mongocxx::pool Class Reference

#include <mongocxx/v_noabi/mongocxx/pool.hpp>

Description

A pool of reusable client objects connected to the same MongoDB topology.

Important

This class does NOT implement Connection Monitoring and Pooling (MongoDB Specifications).

For interoperability with other MongoDB drivers, the minimum and maximum number of connections in the pool is configured using the 'minPoolSize' and 'maxPoolSize' connection string options.

See also

• https://www.mongodb.com/docs/manual/reference/connection-string/#connection-string-options

Remarks

When connecting to a replica set, it is much more efficient to use a pool as opposed to manually constructing client objects. The pool will use a single background thread per server to monitor the topology of the replica set, all of which are shared between the client objects created by the pool. A standalone client will instead "stop the world" every 60 seconds to check the status of the cluster. Because of this, if multiple threads are available, a connection pool should be used even if the application itself is single-threaded.

Classes
class	entry
	An owning handle to a client obtained from a pool. More...

Public Member Functions
	pool (v_noabi::uri const &mongodb_uri={}, v_noabi::options::pool const &options={})
	Creates a pool associated with a connection string.
	~pool ()=default
	Destroys a pool.
entry	acquire ()
	Acquires a client from the pool. The calling thread will block until a connection is available.
void	append_metadata (bsoncxx::v1::stdx::string_view name, bsoncxx::v1::stdx::optional< bsoncxx::v1::stdx::string_view > version={}, bsoncxx::v1::stdx::optional< bsoncxx::v1::stdx::string_view > platform={})
	Append client metadata to the handshake command sent as part of the initial connection handshake.
bsoncxx::v_noabi::stdx::optional< entry >	try_acquire ()
	Acquires a client from the pool. This method will return immediately, but may return a disengaged optional if a client is not available.

Constructor & Destructor Documentation

pool()

mongocxx::v_noabi::pool::pool ( v_noabi::uri const & mongodb_uri = {}, v_noabi::options::pool const & options = {} )

explicit

Creates a pool associated with a connection string.

Parameters

mongodb_uri	A MongoDB URI representing the connection parameters
options	Options to use when connecting to the MongoDB deployment.

Exceptions

mongocxx::v_noabi::exception

if invalid options are provided (whether from the URI or provided client options).

~pool()

mongocxx::v_noabi::pool::~pool ( )

default

Destroys a pool.

Member Function Documentation

acquire()

entry mongocxx::v_noabi::pool::acquire

(

)

Acquires a client from the pool. The calling thread will block until a connection is available.

append_metadata()

void mongocxx::v_noabi::pool::append_metadata	(	bsoncxx::v1::stdx::string_view	name,
		bsoncxx::v1::stdx::optional< bsoncxx::v1::stdx::string_view >	version = {},
		bsoncxx::v1::stdx::optional< bsoncxx::v1::stdx::string_view >	platform = {} )

Append client metadata to the handshake command sent as part of the initial connection handshake.

Parameters

name	The name of the wrapping driver. Must not be empty.
version	The optional version of the wrapping driver.
platform	The optional information about the current platform, for example configure options or compile flags.

Exceptions

mongocxx::v_noabi::operation_exception

when one of the following occurs: The resulting handshake document would exceed the size limit. A string argument contains the metadata delimiter " / ".

See also

• hello (MongoDB Manual)

try_acquire()

bsoncxx::v_noabi::stdx::optional< entry > mongocxx::v_noabi::pool::try_acquire

(

)

Acquires a client from the pool. This method will return immediately, but may return a disengaged optional if a client is not available.

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The documentation for this class was generated from the following file:

• mongocxx/v_noabi/mongocxx/pool.hpp