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<b>DbEnv::rep_set_clockskew</b>
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<b><pre>
#include <db_cxx.h>
<p>
int
DbEnv::rep_set_clockskew(u_int32_t fast_clock, u_int32_t slow_clock);
<p>
DbEnv::rep_get_clockskew(u_int32_t *fast_clockp, u_in32_t *slow_clockp);
</pre></b>
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<b>Description: DbEnv::rep_set_clockskew</b>
<p>The DbEnv::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 <a href="../api_cxx/rep_config.html">DbEnv::rep_set_config</a> method.
Additionally, the user must also set the master lease timeout via the
<a href="../api_cxx/rep_timeout.html">DbEnv::rep_set_timeout</a> method and the number of sites in the replication
group via the <a href="../api_cxx/rep_nsites.html">DbEnv::rep_set_nsites</a> method. These methods may be called in
any order. For a description of the clock skew values, see
<a href="../ref/rep/clock_skew.html">Clock skew</a>. For a description
of master leases, see <a href="../ref/rep/lease.html">Master
leases</a>.</p>
<p>These arguments can be used to express either raw measurements of a
clock timing experiment or a percentage across machines. For instance
a group of sites have a 2% variance, then <b>fast_clock</b> should be
given as 102, and <b>slow_clock</b> should be set at 100. Or, for a
0.03% difference, you can use 10003 and 10000 respectively.</p>
<p>The database environment's replication subsystem may also be configured using the
environment's <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> 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 <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment
is opened, it will silently overrule configuration done before that
time.</p>
<p>The DbEnv::rep_set_clockskew method configures a database environment, not only operations
performed using the specified <a href="../api_cxx/env_class.html">DbEnv</a> handle.</p>
<p>The DbEnv::rep_set_clockskew method may not be called after the <a href="../api_cxx/repmgr_start.html">DbEnv::repmgr_start</a> or <a href="../api_cxx/rep_start.html">DbEnv::rep_start</a> methods are
called.</p>
<p>The DbEnv::rep_set_clockskew method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
<b>fast_clock</b><ul compact><li>The value, relative to the <b>slow_clock</b>, of the fastest clock
in the group of sites.</ul>
<b>slow_clock</b><ul compact><li>The value of the slowest clock in the group of sites.</ul>
<br>
<br><b>Errors</b>
<p>The DbEnv::rep_set_clockskew method
may fail and throw
<a href="../api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:</p>
<br>
<b>EINVAL</b><ul compact><li>An
invalid flag value or parameter was specified.</ul>
<br>
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<b>Description: DbEnv::rep_get_clockskew</b>
<p>The DbEnv::rep_get_clockskew method returns the current clock skew values.</p>
<p>The DbEnv::rep_get_clockskew method may be called at any time during the life of the
application.</p>
<p>The DbEnv::rep_get_clockskew method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
<b>fast_clockp</b><ul compact><li>The <b>fast_clockp</b> parameter references memory into which
the value for the fastest clock in the group of sites is copied.</ul>
<b>slow_clockp</b><ul compact><li>The <b>slow_clockp</b> parameter references memory into which
the value for the slowest clock in the group of sites is copied.</ul>
<br>
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<br><b>Class</b>
<a href="../api_cxx/env_class.html">DbEnv</a>
<br><b>See Also</b>
<a href="../api_cxx/rep_list.html">Replication and Related Methods</a>
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