Increase Block Limits to 100M CUs

Summary

Increase the block limit to 100M CUs.

Motivation

Current block limits are set to 50M CUs. SIMD-0256 will increase them to 60M. Block limits' primary purpose is to ensure the vast majority of network participants are able to keep up with the network, by restricting the amount of work a leader is allowed to pack into a block. However, current mainnet traffic is largely not constrained by large block execution times. This proposal aims a substantial increase in block limits to 100M CUs, in order to provide additional capacity to the network.

New Terminology

No new terms, but the following definitions are given for clarity:

• Max Block Units - The maximum number of CUs that can be included in a block.
• Max Writable Account Units - The maximum number of CUs that can be used to write any given account in a block.
• Max Vote Units - The maximum number of CUs that can be used by simple votes in a block.
• Max Block Accounts Data Size Delta - The maximum size of the accounts data size delta in a block.

Detailed Design

The following table shows the current block limits and the proposed block limits:

This proposal only changes the Max Block Units limit. The purpose is to increase capacity for non-vote transactions. The Max Writable Account Units is left unchanged since there is no specific push to increase the capacity for individual accounts at this time. Keeping Max Writeable Account Units unchanged while raising the Max Block Units , allows for additional parallel capacity.

The intention is for this to follow SIMD-0256 (as opposed to replacing). SIMD-0256 is a much more modest increase in block space. This proposal aims to increase block space more aggressively.

Alternatives Considered

• Smaller increase of limit to 80M CUs
  • Not IBRL'ing fast enough

Impact

• More transactions can be included per block.

Security Considerations

• Blocks may take longer to execute, slowing down network progress and catchup times.

Drawbacks

• Larger blocks may cause unforseen issues in infrastructure beyond the validators.

Backwards Compatibility

• All previously valid blocks are still valid, since limits are only increasing.
• Blocks produced after the change may be rejected by previous versions that do not support the new limits.