Nimbus' Syncing Process

By default, Nimbus uses a recently finalized checkpoint state hosted by AVADO, and only need to catch up to the current head of the blockchain. This process is relatively fast, usually taking only a few minutes to no more than an hour.

Nimbus' DApp and the Logs provide useful information about it's activities. To observe the syncing progress:

  1. Check the status in the Nimbus DApp. The percentage completion starts above 99% (due to Checkpoint Sync) and steadily increases. The "sync distance", which represents the gap between the currently synced block and the chain's head, may fluctuate but should eventually reach zero.

  1. Inspect the Logs. Familiarizing yourself with the Logs enables you to confidently assess whether the process is running smoothly or if any issues require attention. To access the Logs, open the Nimbus Management Page from the My Dapps menu and scroll to the bottom.

Once Nimbus has started up and initialized, you should start to see the following lines in the Logs:

Slot start
Slot end
Eth1 sync progress

This indicates that Nimbus is progressing smoothly.


If you notice that the status in the DApp remains stuck at "Waiting for beacon chain to become ready" without any progress, or if you come across error messages in the Logs, Nimbus might have a problem syncing.

The most common problems are:

  • Nimbus fails to connect to sufficient number of peers. If you are getting a low peer count, there may be a problem with your network setting. See Opening Network Ports to learn how to resolve this (by "opening port 9100" on the router).

  • Nimbus fails to find the Execution Client. It may be the case that you have not yet installed the Execution Client, in which case once you have set up the Execution Client this error will go away.

No synced execution layer available for deposit syncing 

If you have already installed an Execution Client but this error persists, check that you have correctly selected the Execution Engine (Geth or Nethermind) on Nimbus' Settings page, to match with your installed Execution Client. Remember to click Apply changes to update the setting.

If the error persists, check the Logs of the Execution Client to see what is going on there. Sometimes a Restart of the Execution Client and the Consensus Client is all that is needed to resolve the issue. Please also feel free to reach out to our Discord channel for support.

Normal Operations

Here is an example of how the Nimbus Logs should look like when:

  • Nimbus is fully synced;

  • The Execution Client is fully synced;

  • You have loaded Validator Keys into Nimbus, and the Validators have become active on the Beacon Chain; and

  • You have installed and configured MEV-Boost.

Key observations:

  • Nimbus diligently tracks each slot ("Slot start") and each epoch.

  • The line "Attestation sent" indicates that your validators have produced attestations.

  • Nimbus does not announce registering your validators on the builders network, even though MEV-Boost is enabled.

If you notice that your validators are missing attestations, it is often beneficial to inspect the Logs for any abnormal behavior or issues.

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