v1.1.1 (2016-06-16)

• __FIX__: `password` and `database` from the global `parameters` client option were still being applied to sentinels connections making them fail (sentinels do not understand the `AUTH` and `SELECT` commands) (PR #346).
• __FIX__: when a sentinel instance reports no sentinel for a service, invoking `connect()` on the redis-sentinel connection backend should fall back to the master connection instead of failing (ISSUE #342).
• __FIX__: the two connection backends based on ext-phpiredis has some kind of issues with the GC and the internal use of closures as reader callbacks that prevented connections going out of scope from being properly collected and the underlying stream or socket resources from being closed and freed. This should not have had any actual effect in real-world scenarios due to the lifecycle of PHP scripts, but we fixed it anyway (ISSUE #345).

v1.1.0 (2016-06-02)

• The default server profile for the client now targets Redis 3.2.
• Responses to the following commands are not casted into booleans anymore, the original integer value is returned: `SETNX`, `MSETNX`, `SMOVE`, `SISMEMBER`, `HSET`, `HSETNX`, `HEXISTS`, `PFADD`, `EXISTS`, `MOVE`, `PERSIST`, `EXPIRE`, `EXPIREAT`, `RENAMENX`. This change does not have a significant impact unless when using strict comparisons (=== and !==) the returned value.
• Non-boolean string values passed to the `persistent` connection parameter can be used to create different persistent connections. Note that this feature was already present in Predis but required both `persistent` and `path` to be set as illustrated by #139. This change is needed to prevent confusion with how `path` is used to select a database when using the `redis` scheme.
• The client throws exceptions when Redis returns any kind of error response to initialization commands (the ones being automatically sent when a connection is established, such as `SELECT` and `AUTH` when database and password are set in connection parameters) regardless of the value of the exception option.
• Using `unix:///path/to/socket` in URI strings to specify a UNIX domain socket file is now deprecated in favor of the format `unix:/path/to/socket` (note the lack of the double slash after the scheme) and will not be supported starting with the next major release.
• Implemented full support for redis-sentinel.
• Implemented the ability to specify default connection parameters for aggregate connections with the new `parameters` client option. These parameters augment the usual user-supplied connection parameters (but do not take the precedence over them) when creating new connections and they are mostly useful when the client is using aggregate connections such as redis-cluster and redis-sentinel as these backends can create new connections on the fly based on responses and redirections from Redis.
• Redis servers protected by SSL-encrypted connections can be accessed by using the `tls` or `rediss` scheme in connection parameters along with SSL-specific options in the `ssl` parameter (see http://php.net/manual/context.ssl.php).
• `Predis\Client` implements `IteratorAggregate` making it possible to iterate over traversable aggregate connections and get a new client instance for each Redis node.
• Iterating over an instance of `Predis\Connection\Aggregate\RedisCluster` will return all the connections mapped in the slots map instead of just the ones in the pool. This change makes it possible, when the slots map is retrieved from Redis, to iterate over all of the master nodes in the cluster. When the use of `CLUSTER SLOTS` is disabled via the `useClusterSlots()` method, the iteration returns only the connections with slots ranges associated in their parameters or the ones initialized by `-MOVED` responses in order to make the behaviour of the iteration consistent between the two modes of operation.

• Various improvements to `Predis\Connection\Aggregate\MasterSlaveReplication` (the "basic" replication backend, not the new one based on redis-sentinel):

  - When the client is not able to send a read-only command to a slave because the current connection fails or the slave is resyncing (`-LOADING` response returned by Redis), the backend discards the failed connection and performs a new attempt on the next slave. When no other slave is available the master server is used for read-only commands as last resort.

  - It is possible to discover the current replication configuration on the fly by invoking the `discover()` method which internally relies on the output of the command `INFO REPLICATION` executed against the master server or one of the slaves. The backend can also be configured to do this automatically when it fails to reach one of the servers.

  - Implemented the `switchToMaster()` and `switchToSlave()` methods to make it easier to force a switch to the master server or a random slave when needed.

v1.0.4 (2016-05-30)

• Added new profile for Redis 3.2 with its new commands: `HSTRLEN`, `BITFIELD`, `GEOADD`, `GEOHASH`, `GEOPOS`, `GEODIST`, `GEORADIUS`, `GEORADIUSBYMEMBER`. The default server profile for Predis is still the one for Redis 3.0 you must set the `profile` client option to `3.2` when initializing the client in order to be able to use them when connecting to Redis 3.2.

• Various improvements in the handling of redis-cluster:

  - If the connection to a specific node fails when executing a command, the client tries to connect to another node in order to refresh the slots map and perform a new attempt to execute the command.

  - Connections to nodes can be preassigned to non-contiguous slot ranges via the `slots` parameter using a comma separator. This is how it looks like in practice: `tcp://127.0.0.1:6379?slots=0-5460,5500-5600,11000`.

