# Crawler scheduler API
Scheduler

The Crawler scheduler API describes AWS Glue crawler data types, along with the API for creating, deleting, updating, and listing crawlers.

## Data types
 —  data types  —
+ [Schedule structure](#aws-glue-api-crawler-scheduler-Schedule)

## Schedule structure
Schedule

A scheduling object using a `cron` statement to schedule an event.

**Fields**
+ `ScheduleExpression` – UTF-8 string.

  A `cron` expression used to specify the schedule (see [Time-Based Schedules for Jobs and Crawlers](https://docs.aws.amazon.com/glue/latest/dg/monitor-data-warehouse-schedule.html). For example, to run something every day at 12:15 UTC, you would specify: `cron(15 12 * * ? *)`.
+ `State` – UTF-8 string (valid values: `SCHEDULED` \$1 `NOT_SCHEDULED` \$1 `TRANSITIONING`).

  The state of the schedule.

## Operations
 —  operations  —
+ [UpdateCrawlerSchedule action (Python: update\$1crawler\$1schedule)](#aws-glue-api-crawler-scheduler-UpdateCrawlerSchedule)
+ [StartCrawlerSchedule action (Python: start\$1crawler\$1schedule)](#aws-glue-api-crawler-scheduler-StartCrawlerSchedule)
+ [StopCrawlerSchedule action (Python: stop\$1crawler\$1schedule)](#aws-glue-api-crawler-scheduler-StopCrawlerSchedule)

## UpdateCrawlerSchedule action (Python: update\$1crawler\$1schedule)
UpdateCrawlerSchedule (update\$1crawler\$1schedule)

Updates the schedule of a crawler using a `cron` expression. 

**Request**
+ `CrawlerName` – *Required:* UTF-8 string, not less than 1 or more than 255 bytes long, matching the [Single-line string pattern](aws-glue-api-common.md#aws-glue-api-regex-oneLine).

  The name of the crawler whose schedule to update.
+ `Schedule` – UTF-8 string.

  The updated `cron` expression used to specify the schedule (see [Time-Based Schedules for Jobs and Crawlers](https://docs.aws.amazon.com/glue/latest/dg/monitor-data-warehouse-schedule.html). For example, to run something every day at 12:15 UTC, you would specify: `cron(15 12 * * ? *)`.

**Response**
+ *No Response parameters.*

**Errors**
+ `EntityNotFoundException`
+ `InvalidInputException`
+ `VersionMismatchException`
+ `SchedulerTransitioningException`
+ `OperationTimeoutException`

## StartCrawlerSchedule action (Python: start\$1crawler\$1schedule)
StartCrawlerSchedule (start\$1crawler\$1schedule)

Changes the schedule state of the specified crawler to `SCHEDULED`, unless the crawler is already running or the schedule state is already `SCHEDULED`.

**Request**
+ `CrawlerName` – *Required:* UTF-8 string, not less than 1 or more than 255 bytes long, matching the [Single-line string pattern](aws-glue-api-common.md#aws-glue-api-regex-oneLine).

  Name of the crawler to schedule.

**Response**
+ *No Response parameters.*

**Errors**
+ `EntityNotFoundException`
+ `SchedulerRunningException`
+ `SchedulerTransitioningException`
+ `NoScheduleException`
+ `OperationTimeoutException`

## StopCrawlerSchedule action (Python: stop\$1crawler\$1schedule)
StopCrawlerSchedule (stop\$1crawler\$1schedule)

Sets the schedule state of the specified crawler to `NOT_SCHEDULED`, but does not stop the crawler if it is already running.

**Request**
+ `CrawlerName` – *Required:* UTF-8 string, not less than 1 or more than 255 bytes long, matching the [Single-line string pattern](aws-glue-api-common.md#aws-glue-api-regex-oneLine).

  Name of the crawler whose schedule state to set.

**Response**
+ *No Response parameters.*

**Errors**
+ `EntityNotFoundException`
+ `SchedulerNotRunningException`
+ `SchedulerTransitioningException`
+ `OperationTimeoutException`