Serverless Cloud Function
- Release Notes and Announcements
- Product Introduction
- Purchase Guide
- Billable Items and Billing Modes
- SCF Pricing
- User Guide
- Quota Management
- Managing Functions
- Web Function Management
- Concurrence Management
- Trigger Management
- A Custom Domain Name
- Version Management
- Permission Management
- Managing Monitors and Alarms
- Network Configuration
- Layer Management
- Execution Configuration
- Extended Storage Management
- Triggers
- API Gateway Trigger
- Websocket
- COS Trigger
- CLS Trigger
- Timer Trigger
- CKafka Trigger
- Apache Kafka Trigger
- Development Guide
- Developer Tools
- Serverless Cloud Framework
- Calling SDK Across Functions
- Third-Party Tools
- Malagu Framework
- Code Development
- Node.js
- Java
- Custom Runtime
- Deploying Image as Function
- Web Framework Development
- Practical Tutorial
- Business Development
- ServerlessFramework Practices
- API Gateway
- Using API Gateway to Provide API Service
- TRTC Practices
- COS Practices
- Acquire Image on COS and Create a Thumbnail
- MapReduce Method that Uses WordCount as an Example
- CKafka Practice
- CLS
- CLB Practice
- MPS
- Scheduled Task
- Video Processing
- Success Stories
- Online Video Industry
- API Documentation
- Making API Requests
- Function APIs
- Layer Management APIs
- Async Event Management APIs
- Other APIs
- FAQs
- Related Agreement
Timer Trigger Description
Last updated: 2024-12-02 19:58:17
You can write an SCF function to handle a scheduled task (which can be triggered in seconds). The timer will automatically trigger the function at the specified time. Timer triggers have the following characteristics:
Push model: the timer directly calls the
Invoke API of the function to trigger it at the specified time. The event source mapping is retained in the SCF function.Async invocation: a timer trigger always invokes a function asynchronously, and the result is not returned to the invoker. For more information on invocation types, please see Invocation Types.
Timer Trigger Attributes
Timer name (required): it can contain up to 60 characters out of
a-z, A-Z, 0-9, -, and _ and must begin with a letter and be unique under the same function.Triggering cycle (required): this is the specified function triggering time. You can use the default value in the console or customize a standard cron expression to decide when to trigger the function. For more information on cron expressions, please see below.
Input parameter (optional): it can be a string of up to 4 KB, which can be obtained from the
event parameter of the entry function.Cron Expression
When creating a timer trigger, you can customize the triggering time by using a standard cron expression. Timer triggers can trigger functions in a matter of seconds. In order to be compatible with legacy timer triggers, cron expressions can be written in two ways:
Cron expression syntax 1 (recommended)
A cron expression has seven required fields, separated by spaces.
First | Second | Third | Fourth | Fifth | Sixth | Seventh |
Second | Minute | Hour | Day | Month | Week | Year |
Each field has a corresponding value range:
Field | Value | Wildcards |
Second | An integer between 0 and 59 | , - * / |
Minute | An integer between 0 and 59 | , - * / |
Hours | An integer between 0 and 23 | , - * / |
Day | An integer between 1 and 31 (the number of days in the month needs to be considered) | , - * / |
Month | An integer between 1 and 12 or JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC | , - * / |
Week | An integer between 0 and 6 or SUN, MON, TUE, WED, THU, FRI, SAT; where 0 means Sunday, 1 means Monday, and so on | , - * / |
Year | An integer between 1970 and 2099 | , - * / |
Cron expression syntax 2 (not recommended)
A cron expression has five required fields, separated by spaces.
First | Second | Third | Fourth | Fifth |
Minute | Hour | Day | Month | Week |
Each field has a corresponding value range:
Field | Value | Wildcards |
Minute | An integer between 0 and 59 | , - * / |
Hours | An integer between 0 and 23 | , - * / |
Day | An integer between 1 and 31 (the number of days in the month needs to be considered) | , - * / |
Month | An integer between 1 and 12 or JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC | , - * / |
Week | An integer between 0 and 6 or SUN, MON, TUE, WED, THU, FRI, SAT; where 0 means Sunday, 1 means Monday, and so on | , - * / |
Wildcards
Wildcard | Description |
, (comma) | It represents the union of characters separated by commas; for example, 1, 2, 3 in the "Hour" field means 1:00, 2:00 and 3:00 |
- (hyphen) | It contains all values in the specified range; for example, in the "Day" field, 1-15 contains the 1st to the 15th day of the specified month |
* (asterisk) | It means all values; for example, in the "Hour" field, * means every o'clock |
/ (forward slash) | It specifies the increment; for example, in the "Minute" field, you can enter 1/10 to specify repeating every ten minutes from the first minute on (e.g., at the 11th minute, the 21st minute, the 31st minute, and so on) |
Precautions
When both the "Day" and "Week" fields in a cron expression are specified, they are in an "or" relationship, i.e., the conditions of both are effective separately.
Sample
Below are some examples of cron expressions and their meanings:
Expression | Description |
*/5 * * * * * * | Triggers once every 5 seconds |
0 15 10 1 * * * | Triggers at 10:15 am on the 1st day of every month |
0 15 10 * * MON-FRI * | Triggers every day at 10:15 am Monday through Friday |
0 0 10,14,16 * * * * | Triggers every day at 10 am, 2 pm, and 4 pm |
0 */30 9-17 * * * * | Triggers every half hour from 9 am to 5 pm every day |
0 0 12 * * WED * | Triggers at 12:00 noon every Wednesday |
Input Parameters of Timer Triggers
When a timer trigger triggers a function, the following data structures will be encapsulated in
event and passed to the function. In addition, you can specify to pass the message for a timer trigger, which is empty by default.{"Type":"Timer","TriggerName":"EveryDay","Time":"2019-02-21T11:49:00Z","Message":"user define msg body"}
Field | Description |
Type | Type of the trigger, whose value is Timer |
TriggerName | Timer name, which can contain up to 60 characters out of a-z, A-Z, 0-9, -, and _ and must begin with a letter and be unique under the same function |
Time | Trigger creation time, in UTC+0 |
Message | String type |
Was this page helpful?
You can also Contact Sales or Submit a Ticket for help.
Yes
No