Use Amazon CloudWatch Events
CloudWatch Events delivers a near real-time stream of system events that describe changes in Amazon resources to Amazon EC2 instances, Lambda functions, Kinesis streams, Amazon ECS tasks, Step Functions state machines, Amazon SNS topics, Amazon SQS queues, or built-in targets. You can match events and route them to one or more target functions or streams by using simple rules.
Amazon EventBridge is the evolution
Add events
To add custom CloudWatch events, call the CloudWatchEventsClient’s
putEvents
method with a PutEventsRequest
PutEventsRequestEntry
Note
You can specify a maximum of 10 events per call to putEvents
.
Imports
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatchevents.CloudWatchEventsClient; import software.amazon.awssdk.services.cloudwatchevents.model.PutEventsRequest; import software.amazon.awssdk.services.cloudwatchevents.model.PutEventsRequestEntry;
Code
public static void putCWEvents(CloudWatchEventsClient cwe, String resourceArn ) { try { final String EVENT_DETAILS = "{ \"key1\": \"value1\", \"key2\": \"value2\" }"; PutEventsRequestEntry requestEntry = PutEventsRequestEntry.builder() .detail(EVENT_DETAILS) .detailType("sampleSubmitted") .resources(resourceArn) .source("aws-sdk-java-cloudwatch-example") .build(); PutEventsRequest request = PutEventsRequest.builder() .entries(requestEntry) .build(); cwe.putEvents(request); System.out.println("Successfully put CloudWatch event"); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } }
See the complete example
Add rules
To create or update a rule, call the CloudWatchEventsClient’s
putRule
method with a PutRuleRequest
Imports
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatchevents.CloudWatchEventsClient; import software.amazon.awssdk.services.cloudwatchevents.model.PutRuleRequest; import software.amazon.awssdk.services.cloudwatchevents.model.PutRuleResponse; import software.amazon.awssdk.services.cloudwatchevents.model.RuleState;
Code
public static void putCWRule(CloudWatchEventsClient cwe, String ruleName, String roleArn) { try { PutRuleRequest request = PutRuleRequest.builder() .name(ruleName) .roleArn(roleArn) .scheduleExpression("rate(5 minutes)") .state(RuleState.ENABLED) .build(); PutRuleResponse response = cwe.putRule(request); System.out.printf( "Successfully created CloudWatch events rule %s with arn %s", roleArn, response.ruleArn()); } catch ( CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } }
See the complete example
Add targets
Targets are the resources that are invoked when a rule is triggered. Example targets include Amazon EC2 instances, Lambda functions, Kinesis streams, Amazon ECS tasks, Step Functions state machines, and built-in targets.
To add a target to a rule, call the CloudWatchEventsClient’s
putTargets
method with a PutTargetsRequest
Imports
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatchevents.CloudWatchEventsClient; import software.amazon.awssdk.services.cloudwatchevents.model.PutTargetsRequest; import software.amazon.awssdk.services.cloudwatchevents.model.PutTargetsResponse; import software.amazon.awssdk.services.cloudwatchevents.model.Target;
Code
public static void putCWTargets(CloudWatchEventsClient cwe, String ruleName, String functionArn, String targetId ) { try { Target target = Target.builder() .arn(functionArn) .id(targetId) .build(); PutTargetsRequest request = PutTargetsRequest.builder() .targets(target) .rule(ruleName) .build(); PutTargetsResponse response = cwe.putTargets(request); System.out.printf( "Successfully created CloudWatch events target for rule %s", ruleName); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } }
See the complete example
More information
-
Adding Events with PutEvents in the Amazon EventBridge User Guide
-
Schedule Expressions for Rules in the Amazon EventBridge User Guide
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Event Types for CloudWatch Events in the Amazon EventBridge User Guide
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Event Patterns in the Amazon EventBridge User Guide
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PutEvents in the Amazon EventBridge API Reference
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PutTargets in the Amazon EventBridge API Reference
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PutRule in the Amazon EventBridge API Reference