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 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