Transaction PriceLimit is only respected in the txpool (discussion)

[mrwillis]

Transaction PriceLimit is only respected in the txpool

Description

More of a discussion point, but curious why only the pool respects the PriceLimit and not nodes receiving transactions directly.

server --help returns:

--price-limit PRICE_LIMIT
        Sets minimum gas price limit to enforce for acceptance into the pool. Default: 1

For example, if you had a four node cluster, you could submit a transaction with price of 0 to node 1, which it wouldn't propogate to nodes 2,3,4 because of this line.

https://github.com/0xPolygon/polygon-sdk/blob/develop/txpool/txpool.go#L512

Would it not make more sense to discard the transaction on node 1 as well, and reject at the RPC level?

Your environment

• OS and version Ubuntu 20
• version of the Polygon SDK 6efebc6
• branch that causes this issue develop

[Kourin1996]

@mrwillis Hi, if you want to make node1 discard the tx with lower price. You can give --nolocals flag when you start server.

[mrwillis]

Thanks @Kourin1996. Sorry documentation is a little confusing here. So If I set --nolocals on Node 1 that means the node won't accept any transactions lower than the gas limit into Node 1's pool?

[Kourin1996]

@mrwillis Node can accept transactions from JSON-RPC/gRPC even though gas price is less than price limit. Only remote transactions, which come from gossip broadcasted transactions, are restricted by price limit as default. If you give --nolocals, then node checks gas price for local transactions, also.

But @zivkovicmilos opened new PR #244 and merged. It set default price limit to 0. So node will accept all transactions even though its gas price is 0 when you don't give --price-limit, --nolocals

[zivkovicmilos]

Hey @mrwillis,

I'll open up a PR that gives a better understanding of how price-limit works, and how it relates to locals.
Pinging you here once it's up 👍

[zivkovicmilos]

Hey @mrwillis,

I've added additional docs for the price-limit flag. They should be merged out soon 👍
0xPolygon/polygon-edge-docs#34