#+SETUPFILE: "doc/basho-doc-style.iorg"
Welcome to Riak.
* Overview
Riak is a distributed, decentralized data storage system.
Below, you will find the "quick start" directions for setting up and
using Riak. For more information, browse the following files:
- README: this file
- LICENSE: the license under which Riak is released
- doc/
- admin.org: Riak Administration Guide
- architecture.txt: details about the underlying design of Riak
- basic-client.txt: slightly more detail on using Riak
- basic-setup.txt: slightly more detail on setting up Riak
- man/riak.1.gz: manual page for the riak(1) command
- man/riak-admin.1.gz manual page for the riak-admin(1) command
- raw-http-howto.txt: using the Riak HTTP interface
* Where to find more
Below, you'll find a basic introduction to starting and using Riak as
a key/value store. For more information about Riak's extended feature
set, including MapReduce, Search, Secondary Indexes, various storage
strategies, and more, please visit our docs at http://docs.basho.com/.
* Quick Start
This section assumes that you have copy of the Riak source tree. To get
started, you need to:
1. Build Riak
2. Start the Riak server
3. Connect a client and store/fetch data
** Building Riak
Assuming you have a working Erlang (R14B02 or later) installation,
building Riak should be as simple as:
#+BEGIN_EXAMPLE
$ cd $RIAK
$ make rel
#+END_EXAMPLE
** Starting Riak
Once you have successfully built Riak, you can start the server with the
following commands:
#+BEGIN_EXAMPLE
$ cd $RIAK/rel/riak
$ bin/riak start
#+END_EXAMPLE
Now, verify that the server started up cleanly and is working:
: $ bin/riak-admin test
Note that the $RIAK/rel/riak directory is a complete, self-contained instance
of Riak and Erlang. It is strongly suggested that you move this directory
outside the source tree if you plan to run a production instance.
** Connecting a client to Riak
Now that you have a functional server, let's try storing some data in
it. First, start up a erlang node using our embedded version of erlang:
#+BEGIN_EXAMPLE
$ erts-<vsn>/bin/erl -name riaktest@127.0.0.1 -setcookie riak
Eshell V5.7.4 (abort with ^G)
(riaktest@127.0.0.1)1>
#+END_EXAMPLE
Now construct the node name of Riak server and make sure we can talk to it:
#+BEGIN_EXAMPLE
(riaktest@127.0.0.1)4> RiakNode = 'riak@127.0.0.1'.
(riaktest@127.0.0.1)2> net_adm:ping(RiakNode).
pong
(riaktest@127.0.0.1)2>
#+END_EXAMPLE
We are now ready to start the Riak client:
#+BEGIN_EXAMPLE
(riaktest@127.0.0.1)2> {ok, C} = riak:client_connect(RiakNode).
{ok,{riak_client,'riak@127.0.0.1',<<4,136,81,151>>}}
#+END_EXAMPLE
Let's create a shopping list for bread at /groceries/mine:
#+BEGIN_EXAMPLE
(riaktest@127.0.0.1)6> O0 = riak_object:new(<<"groceries">>, <<"mine">>, ["bread"]).
O0 = riak_object:new(<<"groceries">>, <<"mine">>, ["bread"]).
{r_object,<<"groceries">>,<<"mine">>,
[{r_content,{dict,0,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],...},
{{[],[],[],[],[],[],[],[],[],[],[],[],...}}},
["bread"]}],
[],
{dict,1,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],[],...},
{{[],[],[],[],[],[],[],[],[],[],[],[],[],...}}},
undefined}
(riaktest@127.0.0.1)3> C:put(O0, 1).
#+END_EXAMPLE
Now, read the list back from the Riak server and extract the value
#+BEGIN_EXAMPLE
(riaktest@127.0.0.1)4> {ok, O1} = C:get(<<"groceries">>, <<"mine">>, 1).
{ok,{r_object,<<"groceries">>,<<"mine">>,
[{r_content,{dict,2,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],...},
{{[],[],[],[],[],[],
[["X-Riak-Last-Modified",87|...]],
[],[],[],...}}},
["bread"]}],
[{"20090722191020-riaktest@127.0.0.1-riakdemo@127.0.0.1-266664",
{1,63415509105}}],
{dict,0,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],...},
{{[],[],[],[],[],[],[],[],[],[],[],...}}},
undefined}}
(riaktest@127.0.0.1)5> %% extract the value
(riaktest@127.0.0.1)5> V = riak_object:get_value(O1).
["bread"]
#+END_EXAMPLE
Add milk to our list of groceries and write the new value to Riak:
#+BEGIN_EXAMPLE
(riaktest@127.0.0.1)6> %% add milk to the list
(riaktest@127.0.0.1)6> O2 = riak_object:update_value(O1, ["milk" | V]).
{r_object,<<"groceries">>,<<"mine">>,
[{r_content,{dict,2,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],...},
{{[],[],[],[],[],[],
[["X-Riak-Last-Modified",87,101,100|...]],
[],[],[],[],[],...}}},
["bread"]}],
[{"20090722191020-riaktest@127.0.0.1-riakdemo@127.0.0.1-266664",
{1,63415509105}}],
{dict,0,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],[],...},
{{[],[],[],[],[],[],[],[],[],[],[],[],[],...}}},
["milk","bread"]}
(riaktest@127.0.0.1)7> %% store the new list
(riaktest@127.0.0.1)7> C:put(O2, 1).
ok
#+END_EXAMPLE
Finally, see what other keys are available in groceries bucket:
#+BEGIN_EXAMPLE
(riaktest@127.0.0.1)8> C:list_keys(<<"groceries">>).
