redis / redis-py

Redis Python client

This README is just a fast quick start document. You can find more detailed documentation at redis.io.

What is Redis?

Redis is often referred to as a data structures server. What this means is that Redis provides access to mutable data structures via a set of commands, which are sent using a server-client model with TCP sockets and a simple protocol. So different processes can query and modify the same data structures in a shared way.

Data structures implemented into Redis have a few special properties:

• Redis cares to store them on disk, even if they are always served and modified into the server memory. This means that Redis is fast, but that it is also non-volatile.
• The implementation of data structures emphasizes memory efficiency, so data structures inside Redis will likely use less memory compared to the same data structure modelled using a high-level programming language.
• Redis offers a number of features that are natural to find in a database, like replication, tunable levels of durability, clustering, and high availability.

Another good example is to think of Redis as a more complex version of memcached, where the operations are not just SETs and GETs, but operations that work with complex data types like Lists, Sets, ordered data structures, and so forth.

If you want to know more, this is a list of selected starting points:

• Introduction to Redis data types. https://redis.io/topics/data-types-intro
• Try Redis directly inside your browser. https://try.redis.io
• The full list of Redis commands. https://redis.io/commands
• There is much more inside the official Redis documentation. https://redis.io/documentation

What is Redis Community Edition?

Redis OSS was renamed Redis Community Edition (CE) with the v7.4 release.

Redis Ltd. also offers Redis Software, a self-managed software with additional compliance, reliability, and resiliency for enterprise scaling, and Redis Cloud, a fully managed service integrated with Google Cloud, Azure, and AWS for production-ready apps.

Read more about the differences between Redis Community Edition and Redis here.

Building Redis

Redis can be compiled and used on Linux, OSX, OpenBSD, NetBSD, FreeBSD. We support big endian and little endian architectures, and both 32 bit and 64 bit systems.

It may compile on Solaris derived systems (for instance SmartOS) but our support for this platform is best effort and Redis is not guaranteed to work as well as in Linux, OSX, and *BSD.

It is as simple as:

% make

To build with TLS support, you'll need OpenSSL development libraries (e.g. libssl-dev on Debian/Ubuntu) and run:

% make BUILD_TLS=yes

To build with systemd support, you'll need systemd development libraries (such as libsystemd-dev on Debian/Ubuntu or systemd-devel on CentOS) and run:

% make USE_SYSTEMD=yes

To append a suffix to Redis program names, use:

% make PROG_SUFFIX="-alt"

You can build a 32 bit Redis binary using:

% make 32bit

After building Redis, it is a good idea to test it using:

% make test

If TLS is built, running the tests with TLS enabled (you will need tcl-tls installed):

% ./utils/gen-test-certs.sh
% ./runtest --tls

Fixing build problems with dependencies or cached build options

Redis has some dependencies which are included in the deps directory. make does not automatically rebuild dependencies even if something in the source code of dependencies changes.

When you update the source code with git pull or when code inside the dependencies tree is modified in any other way, make sure to use the following command in order to really clean everything and rebuild from scratch:

% make distclean

This will clean: jemalloc, lua, hiredis, linenoise and other dependencies.

Also if you force certain build options like 32bit target, no C compiler optimizations (for debugging purposes), and other similar build time options, those options are cached indefinitely until you issue a make distclean command.

Fixing problems building 32 bit binaries

If after building Redis with a 32 bit target you need to rebuild it with a 64 bit target, or the other way around, you need to perform a make distclean in the root directory of the Redis distribution.

In case of build errors when trying to build a 32 bit binary of Redis, try the following steps:

• Install the package libc6-dev-i386 (also try g++-multilib).
• Try using the following command line instead of make 32bit: make CFLAGS="-m32 -march=native" LDFLAGS="-m32"

Allocator

Selecting a non-default memory allocator when building Redis is done by setting the MALLOC environment variable. Redis is compiled and linked against libc malloc by default, with the exception of jemalloc being the default on Linux systems. This default was picked because jemalloc has proven to have fewer fragmentation problems than libc malloc.

To force compiling against libc malloc, use:

% make MALLOC=libc

To compile against jemalloc on Mac OS X systems, use:

% make MALLOC=jemalloc

Monotonic clock

By default, Redis will build using the POSIX clock_gettime function as the monotonic clock source. On most modern systems, the internal processor clock can be used to improve performance. Cautions can be found here: http://oliveryang.net/2015/09/pitfalls-of-TSC-usage/

To build with support for the processor's internal instruction clock, use:

% make CFLAGS="-DUSE_PROCESSOR_CLOCK"

Verbose build

Redis will build with a user-friendly colorized output by default. If you want to see a more verbose output, use the following:

% make V=1

Running Redis

To run Redis with the default configuration, just type:

% cd src
% ./redis-server

If you want to provide your redis.conf, you have to run it using an additional parameter (the path of the configuration file):

% cd src
% ./redis-server /path/to/redis.conf

It is possible to alter the Redis configuration by passing parameters directly as options using the command line. Examples:

% ./redis-server --port 9999 --replicaof 127.0.0.1 6379
% ./redis-server /etc/redis/6379.conf --loglevel debug

All the options in redis.conf are also supported as options using the command line, with exactly the same name.

Running Redis with TLS

Please consult the TLS.md file for more information on how to use Redis with TLS.

Playing with Redis

You can use redis-cli to play with Redis. Start a redis-server instance, then in another terminal try the following:

% cd src
% ./redis-cli
redis> ping
PONG
redis> set foo bar
OK
redis> get foo
"bar"
redis> incr mycounter
(integer) 1
redis> incr mycounter
(integer) 2
redis>

You can find the list of all the available commands at https://redis.io/commands.

