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Managing Connections Using the PHP SDK with Couchbase Server

This section describes how to connect the PHP SDK to a Couchbase cluster and bucket. It contains best practices as well as information on the connection string, SSL and other advanced connection options.

To manage Couchbase Server connections, you need to configure the client, connect to a bucket, and configure SSL.

Configuring the Client

To configure the client, instantiate a new Cluster object:

$myCluster = new CouchbaseCluster('couchbase://,,');

In addition to the connection string passed to the Cluster object, you can include a user name and password. The user name and password are required to perform management operations against your cluster. If you do not use the cluster management aspects of the SDK, the user name and password parameters are optional. Keep in mind that these credentials are the same ones you use to log in to the Couchbase administrator console, not those specified for the bucket itself.

Connecting to a Bucket

To connect to a bucket, call the openBucket() method against your Cluster instance, passing in the name of the bucket that you want to connect to. If no bucket name is specified, the default bucket is opened. The following example shows how to connect to a bucket:

$myCluster = new CouchbaseCluster();
$myBucket = $myCluster->openBucket('default');

In addition to the bucket name, you can optionally include the bucket password if one has been defined, as shown in the following example:

$myCluster = new CouchbaseCluster();
$myBucket = $myCluster->openBucket('default', 'password');

Disconnecting from a Bucket

To close the connection to a bucket, call its disconnect() method. This method queues the disconnection of all open connections and causes any pending operations to fail.

Scalability and concurrency

Creating a new Bucket object is relatively expensive, and keeping many idle Bucket objects will negatively impact server performance (if done at a large scale).

PHP SDK by default uses persistent connections to reuse underlying IO objects if the connection strings are the same.

Connecting with SSL

You can specify additional options when connecting to the cluster by using the connection string. It indicates to the client where cluster nodes may be found and how to connect to them. Note that it is common to other Couchbase SDKs as well as the command-line client. The connection string uses a URI-like format familiar to what is used in other database systems.

Couchbase Sever features the ability to have clients communicate securely via SSL.

To use SSL, you need Couchbase Server Enterprise 3.0 or later

  1. Obtain the SSl certificate used by the Cluster

  2. Make the certificate available to the file system of the client host.

  3. Employ the couchbases:// scheme for the connection string.

  4. Specify the local path to the certificate as the value for the certpath field.

To connect to a bucket on an SSL-enabled Cluster at the node, with the certificate saved as /var/cbcert.pem:


Specifying Multiple Hosts

You can specify multiple hosts in the connection string so that the client may be able to connect even if the cluster topology changed. To specify multiple hosts, separate them using a comma:


See Failure considerations for the C (libcouchbase) SDK in Couchbase for more information about handling cluster topology changes.

You are not required to enumerate or pass all Couchbase cluster nodes to the client. The client only needs to know about a single node which is a member of the cluster. Once the client has connected to the node, it will query that node about the cluster topology, which in turn contains information about all Couchbase nodes and the services they contain.

Configuration Cache

In environments when lots of short-lived connections are made to Couchbase (for example, a small command-line utility or a fork-and-execute CGI application) the overhead in actually bootstrapping the client may be significant. This is because the client must retrieve the configuration from the cluster, and involves several additional TCP requests and in many cases an additional TCP connection.

You can bypass the initial network bootstrap phase by using the config_cache directive in the connection string. The config_cache option accepts a path to a local file (the file should not exist when using for the first time). When performing the bootstrap process, the client will first check the contents of the given file to see if it contains an existing cluster configuration, and if it does, will use the file as the bootstrap source. If the file does not contain a configuration the client will then retrieve the configuration from the network and then write it to the file, so that future attempts will use the configuration file.

The config_cache feature is intended only for short-lived connections. During a cluster-side topology change the client will need to retrieve the configuration from the network as the file-based configuration will become invalid.

Additional Options

You can pass additional options in the connection string using the URL query format: couchbase://location-info?option1=value1&option2=value2&optionN=valueN. A list of options may be found in Client Settings