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https://github.com/predis/predis.git
synced 2026-08-18 18:31:47 +00:00
Daniele Alessandri
184d583895
When using replication backends, now the role of a connection is not defined by its alias but by the new connection parameter "role" that can be set to "master", "slave" and (for redis-sentinel) "sentinel". This also led to a redesign of how connections can be retrieved from replication backends: the method getConnectionById() now retrieves a connection only by its ID (ip:port pair), to get a connection by its alias there is the new method getConnectionByAlias(). This method is not supported by the redis-sentinel backend due to its dynamic nature (connections are retrieved and initialized at runtime from sentinels) but it is still possible to get a single connection from the pool by using its ID. It is also possible to retrive a connection by its role using the method getConnectionByRole(). NOTE: the "role" parameter is an hint for the internals of aggregate connection backends so it is still possible that the actual role of a connection changes during the execution of a script (e.g. a slave gets promoted to the role of master): in this case the parameters of that connection will not be changed as they are immutable, but the method getConnectionByRole() will return the appropriate connection. Predis\Client::getClientBy() has been updated with the addition of "role" and "alias" as supported selectors.
53 lines
1.7 KiB
PHP
53 lines
1.7 KiB
PHP
<?php
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/*
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* This file is part of the Predis package.
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*
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* (c) Daniele Alessandri <suppakilla@gmail.com>
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*
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* For the full copyright and license information, please view the LICENSE
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* file that was distributed with this source code.
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*/
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require __DIR__.'/shared.php';
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// Predis supports master / slave replication scenarios where write operations
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// are performed on the master server and read operations are executed against
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// one of the slaves. The behavior of commands or EVAL scripts can be customized
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// at will. As soon as a write operation is performed the client switches to the
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// master server for all the subsequent requests (either reads and writes).
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//
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// This example must be executed using the second Redis server configured as the
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// slave of the first one (see the "SLAVEOF" command).
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//
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$parameters = array(
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'tcp://127.0.0.1:6381?role=master&database=15',
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'tcp://127.0.0.1:6382?role=slave&database=15',
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);
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$options = array('replication' => 'predis');
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$client = new Predis\Client($parameters, $options);
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// Read operation.
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$exists = $client->exists('foo') ? 'yes' : 'no';
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$current = $client->getConnection()->getCurrent()->getParameters();
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echo "Does 'foo' exist on {$current->role}? $exists.", PHP_EOL;
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// Write operation.
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$client->set('foo', 'bar');
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$current = $client->getConnection()->getCurrent()->getParameters();
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echo "Now 'foo' has been set to 'bar' on {$current->role}!", PHP_EOL;
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// Read operation.
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$bar = $client->get('foo');
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$current = $client->getConnection()->getCurrent()->getParameters();
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echo "We fetched 'foo' from {$current->role} and its value is '$bar'.", PHP_EOL;
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/* OUTPUT:
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Does 'foo' exist on slave? yes.
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Now 'foo' has been set to 'bar' on master!
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We fetched 'foo' from master and its value is 'bar'.
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*/
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