Installing Redis

In order to install Redis binaries into /usr/local/bin, just use:

% make install

You can use make PREFIX=/some/other/directory install if you wish to use a different destination.

make install will just install binaries in your system, but will not configure init scripts and configuration files in the appropriate place. This is not needed if you just want to play a bit with Redis, but if you are installing it the proper way for a production system, we have a script that does this for Ubuntu and Debian systems:

% cd utils
% ./install_server.sh

Note: install_server.sh will not work on Mac OSX; it is built for Linux only.

The script will ask you a few questions and will setup everything you need to run Redis properly as a background daemon that will start again on system reboots.

You'll be able to stop and start Redis using the script named /etc/init.d/redis_<portnumber>, for instance /etc/init.d/redis_6379.

Code contributions

By contributing code to the Redis project in any form, including sending a pull request via GitHub, a code fragment or patch via private email or public discussion groups, you agree to release your code under the terms of the Redis Software Grant and Contributor License Agreement. Redis software contains contributions to the original Redis core project, which are owned by their contributors and licensed under the 3BSD license. Any copy of that license in this repository applies only to those contributions. Redis releases all Redis Community Edition versions from 7.4.x and thereafter under the RSALv2/SSPL dual-license as described in the LICENSE.txt file included in the Redis Community Edition source distribution.

Please see the CONTRIBUTING.md file in this source distribution for more information. For security bugs and vulnerabilities, please see SECURITY.md.

Redis Trademarks

The purpose of a trademark is to identify the goods and services of a person or company without causing confusion. As the registered owner of its name and logo, Redis accepts certain limited uses of its trademarks but it has requirements that must be followed as described in its Trademark Guidelines available at: https://redis.com/legal/trademark-guidelines/.

Redis internals

If you are reading this README you are likely in front of a GitHub page or you just untarred the Redis distribution tar ball. In both the cases you are basically one step away from the source code, so here we explain the Redis source code layout, what is in each file as a general idea, the most important functions and structures inside the Redis server and so forth. We keep all the discussion at a high level without digging into the details since this document would be huge otherwise and our code base changes continuously, but a general idea should be a good starting point to understand more. Moreover most of the code is heavily commented and easy to follow.

Source code layout

The Redis root directory just contains this README, the Makefile which calls the real Makefile inside the src directory and an example configuration for Redis and Redis Sentinel. You can find a few shell scripts that are used in order to execute the Redis, Redis Cluster and Redis Sentinel unit tests, which are implemented inside the tests directory.

Inside the root are the following important directories:

• src: contains the Redis implementation, written in C.
• tests: contains the unit tests, implemented in Tcl.
• deps: contains libraries Redis uses. Everything needed to compile Redis is inside this directory; your system just needs to provide libc, a POSIX compatible interface and a C compiler. Notably deps contains a copy of jemalloc, which is the default allocator of Redis under Linux. Note that under deps there are also things which started with the Redis project, but for which the main repository is not redis/redis.

There are a few more directories but they are not very important for our goals here. We'll focus mostly on src, where the Redis implementation is contained, exploring what there is inside each file. The order in which files are exposed is the logical one to follow in order to disclose different layers of complexity incrementally.

Note: lately Redis was refactored quite a bit. Function names and file names have been changed, so you may find that this documentation reflects the unstable branch more closely. For instance, in Redis 3.0 the server.c and server.h files were named redis.c and redis.h. However the overall structure is the same. Keep in mind that all the new developments and pull requests should be performed against the unstable branch.

server.h

The simplest way to understand how a program works is to understand the data structures it uses. So we'll start from the main header file of Redis, which is server.h.

All the server configuration and in general all the shared state is defined in a global structure called server, of type struct redisServer. A few important fields in this structure are:

• server.db is an array of Redis databases, where data is stored.
• server.commands is the command table.
• server.clients is a linked list of clients connected to the server.
• server.master is a special client, the master, if the instance is a replica.

There are tons of other fields. Most fields are commented directly inside the structure definition.

Another important Redis data structure is the one defining a client. In the past it was called redisClient, now just client. The structure has many fields, here we'll just show the main ones:

struct client {
    int fd;
    sds querybuf;
    int argc;
    robj **argv;
    redisDb *db;
    int flags;
    list *reply;
    // ... many other fields ...
    char buf[PROTO_REPLY_CHUNK_BYTES];
}

The client structure defines a connected client:

• The fd field is the client socket file descriptor.
• argc and argv are populated with the command the client is executing, so that functions implementing a given Redis command can read the arguments.
• querybuf accumulates the requests from the client, which are parsed by the Redis server according to the Redis protocol and executed by calling the implementations of the commands the client is executing.
• reply and buf are dynamic and static buffers that accumulate the replies the server sends to the client. These buffers are incrementally written to the socket as soon as the file descriptor is writable.

As you can see in the client structure above, arguments in a command are described as robj structures. The following is the full robj structure, which defines a Redis object:

struct redisObject {
    unsigned type:4;
    unsigned encoding:4;
    unsigned lru:LRU_BITS; /* LRU time (relative to global lru_clock) or
                            * LFU data (least significant 8 bits frequency
                            * and most significant 16 bits access time). */
    int refcount;
    void *ptr;
};

Basically this structure can represent all the basic Redis data types like strings, lists, sets, sorted sets and so forth. The interesting thing is that it has a type field, so that it is possible to know what type a given object has, and a refcount, so that the same object can be referenced in multiple places without allocating it multiple times. Finally the ptr field points to the actual representation of the object, which might vary even for the same type, depending on the encoding used.

Redis objects are used extensively in the Redis internals, however in order to avoid the overhead of indirect accesses, recently in many places we just use plain dynamic strings not wrapped inside a Redis object.

server.c

This is the entry point of the Redis server, where the main() function is defined. The following are the most important steps in order to startup the Redis server.

