Trigger a flow if a periodically executed ClickHouse query returns a non-empty result set.

yaml
type: "io.kestra.plugin.jdbc.clickhouse.trigger"

Wait for a SQL query to return results, and then iterate through rows.

yaml
id: jdbc_trigger
namespace: company.team

tasks:
  - id: each
    type: io.kestra.plugin.core.flow.ForEach
    values: "{{ trigger.rows }}"
    tasks:
      - id: return
        type: io.kestra.plugin.core.debug.Return
        format: "{{ json(taskrun.value) }}"

triggers:
  - id: watch
    type: io.kestra.plugin.jdbc.clickhouse.Trigger
    interval: "PT5M"
    url: jdbc:clickhouse://127.0.0.1:56982/
    username: "{{ secret('CLICKHOUSE_USERNAME') }}"
    password: "{{ secret('CLICKHOUSE_PASSWORD') }}"
    sql: "SELECT * FROM my_table"
    fetchType: FETCH

The JDBC URL to connect to the database.

List of conditions in order to limit the flow trigger.

Default false

DEPRECATED, please use fetchType: FETCH instead. Whether to fetch the data from the query result to the task output. This parameter is evaluated after fetchOne and store.

Default false

DEPRECATED, please use fetchType: FETCH_ONE instead. Whether to fetch only one data row from the query result to the task output. This parameter is evaluated before store and fetch.

Default 10000

Number of rows that should be fetched.

Gives the JDBC driver a hint as to the number of rows that should be fetched from the database when more rows are needed for this ResultSet object. If the fetch size specified is zero, the JDBC driver ignores the value and is free to make its own best guess as to what the fetch size should be. Ignored if autoCommit is false.

Default NONE

Possible Values

STOREFETCHFETCH_ONENONE

The way you want to store data.

FETCH_ONE - output the first row. FETCH - output all rows as output variable. STORE - store all rows to a file. NONE - do nothing.

Default PT1M

Format duration

Interval between polling.

The interval between 2 different polls of schedule, this can avoid to overload the remote system with too many calls. For most of the triggers that depend on external systems, a minimal interval must be at least PT30S. See ISO_8601 Durations for more information of available interval values.

Parameters

A map of parameters to bind to the SQL queries. The keys should match the parameter placeholders in the SQL string, e.g., : parameterName.

The database user's password.

The SQL query to run.

SubType string

Possible Values

CREATEDSUBMITTEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINTRESUBMITTED

List of execution states after which a trigger should be stopped (a.k.a. disabled).

Default false

DEPRECATED, please use fetchType: STORE instead. Whether to fetch data row(s) from the query result to a file in internal storage. File will be saved as Amazon Ion (text format). See Amazon Ion documentation This parameter is evaluated after fetchOne but before fetch.

The time zone id to use for date/time manipulation. Default value is the worker's default time zone id.

The database user.

Map containing the first row of fetched data.

Only populated if fetchOne parameter is set to true.

SubType object

List of map containing rows of fetched data.

Only populated if fetch parameter is set to true.

The number of rows fetched.

Only populated if store or fetch parameter is set to true.

Format uri

The URI of the result file on Kestra's internal storage (.ion file / Amazon Ion formatted text file).

Only populated if store is set to true.

Format partial-time

SLA daily deadline

Use it only for DAILY_TIME_DEADLINE SLA.

Format partial-time

SLA daily end time

Use it only for DAILY_TIME_WINDOW SLA.

Format partial-time

SLA daily start time

Use it only for DAILY_TIME_WINDOW SLA.

Default DURATION_WINDOW

Possible Values

DAILY_TIME_DEADLINEDAILY_TIME_WINDOWDURATION_WINDOWSLIDING_WINDOW

The type of the SLA

The default SLA is a sliding window (DURATION_WINDOW) with a window of 24 hours.

Format duration

The duration of the window

Use it only for DURATION_WINDOW or SLIDING_WINDOW SLA. See ISO_8601 Durations for more information of available duration value. The start of the window is always based on midnight except if you set windowAdvance parameter. Eg if you have a 10 minutes (PT10M) window, the first window will be 00: 00 to 00: 10 and a new window will be started each 10 minutes

Format duration

The window advance duration

Use it only for DURATION_WINDOW SLA. Allow to specify the start time of the window Eg: you want a window of 6 hours (window=PT6H), by default the check will be done between: 00: 00 and 06: 00, 06: 00 and 12: 00, 12: 00 and 18: 00, and 18: 00 and 00: 00. If you want to check the window between 03: 00 and 09: 00, 09: 00 and 15: 00, 15: 00 and 21: 00, and 21: 00 and 3: 00, you will have to shift the window of 3 hours by settings windowAdvance: PT3H

The flow id.

The namespace of the flow.

The namespace of the flow or the prefix if prefix is true.

Default false

If we must look at the flow namespace by prefix (checked using startsWith). The prefix is case sensitive.

The flow id.

The namespace of the flow.

Format time

The time to test must be after this one.

Must be a valid ISO 8601 time with offset.

Format time

The time to test must be before this one.

