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 > IBM i > Overview of WebSphere Adapter for IBM i > Technical overview > Inbound processing
Event recovery
You can configure the adapter for inbound processing so that it supports event recovery in case of abrupt termination. When event recovery is specified, the adapter persists the event state in an event recovery table that resides on a data source. Event recovery along with event persistence is not the default; you must specify it by enabling once-only delivery of events during adapter configuration.
Data source
Event recovery for inbound processing requires that a JDBC data source be configured.
You use the administrative console to configure the data source. You select a JDBC provider (for example, Derby) and then create a data source.
Event recovery table
You can create the event recovery table manually, or you can have the adapter create the event table. The value of the EP_CreateTable configuration property determines whether the event recovery table is created automatically. The default value of this property is True (create the table automatically).
To create the table manually, use the information provided in the following table.
Event recovery table fields Table field name Type Description EVNTID VARCHAR(255) Transaction ID for the tRFC (Transactional Remote Function Call) protocol. The tRFC protocol significantly improves the reliability of the data transfer, but it does not ensure that the order of ALE transactions specified in the application is observed. Event ordering is also affected by the number of event listeners. However, at some point all ALE transactions are transferred.
EVNTSTAT INTEGER Event processing status. Possible values are:
- 0 (Created)
- 1 (Executed)
- 0 with XID (In Progress)
- -1 (Failed)
XID VARCHAR(255) An XA resource tracks the transaction IDs (XIDs) in the event recovery table. The adapter queries and updates that XID field. During recovery, WebSphere Application Server calls the resource adapter, querying it for XA resources, and then does transaction recovery on them. The XA resource is used to enable assured once delivery. Make sure the activation specification property Assured Once Delivery is set to true.
BQTOTAL INTEGER Total number of IDocs in the packet. BQPROC INTEGER Sequence number of the IDoc in the packet that the adapter is currently processing. EVNTDATA VARCHAR(255) Not used. To use event recovery for multiple endpoints, configure a separate event recovery table for each endpoint, although you can use the same data source (for example, Derby) to hold all the event recovery tables.
For retries of the failure of event delivery in conditions such as abrupt termination of the adapter or any process failure like network issue, these failed events will be moved to the failed events queue path by the adapter; as soon as it is restarted.