Provisioning Cluster Resources

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    Provisioning cluster resources is managed at the collection or bucket level, depending upon the service affected. Common use cases are outlined here, less common use cases are covered in the API docs.

    The primary means for managing clusters is through the Couchbase Web UI which provides an easy to use interface for adding, removing, monitoring and modifying buckets. In some instances you may wish to have a programmatic interface. For example, if you wish to manage a cluster from a setup script, or if you are setting up buckets in test scaffolding.

    The Scala SDK also comes with some convenience functionality for common Couchbase management requests.

    Management operations in the SDK may be performed through several interfaces depending on the object:

    When using a Couchbase version earlier than 6.5, you must create a valid Bucket connection using Cluster.bucket(name) before you can use cluster-level managers.

    Bucket Management

    The BucketManager interface may be used to create and delete buckets from the Couchbase cluster.

    The CreateBucketSettings and BucketSettings classes are used for creating and updating buckets. BucketSettings is also used for exposing information about existing buckets.

    Note that any property that is not explicitly set when building the bucket settings will use the default value. In the case of the update, this is not necessarily the currently configured value, so you should be careful to set all properties to their correct expected values when updating an existing bucket configuration.

    Here is the list of parameters available for CreateBucketSettings and BucketSettings. The "Updatable" column indicates whether the parameter may only be specified when creating a bucket, or whether it may be updated after creation.

    Name Type Description Updatable

    name

    String

    The name of the bucket, required for creation.

    false

    flushEnabled

    boolean

    Enables flushing to be performed on this bucket (see the Flushing Buckets section below).

    true

    replicaIndexes

    boolean

    Whether or not to replicate indexes.

    false

    ramQuotaMB

    int

    How much memory should each node use for the bucket, required for creation.

    true

    numReplicas

    int

    The number of replicas to use for the bucket.

    true

    bucketType

    BucketType

    The type of the bucket, required for creation.

    false

    ejectionMethod

    EjectionMethod

    The type of the ejection to use for the bucket, defaults to ValueOnly.

    true (note: changing will cause the bucket to restart causing temporary inaccessibility)

    maxTTL

    int

    The default maximum time-to-live to apply to documents in the bucket. (note: This option is only available for Couchbase and Ephemeral buckets in Couchbase Enterprise Edition.)

    true

    compressionMode

    CompressionMode

    The compression mode to apply to documents in the bucket. (note: This option is only available for Couchbase and Ephemeral buckets in Couchbase Enterprise Edition.)

    true

    conflictResolutionType

    ConflictResolutionType

    The conflict resolution type to apply to conflicts on the bucket, defaults to SequenceNumber

    false

    The following example creates a "hello" bucket:

    val bucketManager: BucketManager = cluster.buckets
    
    val result: Try[Unit] = bucketManager.create(
      CreateBucketSettings("hello", ramQuotaMB = 1024)
        .flushEnabled(false)
        .replicaIndexes(false)
        .numReplicas(1)
        .bucketType(BucketType.Couchbase)
        .conflictResolutionType(ConflictResolutionType.SequenceNumber))
    
    result match {
      case Success(_) =>
      case Failure(err) => print(s"Failed with error $err")
    }

    We can now get this bucket and update it to enable Flush:

    val result: Try[Unit] = bucketManager.getBucket("hello")
      .flatMap((bucket: BucketSettings) => {
        val updated = bucket.toCreateBucketSettings.flushEnabled(true)
        bucketManager.updateBucket(updated)
      })
    
    // Result error-checking omitted for brevity

    Once you no longer need to use the bucket, you can remove it:

    val result: Try[Unit] = bucketManager.dropBucket("hello")
    
    // Result error-checking omitted for brevity

    Flushing Buckets

    When a bucket is flushed, all content is removed. Because this operation is potentially dangerous it is disabled by default for each bucket. Bucket flushing may be useful in test environments where it becomes a simpler alternative to removing and creating a test bucket. You may enable bucket flushing on a per-bucket basis using the Couchbase Web Console or when creating a bucket.

