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<title>Berkeley DB: DbEnv::rep_process_message</title>
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<h1>DbEnv::rep_process_message</h1>
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#include <db_cxx.h>
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DbEnv::rep_process_message(Dbt *control, Dbt *rec, int *envid)
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<p>The DbEnv::rep_process_message method processes an incoming replication
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message sent by a member of the replication group to the local database
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<p>The <b>rec</b> and <b>control</b> parameters should reference a copy
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of the parameters specified by Berkeley DB for the <b>rec</b> and
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<b>control</b> parameters on the sending environment.
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<p>The <b>envid</b> parameter should contain the local identifier that
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corresponds to the environment that sent the message to be processed
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(see <a href="../ref/rep/id.html">Replication environment IDs</a> for more
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<p>For implementation reasons, all incoming replication messages must be
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processed using the same <a href="../api_cxx/env_class.html">DbEnv</a> handle. It is not required that
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a single thread of control process all messages, only that all threads
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of control processing messages use the same handle.
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If a new master has been elected, the DbEnv::rep_process_message method will return DB_REP_NEWMASTER.
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The <b>envid</b> parameter contains the environment ID of the new
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master. If the recipient of this error return has been made master, it
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is the application's responsibility to begin acting as the master
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If the system received contact information from a new environment, the DbEnv::rep_process_message method will return DB_REP_NEWSITE.
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The <b>rec</b> parameter contains the opaque data specified in the
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<b>cdata</b> parameter to the <a href="../api_cxx/rep_start.html">DbEnv::rep_start</a>. The application
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should take whatever action is needed to establish a communication
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channel with this new environment.
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If the replication group has more than one master, the DbEnv::rep_process_message method either returns DB_REP_DUPMASTER or throws an exception that encapsulates DB_REP_DUPMASTER.
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The application should reconfigure itself as a client by calling the
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<a href="../api_cxx/rep_start.html">DbEnv::rep_start</a> method, and then call for an election by calling
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<a href="../api_cxx/rep_elect.html">DbEnv::rep_elect</a>.
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If an election is needed, the DbEnv::rep_process_message method either returns DB_REP_HOLDELECTION or throws an exception that encapsulates DB_REP_HOLDELECTION.
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The application should call for an election by
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calling <a href="../api_cxx/rep_elect.html">DbEnv::rep_elect</a>.
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If the current environment's logs are too far out of date with respect
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to the master to be automatically synchronized, the DbEnv::rep_process_message method either returns DB_REP_OUTDATED or throws an exception that encapsulates DB_REP_OUTDATED. The
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application should copy over a hot backup of the environment, run
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recovery, and restart the client.
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Otherwise, the DbEnv::rep_process_message method either returns a non-zero error value or throws an exception that
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encapsulates a non-zero error value on failure, and returns 0 on success.
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<p>The DbEnv::rep_process_message method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods.
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If a catastrophic error has occurred, the DbEnv::rep_process_message method may fail and
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either return <a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a> or throw a
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<a href="../api_cxx/runrec_class.html">DbRunRecoveryException</a>,
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in which case all subsequent Berkeley DB calls will fail in the same way.
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<a href="../api_cxx/env_class.html">DbEnv</a>
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<a href="../api_cxx/rep_list.html">Replication and Related Methods</a>
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