varspool/predisque

Disque client based on Predis

Predisque

, _(*1)

A Disque client for PHP 7.1+ based on (and depending on) Predis. predis : redis :: predisque : disque, yeah?, _(*2)

The library is made up of:, _(*3)

• A set of commands (as in Predis\Command\Command) that you can use with Disque, and a server profile for Predis
• A Predisque\Client that's set up to use port 7711 and the Disque server profile by default
• An aggregate connection (Predisque\Connection\Aggregate\DisqueCluster) that handles talking to a Disque cluster as a whole
  • Supports discovery via HELLO
  • Supports retrying commands transparently if they fail with a ConnectionException (so we handle -LEAVING responses by swapping to another node)

Because Predisque is based on a feature-rich Predis core, we get things like pipelining and nice underlying Redis protocol support "for free". (A Disque client library should probably not contain its own native Redis protocol parser.), _(*4)

Support for all Disque commands is implemented, including exotic ones like DEBUG, MONITOR, and CLUSTER INFO. See TODO.md for progress on reaching a stable API., _(*5)

Not yet stable for production use., _(*6)

Usage

The PHP namespace is \Predisque, _(*7)

To create a client, instantiate a new \Predisque\Client(string|array $parameters = [], array $options = [])., _(*8)

The method signature is similar to a Predis client: the connection parameters (host, port, etc.) come first, and can be given in array or DSN/URI string notation. Then a set of more general options comes after. So, all of the following have the same result (a connection to a single Disque server):, _(*9)

$client = new \Predisque\Client();
$client = new \Predisque\Client('tcp://127.0.0.1:7711');
$client = new \Predisque\Client([
    'host' => '127.0.0.1',
    'port' => 7711
]);

Connecting to multiple servers is as easy as passing an array of node details:, _(*10)

$client = new \Predisque\Client(['tcp://127.0.0.1:7711', 'tcp://127.0.0.1:7712', 'tcp://127.0.0.1:7713']);

Connection Switching

Only one of these connections will be utilized at a time, but the others will be used if the connection to the first server fails, or if it gives a -LEAVING response. Also, details from the cluster's HELLO response will be used to connect to even further backup nodes (so make sure all nodes are accessible to every client)., _(*11)

You can control this behavior with the discover option:, _(*12)

php $client = new \Predisque\Client('tcp://127.0.0.1:7711', ['discover' => false]);, _(*13)

You can also disable all Disque-specific connection niceties (and the aggregate connection in general), by passing the 'cluster' => false option:, _(*14)

php $client = new \Predisque\Client('tcp://127.0.0.1:7711', ['cluster' => false]);, _(*15)

Testing

Warning: the test suite uses the DEBUG FLUSHALL command. Do not run the tests against a Disque instance you care about. Running the tests will destroy all data on the disque instance they use. (You won't have the tests if you're just using the client as a dist from composer.), _(*16)

To execute the test suite, run e.g. DISQUE_SERVER_PORT=7711 ./vendor/bin/phpunit - the port must be specified, or the unhelpful default of 12345 will be used to prevent accidents., _(*17)