    You can flush a bucket in the SDK by using the Flush method:

    val result: Try[Unit] = bucketManager.flushBucket("hello")
    
    result match {
      case Success(_) =>
      case Failure(err: BucketNotFlushableException) =>
        print("Flushing not enabled on this bucket")
      case Failure(err) => print(s"Failed with error $err")
    }

    Collection Management

    The CollectionManager interface may be used to create and delete scopes and collections from the Couchbase cluster. It is instantiated through the Bucket.collections() method. Refer to the CollectionManager and AsyncCollectionManager API documentation for further details.

    val collectionMgr = bucket.collections;

    You can create a scope:

    collectionMgr.createScope("example-scope") match {
      case Success(_) =>
        println("Created scope OK")
      case Failure(err: ScopeExistsException) =>
        println("scope already exists")
      case Failure(err) =>
        println(err)
    }

    You can then create a collection within that scope:

    val spec = CollectionSpec("example-collection", "example-scope");
    
    collectionMgr.createCollection(spec)  match {
      case Success(_) =>
        println("Created collection OK")
      case Failure(err: ScopeNotFoundException) =>
        println("scope not found")
      case Failure(err: CollectionExistsException) =>
        println("collection already exists")
      case Failure(err) =>
        println(err)
    }

    Finally, you can drop unneeded collections and scopes:

    collectionMgr.dropCollection(spec)
    match {
      case Success(_) =>
        println("Dropped collection OK")
      case Failure(err: ScopeNotFoundException) =>
        println("scope not found")
      case Failure(err: CollectionNotFoundException) =>
        println("collection not found")
      case Failure(err) =>
        println(err)
    }
    
    [data-source-url=https://github.com/couchbase/docs-sdk-scala/blob/30c7412ee27b00803fd8a8fce2e5beb74bec404a/modules/howtos/examples/CollectionManagerExample.scala#L110-L118]
    collectionMgr.dropScope("example-scope")
    match {
      case Success(_) =>
        println("Dropped scope OK")
      case Failure(err: ScopeNotFoundException) =>
        println("scope not found")
      case Failure(err) =>
        println(err)
    }

    Note that the most minimal permissions to create and drop a Scope or Collection is Manage Scopes along with Data Reader.

    You can create users with the appropriate RBAC programmatically:

    val users = cluster.users
    val user = User("scopeAdmin")
      .password("password")
      .roles(
        new Role("scope_admin", Some("travel-sample")),
        new Role("data_reader", Some("travel-sample")))
    users.upsertUser(user).get

    Index Management

    In general, you will rarely need to work with Index Managers from the SDK. For those occasions when you do, index management operations can be performed with the following interfaces:

    You will find some of these described in the following section.

    QueryIndexManager

    The QueryIndexManager interface contains the means for managing indexes used for queries.
    It can be accessed via Cluster.queryIndexes.

    val cluster = Cluster.connect("localhost", "Administrator", "password").get
    val queryIndexMgr = cluster.queryIndexes

    Applications can use this manager to perform operations such as creating, deleting, and fetching primary or secondary indexes:

    • A Primary index is built from a document’s key and is mostly suited for simple queries.

    • A Secondary index is the most commonly used type, and is suited for complex queries that require filtering on document fields.

    To perform query index operations, the provided user must either be an Admin or assigned the Query Manage Index role. See the Roles page for more information.

    The example below shows how to create a simple primary index, restricted to a named scope and collection, by calling the createPrimaryIndex() method. Note that you cannot provide a named scope or collection separately, both must be set for the QueryIndexManager to create an index on the relevant keyspace path.

    Creating a primary index
    val result: Try[Unit] = queryIndexMgr.createPrimaryIndex(
      "travel-sample",
      // Set this if you wish to use a custom name
      // indexName = Option("custom_name"),
      scopeName = Option("tenant_agent_01"),
      collectionName = Option("users"),
      ignoreIfExists = true
    )
    result match {
      case Success(_)   =>
      case Failure(err) => throw err
    }

    When a primary index name is not specified, the SDK will create the index as #primary by default. However, if you wish to provide a custom name, you can simply pass an indexName argument to createPrimaryIndex().

    You may have noticed that the example also sets the ignoreIfExists boolean flag. When set to true, this optional argument ensures that an error is not thrown if an index under the same name already exists.

    Creating a secondary index follows a similar approach, with some minor differences:

    Creating a secondary index
    val result: Try[Unit] = queryIndexMgr.createIndex(
      "travel-sample",
      "tenant_agent_01_users_email",
      Array("preferred_email"),
      scopeName = Option("tenant_agent_01"),
      collectionName = Option("users")
    )
    result match {
      case Success(_) =>
      case Failure(err: IndexExistsException) => println("Index already exists!")
      case Failure(err) => throw err
    }

    The createIndex() method requires an index name to be provided, along with the fields to create the index on. Like the primary index, you can restrict a secondary index to a named scope and collection.

