Is my setup robust for Quant calculation engine, and should I use SQLAlchemy 2.0, or an alternative?

Summary

The current setup for the FastAPI application, which serves as a core engine for a derivative trading and quant operations system, uses a relational database (e.g., PostgreSQL or MySQL) with SQLAlchemy for ORM and DB access. The application utilizes session-based DB interaction per request and has logging enabled for queries and application events. The objective is to assess whether this setup is robust and suitable for handling high read/write frequency and concurrent requests without introducing bottlenecks related to connection handling, performance, or logging as the application scales.

Root Cause

The root cause of potential issues with the current setup includes:

  • Inefficient connection handling: The application creates a new database connection for each request, which can lead to connection overhead and potentially cause bottlenecks.
  • Insufficient logging configuration: The current logging setup may not be comprehensive enough to provide detailed insights into application performance and errors.
  • Lack of database connection pooling: Without a connection pool, the application may experience performance issues due to the overhead of creating and closing database connections.

Why This Happens in Real Systems

This happens in real systems because:

  • Scalability requirements: As the application grows, the need for efficient connection handling and logging becomes more critical.
  • Concurrency and parallelism: High read/write frequency and concurrent requests can exacerbate issues with connection handling and logging.
  • Database performance: Inefficient database interactions can lead to performance bottlenecks and impact the overall system.

Real-World Impact

The real-world impact of these issues includes:

  • Performance degradation: Inefficient connection handling and logging can lead to slower response times and decreased system performance.
  • Error rates and downtime: Insufficient logging and connection handling can result in increased error rates and downtime.
  • Scalability limitations: The application may not be able to handle increased traffic or load, limiting its scalability.

Example or Code

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

# Create a database engine with connection pooling
engine = create_engine('postgresql://user:password@host:port/dbname', pool_size=20, max_overflow=10)

# Create a session maker with the engine
Session = sessionmaker(bind=engine)

# Use the session maker to create a new session for each request
def get_session():
    return Session()

How Senior Engineers Fix It

Senior engineers fix these issues by:

  • Implementing connection pooling: Using a connection pool to reduce the overhead of creating and closing database connections.
  • Configuring logging: Setting up comprehensive logging to provide detailed insights into application performance and errors.
  • Optimizing database interactions: Using efficient database interactions, such as batch queries and transactions, to reduce the load on the database.

Why Juniors Miss It

Juniors may miss these issues because:

  • Lack of experience: Limited experience with large-scale systems and high-performance applications.
  • Insufficient knowledge: Limited understanding of database connection handling, logging, and performance optimization.
  • Focus on functionality: Prioritizing functionality over performance and scalability.