A system comprising: a processor-implemented overload determination module configured to: receive , from a first user on a first client device , a first request for an online service to perform an operation; detect at least one overload condition for the online service, the at least one overload condition corresponding to a first request time of the first request; determine a first token and a first return time parameter for the first user based on the determination of the overload condition; store the first token in association with the first return time parameter; receive , from the first user, a second request for the online service to perform the operation, the second request having a corresponding time and comprising the first token; identify the first return time parameter based on the first token; and determine that the corresponding time of the second request satisfies the first return time parameter; a processor implemented notification module configured to transmit the first token and the first return time parameter to the first client device ; and a processor-implemented service module configured to perform the operation in response to the determining that the corresponding time of the second request satisfies the first return time parameter. a processor-implemented overload determination module configured to: receive , from a first user on a first client device , a first request for an online service to perform an operation; detect at least one overload condition for the online service, the at least one overload condition corresponding to a first request time of the first request; determine a first token and a first return time parameter for the first user based on the determination of the overload condition; store the first token in association with the first return time parameter; receive , from the first user, a second request for the online service to perform the operation, the second request having a corresponding time and comprising the first token; identify the first return time parameter based on the first token; and determine that the corresponding time of the second request satisfies the first return time parameter; receive , from a first user on a first client device , a first request for an online service to perform an operation; detect at least one overload condition for the online service, the at least one overload condition corresponding to a first request time of the first request; determine a first token and a first return time parameter for the first user based on the determination of the overload condition; store the first token in association with the first return time parameter; receive , from the first user, a second request for the online service to perform the operation, the second request having a corresponding time and comprising the first token; identify the first return time parameter based on the first token; and determine that the corresponding time of the second request satisfies the first return time parameter; a processor implemented notification module configured to transmit the first token and the first return time parameter to the first client device ; and a processor-implemented service module configured to perform the operation in response to the determining that the corresponding time of the second request satisfies the first return time parameter. <EOS>