An information processing system including a plurality of servers and a load balancing apparatus, each of the plurality of servers comprising: a replication target determination unit that determines an allocation target server as a replication target for communication identifier information in order to identify communication between a client and a server from among the plurality of servers, by using a predetermined algorithm having reproducibility with respect to an input; and a replication unit that replicates the communication identification information to the replication target server determined by the replication target determination unit, and the load balancing apparatus comprising: an allocation target determination unit that determines an allocation target server to which the communication is allocated from among the plurality of servers, by using the predetermined algorithm; and a communication allocation unit that allocates the communication to the allocation target server determined by the allocation target determination unit, wherein the replication target determination unit determines a replication target server for the communication identification information by processing at least part of the communication identification information on the basis of the predetermined algorithm, and the allocation target determination unit determines the allocation target server to which the communication corresponding to the communication identification information is allocated, by processing at least part of the communication identification information, on the basis of the predetermined algorithm. a replication target determination unit that determines an allocation target server as a replication target for communication identifier information in order to identify communication between a client and a server from among the plurality of servers, by using a predetermined algorithm having reproducibility with respect to an input; and a replication unit that replicates the communication identification information to the replication target server determined by the replication target determination unit, and the load balancing apparatus comprising: an allocation target determination unit that determines an allocation target server to which the communication is allocated from among the plurality of servers, by using the predetermined algorithm; and a communication allocation unit that allocates the communication to the allocation target server determined by the allocation target determination unit, wherein the replication target determination unit determines a replication target server for the communication identification information by processing at least part of the communication identification information on the basis of the predetermined algorithm, and the allocation target determination unit determines the allocation target server to which the communication corresponding to the communication identification information is allocated, by processing at least part of the communication identification information, on the basis of the predetermined algorithm. an allocation target determination unit that determines an allocation target server to which the communication is allocated from among the plurality of servers, by using the predetermined algorithm; and a communication allocation unit that allocates the communication to the allocation target server determined by the allocation target determination unit, wherein the replication target determination unit determines a replication target server for the communication identification information by processing at least part of the communication identification information on the basis of the predetermined algorithm, and the allocation target determination unit determines the allocation target server to which the communication corresponding to the communication identification information is allocated, by processing at least part of the communication identification information, on the basis of the predetermined algorithm.