Common use of Retries Clause in Contracts

Retries. In the previous experiments, to better control the rate of cross-shard transactions, clients submit transactions only if they know the contracts are not going to be moved when the transaction is executed. To better model transactions in the presence of conflicts we experiment with the SCoin contract without any help from external sources. Two situa- tions can make clients retry transactions: when performing a single-shard transaction and the interacted contract is moved to another shard or when performing a cross-shard transaction and the called contract is moved to another shard. In the experiment we make clients wait a random time corresponding to the creation of 0 to 10 blocks if the transaction fails for any of these reasons, this is done to prevent contracts moving back and forth in an endless cycle. Figure 7 (right) shows the ideal latency where no conflicts exist, and Figure 7 (left) shows the latency when conflicts can happen. A clear increase in latency is observed when comparing both figures, but when retries can happen the number of times the same transaction fails and has to retry is highly skewed, for instance, 66% of the transactions that retry, do it just once, and only 1% of these transactions are retried more than three times.