07b162fb5b
The doc pages were slightly adjusted during migration not to mention Scylla Enterprise and to fix some whitespace issues.
133 lines
4.0 KiB
ReStructuredText
133 lines
4.0 KiB
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=============================
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Defining Workload Attributes
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=============================
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Introduction
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-------------
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A typical database has more than one :term:`workload <workload>` running simultaneously with a different acceptable level of latency and
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throughput. By defining the attributes of each workload, you can specify how ScyllaDB will handle requests depending on
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the workload to which they are assigned.
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You can define a workload's attribute using the *service level* concept. The service level CQL commands allow you to attach
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attributes to users and roles. When a user logs into the system, all of the attributes attached to that user and to the roles
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granted to that user are combined and become a set of workload attributes.
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See :ref:`Service Level Management <workload-priorization-service-level-management>` for more information about service levels.
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Prerequisites
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---------------
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* An :doc:`authenticated </operating-scylla/security/runtime-authentication>` and :doc:`authorized </operating-scylla/security/enable-authorization>` user
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* At least one :ref:`role created <create-role-statement>`.
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Procedure
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------------
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#. Create a service level with the desired attribute.
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.. code-block:: cql
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CREATE SERVICE LEVEL <service_level_name> WITH <attribute> [ AND <attribute>];
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For example:
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.. code-block:: cql
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CREATE SERVICE LEVEL sl2 WITH timeout = 500ms AND workload_type=interactive;
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See :ref:`Available Attributes <workload-attributes-available-attributes>`.
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#. Assign a service level to a role or user:
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.. code-block:: cql
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ATTACH SERVICE_LEVEL <service_level_name> TO <role_name|user_name>;
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For example:
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.. code-block:: cql
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ATTACH SERVICE LEVEL sl2 TO scylla;
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You can modify the service level attributes with the ``ALTER SERVICE LEVEL`` command:
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.. code-block:: cql
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ALTER SERVICE LEVEL <service_level_name> WITH <attribute> [ AND <attribute>];
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For example:
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.. code-block:: cql
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ALTER SERVICE LEVEL sl2 WITH timeout = null;
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.. _workload-attributes-available-attributes:
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Available Attributes
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-----------------------
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.. list-table::
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:widths: 30 70
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:header-rows: 1
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* - Attribute
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- Details
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* - ``timeout``
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- :ref:`Specifying Service Level Timeout <workload-attributes-timeout>`
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* - ``workload_type``
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- :ref:`Specifying Workload Type<workload-attributes-workload-type>`
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.. _workload-attributes-timeout:
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Specifying Service Level Timeout
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-----------------------------------
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You can specify the timeout for a service level (in milliseconds or seconds) with the ``timeout`` attribute.
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For example:
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.. code-block:: cql
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CREATE SERVICE LEVEL primary WITH timeout = 30ms;
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Specifying the timeout value is useful when your workloads have different acceptable latency levels.
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.. _workload-attributes-workload-type:
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Specifying Workload Type
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----------------------------
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You can specify the workload type for a service level with the ``workload_type`` attribute.
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For example:
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.. code-block:: cql
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CREATE SERVICE LEVEL secondary WITH workload_type = 'batch';
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Specifying the workload type allows ScyllaDB to handle sessions more efficiently (for example, depending on whether the workload is
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sensitive to latency).
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Available Workload Types
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^^^^^^^^^^^^^^^^^^^^^^^^^^^
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.. list-table::
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:widths: 20 80
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:header-rows: 1
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* - Workload type
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- Description
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* - ``unspecified``
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- A generic workload without any specific characteristics (default).
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* - ``interactive``
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- A workload sensitive to latency, expected to have high/unbounded concurrency, with dynamic characteristics, :doc:`OLTP </features/workload-prioritization>`. For example, a workload assigned to users clicking on a website and generating events with their clicks.
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* - ``batch``
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- A workload for processing large amounts of data, not sensitive to latency, expected to have fixed concurrency, :doc:`OLAP </features/workload-prioritization>`. For example, a workload assigned to processing billions of historical sales records to generate statistics.
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