Distributed transactions across multiple consensus groups

A computer-implemented method, comprising:

• performing, by a plurality of computing devices that collectively implement a distributed transaction system operating on a data set and comprising a proposer and a plurality of consensus groups including a first consensus group comprising a first plurality of members storing respective replicas of the data set and a second consensus group comprising a second plurality of members storing respective replicas of the data set:
• sending, from the proposer to at least a portion of the first consensus group and at least a portion of the second consensus group as part of a consensus protocol, a prepare-transaction request for a transaction, wherein a transaction group for the transaction comprises the first consensus group and the second consensus group, wherein the first consensus group and the second consensus group respectively participate in different respective subsets of a plurality of transactions, including the transaction, operating on the data set, wherein the prepare-transaction describes the transaction comprising one or more data updates to be performed by individual members of the transaction group, and wherein a positive response to the prepare-transaction request by an individual member of the transaction group indicates acceptance of the transaction by the individual member;
• and
• performing the transaction comprising the one or more data updates of the transaction on the data set based at least in part on one or more positive responses to the prepare-transaction request, wherein at least some of the one or more positive responses identify an additional transaction of the plurality of transactions, and wherein the performing comprises:
• determining, based at least in part on one or more positive responses to the prepare-transaction request as part of the consensus protocol, that the identified additional transaction, different from the transaction, has been accepted by a particular consensus group of the transaction group, wherein the acceptance locks the particular consensus group from performance of the transaction, wherein the additional transaction involves another transaction group comprising the particular consensus group and one or more additional consensus groups of the plurality of consensus groups;
• and
• unlocking, responsive to the determining, performance of the transaction for the particular consensus group, comprising sending an abort-transaction request of the additional transaction as part of the consensus protocol from the proposer to the particular consensus group of the transaction group.

One or more non-transitory computer-readable storage media storing program instructions that, when executed on or across one or more processors, perform:

• sending, from a proposer to at least a portion of a first consensus group and at least a portion of a second consensus group as part of a consensus protocol, a prepare-transaction request for a transaction, wherein the first consensus group comprises a first plurality of members storing respective replicas of a data set and the second consensus group comprises a second plurality of members storing respective replicas of the data set, wherein the first consensus group and the second consensus group respectively participate in different respective subsets of a plurality of transactions, including the transaction, operating on the data set, wherein the proposer and the first plurality of members and the second plurality of members comprise servers having access to storage resources and implement the consensus protocol, wherein the prepare-transaction describes the transaction comprising one or more data updates to be performed by individual members of the transaction group, and wherein a positive response to the prepare-transaction request by an individual member of the transaction group indicates acceptance of the transaction by the individual member;
• and
• performing the transaction comprising the one or more data updates of the transaction on the data set based at least in part on one or more positive responses to the prepare-transaction request, wherein at least some of the one or more positive responses identify an additional transaction of the plurality of transactions, and wherein the performing comprises:
• determining, based at least in part on one or more positive responses to the prepare-transaction request as part of the consensus protocol, that the identified additional transaction, different from the transaction, has been accepted by a particular consensus group of the transaction group, wherein the acceptance locks the particular consensus group from performance of the transaction, wherein the additional transaction involves another transaction group comprising the particular consensus group and one or more additional consensus groups of the plurality of consensus groups;
• and
• unlocking, responsive to the determining, performance of the transaction for the particular consensus group, comprising sending an abort-transaction request of the additional transaction as part of the consensus protocol from the proposer to the particular consensus group of the transaction group.