• __FIX__: broken values returned by `Predis\Collection\Iterator\HashKey` when iterating hash keys containing integer fields (PR #330, ISSUE #331).
• __FIX__: prevent failures when `Predis\Connection\StreamConnection` serializes commands with holes in their arguments (e.g. `[0 => 'key:0', 2 => 'key:2']`). The same fix has been applied to `Predis\Protocol\Text\RequestSerializer`. (ISSUE #316).

v1.0.3 (2015-07-30)

• __FIX__: the previous release introduced a severe regression on HHVM that made the library unable to connect to Redis when using IPv4 addresses. Code running on the standard PHP interpreter is not affected.

v1.0.2 (2015-07-30)

• IPv6 is now fully supported.
• Added `redis` as an accepted scheme for connection parameters. When using this scheme, the rules used to parse URI strings match the provisional registration published by IANA.
• Added new or missing commands: `HSTRLEN` (>= 3.2), `ZREVRANGEBYLEX` (>= 2.8) and `MIGRATE` (>= 2.6).
• Implemented support for the `ZADD` modifiers `NX|XX`, `CH`, `INCR` (Redis >= 3.0.2) using the simplified signature where scores and members are passed as a named array.
• __FIX__: `Predis\Configuration\Options` must not trigger the autoloader when option values are strings (ISSUE #257).
• __FIX__: `BITPOS` was not defined in the key-prefix processor (ISSUE #265) and in the replication strategy.

v1.0.1 (2015-01-02)

• Added `BITPOS` to the server profile for Redis 2.8.
• Connection timeout for read/write operations can now be set for UNIX sockets where the underlying connection uses PHP's stream.
• __FIX__: broken values returned by `Predis\Collection\Iterator\SortedSetKey` when iterating sorted set containing integer members (ISSUE #216).
• __FIX__: applied a minor workaround for a bug in old versions of PHP < 5.3.9 affecting inheritance.
• __FIX__: prevent E_NOTICE warnings when using INFO [section] returns an empty response due to an unsupported specific set of information requested to Redis.

v1.0.0 (2014-08-01)

• Switched to PSR-4 for autoloading.
• The default server profile for Redis is `3.0`.
• Removed server profile for Redis 1.2.
• Added `SENTINEL` to the profile for Redis 2.6 and `PUBSUB` to the profile for Redis 2.8.
• `Predis\Client` can now send raw commands using `Predis\Client::executeRaw()`.
• Status responses are returned as instances of `Predis\Response\Status`, for example +OK is not returned as boolean TRUE anymore which is a breaking change for those using strict comparisons. Status responses can be casted to string values carrying the original payload, so one can do `$response == 'OK'` which is also more akin to how Redis replies to clients.
• Commands `ZRANGE`, `ZRANGEBYSCORE`, `ZREVRANGE` and `ZREVRANGEBYSCORE` using `WITHSCORE` return a named array of member => score instead of using an array of [member, score] elements. Insertion order is preserved anyway due to how PHP works internally.
• The command `ZSCAN` returns a named array of member => score instead of using an array of [member, score] elements. Insertion order is preserved anyway due to how PHP works internally.
• The rules for redis-cluster are now leveraged for empty key tags when using client-side sharding, which means that when one or the first occurrence of {} is found in a key it will most likely produce a different hash than previous versions of Predis thus leading to a different partitioning in these cases.
• Invoking `Predis\Client::connect()` when the underlying connection has been already established does not throw any exception anymore, now the connection simply does not attempt to perform any operation.
• Added the `aggregate` client option, useful to fully customize how the client should aggregate multiple connections when an array of connection parameters is passed to `Predis\Client::__construct()`.
• Dropped support for streamable multibulk responses. Actually we still ship the iterator response classes just in case anyone would want to build custom stuff at a level lower than the client abstraction (our standard and composable text protocol processors still handle them and can be used as an example).
• Simplified the implementation of connection parameters by removing method used to cast to int / bool / float certain parameters supplied by users. Casting values, if deemed necessary, should be done by the consumer or you can just subclass `Predis\Connection\Parameters` and override the `filter()` method.

• Changed a couple of options for our transaction abstraction:

  - `exceptions`: overrides the value of the client option with the same name. Please note that it does not affect all the transaction control commands such as `MULTI`, `EXEC`, `DISCARD`, `WATCH` and `UNWATCH`. - `on_retry`: this option has been removed.

• Removed pipeline executors, now command pipelines can be easily customized by extending the standard `Predis\Pipeline\Pipeline` class. Accepted options when creating a pipeline using `Predis\Client::pipeline()` are:

  - `atomic`: returns a pipeline wrapped in a MULTI / EXEC transaction (class: `Predis\Pipeline\Atomic`). - `fire-and-forget`: returns a pipeline that does not read back responses (class: `Predis\Pipeline\FireAndForget`).

