---
# System prepended metadata

title: Missed attestations analyse

---

# Missed attestations analyse



| # | Validator | Slot | Block reaches vc (s) | done att data req (s) | vc submits att (s) | att reaches bn (s) | done submission (s) |
| -------- | -------- | -------- | ---- | ---- | ---- | ---- | ---- |
|0| 090     | 4806047     | 1.7     | x | 3.74 | 9.17 | ---- |
|1| 614     | 4806130     | 1.16     | x | 3.32 | 5.7 | 8.13 (count=9) |
|2| 290     | 4806129     | 6.4     | 4.5 | 4.5 | 7.13 | ---- |
|3| 689     | 4806137     | 1.9     | x | 3.95 | 9.3 | ---- |
|4| 436     | 4806142     | 1.36     | x | 3.4 | 7.2 | ---- |
|5| 633     | 4806172     | 1.3     | x | 3.3 | 8.8 | ---- |
|6| 615     | 4806162     | 1.64     | x | 3.78 | 8.9 | ---- |
|7| 690     | 4806189     | 2.6     | x | 4 | 9.95 | ---- |
|8| 632     | 4806215     | 3     | x | 4 | 5.69 | 8.84 (count=6) |
|9| 639     | 4806222     | 1.6     | x | 3.63 | 8.96 | ---- |


**Note**:
* vc = validator client, bn = beacon node, att = attestation
* Time is based on slot time

It shows that 90% of cases are due to attestaions reach bn very late even through the block reaches vc early. It's because vc holds attestation 2s, or up to 1/3 slot before submitting to bn => work around is vc to submit attestations asap and let bn hold attestations until 1/3 of slot then publish.

When block reach vc late (#2, 10% of the time), the I/O lag issue may happen => no work around for now