• initServerConfig() sets up the default values of the server structure.
• initServer() allocates the data structures needed to operate, setup the listening socket, and so forth.
• aeMain() starts the event loop which listens for new connections.

There are two special functions called periodically by the event loop:

1. serverCron() is called periodically (according to server.hz frequency), and performs tasks that must be performed from time to time, like checking for timed out clients.
2. beforeSleep() is called every time the event loop fired, Redis served a few requests, and is returning back into the event loop.

Inside server.c you can find code that handles other vital things of the Redis server:

• call() is used in order to call a given command in the context of a given client.
• activeExpireCycle() handles eviction of keys with a time to live set via the EXPIRE command.
• performEvictions() is called when a new write command should be performed but Redis is out of memory according to the maxmemory directive.
• The global variable redisCommandTable defines all the Redis commands, specifying the name of the command, the function implementing the command, the number of arguments required, and other properties of each command.

commands.c

This file is auto generated by utils/generate-command-code.py, the content is based on the JSON files in the src/commands folder. These are meant to be the single source of truth about the Redis commands, and all the metadata about them. These JSON files are not meant to be used by anyone directly, instead that metadata can be obtained via the COMMAND command.

networking.c

This file defines all the I/O functions with clients, masters and replicas (which in Redis are just special clients):

• createClient() allocates and initializes a new client.
• The addReply*() family of functions are used by command implementations in order to append data to the client structure, that will be transmitted to the client as a reply for a given command executed.
• writeToClient() transmits the data pending in the output buffers to the client and is called by the writable event handler sendReplyToClient().
• readQueryFromClient() is the readable event handler and accumulates data read from the client into the query buffer.
• processInputBuffer() is the entry point in order to parse the client query buffer according to the Redis protocol. Once commands are ready to be processed, it calls processCommand() which is defined inside server.c in order to actually execute the command.
• freeClient() deallocates, disconnects and removes a client.

aof.c and rdb.c

As you can guess from the names, these files implement the RDB and AOF persistence for Redis. Redis uses a persistence model based on the fork() system call in order to create a process with the same (shared) memory content of the main Redis process. This secondary process dumps the content of the memory on disk. This is used by rdb.c to create the snapshots on disk and by aof.c in order to perform the AOF rewrite when the append only file gets too big.

The implementation inside aof.c has additional functions in order to implement an API that allows commands to append new commands into the AOF file as clients execute them.

The call() function defined inside server.c is responsible for calling the functions that in turn will write the commands into the AOF.

db.c

Certain Redis commands operate on specific data types; others are general. Examples of generic commands are DEL and EXPIRE. They operate on keys and not on their values specifically. All those generic commands are defined inside db.c.

Moreover db.c implements an API in order to perform certain operations on the Redis dataset without directly accessing the internal data structures.

The most important functions inside db.c which are used in many command implementations are the following:

• lookupKeyRead() and lookupKeyWrite() are used in order to get a pointer to the value associated to a given key, or NULL if the key does not exist.
• dbAdd() and its higher level counterpart setKey() create a new key in a Redis database.
• dbDelete() removes a key and its associated value.
• emptyData() removes an entire single database or all the databases defined.

The rest of the file implements the generic commands exposed to the client.

object.c

The robj structure defining Redis objects was already described. Inside object.c there are all the functions that operate with Redis objects at a basic level, like functions to allocate new objects, handle the reference counting and so forth. Notable functions inside this file:

• incrRefCount() and decrRefCount() are used in order to increment or decrement an object reference count. When it drops to 0 the object is finally freed.
• createObject() allocates a new object. There are also specialized functions to allocate string objects having a specific content, like createStringObjectFromLongLong() and similar functions.

This file also implements the OBJECT command.

replication.c

This is one of the most complex files inside Redis, it is recommended to approach it only after getting a bit familiar with the rest of the code base. In this file there is the implementation of both the master and replica role of Redis.

One of the most important functions inside this file is replicationFeedSlaves() that writes commands to the clients representing replica instances connected to our master, so that the replicas can get the writes performed by the clients: this way their data set will remain synchronized with the one in the master.

This file also implements both the SYNC and PSYNC commands that are used in order to perform the first synchronization between masters and replicas, or to continue the replication after a disconnection.

Script

The script unit is composed of 3 units:

• script.c - integration of scripts with Redis (commands execution, set replication/resp, ...)
• script_lua.c - responsible to execute Lua code, uses script.c to interact with Redis from within the Lua code.
• function_lua.c - contains the Lua engine implementation, uses script_lua.c to execute the Lua code.
• functions.c - contains Redis Functions implementation (FUNCTION command), uses functions_lua.c if the function it wants to invoke needs the Lua engine.
• eval.c - contains the eval implementation using script_lua.c to invoke the Lua code.

Other C files

• t_hash.c, t_list.c, t_set.c, t_string.c, t_zset.c and t_stream.c contains the implementation of the Redis data types. They implement both an API to access a given data type, and the client command implementations for these data types.
• ae.c implements the Redis event loop, it's a self contained library which is simple to read and understand.
• sds.c is the Redis string library, check https://github.com/antirez/sds for more information.
• anet.c is a library to use POSIX networking in a simpler way compared to the raw interface exposed by the kernel.
• dict.c is an implementation of a non-blocking hash table which rehashes incrementally.
• cluster.c implements the Redis Cluster. Probably a good read only after being very familiar with the rest of the Redis code base. If you want to read cluster.c make sure to read the Redis Cluster specification.