• Renamed the two base abstract command classes:

  - `Predis\Command\AbstractCommand` is now `Predis\Command\Command` - `Predis\Command\ScriptedCommand` is now `Predis\Command\ScriptCommand`

• Dropped `Predis\Command\Command::__toString()` (see issue #151).
• The key prefixing logic has been moved from command classes to the key prefix processor. Developers can define or override handlers used to prefix keys, but they can also define the needed logic in their command classes by implementing `Predis\Command\PrefixableCommandInterface` just like before.
• `Predis\PubSub\DispatcherLoop` now takes a `Predis\PubSub\Consumer` instance as the sole argument of its constructor instead of `Predis\ClientInterface`.
• All of the interfaces and classes related to translated Redis response types have been moved in the new `Predis\Response` namespace and most of them have been renamed to make their fully-qualified name less redundant. Now the base response interface is `Predis\Response\ResponseInterface`.
• Renamed interface `Predis\Command\Processor\CommandProcessorInterface` to a shorter `Predis\Command\Processor\ProcessorInterface`. Also removed interface for chain processors since it is basically useless.
• Renamed `Predis\ExecutableContextInterface` to `Predis\ClientContextInterface` and augmented it with a couple of required methods since this interface is no more comparable to a basic client as it could be misleading.
• The `Predis\Option` namespace is now known as `Predis\Configuration` and have a fully-reworked `Options` class with the ability to lazily initialize values using objects that responds to `__invoke()` (not all the kinds of callables) even for custom options defined by the user.
• Renamed `Predis\Connection\ConnectionInterface::writeCommand()` into `writeRequest()` for consistency with its counterpart, `readResponse()`.
• Renamed `Predis\Connection\SingleConnectionInterface::pushInitCommand()` into `addConnectCommand()` which is more obvious.
• Renamed the connection class based on both ext-phpiredis and ext-socket into `Predis\Connection\PhpiredisSocketConnection`. The one based on PHP's streams is still named `Predis\Connection\PhpiredisStreamConnection`.
• Renamed the connection factory class to `Predis\Connection\Factory`. Now its constructor does not require anymore a profile instance to create `AUTH` and `SELECT` commands when parameters contain both `password` and `database`. Raw commands will be used instead.
• Renamed the connection parameters class to `Predis\Connection\Parameters`. Now its constructor accepts only named arrays, but instances can still be created using both URIs or arrays using the static method `Parameters::create()`.
• The profile factory code has been extracted from the abstract Redis profile class and now lives in `Predis\Profile\Factory`.
• The `Predis\Connection` namespace has been completely reorganized by renaming a few classes and interfaces and adding some sub-namespaces.
• Most classes and interfaces in the `Predis\Protocol` namespace have been moved or renamed while rationalizing the whole API for external protocol processors.

v0.8.7 (2014-08-01)

• Added `3.0` in the server profiles aliases list for Redis 3.0. `2.8` is still the default server profile and `dev` still targets Redis 3.0.
• Added `COMMAND` to the server profile for Redis 2.8.
• Switched internally to the `CLUSTER SLOTS` command instead of `CLUSTER NODES` to fetch the updated slots map from redis-cluster. This change requires users to upgrade Redis nodes to >= 3.0.0b7.
• The updated slots map is now fetched automatically from redis-cluster upon the first `-MOVED` response by default. This change makes it possible to feed the client constructor with only a few nodes of the actual cluster composition, without needing a more complex configuration.
• Implemented support for `PING` in PUB/SUB loop for Redis >= 3.0.0b8.
• The default client-side sharding strategy and the one for redis-cluster now share the same implementations as they follow the same rules. One difference, aside from the different hashing function used to calculate distribution, is in how empty hash tags like {} are treated by redis-cluster.
• __FIX__: the patch applied to fix #180 introduced a regression affecting read/ write timeouts in `Predis\Connection\PhpiredisStreamConnection`. Unfortunately the only possible solution requires PHP 5.4+. On PHP 5.3, read/write timeouts will be ignored from now on.

v0.8.6 (2014-07-15)

• Redis 2.8 is now the default server profile as there are no changes that would break compatibility with previous releases.
• Added `PFADD`, `PFCOUNT`, `PFMERGE` to the server profile for Redis 2.8 for handling the HyperLogLog data structure introduced in Redis 2.8.9.
• Added `ZLEXCOUNT`, `ZRANGEBYLEX`, `ZREMRANGEBYLEX` to the server profile for Redis 2.8 for handling lexicographic operations on members of sorted sets.
• Added support for key hash tags when using redis-cluster (Redis 3.0.0b1).
• __FIX__: minor tweaks to make Predis compatible with HHVM >= 2.4.0.
• __FIX__: responses to `INFO` are now properly parsed and will not break when redis sentinel is being used (ISSUE #154).
• __FIX__: added missing support for `INCRBYFLOAT` in cluster and replication configurations (ISSUE #159).
• __FIX__: fix parsing of the output of `CLUSTER NODES` to fetch the slots map from a node when redis-cluster has slaves in its configuration (ISSUE #165).
• __FIX__: prevent a stack overflow when iterating over large Redis collections using our abstraction for cursor-based iterators (ISSUE #182).
• __FIX__: properly discards transactions when the server immediately returns an error response (e.g. -OOM or -ERR on invalid arguments for a command) instead of a +QUEUED response (ISSUE #187).
• Upgraded to PHPUnit 4.* for the test suite.

v0.8.5 (2014-01-16)

• Added `2.8` in the server profiles aliases list for Redis 2.8. `2.6` is still the default server profile and `dev` now targets Redis 3.0.
• Added `SCAN`, `SSCAN`, `ZSCAN`, `HSCAN` to the server profile for Redis 2.8.

