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Backoff schedule

After you create a custom hostname, Cloudflare has to validate that hostname.

Attempts to validate a Custom Hostname are distributed over 7 days (a total of 75 retries). At the end of this schedule, if the validation is unsuccessful, the custom hostname will be deleted. The function that determines the next check varies based on the number of attempts:

  • For the first 10 attempts:
now() + min((floor(60 * pow(1.05, retry_attempt)) * INTERVAL '1 second'), INTERVAL '4 hours')
  • For the remaining 65 attempts:
now() + min((floor(60 * pow(1.15, retry_attempt)) * INTERVAL '1 second'), INTERVAL '4 hours')

The first 10 checks complete within 2 minutes and most checks complete in the first 4 hours. The check back off is capped to a maximum of 4 hours to avoid exponential growth. The back off behavior causes larger gaps between check intervals towards the end of the back off schedule:

Retry AttemptIn SecondsIn MinutesIn Hours
06010.016667
1631.050.0175
2661.10.018333
3691.150.019167
4721.20.02
5761.2666670.021111
6801.3333330.022222
7841.40.023333
8881.4666670.024444
9931.550.025833
102424.0333330.067222
112794.650.0775
123215.350.089167
133696.150.1025
144247.0666670.117778
154888.1333330.135556
165619.350.155833
1764510.750.179167
1874212.3666670.206111
1985314.2166670.236944
2098116.350.2725
21112918.8166670.313611
22129821.6333330.360556
23149324.8833330.414722
24171728.6166670.476944
25197532.9166670.548611
26227137.850.630833
27261243.5333330.725556
28300350.050.834167
29345457.5666670.959444
30397266.21.103333
31456876.1333331.268889
32525387.551.459167
336041100.6833331.678056
346948115.81.93
357990133.1666672.219444
369189153.152.5525
3710567176.1166672.935278
3812152202.5333333.375556
3913975232.9166673.881944
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