A method comprising: a server receiving, from a client in a second session, a request for an outcome of an identified set of one or more commands that (i) specify two or more transactions and (ii) were previously sent by the client to the server or to a different server in a first session (904A - 904C); wherein the identified set of one or more commands, if completed in the first session (904A - 904C), would cause performance of: a first server operation that commits a transaction of the two or more transactions, and a second server operation that sends, to the client, an indication that the identified set of one or more commands has committed, wherein the indication that the identified set of one or more commands has committed is not sent, to the client, until after the first server operation has committed the transaction and completed the set of one or more commands; the server determining that at least one transaction of the two or more transactions has committed and that at least one other transaction of the two or more transactions has not committed; and based at least in part on determining that at least one transaction of the two or more transactions has committed and that at least one other transaction of the two or more transactions has not committed, the server sending, to the client in the second session, a response to the request that indicates that the at least one transaction has committed but that the at least one other transaction has not committed; wherein the client did not receive, in the first session, the indication that the identified set of one or more commands has committed. a server receiving, from a client in a second session, a request for an outcome of an identified set of one or more commands that (i) specify two or more transactions and (ii) were previously sent by the client to the server or to a different server in a first session (904A - 904C); wherein the identified set of one or more commands, if completed in the first session (904A - 904C), would cause performance of: a first server operation that commits a transaction of the two or more transactions, and a second server operation that sends, to the client, an indication that the identified set of one or more commands has committed, wherein the indication that the identified set of one or more commands has committed is not sent, to the client, until after the first server operation has committed the transaction and completed the set of one or more commands; a first server operation that commits a transaction of the two or more transactions, and a second server operation that sends, to the client, an indication that the identified set of one or more commands has committed, wherein the indication that the identified set of one or more commands has committed is not sent, to the client, until after the first server operation has committed the transaction and completed the set of one or more commands; the server determining that at least one transaction of the two or more transactions has committed and that at least one other transaction of the two or more transactions has not committed; and based at least in part on determining that at least one transaction of the two or more transactions has committed and that at least one other transaction of the two or more transactions has not committed, the server sending, to the client in the second session, a response to the request that indicates that the at least one transaction has committed but that the at least one other transaction has not committed; wherein the client did not receive, in the first session, the indication that the identified set of one or more commands has committed.