Anatomy of a Redis command

All the Redis commands are defined in the following way:

void foobarCommand(client *c) {
    printf("%s",c->argv[1]->ptr); /* Do something with the argument. */
    addReply(c,shared.ok); /* Reply something to the client. */
}

The command function is referenced by a JSON file, together with its metadata, see commands.c described above for details. The command flags are documented in the comment above the struct redisCommand in server.h. For other details, please refer to the COMMAND command. https://redis.io/commands/command/

After the command operates in some way, it returns a reply to the client, usually using addReply() or a similar function defined inside networking.c.

There are tons of command implementations inside the Redis source code that can serve as examples of actual commands implementations (e.g. pingCommand). Writing a few toy commands can be a good exercise to get familiar with the code base.

There are also many other files not described here, but it is useless to cover everything. We just want to help you with the first steps. Eventually you'll find your way inside the Redis code base :-)

Enjoy!

redis-py's Issues

Python Client queues request when link down

What steps will reproduce the problem?

1. r.set("test","testdata") #to make a real connection with the server
2. ifdown eth0 # eth0 is the IF to the redis server
3. r.set("test","testdata") #this one will not return for a long long time
4. ifup eth0
5. the r.set command in step #3 returns OK after serveral minutes.

What is the expected output? What do you see instead?

in step #3 above, the r.set should return immediately or throw an exception

What version of the product are you using? On what operating system?

Linux (Ubuntu 9.04)
Python Redis Client from GIT on May 29. 2010.
Redis 2.0.0 Rc1

No tags for downloadable versions

It would be useful to have tags in the Git repository for all releases which are available for download at http://github.com/andymccurdy/redis-py/downloads

In fact downloads are automatically created for tags in GitHub.

BLPOP and BRPOP return no values

I'm running redis-py f4c8393 with Redis 1.3.10. I can't get BLPOP and BRPOP to work correctly from Python:

$ python
Python 2.6.5 (r265:79063, Apr  3 2010, 01:57:29) 
[GCC 4.4.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import redis
>>> r = redis.Redis()
>>> r.rpush('mylist', 'a')
1
>>> r.rpush('mylist', 'b')
2
>>> r.rpush('mylist', 'c')
3
>>> r.blpop('mylist', 1)
>>> r.blpop('mylist', 1)
>>> r.blpop('mylist', 1)
>>> r.brpop('mylist', 1)
>>> r.brpop('mylist', 1)
>>> r.brpop('mylist', 1)

While the same works correctly in the Redis shell:

$ redis-cli
redis> rpush mylist a
(integer) 1
redis> rpush mylist b
(integer) 2
redis> rpush mylist c
(integer) 3
redis> blpop mylist 1
1. mylist
2. a
redis> brpop mylist 1
1. mylist
2. c
redis> brpop mylist 1
1. mylist
2. b
redis> brpop mylist 1
(nil)

Cannot do psubscribe after subscribe

When a subscribe command is done, i can't do a psubscribe.

I think you should add PSUBSCRIBE and PUNSUBSCRIBE in SUBSCRIPTION_COMMANDS line 245

Twidi

zadd( 'test', 555, 'nan') crashes redis server

For some reason having a value that startswith('nan') crashes my redis server (1.2.2)

I'm not sure if this is a server or client issue, but I was unable to duplicate this crash using redis-cli so I'm leaning towards client.

support for BGREWRITEAOF ?

It seems redis-py has not support for the BGREWRITEAOF command.

Could it be implemented ?

Thanks

ConnectManager causes hour-long bug stalking in some cases :-)

ConnectManager causes hour-long bug stalking in some cases :-)

Scenario:
An application is doing something with redis, then it have to calculate something terribly big. In order to do it faster, it forks. Each fork creates new Redis() instance.
The problem is that connection is reused, and all forked processes share socket, and it causes magic bugs because you haven't asked for connection sharing but it's there! :)

Solve to problem:
Redis instance should accept keyword argument connection_pool=None.
And keep connection_manager inside itself instead on module-level.

I can write a fix in few minutes, but I want to clarify this:
Why share connections by default? I think that pool must be explicit rather than implicit.

hmset with 0 length array fails

it probably should just do a noop. Here's the stack trace

  File "/Users/mike/Documents/Scribd/iseo/sessions/ression.py", line 28, in pipe
    self.p.execute() # execute the remaining commands
  File "build/bdist.macosx-10.6-x86_64/egg/redis/client.py", line 1310, in execute
    return execute(stack)
  File "build/bdist.macosx-10.6-x86_64/egg/redis/client.py", line 1275, in _execute_transaction
    _ = self.parse_response('_')
  File "build/bdist.macosx-10.6-x86_64/egg/redis/client.py", line 390, in parse_response
    response = self._parse_response(command_name, catch_errors)
  File "build/bdist.macosx-10.6-x86_64/egg/redis/client.py", line 349, in _parse_response
    raise ResponseError(response)
ResponseError: wrong number of arguments for 'hmset' command

Type inference does not work with byte buffers

The following code (the last lines of _get_value) does not work properly if the value stored in Redis is a byte buffer.

data = ''.join(buf)[:-2]
try:
    if not '.' in data:
        value = int(data)
    else:
        value = self.float_fn(data)
    return value
except (ValueError, decimal.InvalidOperation):
    return data.decode(self.charset)

Ignoring the general type inference issues (discussed on the Redis mailing list here: http://groups.google.com/group/redis-db/browse_thread/thread/9888eb9ff383c90c), there is a serious issue with the data.decode call in the event that the data is representative of a byte buffer. In this case, decoding the buffer with a codec results in an incorrect response being returned to the client. Instead, data itself should be returned to the caller.

