# Riak Ruby Client (riak-client) `riak-client` is a rich Ruby client/toolkit for Riak, Basho's distributed database that contains a basic wrapper around typical operations, including bucket manipulation, object CRUD, link-walking, and map-reduce. Exhaustive documentation is available at http://basho.github.io/riak-ruby-client/ , and API documentation can be read at http://www.rubydoc.info/gems/riak-client/frames . ## Dependencies Ruby 1.9.3, 2.0, 2.1, and 2.2 are supported. JRuby in 1.9 and 2.0 modes are also supported. `riak-client` is not compatible with Ruby 1.8. In JRuby 1.7.13, OCSP validation is absent, and CRL validation always fails. [This issue is being tracked][1] and this document will be updated when it is fixed. Additionally, client certificate authentication doesn't work in JRuby. [This issue is also being tracked][2], and this document will be updated when it works. [1]: https://github.com/jruby/jruby-openssl/issues/5 [2]: https://github.com/basho/riak_api/issues/65 `riak-client` requires beefcake, cert_validator, i18n, innertube, and multi_json. Development dependencies are handled with bundler. Install bundler (`gem install bundler`) and run this command to get started: ```bash $ bundle install ``` Run the RSpec suite using `bundle exec`: ```bash $ bundle exec rake ``` ## Basic Example ```ruby require 'riak' # Create a client interface client = Riak::Client.new # Create a client that uses secure Protocol Buffers client = Riak::Client.new(authentication: { # certificate authority to validate the server cert ca_file: '/home/zedo/ca.crt', # username, required user: 'zedo', # password for password-based authentication password: 'catnip', # client-cert authentication parameters support filenames, # OpenSSL-compatible string data, or properly initialized # OpenSSL objects client_ca: '/home/zedo/ca.crt', cert: File.read '/home/zedo/zedo.crt', key: OpenSSL::PKey::RSA.new(File.read '/home/zedo/zedo.key') }) # Automatically balance between multiple nodes client = Riak::Client.new(:nodes => [ {:host => '10.0.0.1'}, {:host => '10.0.0.2', :pb_port => 1234}, {:host => '10.0.0.3', :pb_port => 5678} ]) # Retrieve a bucket bucket = client.bucket("doc") # a Riak::Bucket # Get an object from the bucket object = bucket.get_or_new("index.html") # a Riak::RObject # Change the object's data and save object.raw_data = "Hello, world!" object.content_type = "text/html" object.store # Reload an object you already have object.reload # Works if you have the key and vclock, using conditional GET object.reload :force => true # Reloads whether you have the vclock or not # Access more like a hash, client[bucket][key] client['doc']['index.html'] # the Riak::RObject # Create a new object new_one = Riak::RObject.new(bucket, "application.js") new_one.content_type = "application/javascript" # You must set the content type. new_one.raw_data = "alert('Hello, World!')" new_one.store ``` ## Bucket Types Riak 2 uses [bucket types][1] to enable groups of similar buckets to share properties, configuration, and to namespace values within those buckets. Bucket type support is integral to how CRDTs work. [1]: http://docs.basho.com/riak/latest/dev/advanced/bucket-types In versions 2.2.0 and newer of this client, bucket types have a first-class representation, and can be used to create `BucketTyped::Bucket` objects that are namespaced differently from regular `Riak::Bucket` objects. ```ruby # This example assumes you have a "beverages" bucket type. beverages = client.bucket_type 'beverages' coffees = beverages.bucket 'coffees' untyped_coffees = client.bucket 'coffees' chapadao = coffees.new 'chapadao' chapadao.data = "Chapadao de Ferro" chapadao.store # stores this in the "beverages" bucket type untyped_coffees.get 'chapadao' # raises error, not found coffees.get 'chapadao' # succeeds chapadao.reload # succeeds untyped_coffees.delete 'chapadao' # silently fails to delete it chapadao.delete # deletes it coffees.delete 'chapadao' # deletes it ``` Client 