• Implemented PHP iterators for incremental iterations over Redis collections:

  - keyspace (cursor-based iterator using `SCAN`) - sets (cursor-based iterator using `SSCAN`) - sorted sets (cursor-based iterator using `ZSCAN`) - hashes (cursor-based iterator using `HSCAN`) - lists (plain iterator using `LRANGE`)

• It is now possible to execute "raw commands" using `Predis\Command\RawCommand` and a variable list of command arguments. Input arguments are not filtered and responses are not parsed, which means arguments must follow the signature of the command as defined by Redis and complex responses are left untouched.

• URI parsing for connection parameters has been improved and has slightly less overhead when the number of fields in the querystring grows. New features are:

  - Parsing does not break when value of a field contains one or more "=". - Repeated fieldnames using [] produce an array of values. - Empty or incomplete "key=value" pairs result in an empty string for "key".

• Various improvements and fixes to the redis-cluster connection backend:

  - __FIX__: the `ASKING` command is sent upon -ASK redirections. - An updated slots-map can be fetched from nodes using the `CLUSTER NODES` command. By default this is a manual operation but can be enabled to get automatically done upon -MOVED redirections. - It is possible to specify a common set of connection parameters that are applied to connections created on the fly upon redirections to nodes not part of the initial pool.

• List of deprecated methods:

  - `Predis\Client::multiExec()`: superseded by `Predis\Client::transaction()` and to be removed in the next major release. - `Predis\Client::pubSub()`: superseded by `Predis\Client::pubSubLoop()` and to be removed in the next major release. This change was needed due to the recently introduced `PUBSUB` command in Redis 2.8.

v0.8.4 (2013-07-27)

• Added `DUMP` and `RESTORE` to the server profile for Redis 2.6.
• Connection exceptions now report basic host details in their messages.
• Allow `Predis\Connection\PhpiredisConnection` to use a random IP when a host actually has several IPs (ISSUE #116).
• __FIX__: allow `HMSET` when using a cluster of Redis nodes with client-side sharding or redis-cluster (ISSUE #106).
• __FIX__: set `WITHSCORES` modifer for `ZRANGE`, `ZREVRANGE`, `ZRANGEBYSCORE` and `ZREVRANGEBYSCORE` only when the options array passed to these commands has `WITHSCORES` set to `true` (ISSUE #107).
• __FIX__: scripted commands falling back from `EVALSHA` to `EVAL` resulted in PHP errors when using a prefixed client (ISSUE #109).
• __FIX__: `Predis\PubSub\DispatcherLoop` now works properly when using key prefixing (ISSUE #114).

v0.8.3 (2013-02-18)

• Added `CLIENT SETNAME` and `CLIENT GETNAME` (ISSUE #102).
• Implemented the `Predis\Connection\PhpiredisStreamConnection` class using the `phpiredis` extension like `Predis\Connection\PhpiredisStreamConnection`, but without requiring the `socket` extension since it relies on PHP's streams.
• Added support for the TCP_NODELAY flag via the `tcp_nodelay` parameter for stream-based connections, namely `Predis\Connection\StreamConnection` and `Predis\Connection\PhpiredisStreamConnection` (requires PHP >= 5.4.0).
• Updated the aggregated connection class for redis-cluster to work with 16384 hash slots instead of 4096 to reflect the recent change from redis unstable (see this commit).
• The constructor of `Predis\Client` now accepts a callable as first argument returning `Predis\Connection\ConnectionInterface`. Users can create their own self-contained strategies to create and set up the underlying connection.
• Users should return `0` from `Predis\Command\ScriptedCommand::getKeysCount()` instead of `FALSE` to indicate that all of the arguments of a Lua script must be used to populate `ARGV[]`. This does not represent a breaking change.
• The `Predis\Helpers` class has been deprecated and it will be removed in future releases.

v0.8.2 (2013-02-03)

• Added `Predis\Session\SessionHandler` to make it easy to store PHP sessions on Redis using Predis. Please note that this class needs either PHP >= 5.4.0 or a polyfill for PHP's `SessionHandlerInterface`.
• Added the ability to get the default value of a client option directly from `Predis\Option\ClientOption` using the `getDefault()` method by passing the option name or its instance.
• __FIX__: the standard pipeline executor was not using the response parser methods associated to commands to process raw responses (ISSUE #101).

v0.8.1 (2013-01-19)

