forked from 0x2E/fusion
df412f17d3
* Recover after feed fetch failure with exponential backoff The current implementation stops attempting to fetch a feed if fusion encounters any error fetching it. The only way to continue fetching the feed is if the user manually forces a refresh. This allows fusion to recover from feed fetch errors by tracking the number of consecutive failures and slowing down requests for consistent failure. If a feed always fails, we eventually slow to only checking it once per week. Fixes #67 * Add comment
31 lines
913 B
Go
31 lines
913 B
Go
package pull
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import (
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"math"
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"time"
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)
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// maxBackoff is the maximum time to wait before checking a feed due to past
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// errors.
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const maxBackoff = 7 * 24 * time.Hour
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// CalculateBackoffTime calculates the exponential backoff time based on the
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// number of consecutive failures.
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// The formula is: interval * (1.8 ^ consecutiveFailures), capped at maxBackoff.
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func CalculateBackoffTime(consecutiveFailures uint) time.Duration {
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// If no failures, no backoff needed
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if consecutiveFailures == 0 {
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return 0
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}
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intervalMinutes := float64(interval.Minutes())
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backoffMinutes := intervalMinutes * math.Pow(1.8, float64(consecutiveFailures))
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// floats go to Inf if the number is too large to represent in a float type,
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// so check that it's not +/- Inf.
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if math.IsInf(backoffMinutes, 0) || backoffMinutes > maxBackoff.Minutes() {
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return maxBackoff
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}
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return time.Duration(backoffMinutes) * time.Minute
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}
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