Creating Objects in Riak KV

Writes in Riak KV (storing or modifying objects) are like HTTP PUT requests. Here is the basic form of writes:

PUT /types/<type>/buckets/<bucket>/keys/<key>

# If you're using HTTP to interact with Riak, you can also use POST

As an example, let’s store an object containing information about a dog named Rufus. We’ll store that object in the key rufus in the bucket dogs, which bears the animals bucket type.

The object we’re storing will be very simple, just a basic text snippet of something that Rufus might say. Let’s build the object and then store it.

String quote = "WOOF!";
Namespace bucket = new Namespace("animals", "dogs");
Location rufusLocation = new Location(bucket, "rufus");
RiakObject rufusObject = new RiakObject()
        .setContentType("text/plain")
        .setValue(BinaryValue.create(quote));
StoreValue storeOp = new StoreValue.Builder(rufusObject)
        .withLocation(rufusLocation)
        .build();
client.execute(storeOp);

bucket = client.bucket_type('animals').bucket('dogs')
obj = Riak::RObject.new(bucket, 'rufus')
obj.content_type = 'text/plain'
obj.data = 'WOOF!'
obj.store

$response = (new \Riak\Riak\Command\Builder\StoreObject($riak))
  ->buildLocation('rufus', 'users', 'animals')
  ->buildObject('WOOF!', 'text/plain')
  ->build()
  ->execute();

bucket = client.bucket_type('animals').bucket('dogs')
obj = RiakObject(client, bucket, 'rufus')
obj.content_type = 'text/plain'
obj.data = 'WOOF!'
obj.store()

var id = new RiakObjectId("animals", "dogs", "rufus")
var obj = new RiakObject(id, "WOOF!", "text/plain");
var result = client.Put(obj);

var riakObj = new Riak.Commands.KV.RiakObject();
riakObj.setContentType('text/plain');
riakObj.setValue('WOOF!');
client.storeValue({
    bucketType: 'animals', bucket: 'dogs', key: 'rufus',
    value: riakObj
}, function (err, rslt) {
    if (err) {
        throw new Error(err);
    }
});

obj := &riak.Object{
    ContentType:     "text/plain",
    Charset:         "utf-8",
    ContentEncoding: "utf-8",
    Value:           []byte("WOOF!"),
}

cmd, err := riak.NewStoreValueCommandBuilder().
    WithBucketType("animals").
    WithBucket("dogs").
    WithKey("rufus").
    WithContent(obj).
    Build()

if err != nil {
    fmt.Println(err.Error())
    return
}

if err := cluster.Execute(cmd); err != nil {
    fmt.Println(err.Error())
    return
}

svc := cmd.(*riak.StoreValueCommand)
rsp := svc.Response

Notice that we specified both a value for the object, i.e. WOOF!, and a content type, text/plain. See content types for more information.

Now, you run the same read operation as in Reading Objects. If the write operation was successful, you should be able to successfully read the object. Please note that the operation will fail if you don’t first create the bucket-type animals as per the page on bucket types.

Store an Object

Your application will often have its own method of generating the keys for its data, e.g. on the basis of timestamps. If so, storing that data is easy. The basic request looks like this.

PUT /types/TYPE/buckets/BUCKET/keys/KEY

# If you're using HTTP, POST can be used instead of PUT. The only
# difference between POST and PUT is that you should POST in cases where
# you want Riak to auto-generate a key. More on this can be found in the
# examples below.

There is no need to intentionally create buckets in Riak. They pop into existence when keys are added to them, and disappear when all keys have been removed from them. If you don’t specify a bucket’s type, the type default will be applied.

Write Parameters

Write requests support the following parameters:

Parameter	Default	Description
`w`	`quorum`	How many replicas to write to before returning a successful response
`pw`	`0`	How many primary vnodes must respond for a write to be deemed successful
`dw`	`quorum`	How many replicas to commit to durable storage before returning a successful response
`returnbody`	`false`	Whether to return the contents of the stored object

Here is an example of storing an object (another brief text snippet) under the key viper in the bucket dodge, which bears the type cars, with w set to 3:

Location viperKey = new Location(new Namespace("cars", "dodge"), "viper");
BinaryValue text = BinaryValue.create("vroom");
RiakObject obj = new RiakObject()
        .setContentType("text/plain")
        .setValue(text);
StoreValue store = new StoreValue.Builder(myKey, obj)
        .withOption(StoreOption.W, new Quorum(3))
        .build();
client.execute(store);

bucket = client.bucket_type('cars').bucket('dodge')
obj = Riak::RObject.new(bucket, 'viper')
obj.content_type = 'text/plain'
obj.raw_data = 'vroom'
obj.store(w: 3)

