Chapter 29. Dataset
Chapter 29. Dataset Both producer and consumer are supported Testing of distributed and asynchronous processing is notoriously difficult. The Mock , Test and DataSet endpoints work great with the Camel Testing Framework to simplify your unit and integration testing using Enterprise Integration Patterns and Camel's large range of Components together with the powerful Bean Integration. The DataSet component provides a mechanism to easily perform load & soak testing of your system. It works by allowing you to create DataSet instances both as a source of messages and as a way to assert that the data set is received. Camel will use the throughput logger when sending datasets. 29.1. Dependencies When using dataset with Red Hat build of Camel Spring Boot make sure to use the following Maven dependency to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-dataset-starter</artifactId> </dependency> 29.2. URI format Where name is used to find the DataSet instance in the Registry Camel ships with a support implementation of org.apache.camel.component.dataset.DataSet , the org.apache.camel.component.dataset.DataSetSupport class, that can be used as a base for implementing your own DataSet. Camel also ships with some implementations that can be used for testing: org.apache.camel.component.dataset.SimpleDataSet , org.apache.camel.component.dataset.ListDataSet and org.apache.camel.component.dataset.FileDataSet , all of which extend DataSetSupport . 29.3. Configuring Options Camel components are configured on two levels: Component level Endpoint level 29.3.1. Component Level Options The component level is the highest level. The configurations you define at this level are inherited by all the endpoints. For example, a component can have security settings, credentials for authentication, urls for network connection, and so on. Since components typically have pre-configured defaults for the most common cases, you may need to only configure a few component options, or maybe none at all. You can configure components with Component DSL in a configuration file (application.properties|yaml), or directly with Java code. 29.3.2. Endpoint Level Options At the Endpoint level you have many options, which you can use to configure what you want the endpoint to do. The options are categorized according to whether the endpoint is used as a consumer (from) or as a producer (to) or used for both. You can configure endpoints directly in the endpoint URI as path and query parameters. You can also use Endpoint DSL and DataFormat DSL as type safe ways of configuring endpoints and data formats in Java. When configuring options, use Property Placeholders for urls, port numbers, sensitive information, and other settings. Placeholders allows you to externalize the configuration from your code, giving you more flexible and reusable code. 29.4. Component Options The Dataset component supports 5 options, which are listed below. Name Description Default Type bridgeErrorHandler (consumer) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false boolean lazyStartProducer (producer) Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false boolean log (producer) To turn on logging when the mock receives an incoming message. This will log only one time at INFO level for the incoming message. For more detailed logging then set the logger to DEBUG level for the org.apache.camel.component.mock.MockEndpoint class. false boolean autowiredEnabled (advanced) Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true boolean exchangeFormatter (advanced) Autowired Sets a custom ExchangeFormatter to convert the Exchange to a String suitable for logging. If not specified, we default to DefaultExchangeFormatter. ExchangeFormatter 29.5. Endpoint Options The Dataset endpoint is configured using URI syntax: with the following path and query parameters: 29.5.1. Path Parameters (1 parameters) Name Description Default Type name (common) Required Name of DataSet to lookup in the registry. DataSet 29.5.2. Query Parameters (21 parameters) Name Description Default Type dataSetIndex (common) Controls the behaviour of the CamelDataSetIndex header. For Consumers: - off = the header will not be set - strict/lenient = the header will be set For Producers: - off = the header value will not be verified, and will not be set if it is not present = strict = the header value must be present and will be verified = lenient = the header value will be verified if it is present, and will be set if it is not present. Enum values: strict lenient off lenient String bridgeErrorHandler (consumer) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false boolean initialDelay (consumer) Time period in millis to wait before starting sending messages. 1000 long minRate (consumer) Wait until the DataSet contains at least this number of messages. 0 int preloadSize (consumer) Sets how many messages should be preloaded (sent) before the route completes its initialization. 0 long produceDelay (consumer) Allows a delay to be specified which causes a delay when a message is sent by the consumer (to simulate slow processing). 