2.0 and 2.1 code that uses the `type` argument to methods still works: ```ruby coffees = client.bucket 'coffees' chapadao = coffees.new 'chapadao' chapadao.data = "Chapadao de Ferro" chapadao.store type: 'beverages' # stores this in the "beverages" bucket type coffees.get 'chapadao' # raises error, not found coffees.get 'chapadao', type: 'beverages' # succeeds chapadao.reload # raises error, not found chapadao.reload type: 'beverages' # succeeds chapadao.delete # silently fails to delete it coffees.delete 'chapadao' # silently fails to delete it chapadao.delete type: 'beverages' # deletes it coffees.delete 'chapadao', type: 'beverages' # deletes it ``` ## Map-Reduce Example ``` ruby # Assuming you've already instantiated a client, get the album titles for The Beatles results = Riak::MapReduce.new(client). add("artists","Beatles"). link(:bucket => "albums"). map("function(v){ return [JSON.parse(v.values[0].data).title]; }", :keep => true).run p results # => ["Please Please Me", "With The Beatles", "A Hard Day's Night", # "Beatles For Sale", "Help!", "Rubber Soul", # "Revolver", "Sgt. Pepper's Lonely Hearts Club Band", "Magical Mystery Tour", # "The Beatles", "Yellow Submarine", "Abbey Road", "Let It Be"] ``` ## Riak Search Examples This client supports the new Riak Search 2 (codenamed "Yokozuna"). For more information about Riak Search, see [the Riak documentation](http://docs.basho.com/riak/latest/dev/using/search/). This documentation assumes there's a `yokozuna` bucket type created and activated. ``` ruby # Create a client and bucket. client = Riak::Client.new bucket_type = client.bucket_type 'yokozuna' bucket = bucket_type.bucket 'pizzas' # Create an index and add it to a typed bucket. Setting the index on the bucket # may fail until the index creation has propagated. index = Riak::Search::Index.new 'pizzas' index.exist? #=> false index.create! client.set_bucket_props bucket, {search_index: 'pizzas'}, 'yokozuna' # Store some records for indexing meat = bucket.new 'meat' meat.data = {toppings_ss: %w{pepperoni ham sausage}} meat.store type: 'yokozuna' hawaiian = bucket.new 'hawaiian' hawaiian.data = {toppings_ss: %w{ham pineapple}} hawaiian.store type: 'yokozuna' # Search the pizzas index for hashes that have a "ham" entry in the toppings_ss array query = Riak::Search::Query.new client, index, 'toppings_ss:ham' query.rows = 5 # return the first five pizzas result = query.results # returns a ResultsCollection object result.length # number of results returned result.num_found # total number of results found, including ones not returned pizza_result = result.first # a ResultDocument of the first pizza pizza_result.score # score of the match pizza_result.key # also pizza.bucket and pizza.bucket_type pizza = pizza_result.robject # load the actual RObject for the match ``` ## Secondary Index Examples Riak supports secondary indexes. Secondary indexing, or "2i," gives you the ability to tag objects with multiple queryable values at write time, and then query them later. * [Using Secondary Indexes](http://docs.basho.com/riak/latest/dev/using/2i/) * [Secondary Index implementation notes](http://docs.basho.com/riak/latest/dev/advanced/2i/) ### Tagging Objects Objects are tagged with a hash kept behind the `indexes` method. Secondary index storage logic is in `lib/riak/rcontent.rb`. ```ruby object = bucket.get_or_new 'cobb.salad' # Indexes end with the "_bin" suffix to indicate they're binary or string # indexes. They can have multiple values. object.indexes['ingredients_bin'] = %w{lettuce tomato bacon egg chives} # Indexes ending with the "_int" suffix are indexed as integers. They can # have multiple values too. object.indexes['calories_int'] = [220] # You must re-save the object to store indexes. object.store ``` ### Finding Objects Secondary index queries return a list of keys exactly matching a scalar or within a range. ```ruby # The Bucket#get_index method allows querying by scalar... bucket.get_index 'calories_int', 