At a logging service, a representation of a transaction requested by a client is received. The transaction includes at least a first write operation directed to a data object at a first data store. Based at least in part on the contents of the representation and contents of a persistent log of the logging service, a determination is made that the requested transaction is to be committed. A log record corresponding to the first write operation is inserted into the persistent log. The first write is propagated to the first data store after the record has been inserted in the persistent log.