Persistent Connections (version 1.3.0+)
Persistent Connections (version 1.3.0+)
Persistent Connections (version 1.3.0+)
All versions of the driver since 1.3.0 utilize
persistent connections to minimize the number of connections made
to each database server. These connections are saved by the PHP
worker process and may be reused between multiple requests.
Before connecting to a database server, the driver
will create a hash for the connection based on its host, port,
replica set name (if any), any authentication credentials (e.g.
username, password, database), and the process ID. If a connection
already exists for that hash, it will be used in lieu of creating a
new connection associated with that hash. MongoClient::getConnections() may be used to
retrieve info about each persistent connection. Consider the
following program:
<?php
$m1
= new MongoClient('mongodb://localhost');
$m2 = new MongoClient('mongodb://localhost');
$m3 = new MongoClient('mongodb://user:pw@localhost');
$m4 = new MongoClient('mongodb://127.0.0.1');
$m5 = new MongoClient('mongodb://rs1.local:30017,rs2.local:30018/?replicaSet=rs');
$m6 = new MongoClient('mongodb://sharding.local:40017');
foreach (
MongoClient::getConnections() as $conn) {
echo $conn['hash'], "\n";
}
?>The above example will output something similar to:
localhost:27017;-;X;15487 localhost:27017;-;admin/user/c56c…8bbc;15487 127.0.0.1:27017;-;X;15487 rs1.local:30017;rs;X;15487 rs2.local:30018;rs;X;15487 sharding.local:40017;-;X;15487
In this example $m1 and $m2 have
the same hash and share a persistent connection. Connections for
each other MongoClient instance hash to unique values and use their
own sockets. Note that “localhost” and “127.0.0.1” do not share the
same hash; DNS resolution is not taken into account.