220 # => ['cobb.salad'] # or range. bucket.get_index 'calories_int', 100..300 # => ['cobb.salad'] # Binary indexes also support both ranges and scalars. bucket.get_index 'ingredients_bin', 'tomata'..'tomatz' # => ['cobb.salad'] # The collection from #get_index also provides a continuation for pagination: c = bucket.get_index 'ingredients_bin', 'lettuce', max_results: 5 c.length # => 5 c.continuation # => "g2gCbQAAA=" # You can use that continuation to get the next page of results: c2 = bucket.get_index 'ingredients_bin', 'lettuce', max_results: 5, continuation: c.continuation # More complicated operations may benefit by using the `SecondaryIndex` object: q = Riak::SecondaryIndex.new bucket, 'ingredients_bin', 'lettuce', max_results: 5 # SecondaryIndex objects give you access to the keys... q.keys # => ['cobb.salad', 'wedge.salad', 'buffalo_chicken.wrap', ...] # but can also fetch values for you in parallel. q.values # => [, true q2 = q.next_page ``` ## Riak 2 Data Types Riak 2 features new distributed data structures: counters, sets, and maps (containing counters, flags, maps, registers, and sets). These are implemented by the Riak database as Convergent Replicated Data Types. Riak data type support requires bucket types to be configured to support each top-level data type. If you're just playing around, use the [Riak Ruby Vagrant](https://github.com/basho-labs/riak-ruby-vagrant) setup to get started with the appropriate configuration and bucket types quickly. The examples below presume that the appropriate bucket types are named `counters`, `maps`, and `sets`; these bucket type names are the client's defaults. Viewing and changing the defaults is easy: ```ruby Riak::Crdt::DEFAULT_BUCKET_TYPES[:set] #=> "sets" Riak::Crdt::DEFAULT_BUCKET_TYPES[:set] = "a_cooler_set" ``` The top-level CRDT types have both immediate and batch mode. If you're doing multiple writes to a single top-level counter or set, or updating multiple map entries, batch mode will make fewer round-trips to Riak. Top-level CRDT types accept `nil` as a key. This allows Riak to assign a random key for them. Deleting CRDTs requires you to use the key-value API for the time being. ```ruby brews = Riak::Crdt::Set.new bucket, 'brews' brews.add 'espresso' brews.add 'aeropress' bucket.delete brews.key, type: brews.bucket_type ``` ### Counters Riak 2 integer counters have one operation: increment by an integer. ```ruby counter = Riak::Crdt::Counter.new bucket, key counter.value #=> 15 counter.increment counter.value #=> 16 counter.increment 3 counter.value #=> 19 counter.decrement counter.value #=> 18 ``` Counter operations can be batched: ```ruby counter.batch do |c| c.increment c.increment 5 end ``` ### Maps Riak 2 maps can contain counters, flags (booleans), registers (strings), sets, and other maps. Maps are similar but distinct from the standard Ruby `Hash`. Entries are segregated by both name and type, so you can have counters, registers, and sets inside a map that all have the same name. ```ruby map = Riak::Crdt::Map.new bucket, key map.counters['potatoes'].value #=> 5 map.sets['potatoes'].include? 'yukon gold' #=> true map.sets['cacti'].value #=> # map.sets['cacti'].remove 'prickly pear' map.registers['favorite butterfly'] = 'the mighty monarch' map.flags['pet cat'] = true map.maps['atlantis'].registers['location'] #=> 'kennedy space center' map.counters.delete 'thermometers' ``` Maps are a prime candidate for batched operations: ```ruby map.batch do |m| m.counters['hits'].increment m.sets['followers'].add 'basho_elevator' end ``` Frequently, you might want a map with a Riak-assigned name instead of one you come up with yourself: ```ruby map = Riak::Crdt::Map.new bucket, nil map.registers['coat_pattern'] = 'tabby' map.key #=> "2do4NvcurWhXYNQg8HoIR9zedJV" ``` ### Sets Sets are an unordered collection of entries. **PROTIP:** Ruby and Riak Ruby Client both have classes called `Set`. Be careful to refer to the Ruby version as `::Set` and the Riak client version