Class for working with a MongoDB replica set.

This class provides comprehensive replica set support including: - Automatic topology discovery from seed servers - Primary election detection - Connection failover on errors - Read preference routing (primary, secondary, nearest, etc.) - Background topology monitoring - Server health checking

Usage example:

ReplicaSet::Config config;
config.seeds = {
    Net::SocketAddress("mongo1:27017"),
    Net::SocketAddress("mongo2:27017"),
    Net::SocketAddress("mongo3:27017")
};
config.setName = "rs0";
config.readPreference = ReadPreference::primaryPreferred();

ReplicaSet rs(config);
Connection::Ptr conn = rs.getPrimaryConnection();
// Use connection...

REQUIREMENTS: Requires MongoDB 5.1 or later. Earlier versions using the legacy isMaster command are not supported.

THREAD SAFETY: The ReplicaSet class is thread-safe. Multiple threads can call getConnection() and other methods concurrently. However, the returned Connection objects are NOT thread-safe and must be used by only one thread at a time, or protected by external synchronization.

For multi-threaded applications, use ReplicaSetConnection with connection pooling (PoolableObjectFactory pattern).

Creates a ReplicaSet with the given configuration. Performs initial topology discovery. Throws Poco::IOException if initial discovery fails.

Creates a ReplicaSet with default configuration and the given seed addresses. Performs initial topology discovery. Throws Poco::IOException if initial discovery fails.

Creates a ReplicaSet from a MongoDB URI string. Format: mongodb://host1:port1,host2:port2,...?options

Supported URI options:

• replicaSet=name - Replica set name
• readPreference=mode - primary|primaryPreferred|secondary|secondaryPreferred|nearest
• connectTimeoutMS=ms - Connection timeout in milliseconds
• socketTimeoutMS=ms - Socket timeout in milliseconds
• heartbeatFrequencyMS=ms - Heartbeat frequency in milliseconds (default: 10000)
• reconnectRetries=n - Number of reconnection retries (default: 10)
• reconnectDelay=seconds - Delay between reconnection attempts in seconds (default: 1)

Example: mongodb://mongo1:27017,mongo2:27017,mongo3:27017/?replicaSet=rs0&readPreference=primaryPreferred

Throws Poco::SyntaxException if URI is invalid. Throws Poco::UnknownURISchemeException if scheme is not "mongodb".

Creates a ReplicaSet from a ReplicaSetURI object. This allows for programmatic URI construction and modification before creating the replica set connection.

The ReplicaSetURI stores servers as strings without DNS resolution. This constructor resolves the server strings to SocketAddress objects. Servers that cannot be resolved are skipped and will be marked as unavailable during topology discovery.

Example:

ReplicaSetURI uri;
uri.addServer("host1:27017");
uri.addServer("host2:27017");
uri.setReplicaSet("rs0");
uri.setReadPreference("primaryPreferred");
ReplicaSet rs(uri);

Throws Poco::InvalidArgumentException if the URI contains no servers

or if no servers can be resolved.

Throws Poco::IOException if initial discovery fails.

Destroys the ReplicaSet and stops background monitoring.

Returns a connection to a server matching the read preference. Returns null if no suitable server is available.

Returns a connection to the primary server. Returns null if no primary is available.

Returns a connection to a secondary server. Returns null if no secondary is available.

Returns true if a primary server is known.

Returns the default read preference.

Forces an immediate topology refresh by querying all known servers.

Returns the replica set name, or empty if not discovered.

Sets the default read preference.

Sets the socket factory for creating connections. The factory can access timeout configuration via configuration().connectTimeoutSeconds and configuration().socketTimeoutSeconds.

Example:

rs.setSocketFactory(&myCustomFactory);

Starts the background monitoring thread if not already running.

Stops the background monitoring thread.

Returns a copy of the current topology description.

Waits for a server to become available for the given read preference. This method coordinates waiting between multiple threads - only one thread performs the actual sleep and topology refresh, while others benefit from the refresh done by the first thread. Returns a connection if a server becomes available, or null if still unavailable. Thread-safe: uses internal synchronization to prevent redundant refresh attempts.