• The `connections` client option can now accept a callable object returning an instance of `Predis\Connection\ConnectionFactoryInterface`.
• Client options accepting callable objects as factories now pass their actual instance to the callable as the second argument.
• `Predis\Command\Processor\KeyPrefixProcessor` can now be directly casted to string to obtain the current prefix, useful with string interpolation.
• Added an optional callable argument to `Predis\Cluster\Distribution\HashRing` and `Predis\Cluster\Distribution\KetamaPureRing` constructor that can be used to customize how the distributor should extract the connection hash when initializing the nodes distribution (ISSUE #36).
• Correctly handle `TTL` and `PTTL` returning -2 on non existing keys starting with Redis 2.8.
• __FIX__: a missing use directive in `Predis\Transaction\MultiExecContext` caused PHP errors when Redis did not return `+QUEUED` replies to commands when inside a MULTI / EXEC context.
• __FIX__: the `parseResponse()` method implemented for a scripted command was ignored when retrying to execute a Lua script by falling back to `EVAL` after a `-NOSCRIPT` error (ISSUE #94).
• __FIX__: when subclassing `Predis\Client` the `getClientFor()` method returns a new instance of the subclass instead of a new instance of `Predis\Client`.

v0.8.0 (2012-10-23)

• The default server profile for Redis is now `2.6`.

• Certain connection parameters have been renamed:

  - `connection_async` is now `async_connect` - `connection_timeout` is now `timeout` - `connection_persistent` is now `persistent`

• The `throw_errors` connection parameter has been removed and replaced by the new `exceptions` client option since exceptions on `-ERR` replies returned by Redis are not generated by connection classes anymore but instead are thrown by the client class and other abstractions such as pipeline contexts.
• Added smart support for redis-cluster (Redis v3.0) in addition to the usual cluster implementation that uses client-side sharding.
• Various namespaces and classes have been renamed to follow rules inspired by the Symfony2 naming conventions.
• The second argument of the constructor of `Predis\Client` does not accept strings or instances of `Predis\Profile\ServerProfileInterface` anymore. To specify a server profile you must explicitly set `profile` in the array of client options.
• `Predis\Command\ScriptedCommand` internally relies on `EVALSHA` instead of `EVAL` thus avoiding to send Lua scripts bodies on each request. The client automatically resends the command falling back to `EVAL` when Redis returns a `-NOSCRIPT` error. Automatic fallback to `EVAL` does not work with pipelines, inside a `MULTI / EXEC` context or with plain `EVALSHA` commands.
• Complex responses are no more parsed by connection classes as they must be processed by consumer classes using the handler associated to the issued command. This means that executing commands directly on connections only returns simple Redis types, but nothing changes when using `Predis\Client` or the provided abstractions for pipelines and transactions.
• Iterators for multi-bulk replies now skip the response parsing method of the command that generated the response and are passed directly to user code. Pipeline and transaction objects still consume automatically iterators.
• Cluster and replication connections now extend a new common interface, `Predis\Connection\AggregatedConnectionInterface`.
• `Predis\Connection\MasterSlaveReplication` now uses an external strategy class to handle the logic for checking readable / writable commands and Lua scripts.
• Command pipelines have been optimized for both speed and code cleanness, but at the cost of bringing a breaking change in the signature of the interface for pipeline executors.
• Added a new pipeline executor that sends commands wrapped in a MULTI / EXEC context to make the execution atomic: if a pipeline fails at a certain point then the whole pipeline is discarded.
• The key-hashing mechanism for commands is now handled externally and is no more a competence of each command class. This change is neeeded to support both client-side sharding and Redis cluster.
• `Predis\Options\Option` is now abstract, see `Predis\Option\AbstractOption`.

v0.7.3 (2012-06-01)

• New commands available in the Redis v2.6 profile (dev): `BITOP`, `BITCOUNT`.
• When the number of keys `Predis\Commands\ScriptedCommand` is negative, Predis will count from the end of the arguments list to calculate the actual number of keys that will be interpreted as elements for `KEYS` by the underlying `EVAL` command.
• __FIX__: `examples\CustomDistributionStrategy.php` had a mistyped constructor call and produced a bad distribution due to an error as pointed in ISSUE #63. This bug is limited to the above mentioned example and does not affect the classes implemented in the `Predis\Distribution` namespace.
• __FIX__: `Predis\Commands\ServerEvalSHA::getScriptHash()` was calculating the hash while it just needs to return the first argument of the command.
• __FIX__: `Predis\Autoloader` has been modified to allow cascading autoloaders for the `Predis` namespace.

v0.7.2 (2012-04-01)

• Added `2.6` in the server profiles aliases list for the upcoming Redis 2.6. `2.4` is still the default server profile. `dev` now targets Redis 2.8.
• Connection instances can be serialized and unserialized using `serialize()` and `unserialize()`. This is handy in certain scenarios such as client-side clustering or replication to lower the overhead of initializing a connection object with many sub-connections since unserializing them can be up to 5x times faster.
• Reworked the default autoloader to make it faster. It is also possible to prepend it in PHP's autoload stack.
• __FIX__: fixed parsing of the payload returned by `MONITOR` with Redis 2.6.

