d0dd5c08cb
for internal decisions as this error is strongly used by other packages. By checking such wrapped errors the internal decision can be influenced accidentally. In this case the retry mechanism checked if the error is context.DeadlineExceeded and assumed it would be created by the internal context. This assumption was wrong.
83 lines
2.4 KiB
Go
83 lines
2.4 KiB
Go
package util
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import (
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"context"
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"errors"
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"github.com/openHPI/poseidon/pkg/logging"
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"time"
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)
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var (
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log = logging.GetLogger("util")
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// MaxConnectionRetriesExponential is the default number of retries. It's exported for testing reasons.
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MaxConnectionRetriesExponential = 18
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// InitialWaitingDuration is the default initial duration of waiting after a failed time.
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InitialWaitingDuration = time.Second
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ErrRetryContextDone = errors.New("the retry context is done")
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)
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func retryExponential(ctx context.Context, sleep time.Duration, f func() error) func() error {
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return func() error {
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err := f()
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if err != nil {
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select {
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case <-ctx.Done():
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err = ErrRetryContextDone
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case <-time.After(sleep):
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sleep *= 2
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}
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}
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return err
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}
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}
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func retryConstant(ctx context.Context, sleep time.Duration, f func() error) func() error {
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return func() error {
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err := f()
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if err != nil {
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select {
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case <-ctx.Done():
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return ErrRetryContextDone
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case <-time.After(sleep):
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}
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}
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return err
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}
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}
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func retryAttempts(maxAttempts int, f func() error) (err error) {
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for i := 0; i < maxAttempts; i++ {
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err = f()
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if err == nil {
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return nil
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} else if errors.Is(err, ErrRetryContextDone) {
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return err
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}
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log.WithField("count", i).WithError(err).Debug("retrying after error")
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}
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return err
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}
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// RetryExponentialWithContext executes the passed function with exponentially increasing time starting with one second
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// up to a default maximum number of attempts as long as the context is not done.
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func RetryExponentialWithContext(ctx context.Context, f func() error) error {
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return retryAttempts(MaxConnectionRetriesExponential, retryExponential(ctx, InitialWaitingDuration, f))
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}
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// RetryExponential executes the passed function with exponentially increasing time starting with one second
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// up to a default maximum number of attempts.
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func RetryExponential(f func() error) error {
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return retryAttempts(MaxConnectionRetriesExponential,
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retryExponential(context.Background(), InitialWaitingDuration, f))
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}
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// RetryConstantAttemptsWithContext executes the passed function with a constant retry delay of one second
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// up to the passed maximum number of attempts as long as the context is not done.
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func RetryConstantAttemptsWithContext(attempts int, ctx context.Context, f func() error) error {
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return retryAttempts(attempts, retryConstant(ctx, InitialWaitingDuration, f))
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}
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