AnyEvent::Redis::RipeRedis - Flexible non-blocking Redis client with reconnect feature
use AnyEvent; use AnyEvent::Redis::RipeRedis; my $cv = AE::cv(); my $redis = AnyEvent::Redis::RipeRedis->new( host => 'localhost', port => 6379, password => 'yourpass', ); $redis->incr( 'foo', sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; warn "[$err_code] $err_msg\n"; return; } print "$data\n"; } ); $redis->set( 'bar', 'string', { on_error => sub { my $err_msg = shift; my $err_code = shift; warn "[$err_code] $err_msg\n"; } } ); $redis->get( 'bar', { on_done => sub { my $data = shift; print "$data\n"; }, on_error => sub { my $err_msg = shift; my $err_code = shift; warn "[$err_code] $err_msg\n"; }, } ); $redis->quit( sub { shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; warn "[$err_code] $err_msg\n"; } $cv->send(); } ); $cv->recv();
AnyEvent::Redis::RipeRedis is the flexible non-blocking Redis client with reconnect feature. The client supports subscriptions, transactions and connection via UNIX-socket.
Requires Redis 1.2 or higher, and any supported event loop.
my $redis = AnyEvent::Redis::RipeRedis->new( host => 'localhost', port => 6379, password => 'yourpass', database => 7, lazy => 1, connection_timeout => 5, read_timeout => 5, reconnect => 1, min_reconnect_interval => 5, encoding => 'utf8', on_connect => sub { # handling... }, on_disconnect => sub { # handling... }, on_connect_error => sub { my $err_msg = shift; # error handling... }, on_error => sub { my $err_msg = shift; my $err_code = shift; # error handling... }, );
Server hostname (default: 127.0.0.1)
Server port (default: 6379)
If the password is specified, the AUTH command is sent to the server after connection.
AUTH
Database index. If the index is specified, the client is switched to the specified database after connection. You can also switch to another database after connection by using SELECT command. The client remembers last selected database after reconnection.
SELECT
The default database index is 0.
0
Used for encode/decode strings at time of input/output operations.
Not set by default.
Timeout, within which the client will be wait the connection establishment to the Redis server. If the client could not connect to the server after specified timeout, the on_error or on_connect_error callback is called. In case when on_error callback is called, E_CANT_CONN error code is passed to callback in the second argument. The timeout specifies in seconds and can contain a fractional part.
on_error
on_connect_error
E_CANT_CONN
connection_timeout => 10.5,
By default the client use kernel's connection timeout.
Timeout, within which the client will be wait a response on a command from the Redis server. If the client could not receive a response from the server after specified timeout, the client close connection and call on_error callback with the E_READ_TIMEDOUT error code. The timeout is specifies in seconds and can contain a fractional part.
E_READ_TIMEDOUT
read_timeout => 3.5,
If enabled, the connection establishes at time when you will send the first command to the server. By default the connection establishes after calling of the new method.
new
Disabled by default.
If the connection to the Redis server was lost and the parameter reconnect is TRUE, the client try to restore the connection on a next command executuion unless min_reconnect_interval is specified. The client try to reconnect only once and if it fails, is called the on_error callback. If you need several attempts of the reconnection, just retry a command from the on_error callback as many times, as you need. This feature made the client more responsive.
reconnect
min_reconnect_interval
Enabled by default.
If the parameter is specified, the client will try to reconnect not often than through this interval. Command executons between reconnections in this case will be suspended.
min_reconnect_interval => 5,
Parameters, which will be passed to AnyEvent::Handle constructor.
handle_params => { linger => 60, autocork => 1, }
Parameter is DEPRECATED. Use handle_params parameter instead.
handle_params
This option is in effect when, for example, code terminates connection by calling disconnect but there are ongoing operations. In this case destructor of underlying AnyEvent::Handle object will keep the write buffer in memory for long time (see default value) causing temporal 'memory leak'. See AnyEvent::Handle for more info.
disconnect
By default is applied default setting of AnyEvent::Handle (i.e. 3600 seconds).
When enabled, writes to socket will always be queued till the next event loop iteration. This is efficient when you execute many operations per iteration, but less efficient when you execute a single operation only per iteration (or when the write buffer often is full). It also increases operation latency. See AnyEvent::Handle for more info.
The on_connect callback is called when the connection is successfully established.
on_connect
The on_disconnect callback is called when the connection is closed by any reason.
on_disconnect
The on_connect_error callback is called, when the connection could not be established. If this collback isn't specified, the common on_error callback is called with the E_CANT_CONN error code.
