Working with the Design View

Once you add a stream component to a Siddhi application in the design view, the Define Stream form appears below the grid. To configure the stream, following information can be specified in this form:

Stream Name : A unique name for the stream. This should be specified in title caps, and without spaces (e.g., ProductionDataStream).

Attributes: Attributes of streams are specified as name and type pairs in the Attributes table.

The above creates a stream with the following configuration:

define stream SweetProductionStream (amount double, name string);

Once you add a source component to a Siddhi application in the design view, the Define Source form appears below the grid. To configure the event source, following information can be specified in this form:

• Type: This specifies the transport type via which the events are received. The value should be entered in lower case (e.g., tcp).

• Options: To add this section, you need to click Properties next to Source and select the Options check box. This section allows you to add properties you want to configure for the selected transport. You can click + Option to add a new option. The value must be entered in the <PROPERTY_NAME>=<'PROPERTY_VALUE'> format (e.g., context='SweetProductionData').

• Properties: To add this section, you need to click Properties next to Source and select the Map check box.This section specifies the format in which the events are received via the source, and allows you to define the mapping so that incoming events can be converted to Siddhi events. The event format is specified in the Name field of the Type section in lower case (e.g., binary). To configure the mapping based on the mapper type you selected, you can click Properties next to Map and select the Type check box and/or the Attribute Mapping check box.

This source configuration is represented as follows in the source view.

@Source(type = 'tcp', context='SweetProductionData', @map(type='binary'))

The details entered in the above Table Configuration form creates a table definition as follows:

define table ShipmentDetails(name string, supplier string, amount double);

The details entered in the above Window Configuration form creates a window definition as follows:

define window FiveMinTempWindow (roomNo int, temp double) time(5 min) output all events;

The details entered in the above Trigger Configuration form creates a trigger definition as follows:

define trigger FiveMinTriggerStream at every 5 min;

Incremental aggregation allows you to obtain aggregates in an incremental manner for a specified set of time periods. For more information, see Siddhi Query Guide - Incremental Aggregation.

Once a connection is made from a stream to an aggregation, move the cursor over the aggregation and click the settings icon on the aggregation (shown below) to open the Aggregation Configuration form.
 

The following information can be entered in this form:

• Input: In this section, define a unique name for the aggregation in the Name field.
• Select: This section specifies the attributes to be included in the aggregation query. In the Select field, you can select All attributes to perform the aggregation for all the attributes of the stream specified under Input , or select User Defined Attributes to select specific attributes. If you select User Defined Attributes, the User Defined Attributes table appears. In this table, you can enter the the specific attributes to be selected, and specify the name with which each attribute is included in the aggregation. If an attribute value needs to be processed before it is included in the aggregation, you can enter the required expression to process it.
• Aggregate By: Here, you can specify the time values based on which the aggregates are calculated.

The details entered in the above Aggregation Configuration form creates an aggregation definition as follows:

define aggregation TradeAggregation
    from TradeStream
    select symbol, avg(price) as avgPrice, sum(price) as total
    
aggregate every seconds...years;

The details entered in the above Function Configuration form creates a function definition as follows:

define function concatFN[JAVASCRIPT] return string {
    var str1 = data[0];
    var str2 = data[1];
    var str3 = data[2];
    var responce = str1 + str2 + str3;
    return responce;
};

This icon represents a query to project the events in an input stream to an output stream. This invoves selectng the attributes to be included in the output, renaming attributes, introducing constant values, and using mathematical and/or logical expressions. For more information, see Siddhi Query Guide - Query Projection. 

Once you connect the query to an input stream (source) and an output stream (target), move the cursor over the query and click the settings icon on the projection query (shown below) to open the Query Configuration form.

The following information needs to be entered in this form:

• Input: This section specifies the stream to be considered as the input stream with the events to which the query needs to be applied. The input stream connected to the query as the source is automatically displayed.
• Select: This section specifies the attributes to be included in the output. In the Select field, you can select All Attributes to select all the attributes of the events, or select User Defined Attributes to select specific attributes, and the expressions to convert them as required to generate output events.
• Output: This section specifies the action to be performed on the output event. The fields to be configured in this section are as follows:
  • Operation: This field specifies the operation to be performed on the generated output event (e.g., Insert to insert events to a selected stream/table/window).
  • Into: This field specifies the stream/table/window in which the operation specified need to be performed.
  • For: This field specifies whether the operation needs to be performed for all output events, only current events or for only expired events.

The details entered in the above Query Configuration form creates a query definition as follows:

from TradeStream
select symbol, avg(price) as averagePrice, sum(amount) as total
insert all events into OutputStream;

Once you connect the query to an input stream (source) and an output stream (target), move the cursor over the query and click the settings icon on the filter query (shown below) to open the Query Configuration form.

