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MICO2.3.13 corba 环境平台

This example shows a simple scenario in which the load-balancing function of 
the naming service is utilized.  It is about a client looking for a printer 
and asking the latter to print a message.  There are two printers in the 
example.  The shell script 'printer_test' of the example demonstrates 
three cases.

- case 1 : The naming service does not do load-balancing
- case 2 : The naming service is launched with the "--lb round_robin" option
- case 3 : The naming service is launched with the "--lb random" option

The two printers are named 'Laser_Admin.Printer' and 
'InkJet_Marketing.Printer' respectively. In each case, the client is made to
resolve the name 'Laser_Admin.Printer' ten times.  After each resolve()
operation, the client invokes the print() method on the printer whose
reference was returned in the operation, causing the printer to print
a short message to the standard output.

Case 1 should show the printer named 'Laser_Admin.Printer' printing the
short message ten times.  Case 2 should show each of the two printers
printing it five times.  In case 3, each of the two printers prints a random
number of times.

In case 1, the naming service uses both the ID and kind portions of the name
component 'Laser_Admin.Printer' to look for an object reference to return
during a resolve() operation.  The ID is the string preceding the 
character '.', while the kind is the string following the character.  
Only the object reference bound to that name is returned.  In cases 2 and 3, 
it uses only the kind portion, which is 'Printer', of the name component to 
look for an object reference.  An object reference bound to a name with a 
kind value of 'Printer' is treated by the naming service as a potential 
candidate to return during the operation.  How the naming service chooses 
a reference from a list of potential candidates is determined by the name of 
the load-balancing algorithm specified during the startup of the 
naming service.  The names of the algorithms implemented so far are 
'round_robin' and 'random'.

If there are more than one name component in the name passed to the naming
service during a resolve() operation, for example, 
'SubsidiaryA.CompanyA/Laser_Admin.Printer' (which consists of two 
name components 'SubsidiaryA.CompanyA' and 'Laser_Admin.Printer', only the 
last name component, that is, 'Laser_Admin.Printer', is used by the '
naming service to look for potential candidates.