v0.7.1 (2011-12-27)

• The PEAR channel on PearHub has been deprecated in favour of `pear.nrk.io`.
• Miscellaneous minor fixes.
• Added transparent support for master / slave replication configurations where write operations are performed on the master server and read operations are routed to one of the slaves. Please refer to ISSUE #21 for a bit of history and more details about replication support in Predis.
• The `profile` client option now accepts a callable object used to initialize a new instance of `Predis\Profiles\IServerProfile`.
• Exposed a method for MULTI / EXEC contexts that adds the ability to execute instances of Redis commands against transaction objects.

v0.7.0 (2011-12-11)

• Predis now adheres to the PSR-0 standard which means that there is no more a single file holding all the classes of the library, but multiple files (one for each class). You can use any PSR-0 compatible autoloader to load Predis or just leverage the default one shipped with the library by requiring the `Predis/Autoloader.php` and call `Predis\Autoloader::register()`.
• The default server profile for Redis is now 2.4. The `dev` profile supports all the features of Redis 2.6 (currently unstable) such as Lua scripting.
• Support for long aliases (method names) for Redis commands has been dropped.
• Redis 1.0 is no more supported. From now on Predis will use only the unified protocol to serialize commands.
• It is possible to prefix keys transparently on a client-level basis with the new `prefix` client option.
• An external connection factory is used to initialize new connection instances and developers can now register their own connection classes using the new `connections` client option.
• It is possible to connect locally to Redis using UNIX domain sockets. Just use `unix:///path/to/redis.sock` or a named array just like in the following example: `array('scheme' => 'unix', 'path' => '/path/to/redis.sock');`.
• If the `phpiredis` extension is loaded by PHP, it is now possible to use an alternative connection class that leverages it to make Predis faster on many cases, especially when dealing with big multibulk replies, with the the only downside that persistent connections are not supported. Please refer to the documentation to see how to activate this class using the new `connections` client option.
• Predis is capable to talk with Webdis, albeit with some limitations such as the lack of pipelining and transactions, just by using the `http` scheme in in the connection parameters. All is needed is PHP with the `curl` and the `phpiredis` extensions loaded.

• Way too many changes in the public API to make a list here, we just tried to make all the Redis commands compatible with previous releases of v0.6 so that you do not have to worry if you are simply using Predis as a client. Probably the only breaking changes that should be mentioned here are:

  - `throw_on_error` has been renamed to `throw_errors` and it is a connection parameter instead of a client option, along with `iterable_multibulk`.

  - `key_distribution` has been removed from the client options. To customize the distribution strategy you must provide a callable object to the new `cluster` client option to configure and then return a new instance of `Predis\Network\IConnectionCluster`.

  - `Predis\Client::create()` has been removed. Just use the constructor to set up a new instance of `Predis\Client`.

  - `Predis\Client::pipelineSafe()` was deprecated in Predis v0.6.1 and now has finally removed. Use `Predis\Client::pipeline(array('safe' => true))`.

  - `Predis\Client::rawCommand()` has been removed due to inconsistencies with the underlying connection abstractions. You can still get the raw resource out of a connection with `Predis\Network\IConnectionSingle::getResource()` so that you can talk directly with Redis.

• The `Predis\MultiBulkCommand` class has been merged into `Predis\Command` and thus removed. Serialization of commands is now a competence of connections.
• The `Predis\IConnection` interface has been splitted into two new interfaces: `Predis\Network\IConnectionSingle` and `Predis\Network\IConnectionCluster`.
• The constructor of `Predis\Client` now accepts more type of arguments such as instances of `Predis\IConnectionParameters` and `Predis\Network\IConnection`.

v0.6.6 (2011-04-01)

• Switched to Redis 2.2 as the default server profile (there are no changes that would break compatibility with previous releases). Long command names are no more supported by default but if you need them you can still require `Predis_Compatibility.php` to avoid breaking compatibility.
• Added a `VERSION` constant to `Predis\Client`.
• Some performance improvements for multibulk replies (parsing them is about 16% faster than the previous version). A few core classes have been heavily optimized to reduce overhead when creating new instances.
• Predis now uses by default a new protocol reader, more lightweight and faster than the default handler-based one. Users can revert to the old protocol reader with the `reader` client option set to `composable`. This client option can also accept custom reader classes implementing the new `Predis\IResponseReader` interface.
• Added support for connecting to Redis using UNIX domain sockets (ISSUE #25).
• The `read_write_timeout` connection parameter can now be set to 0 or false to disable read and write timeouts on connections. The old behaviour of -1 is still intact.
• `ZUNIONSTORE` and `ZINTERSTORE` can accept an array to specify a list of the source keys to be used to populate the destination key.
• `MGET`, `SINTER`, `SUNION` and `SDIFF` can accept an array to specify a list of keys. `SINTERSTORE`, `SUNIONSTORE` and `SDIFFSTORE` can also accept an array to specify the list of source keys.
• `SUBSCRIBE` and `PSUBSCRIBE` can accept a list of channels for subscription.
• __FIX__: some client-side clean-ups for `MULTI/EXEC` were handled incorrectly in a couple of corner cases (ISSUE #27).

