Understanding Ethereum Nodes When the Transaction Pool is Not Full
The Ethereum blockchain is designed to process transactions in a way that allows it to grow and scale without interruption. However, sometimes the transaction pool of Ethereum nodes, such as Geth or Erigon, is unable to accommodate all new transactions within a block, resulting in partial blocks or even network congestion.
In this article, we will explore what happens when an Ethereum node’s transaction pool is not full, specifically when there are not enough transactions in the pool to fill a new creation block (i.e. a block that contains one or more unconfirmed transactions).
What does Geth/Erigon do if the transaction pool is not full?
When an Ethereum node encounters a situation where the transaction pool is not enough to fill a new block, it will try to:
- Add more blocks: The node can create new blocks and add them to its queue of pending blocks until the transaction pool is full.
- Merge existing blocks with new transactions
: If there are unconfirmed transactions in the pool that can be merged with existing blocks without creating new ones, the node will try to save space and prevent network congestion.
- Use the “partial block” mechanism: In some cases, if the transaction pool is too small to fill the entire block, the node may create a partially filled block (also known as a “partial block”). This means that even though not all of the transactions in the block are included, they will still be visible in the blockchain.
Do nodes immediately create a partially filled block?
Not always. While some nodes may choose to create a partially filled block to prevent congestion and maintain network stability, others may not do so at all or use alternative methods. Here’s why:
- Limited optimization capabilities: Geth/Erigon nodes have limited optimization capabilities compared to other Ethereum clients such as Parity or Remix. They can only process blocks with an average size of around 1-2 MB.
- Resource constraints: Nodes may not be able to create a partially filled block due to resource constraints such as insufficient memory or processing power.
- Network conditions: Poor network conditions such as high congestion or frequent rejection of transactions on the network may cause nodes to prioritize other tasks over creating partial blocks.
Alternatives and Mitigations
Some Ethereum clients and operators use alternative strategies to mitigate the issue of the transaction pool not filling a block completely:
- Using scheduling: Nodes can be scheduled to create new blocks at specific times or intervals to maintain network stability.
- Implementing “queue prioritization”: Some nodes prioritize transactions based on their urgency or importance, ensuring that critical transactions are processed first.
- Using other blockchain protocols
: Other blockchain protocols, such as Polkadot or Cosmos, may be better suited to certain use cases and can help mitigate the issue of the transaction pool not filling a block completely.
In summary, when an Ethereum node encounters a situation where the transaction pool is not full, it attempts to handle the situation in different ways. Although nodes can create partially filled blocks or prioritize other tasks over creating partial blocks, these measures are not always efficient and can lead to network congestion.