The common on_error callback is called when ocurred some error, which was affected on entire client (e. g. connection error). Also this callback is called on other errors if neither on_error callback nor on_reply callback is specified in the command method. If common on_error callback is not specified, the client just print an error messages to STDERR.
on_reply
STDERR
The full list of the Redis commands can be found here: http://redis.io/commands.
$redis->incr( 'foo', sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } print "$data\n"; }, ); $redis->incr( 'foo', { on_reply => sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } print "$data\n"; }, } ); $redis->set( 'bar', 'string' ); $redis->get( 'bar', { on_done => sub { my $data = shift; print "$data\n"; }, on_error => sub { my $err_msg = shift; my $err_code = shift; # error handling... } } ); $redis->lrange( 'list', 0, -1, { on_done => sub { my $data = shift; foreach my $val ( @{$data} ) { print "$val\n"; } }, on_error => sub { my $err_msg = shift; my $err_code = shift; # error handling... }, } );
The on_done callback is called when the current operation was completed successfully.
on_done
The on_error callback is called when some error occurred.
Since version 1.300 of the client you can specify single, on_reply callback, instead of two, on_done and on_error callbacks. The on_reply callback is called in both cases: when operation was completed successfully or when some error occurred. In first case to callback is passed only reply data. In second case to callback is passed three arguments: The undef value or reply data with error objects (see below), error message and error code.
undef
The detailed information abount the Redis transactions can be found here: http://redis.io/topics/transactions.
Marks the start of a transaction block. Subsequent commands will be queued for atomic execution using EXEC.
EXEC
Executes all previously queued commands in a transaction and restores the connection state to normal. When using WATCH, EXEC will execute commands only if the watched keys were not modified.
WATCH
If after execution of EXEC command at least one operation fails, the on_error or on_reply callback is called and in addition to error message and error code to callback is passed reply data, which contain replies of successful operations and error objects for each failed operation. To on_error callback reply data is passed in third argument and to on_reply callback in first argument. Error object is an instance of class AnyEvent::Redis::RipeRedis::Error and has two methods: message() to get error message and code() to get error code.
AnyEvent::Redis::RipeRedis::Error
message()
code()
$redis->multi(); $redis->set( 'foo', 'string' ); $redis->incr( 'foo' ); # causes an error $redis->exec( sub { my $replies = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; if ( defined $replies ) { foreach my $reply ( @{$replies} ) { if ( ref( $reply ) eq 'AnyEvent::Redis::RipeRedis::Error' ) { my $oprn_err_msg = $reply->message(); my $oprn_err_code = $reply->code(); # error handling... } } return; } # error handling... return; } # handling... }, ); $redis->multi(); $redis->set( 'foo', 'string' ); $redis->incr( 'foo' ); # causes an error $redis->exec( { on_done => sub { my $replies = shift; # handling... }, on_error => sub { my $err_msg = shift; my $err_code = shift; my $replies = shift; if ( defined $replies ) { foreach my $reply ( @{$replies} ) { if ( ref( $reply ) eq 'AnyEvent::Redis::RipeRedis::Error' ) { my $oprn_err_msg = $reply->message(); my $oprn_err_code = $reply->code(); # error handling... } } } # error handling... }, } );
Flushes all previously queued commands in a transaction and restores the connection state to normal.
If WATCH was used, DISCARD unwatches all keys.
DISCARD
Marks the given keys to be watched for conditional execution of a transaction.
Forget about all watched keys.
The detailed information about Redis Pub/Sub can be found here: http://redis.io/topics/pubsub
Once the client enters the subscribed state it is not supposed to issue any other commands, except for additional SUBSCRIBE, PSUBSCRIBE, UNSUBSCRIBE, PUNSUBSCRIBE and QUIT commands.
SUBSCRIBE
PSUBSCRIBE
UNSUBSCRIBE
PUNSUBSCRIBE
QUIT
If the connection was lost when the client has active subscriptions, the on_error or on_reply callback in appropriate (p)subscribe method is called.
(p)subscribe
Subscribes the client to the specified channels.
$redis->subscribe( qw( ch_foo ch_bar ), { on_reply => sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } my $ch_name = $data->[0]; my $subs_num = $data->[1]; # handling... }, on_message => sub { my $ch_name = shift; my $msg = shift; # message handling... }, } ); $redis->subscribe( qw( ch_foo ch_bar ), sub { my $ch_name = shift; my $msg = shift; # message handling... } ); $redis->subscribe( qw( ch_foo ch_bar ), { on_done => sub { my $ch_name = shift; my $subs_num = shift; # handling... }, on_message => sub { my $ch_name = shift; my $msg = shift; # message handling... }, on_error => sub { my $err_msg = shift; my $err_code = shift; # error handling... }, } );
The on_done callback is called on every specified channel when the subscription operation was completed successfully.