v0.6.5 (2011-02-12)

• __FIX__: due to an untested internal change introduced in v0.6.4, a wrong handling of bulk reads of zero-length values was producing protocol desynchronization errors (ISSUE #20).

v0.6.4 (2011-02-12)

• Various performance improvements (15% ~ 25%) especially when dealing with long multibulk replies or when using clustered connections.
• Added the `on_retry` option to `Predis\MultiExecBlock` that can be used to specify an external callback (or any callable object) that gets invoked whenever a transaction is aborted by the server.
• Added inline (p)subscribtion via options when initializing an instance of `Predis\PubSubContext`.

v0.6.3 (2011-01-01)

• New commands available in the Redis v2.2 profile (dev): - Strings: `SETRANGE`, `GETRANGE`, `SETBIT`, `GETBIT` - Lists : `BRPOPLPUSH`
• The abstraction for `MULTI/EXEC` transactions has been dramatically improved by providing support for check-and-set (CAS) operations when using Redis >= 2.2. Aborted transactions can also be optionally replayed in automatic up to a user-defined number of times, after which a `Predis\AbortedMultiExec` exception is thrown.

v0.6.2 (2010-11-28)

• Minor internal improvements and clean ups.
• New commands available in the Redis v2.2 profile (dev): - Strings: `STRLEN` - Lists : `LINSERT`, `RPUSHX`, `LPUSHX` - ZSets : `ZREVRANGEBYSCORE` - Misc. : `PERSIST`
• WATCH also accepts a single array parameter with the keys that should be monitored during a transaction.
• Improved the behaviour of `Predis\MultiExecBlock` in certain corner cases.
• Improved parameters checking for the SORT command.
• __FIX__: the `STORE` parameter for the `SORT` command didn't work correctly when using `0` as the target key (ISSUE #13).
• __FIX__: the methods for `UNWATCH` and `DISCARD` do not break anymore method chaining with `Predis\MultiExecBlock`.

v0.6.1 (2010-07-11)

• Minor internal improvements and clean ups.
• New commands available in the Redis v2.2 profile (dev): - Misc. : `WATCH`, `UNWATCH`
• Optional modifiers for `ZRANGE`, `ZREVRANGE` and `ZRANGEBYSCORE` queries are supported using an associative array passed as the last argument of their respective methods.
• The `LIMIT` modifier for `ZRANGEBYSCORE` can be specified using either: - an indexed array: `array($offset, $count)` - an associative array: `array('offset' => $offset, 'count' => $count)`
• The method `Predis\Client::__construct()` now accepts also instances of `Predis\ConnectionParameters`.
• `Predis\MultiExecBlock` and `Predis\PubSubContext` now throw an exception when trying to create their instances using a profile that does not support the required Redis commands or when the client is connected to a cluster of connections.
• Various improvements to `Predis\MultiExecBlock`: - fixes and more consistent behaviour across various usage cases. - support for `WATCH` and `UNWATCH` when using the current development profile (Redis v2.2) and aborted transactions.
• New signature for `Predis\Client::multiExec()` which is now able to accept an array of options for the underlying instance of `Predis\MultiExecBlock`. Backwards compatibility with previous releases of Predis is ensured.
• New signature for `Predis\Client::pipeline()` which is now able to accept an array of options for the underlying instance of Predis\CommandPipeline. Backwards compatibility with previous releases of Predis is ensured. The method `Predis\Client::pipelineSafe()` is to be considered deprecated.
• __FIX__: The `WEIGHT` modifier for `ZUNIONSTORE` and `ZINTERSTORE` was handled incorrectly with more than two weights specified.

v0.6.0 (2010-05-24)

• Switched to the new multi-bulk request protocol for all of the commands in the Redis 1.2 and Redis 2.0 profiles. Inline and bulk requests are now deprecated as they will be removed in future releases of Redis.
• The default server profile is `2.0` (targeting Redis 2.0.x). If you are using older versions of Redis, it is highly recommended that you specify which server profile the client should use (e.g. `1.2` when connecting to instances of Redis 1.2.x).
• Support for Redis 1.0 is now optional and it is provided by requiring 'Predis_Compatibility.php' before creating an instance of `Predis\Client`.
• New commands added to the Redis 2.0 profile since Predis 0.5.1: - Strings: `SETEX`, `APPEND`, `SUBSTR` - ZSets : `ZCOUNT`, `ZRANK`, `ZUNIONSTORE`, `ZINTERSTORE`, `ZREMBYRANK`, `ZREVRANK` - Hashes : `HSET`, `HSETNX`, `HMSET`, `HINCRBY`, `HGET`, `HMGET`, `HDEL`, `HEXISTS`, `HLEN`, `HKEYS`, `HVALS`, `HGETALL` - PubSub : `PUBLISH`, `SUBSCRIBE`, `UNSUBSCRIBE` - Misc. : `DISCARD`, `CONFIG`

