entry from the event table.
When guaranteed event delivery is not required, the adapter can poll for events without the existence of an event persistence table.
The following figure illustrates the event management flow of the adapter.
Figure 1. Event management flow
- Event recovery
The adapter supports event recovery for inbound processing in case of abrupt termination. During event processing, the adapter persists the event state in an event persistence table located on the data source. You must set up this data source before you can create the event persistence table. - Event store structure
The event persistence table is a persistent cache where events are saved until the adapter can process them.