Doesn't work for simple SET/GET

I can't get this to work AT ALL using your library. WinXpsp3 / python 2.6

I installed a redis server on a linux box. I can get set values on the server using its non-localhost IP. I get errors when attempting to use your library from a windows client.

This is the code I ran on the server

import redis
r=redis.Redis("10.41.19.4")
r.set("key","value")
'OK'
r.get("key")
u'value'

This is code I ran on the client after the above:

import redis
r=redis.Redis("10.41.19.4")
r.get("key")
Traceback (most recent call last):
File "", line 1, in
File "redis\client.py", line 497, in get
return self.execute_command('GET', name)
File "redis\client.py", line 296, in execute_command
*_options
File "redis\client.py", line 275, in _execute_command
self.connection.send(command, self)
File "redis\client.py", line 77, in send
self.connect(redis_instance)
File "redis\client.py", line 62, in connect
redis_instance._setup_connection()
File "redis\client.py", line 389, in _setup_connection
self.execute_command('SELECT', self.connection.db)
File "redis\client.py", line 296, in execute_command
*_options
File "redis\client.py", line 278, in _execute_command
return self.parse_response(command_name, **options)
File "redis\client.py", line 355, in parse_response
response = self._parse_response(command_name, catch_errors)
File "redis\client.py", line 315, in _parse_response
raise ResponseError(response)
redis.exceptions.ResponseError: unknown command

Incorrect conversion of numeric return values

Currently all values will be converted using int or float_fn in _get_value if it's possible.
This is done regardless of what was actually put in.
This can lead to some hard to spot errors.

Example

v1 = "1234567" # E.g. hash values or something "non controllable"
v2 = "1ab3dc8"
type(v1), v1, type(v2), v2 => (<type 'str'>, '1234567', <type 'str'>, '1ab3dc8')

redis.Redis().set("a", v1)
redis.Redis().set("b", v2)

v1 = redis.Redis().get("a")
v2 = redis.Redis().get("b")
type(v1), v1, type(v2), v2 => (<type 'int'>, 1234567, <type 'unicode'>, u'1ab3dc8')

As you can see the returned values no longer match in type. It's not very intuitive that some values automatically gets converted while other doesn't.

I think it would be more appropriate to always return the non converted values, unless, if made possible, some other type where explicitly provided.

1.36 returns string for keys() instead of list

In 1.34.1, a call to keys() returns a python list of keys. In 1.36, keys() returns a space-separated string.

Redis.keys: AttributeError: 'int' object has no attribute 'split'

Python 2.6.1 (r261:67515, Jul  7 2009, 23:51:51) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from redis import Redis, ConnectionError, ResponseError
>>> r = Redis(db=0)
>>> r.keys('*')
[]
>>> r.set(1, 'somevalue')
'OK'
>>> r.keys('*')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "build/bdist.macosx-10.6-universal/egg/redis.py", line 337, in keys
AttributeError: 'int' object has no attribute 'split'

pipeline and transactions should not be the same

Since your commit bd411f9 redis-py executes pipelines atomically with MULTI/EXEC commands.
But pipelines and transactions are not the same, redis can handle a pipeline without MULTI/EXEC as before, and sometines it's what we want. After a long talk with Salvatore/Antirez, the two ways should be provided (transactions use more memory and are a bit slower).
Maybe an option to the pipeline command ?

FeatureRequest: add SETEX command

I have added in my tree but would like to see it the main as well..

potential bugs in _send_command and _read

I was browsing the driver source in the course of reviewing Redis for work and found a few potential bugs in the socket code.

The _read() method is calling "return self._fp.readline()", but this is bypassing the code at the end of the method which should be checking to see if self._sock.recv()=='', so a disconnect will likely not be handled correctly. It seems that _get_response() might handle this correctly, but _get_value() will raise a ValueError instead of a ConnectionError.

In the _send_command() method, if an EPIPE is raised, it won't work across platforms because it's checking if the value is 32, and not errno.EPIPE. I've had trouble with this in the past, as Linux and OSX use different enumerations.

Connection pooling can be messed up by select()

The following sequence of commands poses a problem for redis-py. It is a reduction of a real sequence of commands invoked by a copy script I wrote, and needless to say, figuring out the behavior in the comments confused me mightily.

 from redis import Redis
 source = Redis(db=0) # source opens a new connection to localhost/0
 dest = Redis(db=0)   # dest uses the existing connection to localhost/0
 source.select(1)     # since source and dest are sharing a connection,
                      # they will now both operate on database 1

 copy(source, dest)   # doesn't accomplish anything useful!

zscore throws exception for missing member

Redis documentation states that for missing members of zset it returns (nil). It's naturally to expect None on python's side.

Steps to reproduce:
r=Redis()
r.zadd('test', 'foo', 0)
r.zscore('test', 'bar')

Binary strings don't work between redis-node-client and redis-py

I filed this bug under redis-node-client, but it may be an issue with redis-py. The issue is here: http://github.com/fictorial/redis-node-client/issues#issue/22

Feature request: Timeout connection if takes too long by adding optional timeout parameter

def connect(self, redis_instance):
...
    sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
+   sock.settimeout(self.timeout)
    self._sock = sock
    self._fp = sock.makefile('r')
    redis_instance._setup_connection()

No redis.__version__ or redis.VERSION

Having these is pretty much a convention. It would be really nice if this could be added and maintained.

retry_connection

i'm testing my code against the 1.34.1 version and noticed that the retry_connection keyword argument is no longer available. Is this an intentional ommission from the Redis class initialization?

