# Enrich events

***

Semi-static data update infrequently but is critical to be applied promptly within a process when the change occurs. Typically, core business data warehouses manage this type of data, with updates made available either through distribution technology or at the end of the day using traditional batch processing methods. However, a common solution employed by forward-looking businesses is the use of a distributed caching and messaging platforms.

For this example mobile events are enriched with device information using the `TAC` code as the reference data lookup attribute, the `IMEI` value combines both the TAC and device serial code. To gain the required values the `IMEI` value is split into the required component parts using a user defined plugin, see class `IMEIDecoder` for more information on how this was implemented. The resulting `TAC` is used to perform the reference data lookup against the linked data store, Apache Geode in this example, and binds the returned value to the event.

## Use case configuration

*File: app-enrichment.env*

```bash
SOURCEFILE=conf/sources/mobileSimulatedStream.yaml
REFERENCEDATA=conf/sources/mobileReferenceData.yaml
ENGINEFILE=conf/usecases/enrichment/mobileEventEnrichmentProcessWithSelect.yaml
PUBLISHFILE=conf/publishers/enrichedMobileEventFile.yaml
```

The 'REFERENCEDATA' variable defines the platform reference data configuration which can contain many external data stores, currently only Apache Geode is supported. 

Reference data is co-located, in-memory, within the same process as Joule. This improves processing throughput by removing the need to retrieve data from traditional data stores which are typically out of process. A key feature of the implementation is the ability to load reference data on startup from a connected distributed Geode data cluster. This reduces the I/O overhead on cache misses, this feature is generally known as `Get Initial Image`.

## Pipeline configuration <a href="#processor-configuration" id="processor-configuration"></a>

This pipeline will enrich events with mobile device information providing key data existing to perform the key data request requirement.

#### Processing steps

* Filter events without `IMSI` being set
* Gain from the `IMEI` the `tac` and `device serial` code using a custom tokenizer.
* Filter events without `tac` being set
* Enrich the event with mobile device information using the `tac` as the lookup key

```yaml
processing unit:
  pipeline:
    - filter:
          expression: "(imsi !== null ) ? true : false;"
          
    - tokenizer enricher:
       tokenizers:
        imei : com.fractalworks.streams.examples.telco.enricher.IMEIDecoder
     
    - filter:
          expression: "(tac !== null ) ? true : false;"
          
    - enricher:
       enrich:
        deviceType:
         key: device
         using: deviceStore
    
       stores:
        deviceStore:
         storeName: mobiledevices
         primaryKey: tac
         primaryKeyType: java.lang.String
```

### Output Event

The following fields are added to the processed StreamEvent object.

```
// Some code

```