Are you assuming the client will eventually recover here? Or that clients are in general able to "lock" the resource before doing some work? Because otherwise,

Are you assuming the client will eventually recover here? Or that clients are in general able to "lock" the resource before doing some work? Because otherwise, imagine a client may crash and will never recover again, and you have clients sending a beam of electrons in some device, without feedbacks about the beam output. Each client is a device that can send the beam. If the client will never restart again, even with all the cooperation and consensus, there is no way to know if the beam of electrons was generated or not.