The on_message callback is called when a published message was received.
on_message
The on_error callback is called if the subscription operation fails.
The on_reply callback is called in both cases: when the subscription operation was completed successfully or when subscription operation fails. In first case on_reply callback is called on every specified channel. Information about channel name and subscription number is passed to callback in first argument as an array reference.
Subscribes the client to the given patterns.
$redis->psubscribe( qw( foo_* bar_* ), { on_reply => sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } my $ch_pattern = $data->[0]; my $subs_num = $data->[1]; # handling... }, on_message => sub { my $ch_name = shift; my $msg = shift; my $ch_pattern = shift; # message handling... }, } ); $redis->psubscribe( qw( foo_* bar_* ), sub { my $ch_name = shift; my $msg = shift; my $ch_pattern = shift; # message handling... } ); $redis->psubscribe( qw( foo_* bar_* ), { on_done => sub { my $ch_pattern = shift; my $subs_num = shift; # handling... }, on_message => sub { my $ch_name = shift; my $msg = shift; my $ch_pattern = shift; # message handling... }, on_error => sub { my $err_msg = shift; my $err_code = shift; # error handling... }, } );
The on_done callback is called on every specified pattern when the subscription operation was completed successfully.
The on_message callback is called when published message was received.
The on_reply callback is called in both cases: when the subscription operation was completed successfully or when subscription operation fails. In first case on_reply callback is called on every specified pattern. Information about channel pattern and subscription number is passed to callback in first argument as an array reference.
Posts a message to the given channel.
Unsubscribes the client from the given channels, or from all of them if none is given.
When no channels are specified, the client is unsubscribed from all the previously subscribed channels. In this case, a message for every unsubscribed channel will be sent to the client.
$redis->unsubscribe( qw( ch_foo ch_bar ), sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } my $ch_name = $data->[0]; my $subs_num = $data->[1]; # handling... } ); $redis->unsubscribe( qw( ch_foo ch_bar ), { on_done => sub { my $ch_name = shift; my $subs_num = shift; # handling... }, } );
The on_done callback is called on every specified channel when the unsubscription operation was completed successfully.
The on_error callback is called if the unsubscription operation fails.
The on_reply callback is called in both cases: when the unsubscription operation was completed successfully or when unsubscription operation fails. In first case on_reply callback is called on every specified channel. Information about channel name and number of remaining subscriptions is passed to callback in first argument as an array reference.
Unsubscribes the client from the given patterns, or from all of them if none is given.
When no patters are specified, the client is unsubscribed from all the previously subscribed patterns. In this case, a message for every unsubscribed pattern will be sent to the client.
$redis->punsubscribe( qw( foo_* bar_* ), sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } my $ch_pattern = $data->[0]; my $subs_num = $data->[1]; # handling... } ); $redis->punsubscribe( qw( foo_* bar_* ), { on_done => sub { my $ch_pattern = shift; my $subs_num = shift; # handling... }, } );
The on_done callback is called on every specified pattern when the unsubscription operation was completed successfully.
The on_reply callback is called in both cases: when the unsubscription operation was completed successfully or when unsubscription operation fails. In first case on_reply callback is called on every specified pattern. Information about channel pattern and number of remaining subscriptions is passed to callback in first argument as an array reference.
Redis 2.2 and higher support connection via UNIX domain socket. To connect via a UNIX-socket in the parameter host you have to specify unix/, and in the parameter port you have to specify the path to the socket.
host
unix/
port
my $redis = AnyEvent::Redis::RipeRedis->new( host => 'unix/', port => '/tmp/redis.sock', );
Redis 2.6 and higher support execution of Lua scripts on the server side. To execute a Lua script you can send one of the commands EVAL or EVALSHA, or use the special method eval_cached().
EVAL
EVALSHA
eval_cached()
When you call the eval_cached() method, the client first generate a SHA1 hash for a Lua script and cache it in memory. Then the client optimistically send the EVALSHA command under the hood. If the E_NO_SCRIPT error will be returned, the client send the EVAL command.
E_NO_SCRIPT
If you call the eval_cached() method with the same Lua script, client don not generate a SHA1 hash for this script repeatedly, it gets a hash from the cache instead.
$redis->eval_cached( 'return { KEYS[1], KEYS[2], ARGV[1], ARGV[2] }', 2, 'key1', 'key2', 'first', 'second', sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; # error handling... return; } foreach my $val ( @{$data} ) { print "$val\n"; } } );
Be care, passing a different Lua scripts to eval_cached() method every time cause memory leaks.