(new \Riak\Riak\Command\Builder\StoreObject($riak))
  ->buildLocation('viper', 'dodge', 'cars')
  ->buildObject('vroom', 'text/plain')
  ->withParameter('w', 3)
  ->build()
  ->execute();

bucket = client.bucket_type('cars').bucket('dodge')
obj = RiakObject(client, bucket, 'viper')
obj.content_type = 'text/plain'
obj.data = 'vroom'
obj.store(w=3)

var id = new RiakObjectId("cars", "dodge", "viper");
var obj = new RiakObject(id, "vroom", "text/plain");
var options = new RiakPutOptions();
options.SetW(new Quorum(3));
var result = client.Put(obj, options);

var riakObj = new Riak.Commands.KV.RiakObject();
riakObj.setContentType('text/plain');
riakObj.setValue('vroom');

var options = {
    bucketType: 'cars', bucket: 'dodge', key: 'viper',
    w: 3, value: riakObj
};
client.storeValue(options, function (err, rslt) {
    if (err) {
        throw new Error(err);
    }
});

Object = riakc_obj:new({<<"cars">>, <<"dodge">>},
                       <<"viper">>,
                       <<"vroom">>,
                       <<"text/plain">>,
                       [{w, 3}]).
riakc_pb_socket:put(Pid, Object).

obj := &riak.Object{
    ContentType:     "text/plain",
    Charset:         "utf-8",
    ContentEncoding: "utf-8",
    Value:           []byte("vroom"),
}

cmd, err := riak.NewStoreValueCommandBuilder().
    WithBucketType("cars").
    WithBucket("dodge").
    WithKey("viper").
    WithW(3).
    WithContent(obj).
    Build()

if err != nil {
    fmt.Println(err.Error())
    return
}

if err := cluster.Execute(cmd); err != nil {
    fmt.Println(err.Error())
    return
}

curl -XPUT \
  -H "Content-Type: text/plain" \
  -d "vroom" \
  http://localhost:8098/types/cars/buckets/dodge/keys/viper?w=3

Again, the above will only work if the cars bucket type has been created and activated.

Return Body

If returnbody is set to true, any of the response headers expected from a read request may be present. Like a GET request, 300 Multiple Choices may be returned if siblings existed or were created as part of the operation, and the response can be dealt with similarly.

Normal HTTP status codes (responses will vary for client libraries):

200 OK
204 No Content
300 Multiple Choices

For example, using the same object from above:

Location viperKey = new Location(new Namespace("cars", "dodge"), "viper");
BinaryValue text = BinaryValue.create("vroom");
RiakObject obj = new RiakObject()
        .setContentType("text/plain")
        .setValue(text);
StoreValue store = new StoreValue.Builder(myKey, obj)
        .withOption(StoreOption.W, new Quorum(3))
        .withOption(StoreOption.RETURN_BODY, true)
        .build();
client.execute(store);

bucket = client.bucket_type('cars').bucket('dodge')
obj = Riak::RObject.new(bucket, 'viper')
obj.content_type = 'text/plain'
obj.raw_data = 'vroom'
obj.store(w: 3, returnbody: true)

(new \Riak\Riak\Command\Builder\StoreObject($riak))
  ->buildLocation('viper', 'dodge', 'cars')
  ->buildObject('vroom', 'text/plain')
  ->withParameter('w', 3)
  ->withParameter('returnbody', 'true')
  ->build()
  ->execute();

bucket = client.bucket_type('cars').bucket('dodge')
obj = RiakObject(client, bucket, 'viper')
obj.content_type = 'text/plain'
obj.data = 'vroom'
obj.store(w=3, return_body=True)

var id = new RiakObjectId("cars", "dodge", "viper");
var obj = new RiakObject(id, "vroom", "text/plain");
var options = new RiakPutOptions();
options.SetW(new Quorum(3));
options.SetReturnBody(true);
var result = client.Put(obj, options);

var riakObj = new Riak.Commands.KV.RiakObject();
riakObj.setContentType('text/plain');
riakObj.setValue('vroom');

var options = {
    bucketType: 'cars', bucket: 'dodge', key: 'viper',
    w: 3, returnBody: true, value: riakObj
};
client.storeValue(options, function (err, rslt) {
    if (err) {
        throw new Error(err);
    }
    var riakObj = rslt.values.shift();
    var viper = riakObj.value;
    logger.info("dodge viper: %s", viper.toString('utf8'));
});

Object = riakc_obj:new({<<"cars">>, <<"dodge">>},
                       <<"viper">>,
                       <<"vroom">>,
                       <<"text/plain">>).
riakc_pb_socket:put(Pid, Object, [return_body]).

obj := &riak.Object{
    ContentType:     "text/plain",
    Charset:         "utf-8",
    ContentEncoding: "utf-8",
    Value:           []byte("vroom"),
}

cmd, err := riak.NewStoreValueCommandBuilder().
    WithBucketType("cars").
    WithBucket("dodge").
    WithKey("viper").
    WithW(3).
    WithContent(obj).
    WithReturnBody(true).
    Build()

if err != nil {
    fmt.Println(err.Error())
    return
}

if err := cluster.Execute(cmd); err != nil {
    fmt.Println(err.Error())
    return
}

curl -XPUT \
  -H "Content-Type: text/plain" \
  -d "vroom" \
  http://localhost:8098/types/cars/buckets/dodge/keys/viper?w=3&returnbody=true

Store a New Object and Assign a Random Key

If your application would rather leave key-generation up to Riak, issue a POST request to the bucket URL instead of a PUT to a bucket/key pair:

POST /types/TYPE/buckets/BUCKET/keys

If you don’t pass Riak a key name after the bucket, it will know to create one for you.