Must be a valid ISO 8601 time with offset.

Default {{ trigger.date }}

The time to test.

Can be any variable or any valid ISO 8601 time. By default, it will use the trigger date.

List of labels to match in the execution.

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

Min items 1

The list of conditions to validate.

If any condition is true, it will allow the event's execution.

String against which to match the execution namespace depending on the provided comparison.

Possible Values

EQUALSPREFIXSUFFIX

Comparison to use when checking if namespace matches. If not provided, it will use EQUALS by default.

Default false

Whether to look at the flow namespace by prefix. Shortcut for comparison: PREFIX.

Only used when comparison is not set

SubType

The list of preconditions to wait for

The key must be unique for a trigger because it will be used to store the previous evaluation result.

Validation RegExp ^[a-zA-Z0-9][a-zA-Z0-9_-]*

Min length 1

A unique id for the condition

Default true

Whether to reset the evaluation results of SLA conditions after a first successful evaluation within the given time period.

By default, after a successful evaluation of the set of SLA conditions, the evaluation result is reset, so, the same set of conditions needs to be successfully evaluated again in the same time period to trigger a new execution. This means that to create multiple executions, the same set of conditions needs to be evaluated to true multiple times. You can disable this by setting this property to false so that, within the same period, each time one of the conditions is satisfied again after a successful evaluation, it will trigger a new execution.

Default

{
  "type": "DURATION_WINDOW"
}

Define the time period (or window) for evaluating preconditions.

You can set the type of sla to one of the following values:

DURATION_WINDOW: this is the default type. It uses a start time (windowAdvance) and end time (window) that are moving forward to the next interval whenever the evaluation time reaches the end time, based on the defined duration window. For example, with a 1-day window (the default option: window: PT1D), the SLA conditions are always evaluated during 24h starting at midnight (i.e. at time 00: 00: 00) each day. If you set windowAdvance: PT6H, the window will start at 6 AM each day. If you set windowAdvance: PT6H and you also override the window property to PT6H, the window will start at 6 AM and last for 6 hours — as a result, Kestra will check the SLA conditions during the following time periods: 06: 00 to 12: 00, 12: 00 to 18: 00, 18: 00 to 00: 00, and 00: 00 to 06: 00, and so on.
SLIDING_WINDOW: this option also evaluates SLA conditions over a fixed time window, but it always goes backward from the current time. For example, a sliding window of 1 hour (window: PT1H) will evaluate executions for the past hour (so between now and one hour before now). It uses a default window of 1 day.
DAILY_TIME_DEADLINE: this option declares that some SLA conditions should be met "before a specific time in a day". With the string property deadline, you can configure a daily cutoff for checking conditions. For example, deadline: "09: 00: 00" means that the defined SLA conditions should be met from midnight until 9 AM each day; otherwise, the flow will not be triggered.
DAILY_TIME_WINDOW: this option declares that some SLA conditions should be met "within a given time range in a day". For example, a window from startTime: "06: 00: 00" to endTime: "09: 00: 00" evaluates executions within that interval each day. This option is particularly useful for declarative definition of freshness conditions when building data pipelines. For example, if you only need one successful execution within a given time range to guarantee that some data has been successfully refreshed in order for you to proceed with the next steps of your pipeline, this option can be more useful than a strict DAG-based approach. Usually, each failure in your flow would block the entire pipeline, whereas with this option, you can proceed with the next steps of the pipeline as soon as the data is successfully refreshed at least once within the given time range.

Format duration

The duration of the window

Deprecated, use timeWindow.window instead.

Format duration

The window advance duration

Deprecated, use timeWindow.windowAdvance instead.

Min items 1

The list of conditions to exclude.

If any condition is true, it will prevent the event's execution.

Possible Values

FIRSTLASTSECONDTHIRDFOURTH

Are you looking for the first or the last day in the month?

Possible Values

MONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAYSATURDAYSUNDAY

The day of week.

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

Possible Values

MONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAYSATURDAYSUNDAY

The day of week.

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

SubType string

Possible Values

CREATEDSUBMITTEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINTRESUBMITTED

List of states that are authorized.

SubType string

Possible Values

CREATEDSUBMITTEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINTRESUBMITTED

List of states that aren't authorized.

Format date-time

The date to test must be after this one.

Must be a valid ISO 8601 datetime with the zone identifier (use 'Z' for the default zone identifier).

Format date-time

The date to test must be before this one.

Must be a valid ISO 8601 datetime with the zone identifier (use 'Z' for the default zone identifier).

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

SubType string

Possible Values

CREATEDSUBMITTEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINTRESUBMITTED

List of states that are authorized.

SubType string

Possible Values

CREATEDSUBMITTEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINTRESUBMITTED

List of states that aren't authorized.

ISO 3166-1 alpha-2 country code. If not set, it uses the country code from the default locale.

It uses the Jollyday library for public holiday calendar that supports more than 70 countries.

Default {{ trigger.date}}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

ISO 3166-2 country subdivision (e.g., provinces and states) code.

It uses the Jollyday library for public holiday calendar that supports more than 70 countries.