• Introduced client-level options with the new `Predis\ClientOptions` class. Options can be passed to the constructor of `Predis\Client` in its second argument as an array or an instance of `Predis\ClientOptions`. For brevity's sake and compatibility with older versions, the constructor still accepts an instance of `Predis\RedisServerProfile` in its second argument. The currently supported client options are:

  - `profile` [default: `2.0` as of Predis 0.6.0]: specifies which server profile to use when connecting to Redis. This option accepts an instance of `Predis\RedisServerProfile` or a string that indicates the version.

  - `key_distribution` [default: `Predis\Distribution\HashRing`]: specifies which key distribution strategy to use to distribute keys among the servers that compose a cluster. This option accepts an instance of `Predis\Distribution\IDistributionStrategy` so that users can implement their own key distribution strategy. `Predis\Distribution\KetamaPureRing` is an alternative distribution strategy providing a pure-PHP implementation of the same algorithm used by libketama.

  - `throw_on_error` [default: `TRUE`]: server errors can optionally be handled "silently": instead of throwing an exception, the client returns an error response type.

  - `iterable_multibulk` [EXPERIMENTAL - default: `FALSE`]: in addition to the classic way of fetching a whole multibulk reply into an array, the client can now optionally stream a multibulk reply down to the user code by using PHP iterators. It is just a little bit slower, but it can save a lot of memory in certain scenarios.

• New parameters for connections:

  - `alias` [default: not set]: every connection can now be identified by an alias that is useful to get a specific connections when connected to a cluster of Redis servers. - `weight` [default: not set]: allows to balance keys asymmetrically across multiple servers. This is useful when you have servers with different amounts of memory to distribute the load of your keys accordingly. - `connection_async` [default: `FALSE`]: estabilish connections to servers in a non-blocking way, so that the client is not blocked while the socket resource performs the actual connection. - `connection_persistent` [default: `FALSE`]: the underlying socket resource is left open when a script ends its lifecycle. Persistent connections can lead to unpredictable or strange behaviours, so they should be used with extreme care.

• Introduced the `Predis\Pipeline\IPipelineExecutor` interface. Classes that implements this interface are used internally by the `Predis\CommandPipeline` class to change the behaviour of the pipeline when writing/reading commands from one or multiple servers. Here is the list of the default executors:

  - `Predis\Pipeline\StandardExecutor`: exceptions generated by server errors might be thrown depending on the options passed to the client (see the `throw_on_error` client option). Instead, protocol or network errors always throw exceptions. This is the default executor for single and clustered connections and shares the same behaviour of Predis 0.5.x. - `Predis\Pipeline\SafeExecutor`: exceptions generated by server, protocol or network errors are not thrown but returned in the response array as instances of `Predis\ResponseError` or `Predis\CommunicationException`. - `Predis\Pipeline\SafeClusterExecutor`: this executor shares the same behaviour of `Predis\Pipeline\SafeExecutor` but it is geared towards clustered connections.

• Support for PUB/SUB is handled by the new `Predis\PubSubContext` class, which could also be used to build a callback dispatcher for PUB/SUB scenarios.
• When connected to a cluster of connections, it is now possible to get a new `Predis\Client` instance for a single connection of the cluster by passing its alias/index to the new `Predis\Client::getClientFor()` method.
• `Predis\CommandPipeline` and `Predis\MultiExecBlock` return their instances when invokink commands, thus allowing method chaining in pipelines and multi-exec blocks.
• `Predis\MultiExecBlock` can handle the new `DISCARD` command.
• Connections now support float values for the `connection_timeout` parameter to express timeouts with a microsecond resolution.
• __FIX__: TCP connections now respect the read/write timeout parameter when reading the payload of server responses. Previously, `stream_get_contents()` was being used internally to read data from a connection but it looks like PHP does not honour the specified timeout for socket streams when inside this function.
• __FIX__: The `GET` parameter for the `SORT` command now accepts also multiple key patterns by passing an array of strings. (ISSUE #1).
• __FIX__: Replies to the `DEL` command return the number of elements deleted by the server and not 0 or 1 interpreted as a boolean response. (ISSUE #4).

v0.5.1 (2010-01-23)

• `RPOPLPUSH` has been changed from bulk command to inline command in Redis 1.2.1, so `ListPopLastPushHead` now extends `InlineCommand`. The old behavior is still available via the `ListPopLastPushHeadBulk` class so that you can override the server profile if you need the old (and uncorrect) behaviour when connecting to a Redis 1.2.0 instance.
• Added missing support for `BGREWRITEAOF` for Redis >= 1.2.0.
• Implemented a factory method for the `RedisServerProfile` class to ease the creation of new server profile instances based on a version string.

v0.5.0 (2010-01-09)

• First versioned release of Predis