as `Riak::Crdt::Set`. ```ruby set = Riak::Crdt::Set.new bucket, key set.members #=> # set.add "Newcastle" set.remove "London" set.include? "Leeds" #=> true ``` Sets support batched operations: ```ruby set.batch do |s| s.add "York" s.add "Aberdeen" s.remove "Newcastle" end ``` ### Client Implementation Notes The client code for these types is in the `Riak::Crdt` namespace, and mostly in the `lib/riak/crdt` directory. ## Riak 1.4 Counters For more information about 1.4-style counters in Riak, see [the Basho documentation](http://docs.basho.com/riak/latest/dev/references/http/counters/). Counter records are automatically persisted on increment or decrement. The initial default value is 0. ``` ruby # Firstly, ensure that your bucket is allow_mult set to true bucket = client.bucket "counters" bucket.allow_mult = true # You can create a counter by using the bucket's counter method counter = bucket.counter("counter-key-here") counter.increment => nil p counter.value 1 => 1 # Let's increment one more time and then retrieve it from the database counter.increment # Retrieval is similar to creation persisted_counter = Riak::Counter.new(bucket, "counter-key-here") p persisted_counter.value 2 => 2 # We can also increment by a specified number persisted_counter.increment(20) p persisted_counter.value 22 => 22 # Decrement works much the same persisted_counter.decrement persisted_counter.value => 21 persisted_counter.decrement(6) persisted_counter.value => 15 # Incrementing by anything other than integer will throw an ArgumentError persisted_counter.increment "nonsense" ArgumentError: Counters can only be incremented or decremented by integers. ``` That's about it. PN Counters in Riak are distributed, so each node will receive the proper increment/decrement operation. Enjoy using them. ## Instrumentation The Riak client has built-in event hooks for all major over-the-wire operations including: * riak.list_buckets * riak.list_keys * riak.set_bucket_props * riak.get_bucket_props * riak.clear_bucket_props * riak.get_index * riak.store_object * riak.get_object * riak.reload_object * riak.delete_object * riak.map_reduce * riak.ping Events are propogated using [ActiveSupport::Notifications](http://api.rubyonrails.org/classes/ActiveSupport/Notifications.html), provided by the [Instrumentable](https://github.com/siyegen/instrumentable) gem. ### Enabling Instrumentation is opt-in. If `instrumentable` is not available, instrumentation will not be available. To turn on instrumentation, simply require the `instrumentable` gem in your app's Gemfile: ```ruby gem 'instrumentable', '~> 1.1.0' ``` Then, to subscribe to events: ```ruby ActiveSupport::Notifications.subscribe(/^riak\.*/) do |name, start, finish, id, payload| name # => String, name of the event (such as 'riak.get_object' from above) start # => Time, when the instrumented block started execution finish # => Time, when the instrumented block ended execution id # => String, unique ID for this notification payload # => Hash, the payload end ``` The payload for each event contains the following keys: * `:client_id`: The client_id of the Riak client * `:_method_args`: The array of method arguments for the instrumented method. For instance, for `riak.get_object`, this value would resemble `[, 'key', {}]` ## Running Specs We aim to have a comprehensive and fast set of tests, implemented using a modern, well-supported version of RSpec. These tests include both unit specs for individual classes, and integration specs that ensure the client works properly with an actual Riak instance. The [Riak Ruby Vagrant][1] virtual machine's Riak configuration is normally used to test this client in development. Once it's up and running, configure the Ruby `test_client.yml` on the host machine to connect to `pb_port: 17017` and test away. [1]: https://github.com/basho-labs/riak-ruby-vagrant Configuring the Riak node the tests connect to is done via the `spec/support/test_client.yml` file, which is loaded into