These values are thresholds only. Replication Manager applications
use these values to determine when to automatically request
retransmission of missing messages. For Base API applications,
Berkeley DB has no thread available in the library as a timer, so
the threshold is only checked when a thread enters the Berkeley DB
library to process an incoming replication message. Any amount of
time may have passed since the last message arrived and Berkeley
DB only checks whether the amount of time since a request was made
is beyond the threshold value or not.
</p>
<p>
By default the minimum is 40000 and the maximum is 1280000 (1.28
seconds). These defaults are fairly arbitrary and the application
likely needs to adjust these. The values should be based on
expected load and performance characteristics of the master and
client host platforms and transport infrastructure as well as
round-trip message time.
</p>
<p>
The database environment's replication subsystem may also be
configured using the environment's <ahref="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG"class="olink">DB_CONFIG</a> file. The syntax
of the entry in that file is a single line with the string
"rep_set_request", one or more whitespace characters, and the
request times specified in two parts: the min and the max. For
example, "rep_set_request 40000 1280000". Because the <ahref="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG"class="olink">DB_CONFIG</a>
file is read when the database environment is opened, it will
silently overrule configuration done before that time.
</p>
<p>
The <codeclass="methodname">DB_ENV->rep_set_request()</code> method
configures a database environment, not only operations performed
using the specified <aclass="link"href="env.html"title="Chapter5. The DB_ENV Handle">DB_ENV</a>
handle.
</p>
<p>
The <codeclass="methodname">DB_ENV->rep_set_request()</code> method may be
called at any time during the life of the application.
</p>
<p>
The <codeclass="methodname">DB_ENV->rep_set_request()</code><span>
<span>
method returns a non-zero error value on failure and 0 on success.
