August 15, 2023

Scenario: Catching flow metrics from a Job – Docs for ESB 6.x

Scenario: Catching flow metrics from a Job

The following basic Job aims at catching the number of rows being passed in the flow
processed. The measures are taken twice, once after the input component, that is, before
the filtering step and once right after the filtering step, that is, before the output

  • Drop the following components from the Palette to the design workspace: tMysqlInput, tFlowMeter (x2),
    tMap, tLogRow, tFlowMeterCatcher and

  • Link components using row main connections and click on the label to give
    consistent name throughout the Job, such as US_States from
    the input component and filtered_states for the output from
    the tMap component, for example.

  • Link the tFlowMeterCatcher to the tFileOutputDelimited component using a row main link
    also as data is passed.

  • On the tMysqlInput Component view, configure
    the connection properties as Repository, if the
    table metadata are stored in the Repository. Or else, set the Type as Built-in and configure manually the connection and
    schema details if they are built-in for this Job.

  • The 50 States of the USA are recorded in the table
    states. In order for all 50 entries of the table to get
    selected, the query to run onto the Mysql database is as follows:

    select * from states.

  • Select the relevant encoding type on the
    Advanced settings vertical tab.

  • Then select the following component which is a tFlowMeter and set its properties.

  • Select the check box Use input connection name as
    , in order to reuse the label you chose in the log output
    file (tFileOutputDelimited).

  • The mode is Absolute as there is no reference
    flow to meter against, also no Threshold is to
    be set for this example.


The Thresholds information is
of use within a supervising tool such as
Talend Activity Monitoring Console
in order to get a proportional representation of the flow process. See
Talend Activity Monitoring Console User guide

for more information.

  • Then launch the tMap editor to set the
    filtering properties.

  • For this use case, drag and drop the ID and State columns from the Input area
    of the tMap towards the Output area. No
    variable is used in this example.

  • On the Output flow area (labelled filtered_states in this
    example), click the arrow & plus button to activate the expression filter

  • Drag the State column from the Input area
    (row2) towards the expression filter field and type in
    the rest of the expression in order to filter the state labels starting with the
    letter M. The final expression looks like:

  • Click OK to validate the setting.

  • Then select the second tFlowMeter component
    and set its properties.

  • Select the check box Use input connection name as

  • Select Relative as Mode and in the Reference
    list, select US_States as
    reference to be measured against.

  • Once again, no threshold is used for this use case.

  • No particular setting is required in the tLogRow.

  • Neither does the tFlowMeterCatcher as this
    component’s properties are limited to a preset schema which includes typical log

  • So eventually set the log output component (tFileOutputDelimited).

  • Select the Append check box in order to log
    all tFlowMeter measures.

  • Then save your Job and press F6 to execute


The Run view shows the filtered state labels as
defined in the Job.


In the delimited csv file, the number of rows shown in column count varies between tFlowMeter1 and
tFlowMeter2 as the filtering has then been carried
out. The reference column shows also this difference.

Document get from Talend
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