Hostname verification backoff schedule
After you create a custom hostname, Cloudflare has to verify that hostname.
Attempts to verify a Custom Hostname are distributed over 7 days (a total of 75 retries). 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 Attempt | In Seconds | In Minutes | In Hours |
---|---|---|---|
0 | 60 | 1 | 0.016667 |
1 | 63 | 1.05 | 0.0175 |
2 | 66 | 1.1 | 0.018333 |
3 | 69 | 1.15 | 0.019167 |
4 | 72 | 1.2 | 0.02 |
5 | 76 | 1.266667 | 0.021111 |
6 | 80 | 1.333333 | 0.022222 |
7 | 84 | 1.4 | 0.023333 |
8 | 88 | 1.466667 | 0.024444 |
9 | 93 | 1.55 | 0.025833 |
10 | 242 | 4.033333 | 0.067222 |
11 | 279 | 4.65 | 0.0775 |
12 | 321 | 5.35 | 0.089167 |
13 | 369 | 6.15 | 0.1025 |
14 | 424 | 7.066667 | 0.117778 |
15 | 488 | 8.133333 | 0.135556 |
16 | 561 | 9.35 | 0.155833 |
17 | 645 | 10.75 | 0.179167 |
18 | 742 | 12.366667 | 0.206111 |
19 | 853 | 14.216667 | 0.236944 |
20 | 981 | 16.35 | 0.2725 |
21 | 1129 | 18.816667 | 0.313611 |
22 | 1298 | 21.633333 | 0.360556 |
23 | 1493 | 24.883333 | 0.414722 |
24 | 1717 | 28.616667 | 0.476944 |
25 | 1975 | 32.916667 | 0.548611 |
26 | 2271 | 37.85 | 0.630833 |
27 | 2612 | 43.533333 | 0.725556 |
28 | 3003 | 50.05 | 0.834167 |
29 | 3454 | 57.566667 | 0.959444 |
30 | 3972 | 66.2 | 1.103333 |
31 | 4568 | 76.133333 | 1.268889 |
32 | 5253 | 87.55 | 1.459167 |
33 | 6041 | 100.683333 | 1.678056 |
34 | 6948 | 115.8 | 1.93 |
35 | 7990 | 133.166667 | 2.219444 |
36 | 9189 | 153.15 | 2.5525 |
37 | 10567 | 176.116667 | 2.935278 |
38 | 12152 | 202.533333 | 3.375556 |
39 | 13975 | 232.916667 | 3.881944 |
40 | 14400 | 240 | 4 |
41 | 14400 | 240 | 4 |
42 | 14400 | 240 | 4 |
43 | 14400 | 240 | 4 |
44 | 14400 | 240 | 4 |
45 | 14400 | 240 | 4 |
46 | 14400 | 240 | 4 |
47 | 14400 | 240 | 4 |
48 | 14400 | 240 | 4 |
49 | 14400 | 240 | 4 |
50 | 14400 | 240 | 4 |
51 | 14400 | 240 | 4 |
52 | 14400 | 240 | 4 |
53 | 14400 | 240 | 4 |
54 | 14400 | 240 | 4 |
55 | 14400 | 240 | 4 |
56 | 14400 | 240 | 4 |
57 | 14400 | 240 | 4 |
58 | 14400 | 240 | 4 |
59 | 14400 | 240 | 4 |
60 | 14400 | 240 | 4 |
61 | 14400 | 240 | 4 |
62 | 14400 | 240 | 4 |
63 | 14400 | 240 | 4 |
64 | 14400 | 240 | 4 |
65 | 14400 | 240 | 4 |
66 | 14400 | 240 | 4 |
67 | 14400 | 240 | 4 |
68 | 14400 | 240 | 4 |
69 | 14400 | 240 | 4 |
70 | 14400 | 240 | 4 |
71 | 14400 | 240 | 4 |
72 | 14400 | 240 | 4 |
73 | 14400 | 240 | 4 |
74 | 14400 | 240 | 4 |
75 | 14400 | 240 | 4 |