#include <db.h>
int
DB_ENV->rep_set_clockskew(DB_ENV *env,
    u_int32_t fast_clock, u_int32_t slow_clock);  
      
         The DB_ENV->rep_set_clockskew() method sets the
         clock skew ratio among replication group members based on the fastest
         and slowest measurements among the group for use with master leases.
         Calling this method is optional; the default values for clock skew
         assume no skew.  The user must also configure leases via the 
         DB_ENV->rep_set_config() 
         method. Additionally, the user must also set the master lease timeout
         via the 
         DB_ENV->rep_set_timeout() 
         method. For Base API applications, the user must also set the number of
         sites in the replication group via the 
         DB_ENV->rep_set_nsites() 
         method.  These methods may be called in any order.  For a description
         of the clock skew values, see 
         Clock skew
         in the Berkeley DB Programmer's Reference Guide.  For a description of
         master leases, see 
         Master leases in the
         Berkeley DB Programmer's Reference Guide.
    
These arguments can be used to express either raw measurements of a clock timing experiment or a percentage across machines. For example, if a group of sites has a 2% variance, then fast_clock should be set to 102, and slow_clock should be set to 100. Or, for a 0.03% difference, you can use 10003 and 10000 respectively.
The database environment's replication subsystem may also be configured using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "rep_set_clockskew", one or more whitespace characters, and the clockskew specified in two parts: the fast_clock and the slow_clock. For example, "rep_set_clockskew 102 100". Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.
         The DB_ENV->rep_set_clockskew() method configures a database
         environment, not only operations performed using the specified 
         DB_ENV  handle.
    
         The DB_ENV->rep_set_clockskew() method may not be called after the
         DB_ENV->repmgr_start()  or
         DB_ENV->rep_start() 
         methods are called.
    
         The DB_ENV->rep_set_clockskew() 
            
                  method returns a non-zero error value on failure and 0 on success.
            
            
        
    
             The DB_ENV->rep_set_clockskew() 
            
                 method may fail and return one of the following non-zero errors:
            
            
        
        
If the method was called after replication is started with a call to the DB_ENV->repmgr_start() or the DB_ENV->rep_start() method; or if an invalid flag value or parameter was specified.