3 long exceptionHandler (consumer (advanced)) To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. ExceptionHandler exchangePattern (consumer (advanced)) Sets the exchange pattern when the consumer creates an exchange. Enum values: InOnly InOut InOptionalOut ExchangePattern assertPeriod (producer) Sets a grace period after which the mock endpoint will re-assert to ensure the preliminary assertion is still valid. This is used for example to assert that exactly a number of messages arrives. For example if expectedMessageCount(int) was set to 5, then the assertion is satisfied when 5 or more message arrives. To ensure that exactly 5 messages arrives, then you would need to wait a little period to ensure no further message arrives. This is what you can use this method for. By default this period is disabled. long consumeDelay (producer) Allows a delay to be specified which causes a delay when a message is consumed by the producer (to simulate slow processing). 0 long expectedCount (producer) Specifies the expected number of message exchanges that should be received by this endpoint. Beware: If you want to expect that 0 messages, then take extra care, as 0 matches when the tests starts, so you need to set a assert period time to let the test run for a while to make sure there are still no messages arrived; for that use setAssertPeriod(long). An alternative is to use NotifyBuilder, and use the notifier to know when Camel is done routing some messages, before you call the assertIsSatisfied() method on the mocks. This allows you to not use a fixed assert period, to speedup testing times. If you want to assert that exactly n'th message arrives to this mock endpoint, then see also the setAssertPeriod(long) method for further details. -1 int failFast (producer) Sets whether assertIsSatisfied() should fail fast at the first detected failed expectation while it may otherwise wait for all expected messages to arrive before performing expectations verifications. Is by default true. Set to false to use behavior as in Camel 2.x. false boolean lazyStartProducer (producer) Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false boolean log (producer) To turn on logging when the mock receives an incoming message. This will log only one time at INFO level for the incoming message. For more detailed logging then set the logger to DEBUG level for the org.apache.camel.component.mock.MockEndpoint class. false boolean reportGroup (producer) A number that is used to turn on throughput logging based on groups of the size. int resultMinimumWaitTime (producer) Sets the minimum expected amount of time (in millis) the assertIsSatisfied() will wait on a latch until it is satisfied. long resultWaitTime (producer) Sets the maximum amount of time (in millis) the assertIsSatisfied() will wait on a latch until it is satisfied. long retainFirst (producer) Specifies to only retain the first n'th number of received Exchanges. This is used when testing with big data, to reduce memory consumption by not storing copies of every Exchange this mock endpoint receives. Important: When using this limitation, then the getReceivedCounter() will still return the actual number of received Exchanges. For example if we have received 5000 Exchanges, and have configured to only retain the first 10 Exchanges, then the getReceivedCounter() will still return 5000 but there is only the first 10 Exchanges in the getExchanges() and getReceivedExchanges() methods. When using this method, then some of the other expectation methods is not supported, for example the expectedBodiesReceived(Object... ) sets a expectation on the first number of bodies received. You can configure both setRetainFirst(int) and setRetainLast(int) methods, to limit both the first and last received. -1 int retainLast (producer) Specifies to only retain the last n'th number of received Exchanges. This is used when testing with big data, to reduce memory consumption by not storing copies of every Exchange this mock endpoint receives. Important: When using this limitation, then the getReceivedCounter() will still return the actual number of received Exchanges. For example if we have received 5000 Exchanges, and have configured to only retain the last 20 Exchanges, then the getReceivedCounter() will still return 5000 but there is only the last 20 Exchanges in the getExchanges() and getReceivedExchanges() methods. When using this method, then some of the other expectation methods is not supported, for example the expectedBodiesReceived(Object... ) sets a expectation on the first number of bodies received. You can configure both setRetainFirst(int) and setRetainLast(int) methods, to limit both the first and last received. -1 int sleepForEmptyTest (producer) Allows a sleep to be specified to wait to check that this endpoint really is empty when expectedMessageCount(int) is called with zero. long copyOnExchange (producer (advanced)) Sets whether to make a deep copy of the incoming Exchange when received at this mock endpoint. Is by default true. true boolean 29.6. Configuring DataSet Camel will lookup in the Registry for a bean implementing the DataSet interface. So you can register your own DataSet as: <bean id="myDataSet" class="com.mycompany.MyDataSet"> <property name="size" value="100"/> </bean> 29.7. Example For example, to test that a set of messages are sent to a queue and then consumed from the queue without losing any messages: // send the dataset to a queue from("dataset:foo").to("activemq:SomeQueue"); // now lets test that the messages are consumed correctly from("activemq:SomeQueue").to("dataset:foo"); The above would look in the Registry to find the foo DataSet instance which is used to create the messages. Then you create a DataSet implementation, such as using the SimpleDataSet as described below, configuring things like how big the data set is and what the messages look like etc. 29.8. DataSetSupport (abstract class) The DataSetSupport abstract class is a nice starting point for new DataSets, and provides some useful features to derived classes. 