Layer 1 scaling: sharding and composability

 Ethereum and other public chains are trying to use the multi-chain structure to expand capacity, such as the homogeneous sharding that may be realized by Ethereum 2.0, the heterogeneous sharding that Polkadot is implementing, and the cross-chain structure of COSMOS. Networks such as the Avalanche Protocol, in the multi-chain structure, define function stratification and function modularization in a more detailed manner to achieve capacity expansion.

These are huge and long-term designs. Polkadot is still going through slot auctions, COSMOS is still building infrastructure, and the technical progress and ecological construction of the rest of the chains are still in their early stages.

For other projects that focus more on expansion, they may also focus more on a single network structure, such as implementing sharding in layer1, representing the project Near. In the long run, the expansion of layer1 (such as sharding) is inevitable. After these networks are compatible with EVM, DApps such as Defi can be quickly migrated to the network. If the asset transfer problem is solved, these networks will become the extended network of Ethereum.

So what kind of layer1 does DApp need? The preceding principles are 2:

1. Solve the performance bottleneck caused by the consensus problem.

2. Do your best to be composable.

The homogeneous sharding and heterogeneous sharding we mentioned earlier, the distributed shards are a chain composed of some nodes. It can be understood that some nodes are divided into a partition, this partition exists independently of other partitions, and tasks are processed separately.

For example, in Ethereum 2.0, if you still follow the original roadmap for sharding, 64 shards may be established in the initial stage, and these shards will eventually be verified by the beacon chain. The communication between shards is called "cross-linking" , if one of the shards needs to verify the other shards, the communication between the shards will be carried out. Because of the existence of shards, DApp developers need to choose a shard as the main processing area when developing DApps on Ethereum.

This means that if this DApp needs to obtain data from other shards, there will be some complicated steps. The same is true for the structures implemented by Polkadot and COSMOS. Polkadot’s parachains are shards in a heterogeneous sharding structure. The interaction between parachains is carried out through the relay chain, but the interaction process is more complicated and requires parallel chains. to be defined separately. The same goes for COSMOS.

Such sharding is a design that delimits boundaries. Each sharding chain may form a certain island effect, so it is necessary to ensure that communication capabilities are maintained between chains, or between shards and shards, and this communication is effective. And can solve the underlying data availability. That is, when DApp needs data across slices, it does not need to consider the situation that the data is not universal and the standards on both sides are different.

Polkadot's XCM and COSMOS' IBC are all doing this.

But if you change your thinking, you may generate some new technical ideas.

For example, a new consensus mechanism can be designed in the form of database sharding. It can be understood as a new sharding structure of database sharding + consensus.

This kind of sharding is different from the above-mentioned definition of some nodes as sharding chains. Instead, all computing resources added to the network are first divided into different shards. The shards are not divided by chains and nodes, but by The random command is randomly assigned to the determined shard location, and these shards divided by the command form a large partition.

This method of pre-setting the shard locations, and then dynamically assigning commands to various locations to form shards requires consensus to confirm the final state. This approach is much like the hybrid form of shard chains in Ethereum 2.0, where the dominant consensus process needs to be the same as the beacon chain's ghost algorithm to achieve finality.

The best way to do this is to achieve greater parallelism and mobilize all resources to use instead of some boundary problems caused by fixed partitions.

Second, possibly important issue is compositionality.

Compared with Ethereum, the on-chain compositionality is the interaction between smart contracts. For example, cTokens borrowed through Compound can be mined and swapped in other DeFi. This means that the DeFi contract needs to call the Compound contract to confirm the cToken. The invocation between the contracts is a manifestation of compositionality.

If the two are not deployed in the same network or shard, it is difficult to combine them, requiring gateway processing or the existence of a mapped smart contract. Without boundary issues, these composability would not be constrained.

Of course, there is obviously a problem with the structure of the chain. That is, in the entire ecosystem, whether the chain that is more inclined to the bottom is universal.

This general problem will also affect the definition of how to divide a certain layer. It can be said that sharding is an option for one-layer expansion, but in other networks, sharding can be a two-layer structure.

In addition to technical definition and design, the overall progress may be related to several other factors.

For example, Ethereum 2.0 is homogeneous sharding, and the chain and node standards of sharding are unified. However, if it is not considered technically and decentralization is considered, the realization of sharding in Ethereum will be limited to "maintain" and "do as well as possible" decentralization. That is, building shards, building nodes, node rewards, and subsequent stability all require users to complete them spontaneously.

However, many public chains directly use partners or self-built nodes to solve these problems. Instead, come first. This makes Ethereum lose a lot of advantages and changes the structure of the entire market.

When the huge public chain structures such as Ethereum, Polkadot, and COSMOS have not yet progressed, many chains have already overtaken them, such as Near and Solana, but there are still many changes in development. Ethereum will realize the split in 2023. The development progress of Cosmos and Polkadot may also be concentrated in 2023, which can be expected.