Crypto advise service

Plugins Used

This project uses the following Gradle plugins:

Core Plugins:

• Java Plugin: Provides support to compile and test Java source. More Info

• Spring Boot (3.1.2): Helps in creating standalone, production-grade Spring-based applications. More Info

• Spring Dependency Management (1.1.2): Offers Maven-like dependency management. It centralizes dependency versions in a multi-module project. More Info

Documentation:

• Asciidoctor (3.3.2): Converts AsciiDoc content into HTML, PDF, and other formats. More Info

Deployment:

• Google Jib (3.3.1): Builds optimized Docker and OCI images for Java applications without requiring a Docker daemon. More Info
• By running ./gradlew jib the image will be built and pushed to the docker hub repository, by running ./gradlew jibDockerBuild the image will be built and stored locally.

Code Quality:

• Lombok (8.1.0): Reduces boilerplate in Java code like getters, setters, equals, etc. using annotations. More Info

• Checkstyle: Ensures Java code adheres to a coding standard. More Info

• PMD: Source code analyzer that detects common programming flaws. More Info

• SpotBugs (4.7.0): Uses static analysis to identify bugs in Java code. More Info

Testing:

• JaCoCo: A Java Code Coverage tool. More Info

Getting Started

1. Clone the repository.
2. Navigate to the project directory.
3. Run the project using:

./gradlew bootRun

Configuration Details

The application has several configuration options that are defined in the application.yml file. Here's a breakdown:

Application Configurations:

Files:

• header-columns: Defines the columns to be used as headers in the file.
  • Default: timestamp,symbol,price
• sourceDir: The directory where files are located.
  • Default: src/main/resources/templates/
• name-pattern: Pattern to match file names.
  • Default: *_values.csv
• chunks: Number of rows to process in a batch.
  • Default: 10000

Forbidden Symbols:

Symbols that are not allowed for processing:

• ETH, SOL, SHIB

Spring Configurations:

Server:

• port: Port on which the application runs.
  • Default: 8080

Datasource:

Configuration details for the database:

• URL: jdbc:h2:mem:crypto_db;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
• Driver: org.h2.Driver
• Username: sa

H2:

• Console access for H2 database is enabled.

JPA:

JPA configurations and properties:

• Hibernate properties are set, with show-sql enabled to display SQL statements.
• ddl-auto is set to update.

Batch:

Spring Batch configurations, including:

• Job initializer status.
• JDBC schema initialization settings.

Springdoc:

• The Swagger UI path for API documentation: /swagger-ui.html.
• By running a service and accessing the URL you can see the API documentation.

Resilience4j Configurations:

RateLimiter:

Configurations for the rate limiting on REST endpoints:

• restEndpointRateLimiter:
  • limitForPeriod: 5 (number of requests per cycle)
  • limitRefreshPeriod: 1s (duration of a cycle)
  • timeoutDuration: 0 (maximum waiting time for a permit)

Open Question and possible answers

1. How long we want ot keep data in the database and provide sufficient performance.
   • Possible solution: We can use a cron job to delete the data older than 1 year or archive them to another table which will not be used for database queries.
   • After some amount of time we can aggregate statistic together and store them in a separate table in a single record which will lighten query and computation effort.
2. After some time some endpoints might return high volume of record which is not desirable.
   • Possible solution: We can use pagination to limit the number of records returned by the endpoint.
3. After CSV batch load we should consider a mechanism how to archive these file for possible further investigation or analysis.
   • Possible solution: We can use a cron job to archive the files after a certain amount of time.
4. We should consider some caching mechanism to improve performance.
   • Possible solution: We can use Redis to cache the data.