Increase Transaction Size

[jacobcreech]

Summary

Currently transaction size is capped at 1280 bytes, or 1232 bytes available for developers to use while building their applications. This is limiting for a bunch of usecases, some of them being the following:

• Transferring with fees on a token with confidential balances enabled requires 3x the size
• Untruncated Winternitz signatures can be accomplished with 37 more bytes than what is currently provided
• More routes can be added to trades using markets such as Jupiter

The current transaction cap was originally limited by the maximum IPv6 MTU size, but that is not longer a restriction. Increasing this cap would both enable new usecases like above for developers, as well as allow potential apps that were previous limited to be built.

What needs to be discussed/researched?

1. Is this a change that is reasonable to make to the Solana network?
2. What cost model should be applied to transaction size increases?

In SIMD-108, instead of having a separate fee, it was decided to pull the transaction size increase into the CU model.

3. What impact does a transaction increase have on cluster performance?

Very old research, but when testing average increased transaction sizes, it was found that as the transaction size went up, max TPS on the cluster went down exponentially. This test is likely not valid anymore and would need a retest before any consideration of writing a SIMD.

4. What should be the new max transaction size? Should we test a smaller increase followed by a later larger increase like is potentially being done with CU?

5. What is the effort to include this change?