    Indexes can easily take a long time to build if they contain a lot of documents. In these situations, it is more ideal to build indexes in the background. To achieve this we can use the deferred boolean option, and set it to true.

    Deferring index creation
    // Create a deferred index
    var result: Try[Unit] = queryIndexMgr.createIndex(
      "travel-sample",
      "tenant_agent_01_users_phone",
      Array("preferred_phone"),
      scopeName = Option("tenant_agent_01"),
      collectionName = Option("users"),
      deferred = Option(true)
    )
    result match {
      case Success(_) =>
      case Failure(err: IndexExistsException) => println("Index already exists!")
      case Failure(err) => throw err
    }
    
    // Build any deferred indexes within `travel-sample`.tenant_agent_01.users
    result = queryIndexMgr.buildDeferredIndexes(
      "travel-sample",
      scopeName = Option("tenant_agent_01"),
      collectionName = Option("users")
    )
    result match {
      case Success(_)   =>
      case Failure(err) => throw err
    }
    
    // Wait for indexes to come online
    result = queryIndexMgr.watchIndexes(
      "travel-sample",
      Array("tenant_agent_01_users_phone"),
      Duration("30 seconds"),
      scopeName = Option("tenant_agent_01"),
      collectionName = Option("users")
    )
    result match {
      case Success(_) =>
      case Failure(err: IndexExistsException) => println("Index already exists!")
      case Failure(err) => throw err
    }

    To delete a query index you can use the dropIndex() or dropPrimaryIndex() methods. Which one you use depends on the type of query index you wish to drop from the database.

    Deleting an index
     // Drop a primary index
     var result: Try[Unit] = queryIndexMgr.dropPrimaryIndex(
       "travel-sample",
       scopeName = Option("tenant_agent_01"),
       collectionName = Option("users")
     )
     result match {
       case Success(_)   =>
       case Failure(err) => throw err
     }
    
     // Drop a secondary index
    result = queryIndexMgr.dropIndex(
       "travel-sample",
       "tenant_agent_01_users_email",
       scopeName = Option("tenant_agent_01"),
       collectionName = Option("users")
     )
     result match {
       case Success(_)   =>
       case Failure(err) => throw err
     }

    View Management

    Views are stored in design documents. The SDK provides convenient methods to create, retrieve, and remove design documents. To set up views, you create design documents that contain one or more view definitions, and then insert the design documents into a bucket. Each view in a design document is represented by a name and a set of MapReduce functions. The mandatory map function describes how to select and transform the data from the bucket, and the optional reduce function describes how to aggregate the results.

    In the SDK, design documents are represented by the DesignDocument and View structs. All operations on design documents are performed on the ViewIndexManager instance:

    val viewIndexManager: ViewIndexManager = bucket.viewIndexes

    The following example upserts a design document with two views:

    val view1 = View("function (doc, meta) { if (doc.type == 'landmark') { emit([doc.country, doc.city], null); } }")
    val view2 = View("function (doc, meta) { if (doc.type == 'landmark') { emit(doc.activity, null); } }", reduce = Some("_count"))
    
    val designDoc = DesignDocument("landmarks",
      Map("by_country" -> view1, "by_activity " -> view2))
    
    viewIndexManager.upsertDesignDocument(designDoc, DesignDocumentNamespace.Development)

    When you want to update an existing document with a new view (or a modification of a view’s definition), you can use the upsertDesignDocument method.

    However, this method needs the list of views in the document to be exhaustive, meaning that if you just create the new view definition as previously and add it to a new design document that you upsert, all your other views will be erased!

    The solution is to perform a getDesignDocument, add your view definition to the DesignDocument’s views list, then upsert it. This also works with view modifications, provided the change is in the map or reduce functions (just reuse the same name for the modified view), or for deletion of one out of several views in the document.

    Note the use of DesignDocumentNamespace.Development, the other option is DesignDocumentNamespace.Production. This parameter specifies whether the design document should be created as development, or as production — with the former running over only a small fraction of the documents.

    Now that we’ve created a design document we can fetch it:

    val designDoc: Try[DesignDocument] =
      viewIndexManager.getDesignDocument("landmarks", DesignDocumentNamespace.Development)

    We’ve created the design document using DesignDocumentNamespace.Development and now want to push it to production, we can do this with:

    val publishResult = viewIndexManager.publishDesignDocument("landmarks")
    
    // Result error-handling omitted for brevity

    To remove this design document:

    val dropResult = viewIndexManager.dropDesignDocument("landmarks", DesignDocumentNamespace.Production)
    // Result error-handling omitted for brevity