If Lua script returns multi-bulk reply with at least one error reply, the on_error or on_reply callback is called and in addition to error message and error code to callback is passed reply data, which contain successful replies and error objects for each error reply, as well as described for EXEC command.
$redis->eval_cached( "return { 'foo', redis.error_reply( 'Error.' ) }", 0, sub { my $data = shift; if ( @_ ) { my $err_msg = shift; my $err_code = shift; if ( defined $data ) { foreach my $chunk ( @{$data} ) { if ( ref( $chunk ) eq 'AnyEvent::Redis::RipeRedis::Error' ) { my $nested_err_msg = $chunk->message(); my $nested_err_code = $chunk->code(); # error handling... } } } # error handling... return; } # handling... } ); $redis->eval_cached( "return { 'foo', redis.error_reply( 'Error.' ) }", 0, { on_done => sub { my $data = shift; # handling... }, on_error => sub { my $err_msg = shift; my $err_code = shift; my $data = shift; if ( defined $data ) { foreach my $chunk ( @{$data} ) { if ( ref( $chunk ) eq 'AnyEvent::Redis::RipeRedis::Error' ) { my $nested_err_msg = $chunk->message(); my $nested_err_code = $chunk->code(); # error handling... } } } # error handling... } } );
Gets and parses information and statistics about the server. The result is passed to on_done or on_reply callback as a hash reference.
More information abount INFO command can be found here: http://redis.io/commands/info
INFO
Every time when error occurred the error code is passed to on_error or to on_reply callback. Error codes can be used for programmatic handling of errors.
AnyEvent::Redis::RipeRedis provides constants of error codes, which can be imported and used in expressions.
use AnyEvent::Redis::RipeRedis qw( :err_codes );
Can't connect to the server. All operations were aborted.
Redis is loading the dataset in memory.
Input/Output operation error. The connection to the Redis server was closed and all operations were aborted.
The connection closed by remote host. All operations were aborted.
Connection closed by client prematurely. Uncompleted operations were aborted.
No connection to the Redis server. Connection was lost by any reason on previous operation.
Operation error. For example, wrong number of arguments for a command.
The client received unexpected data from the server. The connection to the Redis server was closed and all operations were aborted.
Read timed out. The connection to the Redis server was closed and all operations were aborted.
Error codes available since Redis 2.6.
No matching script. Use the EVAL command.
Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE.
SCRIPT KILL
SHUTDOWN NOSAVE
Link with MASTER is down and slave-serve-stale-data is set to 'no'.
Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error.
You can't write against a read only slave.
Command not allowed when used memory > 'maxmemory'.
Transaction discarded because of previous errors.
Error codes available since Redis 2.8.
Authentication required.
Operation against a key holding the wrong kind of value.
Not enough good slaves to write.
Target key name already exists.
Error codes available since Redis 3.0.
Keys in request don't hash to the same slot.
Multiple keys request during rehashing of slot.
Redirection required. For more information see: http://redis.io/topics/cluster-spec
The cluster is down or hash slot not served.
When the connection to the server is no longer needed you can close it in three ways: call the method disconnect(), send the QUIT command or you can just "forget" any references to an AnyEvent::Redis::RipeRedis object, but in this case a client object is destroyed without calling any callbacks, including the on_disconnect callback, to avoid an unexpected behavior.
disconnect()
The method for synchronous disconnection. All uncompleted operations will be aborted.
$redis->disconnect();
The method for asynchronous disconnection.
$redis->quit( sub { # handling... } );
Get or set the connection_timeout of the client. The undef value resets the connection_timeout to default value.
connection_timeout
Get or set the read_timeout of the client.
read_timeout
Enables or disables reconnection mode of the client.
Get or set min_reconnect_interval of the client.
Get or set the current encoding of the client.
encoding
Get or set the on_connect callback.
Get or set the on_disconnect callback.
Get or set the on_connect_error callback.
Get or set the on_error callback.
Get currently selected database index.
AnyEvent, AnyEvent::Redis, Redis, Redis::hiredis, RedisDB
Eugene Ponizovsky, <ponizovsky@gmail.com>
Alexey Shrub
Vadim Vlasov
Konstantin Uvarin
Ivan Kruglov
Copyright (c) 2012-2015, Eugene Ponizovsky, <ponizovsky@gmail.com>. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install AnyEvent::Redis::RipeRedis, copy and paste the appropriate command in to your terminal.
cpanm
cpanm AnyEvent::Redis::RipeRedis
CPAN shell
perl -MCPAN -e shell install AnyEvent::Redis::RipeRedis
For more information on module installation, please visit the detailed CPAN module installation guide.