29.8.1. Properties on DataSetSupport Property Type Default Description defaultHeaders Map<String,Object> null Specifies the default message body. For SimpleDataSet it is a constant payload; though if you want to create custom payloads per message, create your own derivation of DataSetSupport . outputTransformer org.apache.camel.Processor null size long 10 Specifies how many messages to send/consume. reportCount long -1 Specifies the number of messages to be received before reporting progress. Useful for showing progress of a large load test. If < 0, then size / 5, if is 0 then size , else set to reportCount value. 29.9. SimpleDataSet The SimpleDataSet extends DataSetSupport , and adds a default body. 29.9.1. Additional Properties on SimpleDataSet Property Type Default Description defaultBody Object <hello>world!</hello> Specifies the default message body. By default, the SimpleDataSet produces the same constant payload for each exchange. If you want to customize the payload for each exchange, create a Camel Processor and configure the SimpleDataSet to use it by setting the outputTransformer property. 29.10. ListDataSet The List`DataSet` extends DataSetSupport , and adds a list of default bodies. 29.10.1. Additional Properties on ListDataSet Property Type Default Description defaultBodies List<Object> empty LinkedList<Object> Specifies the default message body. By default, the ListDataSet selects a constant payload from the list of defaultBodies using the CamelDataSetIndex . If you want to customize the payload, create a Camel Processor and configure the ListDataSet to use it by setting the outputTransformer property. size long the size of the defaultBodies list Specifies how many messages to send/consume. This value can be different from the size of the defaultBodies list. If the value is less than the size of the defaultBodies list, some of the list elements will not be used. If the value is greater than the size of the defaultBodies list, the payload for the exchange will be selected using the modulus of the CamelDataSetIndex and the size of the defaultBodies list (i.e. CamelDataSetIndex % defaultBodies.size() ) 29.11. FileDataSet The FileDataSet extends ListDataSet , and adds support for loading the bodies from a file. 29.11.1. Additional Properties on FileDataSet Property Type Default Description sourceFile File null Specifies the source file for payloads delimiter String \z Specifies the delimiter pattern used by a java.util.Scanner to split the file into multiple payloads. 29.12. Spring Boot Auto-Configuration The component supports 11 options, which are listed below. Name Description Default Type camel.component.dataset-test.autowired-enabled Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true Boolean camel.component.dataset-test.enabled Whether to enable auto configuration of the dataset-test component. This is enabled by default. Boolean camel.component.dataset-test.exchange-formatter Sets a custom ExchangeFormatter to convert the Exchange to a String suitable for logging. If not specified, we default to DefaultExchangeFormatter. The option is a org.apache.camel.spi.ExchangeFormatter type. ExchangeFormatter camel.component.dataset-test.lazy-start-producer Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false Boolean camel.component.dataset-test.log To turn on logging when the mock receives an incoming message. This will log only one time at INFO level for the incoming message. For more detailed logging then set the logger to DEBUG level for the org.apache.camel.component.mock.MockEndpoint class. false Boolean camel.component.dataset.autowired-enabled Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true Boolean camel.component.dataset.bridge-error-handler Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. false Boolean camel.component.dataset.enabled Whether to enable auto configuration of the dataset component. This is enabled by default. Boolean camel.component.dataset.exchange-formatter Sets a custom ExchangeFormatter to convert the Exchange to a String suitable for logging. If not specified, we default to DefaultExchangeFormatter. The option is a org.apache.camel.spi.ExchangeFormatter type. ExchangeFormatter camel.component.dataset.lazy-start-producer Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. false Boolean camel.component.dataset.log To turn on logging when the mock receives an incoming message. This will log only one time at INFO level for the incoming message. For more detailed logging then set the logger to DEBUG level for the org.apache.camel.component.mock.MockEndpoint class. false Boolean
<dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-dataset-starter</artifactId> </dependency> dataset:name[?options] dataset:name <bean id="myDataSet" class="com.mycompany.MyDataSet"> <property name="size" value="100"/> </bean> // send the dataset to a queue from("dataset:foo").to("activemq:SomeQueue"); // now lets test that the messages are consumed correctly from("activemq:SomeQueue").to("dataset:foo");