# Erasure code sizing guide

## Toy Setups

Capacity constrained environments, MinIO will work but not recommended for production.

| servers | drives (per node) | stripe_size | parity chosen (default) | tolerance for reads (servers) | tolerance for writes (servers) |
|--------:|------------------:|------------:|------------------------:|------------------------------:|-------------------------------:|

	if d < 0 {
		return -d
	}
	return d
}

func withinTolerance(c0, c1 color.Color, tolerance int) bool {
	r0, g0, b0, a0 := c0.RGBA()
	r1, g1, b1, a1 := c1.RGBA()
	r := delta(r0, r1)
	g := delta(g0, g1)
	b := delta(b0, b1)
	a := delta(a0, a1)
	return r <= tolerance && g <= tolerance && b <= tolerance && a <= tolerance
}

func TestDecode(t *testing.T) {
	rgba := func(c color.Color) string {

To verify the above sample alert follow below steps

1. Start a distributed MinIO instance (4 nodes setup)
2. Start Prometheus server and AlertManager
3. Bring down couple of MinIO instances to bring down the Erasure Set tolerance to -1 and verify the same with `mc admin prometheus metrics ALIAS | grep minio_cluster_health_erasure_set_status`

			continue
		}
		if m0.Bounds() != m1.Bounds() {
			t.Errorf("%s, bounds differ: %v and %v", tc.filename, m0.Bounds(), m1.Bounds())
			continue
		}
		// Compare the average delta to the tolerance level.
		if averageDelta(m0, m1) > tc.tolerance {
			t.Errorf("%s, quality=%d: average delta is too high", tc.filename, tc.quality)
			continue
		}
	}
}

// TestWriteGrayscale tests that a grayscale images survives a round-trip

	cert := &x509.Certificate{
		NotAfter: time.Now().Add(validity),
	}

	e := newExpirationInfo("x", cert, false)

	if math.Abs(float64(validity-e.ResidualTime())) > float64(5*time.Second) { // using 5s of tolerance because the function is not deterministic (it uses time.Now()) and we want to avoid flakes
		t.Errorf("expected IsInRenewalWindow equal to %v, saw %v", validity, e.ResidualTime())
	}

// CHECK-NEXT:  } ]
// CHECK-NEXT:  signature_defs: [ ]
// CHECK-NEXT:}

func.func @main(%arg0: tensor<4xf32>, %arg1: tensor<4x!quant.uniform<u8:f32, 0.1>>) -> tensor<4xf32> {
  "tfl.NumericVerify"(%arg1, %arg0) {tolerance = 0.1 : f32} : (tensor<4x!quant.uniform<u8:f32, 0.1>>, tensor<4xf32>) -> (tensor<4xf32>)
  func.return %arg0 : tensor<4xf32>

	// backwards and not scale down below any recommendation it made during that period.
	HorizontalPodAutoscalerDownscaleStabilizationWindow metav1.Duration
	// horizontalPodAutoscalerTolerance is the tolerance for when
	// resource usage suggests upscaling/downscaling
	HorizontalPodAutoscalerTolerance float64
	// HorizontalPodAutoscalerCPUInitializationPeriod is the period after pod start when CPU samples
	// might be skipped.

	fs.Float64Var(&o.HorizontalPodAutoscalerTolerance, "horizontal-pod-autoscaler-tolerance", o.HorizontalPodAutoscalerTolerance, "The minimum change (from 1.0) in the desired-to-actual metrics ratio for the horizontal pod autoscaler to consider scaling.")

			r0, g0, b0, a0, r1, g1, b1, a1)
	}
	return nil
}

// TestYCbCrRoundtrip tests that a subset of RGB space can be converted to YCbCr
// and back to within 2/256 tolerance.
func TestYCbCrRoundtrip(t *testing.T) {
	for r := 0; r < 256; r += 7 {
		for g := 0; g < 256; g += 5 {
			for b := 0; b < 256; b += 3 {
				r0, g0, b0 := uint8(r), uint8(g), uint8(b)

 * [CWAC-NetSecurity](https://github.com/commonsguy/cwac-netsecurity): Simplifying Secure Internet Access.
 * [Failsafe](https://failsafe.dev/okhttp/): Fault tolerance and resilience patterns.
 * [Flipper](https://fbflipper.com/): A desktop debugging platform for mobile developers.
 * [Fresco](https://github.com/facebook/fresco): An Android library for managing images and the memory they use.