If the adapter is routinely retrieving large files from the enterprise information file system, you can choose to chunk the files into smaller chunks using the file splitting functionality of the adapter. When file splitting is enabled, event files will be split into several chunks and posted to the endpoint separately. The adapter does not reassemble the chunks at the end point, however the adapter provides the required information in the business graph to reassemble the chunks.
When one or more characters such as commas (,), semicolon (;), quotes ( ", ' ), braces ({}) or slashes ( / \ ) are used to separate a business object, the adapter can use this information to split files into smaller chunks. These chunks are forwarded to the server separately and then reassembled by the Event Sequencing feature of WebSphere Process Server. This is called delimiter file splitting and it can be enabled using the SplitCriteria activation specification property.
When event files are split into such chunks, it is important to remember that each chunk creates a business object. This means that the value specified for the PollQuantity property and the number of business objects obtained at the endpoint can be different. When file splitting based on a delimiter is enabled, the PollQuantity property specifies the number of such event files that are present in the Event Store and the class used to split the event file is set in the Splitting Function Class Name activation specification property.
To demonstrate how the PollQuantity value works with delimiter file splitting, consider two event files. The first event file contains a business object and the second file contains two business objects. If the PollQuantity value is 2, then the first business object from the first event file and the next business record from the second event file are sent in the first poll cycle. The second business object from the second file is sent in the next poll cycle.
Name=Smith
Company=IBM
##this is the content which will be skipped by the adapter$$
The adapter will consider the delimiter as ##$$ and skip "this is the content which will be skipped by the adapter".
File splitting by size is performed based on the value specified in the SplitCriteria property. If the event file size is greater than the value specified in the SplitCriteria property, the files is split into chunks and each chunk is posted to the endpoint separately. If the event file size is less than the SplitCriteria value, then the entire event file is posted to the endpoint. When event files are split into chunks, it is important to remember that each chunk creates a business object. This means that the value specified for the PollQuantity property and the number of business objects obtained at the endpoint can be different. While the adapter polls based on the PollQuantity value, the adapter actually processes the number of business objects in the file one at a time. For example, if an event file is chunked into three parts, then one file will be polled and three business objects will be received by the endpoint (since each chunk creates a single business object).
At the endpoint, the adapter does not reassemble chunked data into a single file. Rather, this functionality is handled by the Event Sequencing feature of WebSphere Process Server. However, the Flat Files adapter does provide information about a chunk that enables WebSphere Process Server to reassemble the chunks into a single file. The chunk information is included in the chunkFileName property of the FlatFile wrapper business object. The chunk information includes the chunk size in bytes and the event ID. The event ID of a chunk uses the following form: eventFileLocation_/_timestampStr_/_MofN, where M is the current chunk number and N is the total number of chunks. An example event ID would look like the following: C:\flatfile\eventdir\eventfile.in_/_2005_01_10_10_17_49_864_/_3of5, where timestampStr has the following format: year_month_day_hour_minutes_seconds_milliseconds.
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