Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Specify the number of sidecar subnets #3346

Merged
merged 2 commits into from
May 18, 2023
Merged

Specify the number of sidecar subnets #3346

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
2f218f8
Specify the number of sidecar subnets
ppopth May 5, 2023
08a1326
Use SubnetID instead of uint64
ppopth May 9, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 4 additions & 4 deletions specs/deneb/p2p-interface.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,7 @@ The specification of these changes continues in the same format as the network s
- [Topics and messages](#topics-and-messages)
- [Global topics](#global-topics)
- [`beacon_block`](#beacon_block)
- [`blob_sidecar_{index}`](#blob_sidecar_index)
- [`blob_sidecar_{subnet_id}`](#blob_sidecar_subnet_id)
- [Transitioning the gossip](#transitioning-the-gossip)
- [The Req/Resp domain](#the-reqresp-domain)
- [Messages](#messages)
Expand Down Expand Up @@ -107,7 +107,7 @@ The new topics along with the type of the `data` field of a gossipsub message ar

| Name | Message Type |
| - | - |
| `blob_sidecar_{index}` | `SignedBlobSidecar` (new) |
| `blob_sidecar_{subnet_id}` | `SignedBlobSidecar` (new) |

##### Global topics

Expand All @@ -117,13 +117,13 @@ Deneb introduces new global topics for blob sidecars.

The *type* of the payload of this topic changes to the (modified) `SignedBeaconBlock` found in deneb.

###### `blob_sidecar_{index}`
###### `blob_sidecar_{subnet_id}`

This topic is used to propagate signed blob sidecars, one for each sidecar index. The number of indices is defined by `MAX_BLOBS_PER_BLOCK`.

The following validations MUST pass before forwarding the `signed_blob_sidecar` on the network, assuming the alias `sidecar = signed_blob_sidecar.message`:

- _[REJECT]_ The sidecar is for the correct topic -- i.e. `sidecar.index` matches the topic `{index}`.
- _[REJECT]_ The sidecar is for the correct subnet -- i.e. `compute_subnet_for_blob_sidecar(sidecar.index) == subnet_id`.
- _[IGNORE]_ The sidecar is not from a future slot (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) -- i.e. validate that `sidecar.slot <= current_slot` (a client MAY queue future sidecars for processing at the appropriate slot).
- _[IGNORE]_ The sidecar is from a slot greater than the latest finalized slot -- i.e. validate that `sidecar.slot > compute_start_slot_at_epoch(state.finalized_checkpoint.epoch)`
- _[IGNORE]_ The sidecar's block's parent (defined by `sidecar.block_parent_root`) has been seen (via both gossip and non-gossip sources) (a client MAY queue sidecars for processing once the parent block is retrieved).
Expand Down
21 changes: 20 additions & 1 deletion specs/deneb/validator.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,8 @@

- [Introduction](#introduction)
- [Prerequisites](#prerequisites)
- [Constants](#constants)
- [Misc](#misc)
- [Helpers](#helpers)
- [`BlobsBundle`](#blobsbundle)
- [Modified `GetPayloadResponse`](#modified-getpayloadresponse)
Expand Down Expand Up @@ -38,6 +40,14 @@ All behaviors and definitions defined in this document, and documents it extends
All terminology, constants, functions, and protocol mechanics defined in the updated [Beacon Chain doc of Deneb](./beacon-chain.md) are requisite for this document and used throughout.
Please see related Beacon Chain doc before continuing and use them as a reference throughout.

## Constants

### Misc

| Name | Value | Unit |
| - | - | :-: |
| `BLOB_SIDECAR_SUBNET_COUNT` | `4` | The number of blob sidecar subnets used in the gossipsub protocol. |

## Helpers

### `BlobsBundle`
Expand Down Expand Up @@ -136,7 +146,7 @@ def get_blob_sidecars(block: BeaconBlock,

```

Then for each sidecar, `signed_sidecar = SignedBlobSidecar(message=sidecar, signature=signature)` is constructed and published to the `blob_sidecar_{index}` topics according to its index.
Then for each sidecar, `signed_sidecar = SignedBlobSidecar(message=sidecar, signature=signature)` is constructed and published to the associated sidecar topic, the `blob_sidecar_{subnet_id}` pubsub topic.

`signature` is obtained from:

Expand All @@ -149,6 +159,15 @@ def get_blob_sidecar_signature(state: BeaconState,
return bls.Sign(privkey, signing_root)
```

The `subnet_id` for the `signed_sidecar` is calculated with:
- Let `blob_index = signed_sidecar.message.index`.
- Let `subnet_id = compute_subnet_for_blob_sidecar(blob_index)`.

```python
def compute_subnet_for_blob_sidecar(blob_index: BlobIndex) -> SubnetID:
return SubnetID(blob_index % BLOB_SIDECAR_SUBNET_COUNT)
```

After publishing the peers on the network may request the sidecar through sync-requests, or a local user may be interested.

The validator MUST hold on to sidecars for `MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS` epochs and serve when capable,
Expand Down