import { describe, expect, it } from "vitest";
/**
* IMPORTANT: These are CONCEPT/DOCUMENTATION tests, not implementation tests!
*
* These tests validate arithmetic and theoretical concepts (retry logic,
* backoff calculations, throughput estimates) but DO NOT execute actual
* SSH pool code. They will pass even if the pool implementation is broken.
*
* For actual implementation tests, see:
* - ssh-pool.benchmark.test.ts (integration tests with real pool behavior)
* - ssh-connection-pool.test.ts (unit tests)
*
* WARNING: Do not rely on these tests for coverage metrics. They document
* design decisions and validate math, but provide no assurance that the
* actual code works correctly.
*/
describe("SSHPool - load and stress test concepts", () => {
describe("Connection pooling concepts", () => {
it("should validate connection limits are reasonable", () => {
const maxConnections = 5;
const requestCount = 10;
// Concept: With 5 max connections and 10 requests, we expect:
// - 5 connections created
// - 5 requests wait for release
const expectedConnections = Math.min(maxConnections, requestCount);
expect(expectedConnections).toBe(5);
expect(requestCount - expectedConnections).toBe(5); // Queued requests
});
it("should calculate connection reuse rate", () => {
const totalRequests = 100;
const maxPoolSize = 5;
// Concept: With good reuse, we should have high reuse rate
const minReuses = totalRequests - maxPoolSize;
const reuseRate = (minReuses / totalRequests) * 100;
expect(reuseRate).toBeGreaterThan(90); // >90% reuse expected
});
it("should define safe queue limits", () => {
const maxConnections = 5;
const safeQueueMultiplier = 3;
// Concept: Queue should not exceed 3x pool size to prevent memory issues
const maxQueueSize = maxConnections * safeQueueMultiplier;
expect(maxQueueSize).toBe(15);
});
});
describe("Error recovery strategies", () => {
it("should define retry logic for transient failures", () => {
const maxRetries = 3;
const retryDelay = 1000; // ms
// Concept: Retry strategy should have reasonable limits
expect(maxRetries).toBeGreaterThanOrEqual(2);
expect(maxRetries).toBeLessThanOrEqual(5);
expect(retryDelay).toBeGreaterThanOrEqual(500);
});
it("should calculate backoff intervals", () => {
const baseDelay = 1000;
const attempts = [1, 2, 3, 4];
// Concept: Exponential backoff with cap
const delays = attempts.map((attempt) => Math.min(baseDelay * 2 ** (attempt - 1), 30000));
expect(delays).toEqual([1000, 2000, 4000, 8000]);
});
it("should define circuit breaker thresholds", () => {
const failureThreshold = 5; // failures to trigger circuit breaker
const timeout = 60000; // ms to wait before retry
// Concept: Circuit breaker prevents cascade failures
expect(failureThreshold).toBeGreaterThanOrEqual(3);
expect(timeout).toBeGreaterThanOrEqual(30000);
});
});
describe("Resource cleanup policies", () => {
it("should define reasonable idle timeout", () => {
const idleTimeout = 60000; // 1 minute
// Concept: Idle connections should be closed after reasonable timeout
expect(idleTimeout).toBeGreaterThanOrEqual(30000); // At least 30s
expect(idleTimeout).toBeLessThanOrEqual(300000); // At most 5min
});
it("should validate connection age limits", () => {
const maxConnectionAge = 3600000; // 1 hour
// Concept: Long-lived connections should be recycled
expect(maxConnectionAge).toBeGreaterThanOrEqual(600000); // At least 10min
expect(maxConnectionAge).toBeLessThanOrEqual(86400000); // At most 24hr
});
it("should define cleanup interval", () => {
const cleanupInterval = 30000; // 30 seconds
// Concept: Regular cleanup prevents resource leaks
expect(cleanupInterval).toBeGreaterThanOrEqual(10000);
expect(cleanupInterval).toBeLessThanOrEqual(60000);
});
});
describe("Load characteristics", () => {
it("should calculate expected throughput", () => {
const maxConnections = 5;
const avgOperationTime = 100; // ms
// Concept: Throughput = connections * (1000ms / operation time)
const expectedThroughput = maxConnections * (1000 / avgOperationTime);
expect(expectedThroughput).toBe(50); // 50 operations/second
});
it("should validate memory limits for large pools", () => {
const maxConnections = 100;
const avgConnectionMemory = 10 * 1024 * 1024; // 10MB per connection
// Concept: Total memory should be reasonable
const totalMemory = maxConnections * avgConnectionMemory;
const totalMemoryMB = totalMemory / (1024 * 1024);
expect(totalMemoryMB).toBeLessThanOrEqual(2000); // Max 2GB for pool
});
it("should define rate limiting for DoS prevention", () => {
const maxRequestsPerSecond = 100;
const windowSize = 1000; // ms
// Concept: Rate limiting prevents resource exhaustion
const tokensPerWindow = maxRequestsPerSecond * (windowSize / 1000);
expect(tokensPerWindow).toBe(100);
expect(maxRequestsPerSecond).toBeGreaterThanOrEqual(10);
expect(maxRequestsPerSecond).toBeLessThanOrEqual(1000);
});
});
describe("Multi-host scenarios", () => {
it("should isolate pools by host", () => {
const maxPerHost = 5;
// Concept: Each host gets its own pool
const totalConnections = maxPerHost * 2; // 2 hosts
expect(totalConnections).toBe(10);
});
it("should handle host failover scenarios", () => {
const failoverTimeout = 5000; // ms
// Concept: Failover should happen within timeout
expect(failoverTimeout).toBeGreaterThanOrEqual(1000);
expect(failoverTimeout).toBeLessThanOrEqual(10000);
});
it("should validate connection distribution across hosts", () => {
const hosts = 5;
const totalConnections = 50;
// Concept: Connections should be roughly evenly distributed
const avgPerHost = totalConnections / hosts;
const tolerance = avgPerHost * 0.2; // 20% tolerance
expect(avgPerHost).toBe(10);
expect(tolerance).toBe(2);
});
});
});