Multithreaded PubSub - Outside thread subscribes to new channel

I'm not quite sure if this is supposed to work but, it feels like it should. The use case demonstrated here:

• a "listener" thread is used since the .listen() function is blocking
• a separate thread tries to subscribe to a new channel
• messages from the new channel should come through the "listener" thread but, don't

  import redis
  import threading
  from time import sleep
  
  

r = redis.Redis()

def listener():
r.subscribe("channel1")
for m in r.listen():
print m

def publisher():
while True:
sleep(1)
r.publish("channel1", "message")
r.publish("channel2", "message")

def wait_then_subscribe():
sleep(5)
r.subscribe("channel2")
print "subscribed to channel 2"

threading.Thread(target=listener).start()
threading.Thread(target=publisher).start()
threading.Thread(target=wait_then_subscribe).start()

Output:

$ python redis-thread-test.py 
{'data': 1, 'type': 'subscribe', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
subscribed to channel 2
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}
{'data': 'message', 'type': 'message', 'channel': 'channel1'}

not work on multi threads

try the code below. you will found that the output is not what we want. what we want is like string of valuexxx. but there is many 1 and OK ... sometimes errors occurs.

from redis import Redis
import threading

r = Redis()

def t1():
    while True:
        r.set('key1', 'value1')

def t2():
    i = 1
    while True:
        i = i + 1
        r.sadd('key2', 'value%d' % i)

def t3():
    while True:
        print r.spop('key2')

threading.Thread(target=t1).start()
threading.Thread(target=t2).start()
threading.Thread(target=t3).start()

UNSUBSCRIBE does not actually UNSUB consumer.

Issuing an UNSUBSCRIBE request does not actually cause an UNSUBSCRIBE on the latest Git repo version.

The following code generates a "Cannot issue commands other than SUBSCRIBE and UNSUBSCRIBE while channels are open" when the the .get() is hit:

scan_cache_server.subscribe(txn_scan_key)
chan_msgs_gen = scan_cache_server.listen()
chan_msgs_gen.next()
scan_cache_server.unsubscribe()
master_result = scan_cache_server.get(txn_scan_key)

Traceback (most recent call last):
master_result = scan_cache_server.get(txn_scan_key)
File "/git/charon/charon.py", line 1515, in do_content_scan
File "build/bdist.macosx-10.6-universal/egg/redis/client.py", line 549, in get
master_result = scan_cache_server.get(txn_scan_key)
return self.execute_command('GET', name)
File "build/bdist.macosx-10.6-universal/egg/redis/client.py", line 549, in get
File "build/bdist.macosx-10.6-universal/egg/redis/client.py", line 330, in execute_command
*_options
File "build/bdist.macosx-10.6-universal/egg/redis/client.py", line 306, in _execute_command
raise RedisError("Cannot issue commands other than SUBSCRIBE and "
return self.execute_command('GET', name)
File "build/bdist.macosx-10.6-universal/egg/redis/client.py", line 330, in execute_command
*_options
File "build/bdist.macosx-10.6-universal/egg/redis/client.py", line 306, in _execute_command
raise RedisError("Cannot issue commands other than SUBSCRIBE and "

support for BGREWRITEAOF ?

It seems redis-py has not support for the BGREWRITEAOF command.

Could it be implemented ?

Thanks

here is a patch : http://gist.github.com/351975

keys now returns a list (mbulk) in redis 1.3.4

Please notice that in redis 1.3.4 the 'KEYS' command returns a MBULK and not a BULK to be splitter with spaces
http://github.com/antirez/redis/commit/a3f9eec291993853095941348e80818d91e07c5f

offset & count parameters to zrangebyscore()

Hi,

I have just added support for the offset & count parameters in zrangebyscore(). You can see the change in my forked redis-py repo here:

http://github.com/adamcharnock/redis-py/commit/30980d331dbf28af4c01c526ed7fd440171dc574

Would you consider merging this (or something similar) into redis-py?

Thanks!

Adam

sort start/num check is broken

0 is False in Python, so passing start=0, num=20 to sort will return all the results.

Line 676:
if start and num
Should be:
if start != None and num != None:

issue with SUBSCRIBE and pipes

Sample code:

redis = Redis()

# If I enable this line it works (i.e. executing any redis command before executing the pipe). This shouldn't be required though.
#redis.exists('z')

pipe = redis.pipeline()
pipe.subscribe('z')
print 'exec', pipe.execute()

for msg in pipe.listen():
    print msg


Output:

Traceback (most recent call last):
  File "sub.py", line 14, in 
    print 'exec', pipe.execute()
  File "/home/tom/lib/redis/client.py", line 1151, in execute
    return execute(stack)
  File "/home/tom/lib/redis/client.py", line 1113, in _execute_transaction
    self.connection.send(all_cmds, self)
  File "/home/tom/lib/redis/client.py", line 81, in send
    self.connect(redis_instance)
  File "/home/tom/lib/redis/client.py", line 66, in connect
    redis_instance._setup_connection()
  File "/home/tom/lib/redis/client.py", line 395, in _setup_connection
    self.execute_command('SELECT', self.connection.db)
  File "/home/tom/lib/redis/client.py", line 302, in execute_command
    **options
  File "/home/tom/lib/redis/client.py", line 1100, in _execute_command
    command_name, command, **options)
  File "/home/tom/lib/redis/client.py", line 278, in _execute_command
    raise RedisError("Cannot issue commands other than SUBSCRIBE and "
redis.exceptions.RedisError: Cannot issue commands other than SUBSCRIBE and UNSUBSCRIBE while channels are open

zrank throws TypeError for items not in a zset

sorry, i'm not an experienced issue reporter, hope the above code helps reproduce the problem.

In [48]: cache = Redis()
In [49]: cache.zadd("test", 'a', 1)
Out[49]: True
In [50]: cache.zadd("test", 'b', 2)
Out[50]: True
In [51]: cache.zrange("test", 0, 10)
Out[51]: ['a', 'b']
In [52]: cache.zrank("test", 'a')
Out[52]: 0
In [53]: cache.zrank("test", 'b')
Out[53]: 1
In [54]: cache.zrank("test", 'c')

TypeError Traceback (most recent call last)

[...]

