StackExchange.Redis is a high performance general purpose redis client for .NET languages (C# etc). It is the logical successor to [BookSleeve](https://code.google.com/archive/p/booksleeve/),
and is the client developed-by (and used-by) [Stack Exchange](http://stackexchange.com/) for busy sites like [Stack Overflow](http://stackoverflow.com/). For the full reasons
why this library was created (i.e. "What about BookSleeve?") [please see here](http://marcgravell.blogspot.com/2014/03/so-i-went-and-wrote-another-redis-client.html).
Features
--
- High performance multiplexed design, allowing for efficient use of shared connections from multiple calling threads
- Abstraction over redis node configuration: the client can silently negotiate multiple redis servers for robustness and availability
- Convenient access to the full redis feature-set
- Full dual programming model both synchronous and asynchronous usage, without requiring "sync over async" usage of the [TPL][1]
- Support for redis "cluster"
Installation
---
StackExchange.Redis can be installed via the nuget UI (as [StackExchange.Redis](https://www.nuget.org/packages/StackExchange.Redis/)), or via the nuget package manager console:
```PowerShell
PM> Install-Package StackExchange.Redis
```
If you require a strong-named package (because your project is strong-named), then you may wish to use instead:
([for further reading, see here](http://blog.marcgravell.com/2014/06/snk-we-need-to-talk.html))
Documentation
---
-[Basic Usage](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Basics.md) - getting started and basic usage
-[Configuration](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Configuration.md) - options available when connecting to redis
-[Pipelines and Multiplexers](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/PipelinesMultiplexers.md) - what is a multiplexer?
-[Keys, Values and Channels](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/KeysValues.md) - discusses the data-types used on the API
-[Transactions](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Transactions.md) - how atomic transactions work in redis
-[Events](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Events.md) - the events available for logging / information purposes
-[Pub/Sub Message Order](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/PubSubOrder.md) - advice on sequential and concurrent processing
-[Where are `KEYS` / `SCAN` / `FLUSH*`?](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/KeysScan.md) - how to use server-based commands
-[Profiling](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Profiling.md) - profiling interfaces, as well as how to profile in an `async` world
-[Scripting](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Scripting.md) - running Lua scripts with convenient named parameter replacement
Questions and Contributions
---
If you think you have found a bug or have a feature request, please [report an issue][2], or if appropriate: submit a pull request. If you have a question, feel free to [contact me](https://github.com/mgravell).
This will (virtually instantaneously) write `"hello"` to the console of the subscribed process. As before, both channel-names and messages can be binary.
Please also see [Pub / Sub Message Order](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/PubSubOrder.md) for guidance on sequential versus concurrent message processing.
Please also see [Pub / Sub Message Order](/PubSubOrder) for guidance on sequential versus concurrent message processing.
Pipelining is all well and good, but often any single block of code only wants a single value (or maybe wants to perform a few operations, but which depend on each-other). This means that we still have the problem that we spend most of our time waiting for data to transfer between client and server. Now consider a busy application, perhaps a web-server. Such applications are generally inherently concurrent, so if you have 20 parallel application requests all requiring data, you might think of spinning up 20 connections, or you could synchronize access to a single connection (which would mean the last caller would need to wait for the latency of all the other 19 before it even got started). Or as a compromise, perhaps a pool of 5 connections which are leased - no matter how you are doing it, there is going to be a lot of waiting. **StackExchange.Redis does not do this**; instead, it does a *lot* of work for you to make effective use of all this idle time by *multiplexing* a single connection. When used concurrently by different callers, it **automatically pipelines the separate requests**, so regardless of whether the requests use blocking or asynchronous access, the work is all pipelined. So we could have 10 or 20 of our "get a and b" scenario from earlier (from different application requests), and they would all get onto the connection as soon as possible. Essentially, it fills the `waiting` time with work from other callers.
For this reason, the only redis features that StackExchange.Redis does not offer (and *will not ever offer*) are the "blocking pops" ([BLPOP](http://redis.io/commands/blpop), [BRPOP](http://redis.io/commands/brpop) and [BRPOPLPUSH](http://redis.io/commands/brpoplpush)) - because this would allow a single caller to stall the entire multiplexer, blocking all other callers. The only other time that StackExchange.Redis needs to hold work is when verifying pre-conditions for a transaction, which is why StackExchange.Redis encapsulates such conditions into internally managed `Condition` instances. [Read more about transactions here](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Transactions.md). If you feel you want "blocking pops", then I strongly suggest you consider pub/sub instead:
For this reason, the only redis features that StackExchange.Redis does not offer (and *will not ever offer*) are the "blocking pops" ([BLPOP](http://redis.io/commands/blpop), [BRPOP](http://redis.io/commands/brpop) and [BRPOPLPUSH](http://redis.io/commands/brpoplpush)) - because this would allow a single caller to stall the entire multiplexer, blocking all other callers. The only other time that StackExchange.Redis needs to hold work is when verifying pre-conditions for a transaction, which is why StackExchange.Redis encapsulates such conditions into internally managed `Condition` instances. [Read more about transactions here](/Transactions). If you feel you want "blocking pops", then I strongly suggest you consider pub/sub instead:
-[Basic Usage](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Basics.md) - getting started and basic usage
-[Configuration](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Configuration.md) - options available when connecting to redis
-[Pipelines and Multiplexers](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/PipelinesMultiplexers.md) - what is a multiplexer?
-[Keys, Values and Channels](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/KeysValues.md) - discusses the data-types used on the API
-[Transactions](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Transactions.md) - how atomic transactions work in redis
-[Events](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Events.md) - the events available for logging / information purposes
-[Pub/Sub Message Order](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/PubSubOrder.md) - advice on sequential and concurrent processing
-[Where are `KEYS` / `SCAN` / `FLUSH*`?](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/KeysScan.md) - how to use server-based commands
-[Profiling](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Profiling.md) - profiling interfaces, as well as how to profile in an `async` world
-[Scripting](https://github.com/StackExchange/StackExchange.Redis/blob/master/Docs/Scripting.md) - running Lua scripts with convenient named parameter replacement
-[Basic Usage](/Basics) - getting started and basic usage
-[Configuration](/Configuration) - options available when connecting to redis
-[Pipelines and Multiplexers](/PipelinesMultiplexers) - what is a multiplexer?
-[Keys, Values and Channels](/KeysValues) - discusses the data-types used on the API
-[Transactions](/Transactions) - how atomic transactions work in redis
-[Events](/Events) - the events available for logging / information purposes
-[Pub/Sub Message Order](/PubSubOrder) - advice on sequential and concurrent processing
-[Where are `KEYS` / `SCAN` / `FLUSH*`?](/KeysScan) - how to use server-based commands
-[Profiling](/Profiling) - profiling interfaces, as well as how to profile in an `async` world
-[Scripting](/Scripting) - running Lua scripts with convenient named parameter replacement
