The Ethereum Foundation has outlined their current and anticipated expectations for the maximum possible depth of on-chain restructuring. Transactions at this level are not likely to be permanent, and these expectations should not be taken as guarantees of any kind of service. These are based on theoretical considerations, empirical data, contingency plan, and past experience of security personnel.
We will be monitoring the protocol level chain the same way as others do in the space. If we think there may be a protocol issue, we will provide updates on both the forums and the official blog. If you are interested in our suggestions and expectations, then it would be best to regularly check the blog.
ROADMAP
Until 08/08/2015 18:00:00 CEST: 6000
As 08/08/2015 18:00:00 CEST 3000 (approx. 12 hours)
(1 day)
As As of 08/09/2015, 18:00:00 CEST 1500 (approximately 6 hours)
(3 days)
As 08/12/2015 18:00:00 CEST 750 (approximately 3 hours)
(3 days)
As 08/15/2015 18:00:00 CEST 375 (approximately 90 minutes)
(Rest The Border)
ADDENDUM 2015/08/08 To get a better understanding of “chain reorganization depth”, think about it like this. When a node on the chain is reorganized, the Ethereum network (owned by anyone – an individual, exchange, miner, etc.) notices that the canonical string isn’t what it originally was. This happens when the transactions in its most recent part are rolled over and the transactions that are in the substitute are executed instead.
Since Ethereum has a target block time of just 15 seconds, reorganizations occur quite frequently. Due to blocks taking some time to filter through the network, it is common for there to be a different last block among different parts since miners often find them around the same time. This is referred to as a short-lived fork. In fact, many of the ommers (tíos) that can be seen in the Ethereum Network Monitor were previously assumed by some nodes to be the final block of the canonical chain.
Reorganization occurs when the network has a wider consensus than it previously had. This is when the fork is solved, and the nodes that had the defunct chain will discard the most recent, non-canonical blocks. Transactions are rolled back and others are executed to align with the other side of the fork.
Transactions can be mutually exclusive, like checks. If I have $100 in my bank account, I can write two $100 checks each. This means that a reorganization may result in the reversal of one transaction and the execution of another mutually exclusive transaction. This is why it is essential to be aware of the risks involved in reorganization if you are planning to make irreversible