TypeError: int() argument must be a string or a number, not 'NoneType'

More Pythonic to return empty list/set rather than None?

What steps will reproduce the problem?

1. Execute a command which doesn't have any results.

What is the expected output? What do you see instead?
Expected to return an empty list/set, instead got None.

What version of the product are you using? On what operating system?
redis-1.34.1-py2.6

E.g.

for x in red.zrange('non_existent_key', 0, -1):
do_something()
Traceback (most recent call last):
File "", line 1, in
TypeError: 'NoneType' object is not iterable

No release download with KEYS fix for Redis 1.3.x compatibility

The current newest download 1.34.1 of redis-py doesn't include this fix:
9e3e1aa

It is needed in order to use the KEYS command with recent 1.3.x versions of Redis available at http://github.com/antirez/redis/downloads

It would be nice to have a .tar.gz download with this fix (or compatibility with both new and old versions or Redis).

Redis.smove does not encode value

All other operations pass the value through the _encode method to convert ints, floats, and unicode into the proper string object with appropriate charset. smove does not do this, and passes the value (named member) directly into the command. This results in an AttributeError if the member being passed in is not a string type. Further errors may also occur if the type is a unicode with unsupported characters, or is a list/set/dict.

e.g.:
r = redis.Redis()
r.smove('set', 'list', 3)
Traceback (most recent call last):
File "", line 1, in
File "redis.py", line 808, in smove
src, dst, len(member), member
TypeError: object of type 'int' has no len()

not work with pipeline if extend Redis

Pipeline extends Redis, If I want to write a subclass extends Redis ,add some new method just like set_obj,get_obj in my own serialization, the pipeline should not work with these method. Because it extends Redis not my subclass.

Should pipeline be a embedded executor ?

Any good ideas?

r.keys() from redis-py v1.34.1 failing against redis 2.0.0-rc1

See here for original submission; http://code.google.com/p/redis/issues/detail?id=260

Running the client against this DB produces;

Traceback (most recent call last):
File "", line 1, in
File "build/bdist.macosx-10.5-i386/egg/redis/client.py", line 440, in keys
File "build/bdist.macosx-10.5-i386/egg/redis/client.py", line 284, in format_inline
File "build/bdist.macosx-10.5-i386/egg/redis/client.py", line 220, in execute_command
File "build/bdist.macosx-10.5-i386/egg/redis/client.py", line 215, in _execute_command
File "build/bdist.macosx-10.5-i386/egg/redis/client.py", line 269, in parse_response
File "build/bdist.macosx-10.5-i386/egg/redis/client.py", line 181, in
AttributeError: 'list' object has no attribute 'split'

From:
import redis
r = redis.Redis()
r.keys('*')

AUTH doesn't work

I'm using something like this:

    self.redis = Redis(host=options.redis_host, port=options.redis_port, db=options.redis_db)
    self.redis.auth('fooword')

And I get this output:

[frank@isamu 61924]$ python index.py 
Traceback (most recent call last):
  File "index.py", line 651, in <module>
    main()
  File "index.py", line 644, in main
    http_server = tornado.httpserver.HTTPServer(Application())
  File "index.py", line 126, in __init__
    self.redis.auth('fooword')
  File "/srv/http/nginx/61924/modules/redis.py", line 1261, in auth
    return self.send_command('AUTH %s\r\n' % passwd)
  File "/srv/http/nginx/61924/modules/redis.py", line 122, in _send_command_retry
    return self._send_command(s)
  File "/srv/http/nginx/61924/modules/redis.py", line 110, in _send_command
    self.connect()
  File "/srv/http/nginx/61924/modules/redis.py", line 1355, in connect
    self.select(self.db)
  File "/srv/http/nginx/61924/modules/redis.py", line 1164, in select
    return self.send_command('SELECT %s\r\n' % db)
  File "/srv/http/nginx/61924/modules/redis.py", line 122, in _send_command_retry
    return self._send_command(s)
  File "/srv/http/nginx/61924/modules/redis.py", line 118, in _send_command
    return self._get_response()
  File "/srv/http/nginx/61924/modules/redis.py", line 1273, in _get_response
    raise ResponseError(err)
modules.redis.ResponseError: operation not permitted

When I use telnet it works:

[frank@isamu 61924]$ telnet localhost 6379
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
AUTH fooword
+OK

args[1] throwing indexerror when socket times out

http://github.com/andymccurdy/redis-py/blob/master/redis/client.py#L57

Feature request: support for multiple parameters to delete()

The DEL supports multiple parameters, can redis-py also support this?

I expect it could be done as follows:

def delete(self, *args):
    """
    >>> r = Redis(db=9)
    >>> r.delete('dsjhfksjdhfkdsjfh')
    0
    >>> r.set('a', 'a')
    'OK'
    >>> r.delete('a')
    1
    >>> r.exists('a')
    0
    >>> r.delete('a')
    0
    >>> 
    """
    return self.send_command('DEL %s\r\n' % " ".join(args))

Thank you!

Redis.select() requires host and port

From the documentation for the select method of Redis:

Switch to a different database on the current host/port

However, host and port are required parameters:

def select(self, host, port, db, password=None, socket_timeout=None):

Can we make host and port optional, with db the only required parameter?

Pipeline case does a lot of socket 'sendto' system calls

Hi,

In the pipeline use-case it might be benificial to build up a string containing a number of commands and write them out in 1 call to socket.sendall. This will most probably result in better bandwidth usage for the socket connection and thus higher overall number of commands/sec.