{ok,[<<"mine">>]}
#+END_EXAMPLE
** Clients for Other Languages
Client libraries are available for many languages. Rather than
bundle them with the Riak server source code, we have given them
each their own source repository. Currently, official Riak
client language libraries include:
+ Javascript
https://github.com/basho/riak-javascript-client
+ Python
https://github.com/basho/riak-python-client
+ Ruby
https://github.com/basho/riak-ruby-client
+ Java
https://github.com/basho/riak-java-client
+ PHP
https://github.com/basho/riak-php-client
+ Erlang
https://github.com/basho/riak-erlang-client
(using protocol buffers instead of distributed Erlang)
* Server Management
** Configuration
Configuration for the Riak server is stored in $RIAK/rel/riak/etc
directory. There are two files:
- vm.args
This file contains the arguments that are passed to the Erlang VM
in which Riak runs. The default settings in this file shouldn't need to be
changed for most environments.
- app.config
This file contains the configuration for the Erlang applications
that run on the Riak server.
More information about this files is available in doc/basic-setup.txt.
** Server Control
*** bin/riak
This script is the primary interface for starting and stopping the Riak
server.
To start a daemonized (background) instance of Riak:
: $ bin/riak start
Once a server is running in the background you can attach to the Erlang
console via:
: $ bin/riak attach
Alternatively, if you want to run a foreground instance of Riak, start it
with:
: $ bin/riak console
Stopping a foreground or background instance of Riak can be done from a
shell prompt via:
: $ bin/riak stop
Or if you are attached/on the Erlang console:
: (riak@127.0.0.1)1> q().
You can determine if the server is running by:
: $ bin/riak ping
*** bin/riak-admin
This script provides access to general administration of the Riak server.
The below commands assume you are running a default configuration for
parameters such as cookie.
To join a new Riak node to an existing cluster:
#+BEGIN_EXAMPLE
$ bin/riak start # If a local server is not already running
$ bin/riak-admin join <node in cluster>
#+END_EXAMPLE
(Note that you must have a local node already running for this to work)
To verify that the local Riak node is able to read/write data:
: $ bin/riak-admin test
To backup a node or cluster run the following:
: $ bin/riak-admin backup riak@X.X.X.X riak <directory/backup_file> node
: $ bin/riak-admin backup riak@X.X.X.X riak <directory/backup_file> all
Restores can function in two ways, if the backup file was of a node the
node will be restored and if the backup file contains the data for a
cluster all nodes in the cluster will be restored.
To restore from a backup file:
: $ riak-admin restore riak@X.X.X.X riak <directory/backup_file>
To view the status of a node:
: $ bin/riak-admin status
If you change the IP or node name you will need to use the reip command:
: $ bin/riak-admin reip <old_nodename> <new_nodename>
* Contributing to Riak
Basho encourages contributions to Riak from the community. Here's
how to get started.
- Fork the appropriate sub-projects that are affected by your
change. Fork this repository if your changes are for release
generation or packaging.
- Make your changes and run the test suite. (see below)
- Commit your changes and push them to your fork.
- Open pull-requests for the appropriate projects.
- If a Bugzilla issue exists that is related to your change, modify
the issue, giving a link to the pull-request(s). Be sure to mention
the Bugzilla issue number in your pull-requests.
- Basho engineers will review your pull-request, suggest changes,
and merge it when it's ready.
** How to Report a Bug
- The Basho Bug Tracker: [[https://issues.basho.com]]
- Read More at: [[http://wiki.basho.com/How-to-Report-a-Bug.html]]
** Testing
To make sure your patch works, be sure to run the test suite in each
modified sub-project, and dialyzer from the top-level project to
detect static code errors.
To run the QuickCheck properties included in Riak sub-projects,
download QuickCheck Mini: http://quviq.com/downloads.htm NOTE: Some
properties that require features in the Full version will fail.
*** Running unit tests
The unit tests for each subproject can be run with =make= or
=rebar= like so:
#+BEGIN_SRC shell
make eunit
#+END_SRC
#+BEGIN_SRC shell
./rebar skip_deps=true eunit
#+END_SRC
*** Running dialyzer
Dialyzer performs static analysis of the code to discover defects,
edge-cases and discrepancies between type specifications and the
actual implementation.
Dialyzer requires a pre-built code analysis table called a PLT.
Building a PLT is expensive and can take up to 30 minutes on some
machines. Once built, you generally want to avoid clearing or
rebuilding the PLT unless you have had significant changes in your
build (a new version of Erlang, for example).
**** Build the PLT
Run the command below to build the PLT.
#+BEGIN_SRC shell
make build_plt
#+END_SRC
**** Check the PLT
If you have built the PLT before, check it before you run
Dialyzer again. This will take much less time than building the
PLT from scratch.
#+BEGIN_SRC shell
make check_plt
#+END_SRC
**** Run Dialyzer
#+BEGIN_SRC shell
make dialyzer
#+END_SRC
