# eredis_cluster
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## Description

eredis_cluster is a wrapper for eredis to support cluster mode of redis 3.0.0+
This project is under development.

## TODO

- Fix/Add specs of functions
- Add safeguard if keys of a pipeline command is not located in the same server
- Improve unit tests

## Compilation && Test

The directory contains a Makefile and rebar3

	make
	make test

## Configuration

To configure the redis cluster, you can use an application variable (probably in your app.config):

	{eredis_cluster,
	    [
	        {init_nodes,[
	            {"127.0.0.1",30001},
	            {"127.0.0.1",30002}
	        ]},
	        {pool_size, 5},
	        {pool_max_overflow, 0}
	    ]
	}

You don't need to specify all nodes of your configuration as eredis_cluster will
retrieve them through the command `CLUSTER SLOTS` at runtime.

## Usage

	%% Start the application
	eredis_cluster:start().

	%% Simple command
	eredis_cluster:q(["GET","abc"]).

	%% Pipeline
	eredis_cluster:qp([["LPUSH", "a", "a"], ["LPUSH", "a", "b"], ["LPUSH", "a", "c"]]).

	%% Transaction
	eredis_cluster:transaction([["LPUSH", "a", "a"], ["LPUSH", "a", "b"], ["LPUSH", "a", "c"]]).

    %% Transaction Function
    Function = fun(Worker) ->
        eredis_cluster:qw(Worker,["WATCH", "abc"]),
        {ok, Var} = eredis_cluster:qw(Worker,["GET", "abc"]),

        %% Do something with Var %%
        Var2 = binary_to_integer(Var) + 1,

        {ok, Result} eredis_cluster:qw(Worker,[["MULTI"],["SET","abc",Var2],["EXEC"]]),
        lists:last(Result)
    end,
	eredis_cluster:transaction(Function,"abc").

    %% Atomic Key update
    Fun = fun(Var) -> binary_to_integer(Var) + 1 end,
    eredis_cluster:update_key("abc", Fun).

    %% Flush DB
	eredis_cluster:flushdb().