a Ruby hash with symbolized keys, and passed to `Riak::Client.new`. ```yml # test_client.yml pb_port: 10017 # UNCOMMENT AUTHENTICATION SECTION WHEN RIAK HAS SECURITY ENABLED # authentication: # user: user # password: password # ca_file: spec/support/certs/ca.crt ``` ### Spec dependencies Specs depend on the following Riak configurations: * The **LevelDB backend** is necessary for testing secondary indexes. * **allow_mult** is required for many features: conflict resolution, and legacy counters among them. * **Riak Search 2.0** ("Yokozuna") must be configured for testing full-text search. The following bucket types are used during testing: ```shell riak-admin bucket-type create counters '{"props":{"datatype":"counter", "allow_mult":true}}' riak-admin bucket-type create other_counters '{"props":{"datatype":"counter", "allow_mult":true}}' riak-admin bucket-type create maps '{"props":{"datatype":"map", "allow_mult":true}}' riak-admin bucket-type create sets '{"props":{"datatype":"set", "allow_mult":true}}' riak-admin bucket-type create yokozuna '{"props":{}}' riak-admin bucket-type activate other_counters riak-admin bucket-type activate counters riak-admin bucket-type activate maps riak-admin bucket-type activate sets riak-admin bucket-type activate yokozuna ``` Client tests run both with and without security enabled, as we have to test several positive and negative paths. The tests broadly depend on these users and roles: ```shell riak-admin security add-user user password=password riak-admin security add-user certuser riak-admin security add-source user 0.0.0.0/0 password riak-admin security add-source certuser 0.0.0.0/0 certificate riak-admin security grant riak_kv.get,riak_kv.put,riak_kv.delete,\ riak_kv.index,riak_kv.list_keys,riak_kv.list_buckets,\ riak_core.get_bucket,riak_core.set_bucket,\ riak_core.get_bucket_type,riak_core.set_bucket_type,\ search.admin,search.query,riak_kv.mapreduce on any to user ``` ## How to Contribute * Fork the project on [Github](http://github.com/basho/riak-ruby-client). If you have already forked, use `git pull --rebase` to reapply your changes on top of the mainline. Example: ``` bash $ git checkout master $ git pull --rebase basho master ``` * Copy spec/support/test_server.yml.example to spec/support/test_server.yml and change that file according to your local installation of riak. * Create a topic branch. If you've already created a topic branch, rebase it on top of changes from the mainline "master" branch. Examples: * New branch: ``` bash $ git checkout -b topic ``` * Existing branch: ``` bash $ git rebase master ``` * Write an RSpec example or set of examples that demonstrate the necessity and validity of your changes. **Patches without specs will most often be ignored. Just do it, you'll thank me later.** Documentation patches need no specs, of course. * Make your feature addition or bug fix. Make your specs and stories pass (green). * Run the suite using multiruby or rvm to ensure cross-version compatibility. * Cleanup any trailing whitespace in your code (try @whitespace-mode@ in Emacs, or "Remove Trailing Spaces in Document" in the "Text" bundle in Textmate). You can use the `clean_whitespace` Rake task if you like. * Commit, do not mess with Rakefile. If related to an existing issue in the [tracker](http://github.com/basho/ruby-riak-client/issues), include "Closes #X" in the commit message (where X is the issue number). * Send a pull request to the Basho repository. ## License & Copyright Copyright ©2010-2015 Sean Cribbs and Basho Technologies, Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0) Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. ## Auxillary Licenses The included photo (spec/fixtures/cat.jpg) is Copyright ©2009 [Sean Cribbs](http://seancribbs.com/), and is licensed under the [Creative Commons Attribution Non-Commercial 3.0](http://creativecommons.org/licenses/by-nc/3.0) license. !["Creative Commons"](http://i.creativecommons.org/l/by-nc/3.0/88x31.png)