Do not support hash of the redis latest version

http://code.google.com/p/redis/wiki/HsetCommand

HashCommands are not be support yet.

Cannot reconnect (auth/select) if subscribed==True

If we are in "subscribed" mode (after doing a subscribe or psubscribe), and if the connection need to be reopened, it's not possible because AUTH (if password given) and SELECT are not in SUBSCRIPTIONS_COMMAND.

Is the good way to intercept the exception and then reauth et resubscribe ?

client doesn't recover after invalid argument in Redis.set()

Following code does not work:

import redis.client
db = redis.client.Redis('localhost', 6379)
db.set("example","123")
True
try:
... db.set("invalid key","123")
... except Exception, e:
... print str(e)
...
wrong number of arguments for 'set' command
db.set("example","123")
Traceback (most recent call last):
...
File "<...>\redis\client.py", line 274, in _parse_response
raise ResponseError(response)
redis.exceptions.ResponseError: unknown command '123'

The same behavior is with Redis server 1.2.2 and 1.3.7

BUG: redis-py 1.3.4 with a redis-1.3.4 server - keys response parsed incorrectly

It looks like the protocol response from the server has changed slightly for the keys function (and possibly others untested). Where our old servers (1.2.1) used to say this;

KEYS *
$3
foo

... the new server (1.3.4) says this;

KEYS *
*1
$3
foo

I think it is preceding the #bytes with the #responses, in this case 1. What this means for the lambda called from RESPONSE_CALLBACKS for keys, is that it gets a list and attempts to split it (because it is expecting a string)

'KEYS' : lambda r: r and r.split(' ') or [],

To see it in action, start up a 1.3.4 server (got mine from github), crank up a python interpreter, and fire away;

r.info()
{'bgrewriteaof_in_progress': 0, 'uptime_in_days': 0, 'multiplexing_api': 'epoll', 'last_save_time': 1268698696, 'redis_version': '1.3.4', 'connected_clients': 1, 'hash_max_zipmap_value': 512, 'vm_enabled': 0, 'role': 'master', 'total_commands_processed': 30, 'total_connections_received': 9, 'used_memory_human': '523.43K', 'blocked_clients': 0, 'process_id': 19110, 'connected_slaves': 0, 'db0': {'keys': 1, 'expires': 0}, 'arch_bits': 64, 'hash_max_zipmap_entries': 64, 'bgsave_in_progress': 0, 'used_memory': 535993, 'uptime_in_seconds': 4054, 'changes_since_last_save': 1}

r.keys('*')
[]

r.set('foo', 'zoo')
True

r.keys('*')
Traceback (most recent call last):
File "", line 1, in
File "build/bdist.linux-x86_64/egg/redis/client.py", line 440, in keys
File "build/bdist.linux-x86_64/egg/redis/client.py", line 284, in format_inline
File "build/bdist.linux-x86_64/egg/redis/client.py", line 220, in execute_command
File "build/bdist.linux-x86_64/egg/redis/client.py", line 215, in _execute_command
File "build/bdist.linux-x86_64/egg/redis/client.py", line 269, in parse_response
File "build/bdist.linux-x86_64/egg/redis/client.py", line 181, in
AttributeError: 'list' object has no attribute 'split'

I'm in the process of porting some code from 0.6.3(?) because you now have pipelining (yay), but this is a bit of a bu99er because I use the keys call a lot. It is possible that other calls I haven't come across could be affected by this variation in protocol response.

Cheers
Sam

blpop / brpop; unexpected behavior if you pass a single string as the 'keys' arg

doesn't really decide if this a bug but i thought i should mention it.

if you pass a single string as the 'keys' arg to blpop or brpop it will become a list of chars of that string (because of the call of list(keys)) which is obviously not what you want.

i'd write something like this instead:

    [...]
    if isinstance(keys, basestring):
        keys = [keys]
    keys = list(keys)
    [...]

RFE: Sharding

Would it be possible to implement automatic sharding similar to the redis Ruby library?

pairs_to_dict forces float cast for values

Heya Andy, thanks for the speedy turnaround on the new hash functions. I notice however that the pairs_to_dict function is forcing values to be cast as float via a map call. Is this intended? It means I can't put string values into a hash.

r.hset('foo', 'bar', 'zoo')
1
r.hgetall('foo')
Traceback (most recent call last):
File "", line 1, in
File "redis/client.py", line 902, in hgetall
File "redis/client.py", line 325, in format_inline
File "redis/client.py", line 247, in execute_command
File "redis/client.py", line 242, in _execute_command
File "redis/client.py", line 310, in parse_response
File "redis/client.py", line 207, in
File "redis/client.py", line 158, in pairs_to_dict
ValueError: invalid literal for float(): zoo

Not sure what side effect there would be from removing the float call - other than everything coming back as a string. Maybe instead of mapping to float, it could use a function like this?

def map_type(value):
... try:
... return '.' in value and float(value) or int(value)
... except ValueError:
... return value

Anyway, thought I would let you know =]

Cheers
Sam

message not retrieved with psubscribe

With psubscribe, the original message is the fourth parts of the response, not the third (the third is the original channel), but only the three firsts aretaken from the response.

You should add a condition in the listen method (and one day i shloud fork redis-py to make this and do some pull requests time to time... )

Feature request: Namespace support

Proposal:

r = redis.Redis(namespace='foobar')

Behind-the-scenes, this would prefix every key with foobar.

For example, if I issued the following command:

r.set('abc', 'xyz')

It would be equivalent to the following:

redis-cli set foobar:abc xyz

In Ruby, the redis-namespace class does the same thing.

However, I think that it would be preferable if this were a core feature of the Python client.