maha | rapid reporting API development ; with out of the box support | SQL Database library

For this example, you need druid instance running in local and wikitikcer dataset indexed into druid, please take look at http://druid.io/docs/latest/tutorials/quickstart.html. Fact definition is the static object specification for the facts and dimension columns present in the table in the data-source, you can say it is object image of the table. DimCol has the base name, data-types, annotation. Annotations are the configurations stating the primary key/foreign key configuration, special character escaping in the query generation, static value mapping ie StrType(100, (Map("Main" -> "Main Namespace", "User" -> "User Namespace", "Category" -> "Category Namespace", "User Talk"-> "User Talk Namespace"), "Unknown Namespace")) . Fact definition can have derived columns, maha supports most common arithmetic derived expression. Public Fact : Public fact contains the base name to public name mapping. Public Names can be directly used in the Request Json. Public fact are identified by the name called cube name ie 'wikiticker_stats'. Maha supports versioning on the cubes, you have multiple versions of the same cube. Fact/Dimension Registration Factory: Facts and dimensions are registered under the derived static class object of FactRegistrationFactory or DimensionRegistration Factory. Factory Classes used in the maha-service-json-config. Maha Service Config json contains one place config for launching maha-apis which includes the following. We have created api-jersey/src/test/resources/maha-service-config.json configuration to start with, this is maha api configuration for student and wiki registry. Debugging maha-service-config json: For the configuration syntax of this json, you can take look at JsonModels/Factories in the service module. Once Maha Service loads this configuration, if there are some failures in loading the configuration then mahaService will return the list of FailedToConstructFactory/ ServiceConfigurationError/ JsonParseError. Api-jersey uses maha-service-config json and create MahaResource beans. All you need to do is to create the following three beans 'mahaService', 'baseRequest', 'exceptionHandler' etc. Once your application context is ready, you are good to launch the war file on the web server. You can take look at the test application context that we have created for running local demo and unit test api-jersey/src/test/resources/testapplicationContext.xml. you can find student.json in the api-example module, **make sure you change the dates to latest date range in YYYY-MM-dd to avoid max look back window error. please note that we have loaded the test data for demo in current day and day before. For timeshift curator demo, we have loaded data for 11 days back of current date. Please make sure that you update the requested to and from dates according to current dates.
We have published the packages in Maven Central distribution, you can have look at the latest version at https://mvnrepository.com/artifact/com.yahoo.maha/maha-api-jersey
maha-api-jersey includes all the dependencies of other modules
Maha-Service Examples Druid Wiki Ticker Example as pre-requisite you need to follow Druid.io Getting Started Guide and need local running druid instance with wikiticker indexed) H2 Database Student Course Example you can run in the local as unit test
Set of Public Facts registered under Registry Name ie wikiticker_stats cube is registered under the registry name called wiki
Set of Registries
Set of Query of generator and their config
Set of Query Executors and their config
Bucketing configurations containing the cube version based routing of the reporting requests
UTC Time provider Maps , if the date /time is local date then you can have utc time provider to convert it to utc in query generation phase.
Parallel Service Executor Maps for serving the reporting request utilising the thread-pool config.
Maha Request Logging Config, kafka configuration for logging the maha request debug logs to kafka queue.
druid.io getting started guide in local for wikitiker demo
Postman (optional)
Step 1: Checkout yahoo/maha repository
Step 2: Run mvn clean install in maha
Step 3: Go to cd api-example module and run mvn jetty:run, you can run it with -X for debug logs.
Step 4: Step 2 will launch jetty server in local and will deploy maha-api example war and you are good to play with it!
GET Domain request: Dimension and Facts You can fetch wiki registry domain using curl http://localhost:8080/mahademo/registry/wiki/domain Domain tells you lit of cubes and their corresponding list of fields that you can request for particular registry. Here wiki is the registry name.
GET Flatten Domain request : Flatten dimension and facts fields You can get flatten domain using curl http://localhost:8080/mahademo/registry/wiki/flattenDomain
POST Maha Reporting Request for example student schema MahaRequest will look like following, you need to pass cube name, list of fields you want to fetch, filters, sorting columns etc.
POST Maha Reporting Request for example wiki schema
POST Maha Reporting Request for example student schema with TimeShift Curator MahaRequest will look like following, you need to pass cube name, list of fields you want to fetch, filters, sorting columns in the base request and timeshift curator configs (daysOffset is an day offset for requesting previous period's to and from dates)
POST Maha Reporting Request for example wiki schema with Total metrics curator