The following information needs to be entered in this form:

• Input: This section specifies the stream to be considered as the input stream with the events to which the query needs to be applied. The input stream connected to the query as the source is automatically displayed.
• Select: This section specifies the attributes to be included in the output. In the Select field, you can select All Attributes to select all the attributes of the events, or select User Defined Attributes to select specific attributes, and the expressions to convert them as required to generate output events.
• Output: This section specifies the action to be performed on the output event. The fields to be configured in this section are as follows:
  • Operation: This field specifies the operation to be performed on the generated output event (e.g., Insert to insert events to a selected stream/table/window).
  • Into: This field specifies the stream/table/window in which the operation specified need to be performed.
  • For: This field specifies whether the operation needs to be performed for all output events, only current events or for only expired events.

• Stream Handlers: This section can be used to specify the filter criterion. To do this, select Filter in the Stream Handler field, and then enter the filter condition in the Filter Condition field.

  A Siddhi application can have multiple stream handlers. To add another stream handler, click the + Stream Handler. Multiple functions, filters and windows can be defined within the same form as stream handlers.

The details entered in the above Query Configuration form creates a query definition with a filter as follows:

from TradeStream[sum(amount) > 10000]
select symbol, avg(price) as averagePrice, sum(amount) as total
insert all events into OutputStream;

Window queries include a window to select a subset of events to be processed based on a specific criterion. For more information, see Siddhi Query Guide - (Defined) Window .

Once you connect the query to an input stream (source) and an output stream (target), move the cursor over the query and click the settings icon on the window query (shown below) to open the Query Configuration form.

• Input: This section specifies the stream to be considered as the input stream with the events to which the query needs to be applied. The input stream connected to the query as the source is automatically displayed.
• Select: This section specifies the attributes to be included in the output. In the Select field, you can select All Attributes to select all the attributes of the events, or select User Defined Attributes to select specific attributes, and the expressions to convert them as required to generate output events.
• Output: This section specifies the action to be performed on the output event. The fields to be configured in this section are as follows:
  • Operation: This field specifies the operation to be performed on the generated output event (e.g., Insert to insert events to a selected stream/table/window).
  • Into: This field specifies the stream/table/window in which the operation specified need to be performed.
  • For: This field specifies whether the operation needs to be performed for all output events, only current events or for only expired events.

• Stream Handlers: This section can be used to configure the window. To do this, select Window in the Stream Handler field, and then enter information in the following fields.

  • Window Name: A unique name for the window.
  • Parameter Value: This specifies a criterion based on which the window selects a subset of events to be processed. Multiple parameters can be added by clicking +Attribute.

  A Siddhi application can have multiple stream handlers. To add another stream handler, click the + Stream Handler. Multiple functions, filters and windows can be defined within the same form as stream handlers.

The details entered in the above Query Configuration form creates a query definition with a window as follows:

from TradeStream#window.time(1 month)
select symbol, avg(price) as averagePrice, sum(amount) as total
insert all events into OutputStream;

• Streams
• Tables
• Triggers
• Windows

Once you connect two Siddhi components to the join query as sources and another Siddhi component as the target, move the cursor over the join query and click the settings icon on the projection query (shown below) to open the Join Query Configuration form.

The following information needs to be entered in this form:

Configurations common for both sources

• Select: This section specifies the attributes to be included in the output. In the Select field, you can select All Attributes to select all the attributes of the events, or select User Defined Attributes to select specific attributes, and the expressions to convert them as required to generate output events.
• Output: This section specifies the action to be performed on the output event. The fields to be configured in this section are as follows:
  • Operation: This field specifies the operation to be performed on the generated output event (e.g., Insert to insert events to a selected stream/table/window).
  • Into: This field specifies the stream/table/window in which the operation specified need to be performed.
  • For: This field specifies whether the operation needs to be performed for all output events, only current events or for only expired events.

The stream handlers need to be separateley configured for the left source and the right source of the join.

Configurations for each source

The following configurations are entered under Left Source and Right Source.

• Input: Thes section specifies the input. This can be a stream, aggregation, window or a table for each source.
• Stream Handlers: This section defines the functions, filters, and windows that can be included in the query to extract events from the left/right source.

A join query is configured as follows:

• Common configurations
  
• Left source configuration
  
   
• Right source configuration
   

The above configurations result in creating the following join query.

from TempStream[temp > 30.0]#window.time(1 min) as T
  join RegulatorStream[isOn == false]#window.length(1) as R
  on T.roomNo == R.roomNo
select T.roomNo, R.deviceID, 'start' as action
insert into RegulatorActionStream;

• Streams
• Tables
• Aggregations
• Windows

• Streams
• Tables
• Windows