updateNumber

In the streamMap definition, the updateNumber element maps a column in Event Stream Processor source stream that are populated by a unique number generated by the adapter, not provided as part of the data from RMDS.

Summary

adapter                                      (required, limit one)
  |----publication                           (required, limit one)
  |----streamMaps                            (required, limit one)
  |      '----streamMap                      (required)
  |             |----dataField               (required)
  |             |----hiResTimestampField     (optional)
  |             |----imageField              (required for L2 data)
  |             |----itemName                (required, limit one)
  |             |----itemStale               (optional)
  |             |----marketByOrderKeyField   (required)
  |             |----marketByPriceKeyField   (required)
  |             |----marketMakerKeyField     (required)
  |             |----nullField               (optional)
  |             |----respTypeNumField        (optional)
  |             |----sequenceNumber          (optional)
  |             |----serviceName             (optional)
  |             '----updateNumber            (optional)
  |----rfa                                   (required, limit one)
  '----itemLists                             (required, limit one)
         '----itemList                       (required)
                '----item                    (optional)

Parent

streamMap

Children

None

Attributes

Name	Description	Requirement
key	true or false, depending on whether this column is part of the source stream's unique key	See Notes
name	A string that appears in log entries	Optional

Notes

The adapter infers whether or not a column is part of the stream's unique key from the schema; the key attribute is included here only for backward compatibility.

The adapter maintains a separate counter for each RIC to which it is subscribed. Each time it receives an update for a RIC, it increments its counter for that RIC. This number is sent to the column in the stream mapped by the updateNumber element.

Many source stream definitions include a column specification similar to:

<Column datatype="int64" name="Id"/>

This line specifies a unique ID for the source stream. The updateNumber pseudo-field is a good match for this column in the input adapter map file.

Example

<streamMap name="marketByOrderStream">
        <itemName key="true"/>
        <updateNumber />
        <itemStale/>
        <dataField name="BID"/>
        <dataField name="ASK"/>
        <dataField name="TRDPRC_1"/>
        <dataField name="ACVOL_1"/>
        <dateTimeField timeName="TIMACT" dateName="ACTIV_DATE"/>
</streamMap>

In this example, the second column of the source stream is mapped to the update number provided by the adapter. This column is also identified as part of the source stream's unique key. To see additional examples, look in the $ESP_RMDSOMM_HOME/examples directory.