What happens to transactions that contain a blobs that are too large?

[rootulp]

Context

#2108

Problem

Consensus nodes may not reject transactions that contain a blob that is too large to fit in a block. As a result, the transaction may sit in the mempool until it eventually expires (depends on mepool config).

Proposal

Explore if the mempool will reject PFB transactions that contain a blob that will not fit in the maximum data square. If it doesn't, consider:

Option A

Add a stateless check to ValidateBasic on a transaction that verifies that the blob size is <= the maximum blob size. Compute the maximum blob size based on the upper bound values for max square size and max block bytes.

Option B

Decrease max_tx_bytes in the mempool config to the size of a tx that contains the largest blob that can fit in the largest data square.

Option C

Add a stateful check via blob ante handler that verifies that the blob size is <= the maximum blob size. Compute the maximum blob size based on the governance parameters for max square size.

Option D

Introduce a new versioned constant that acts as a max supported blob size.

• Pros: Since this is a versioned constant, a user can know prior to submitting their blob if it is valid. They don’t need to query the current chain state to determine if their constructed blob is valid.
• Cons: One additional parameter that needs to be re-evaluated when other square parameters are modified.

[rootulp]

Since there isn't a versioned constant for the maximum supported blob size, it must be computed based on a number of other parameters (see #2108). Since these parameters require access to the state, option A must be a stateful check.

[rootulp]

I started working on validating that blobs are < max blob size in https://github.com/rootulp/celestia-app/tree/rp/improve-too-big-blob

[evan-forbes]

Option A makes a lot of sense, since this will get hit before even submitting a blob. Do we also have an option C (no mutually exclusive to A!), where we add an ante handler that checks the the size of the blob using the stateful parameters? This will get hit upon submitting a blobtx and when we are gossiping blobs

[rootulp]

Good idea! Added Option C above and it seems like we can do Option A and Option C.