Supported headers are the same as for bucket/key write requests, though X-Riak-Vclock will never be relevant for these POST requests. Supported query parameters are also the same as for bucket/key PUT requests.

Normal status codes:

201 Created

This command will store an object in the bucket random_user_keys, which bears the bucket type users.

Namespace locationWithoutKey = new Namespace("users", "random_user_keys");
BinaryValue text = BinaryValue.create("{'user':'data'}");
RiakObject obj = new RiakObject()
        .setContentType("application/json")
        .setValue(text);
StoreValue store = new StoreValue.Builder(locationWithoutKey, obj)
        .build();
String key = client.execute(store).getLocation().getKeyAsString();

// The Java client will assign a random key along the following lines:
"ZPFF18PUqGW9efVou7EHhfE6h8a"

bucket = client.bucket_type('users').bucket('random_user_keys')
obj = Riak::RObject.new(bucket)
obj.content_type = 'application/json'
obj.raw_data = '{"user":"data"}'

obj.store

# The client will assign a key like the following:
obj.key
"GB8fW6DDZtXogK19OLmaJf247DN"

$response = (new \Riak\Riak\Command\Builder\StoreObject($riak))
  ->buildBucket('random_user_keys', 'users')
  ->buildJsonObject(['user'=>'data'])
  ->build()
  ->execute();

echo $response->getLocation()->getKey(); // GB8fW6DDZtXogK19OLmaJf247DN

bucket = client.bucket_type('users').bucket('random_user_keys')
obj = RiakObject(client, bucket)
obj.content_type = 'application/json'
obj.data = '{"user":"data"}'
obj.store()

obj.key

# The Python client will assign a random key along the following lines:
'ZPFF18PUqGW9efVou7EHhfE6h8a'

var id = new RiakObjectId("users", "random_user_keys", null);
var obj = new RiakObject(id, @"{'user':'data'}",
    RiakConstants.ContentTypes.ApplicationJson);
var rslt = client.Put(obj);
Debug.WriteLine(format: "Generated key: {0}", args: rslt.Value.Key);

// The .NET client will output a random key similar to this:
// Generated key: DWDsnpYSqOU363c0Bqe8hCwAM7Q

var user = {
    user: 'data'
};
var options = {
    bucketType: 'users', bucket: 'random_user_keys',
    returnBody: true, value: user
};
client.storeValue(options, function (err, rslt) {
    if (err) {
        throw new Error(err);
    }
    var riakObj = rslt.values.shift();
    var generatedKey = riakObj.getKey();
    logger.info("Generated key: %s", generatedKey);
});

// The Node.js client will output a random key similar to this:
// info: Generated key: VBAMoX0OOucymVCxeQEYzLzzAh2

Object = riakc_obj:new({<<"users">>, <<"random_user_keys">>}, undefined, <<"{'user':'data'}">>, <<"application/json">>).
riakc_pb_socket:put(Pid, Object).

%% The key can be retrieved from the output of the above call.
%% It will look something like this:

{ok,{riakc_obj,{<<"users">>,<<"random_user_keys">>},
               <<"EZ7pp4bpdfpZw0fPUdTUafveQjO">>,undefined,[],undefined,
               undefined}}

obj := &riak.Object{
    ContentType:     "application/json",
    Charset:         "utf-8",
    ContentEncoding: "utf-8",
    Value:           []byte("{'user':'data'}"),
}

cmd, err := riak.NewStoreValueCommandBuilder().
    WithBucketType("users").
    WithBucket("random_user_keys").
    WithContent(obj).
    Build()

if err != nil {
    fmt.Println(err.Error())
    return
}

if err := cluster.Execute(cmd); err != nil {
    fmt.Println(err.Error())
    return
}

svc := cmd.(*riak.StoreValueCommand)
rsp := svc.Response
fmt.Printf("Generated key: %v\n", rsp.GeneratedKey)

// Output:
// Generated key: QSHkZjFdWwfrxtKl3wtUhL2gz7N

curl -i -XPOST \
  -H "Content-Type: text/plain" \
  -d "this is a test" \
  http://localhost:8098/types/users/buckets/random_user_keys/keys

# In the output, you should see a Location header that will give you the
# location of the object in Riak, with the key at the end:

Location: /buckets/test/keys/G7FYUXtTsEdru4NP32eijMIRK3o