org.hawkular.metrics.tasks.api.Task2 Maven / Gradle / Ivy
/*
* Copyright 2014-2015 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* 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
*
* 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.
*/
package org.hawkular.metrics.tasks.api;
import java.util.Map;
import java.util.UUID;
/**
* @author jsanda
*/
public interface Task2 {
/**
* This is essentially a primary key that uniquely identifies a task.
*/
UUID getId();
/**
*
* The group key provides a way to logically and physically group tasks. In conjunction with the
* {@link #getOrder() priority} it can be used to control the order of execution of tasks which is desirable
* when there are interdependencies between tasks. For example, suppose we have a task, T1, that aggregates data
* from multiple time series to produce a new time series. Then we have a task, T2, that aggregates the data from
* the time series produced by T2. T2 in effect depends on T1. They should use the same group key.
*
*
* For Hawkular the group key will generally be the tenant ID. It is a good choice because tenants and all of their
* data are isolated from one another.
*
*
* In terms of implementation, all tasks with the same group key will be stored in the same queue shard, which
* means that they will all be stored within the same physical partition. This should be taken into consideration
* when choosing a group key because you do not want to wind up with queue shards/partitions that are excessively
* large.
*
*/
String getGroupKey();
/**
* Identifies the type of task. Multiple tasks can have the same name.
*/
String getName();
/**
* Defines the order of execution of tasks within a group. Lower values are executed first. Note that this
* ordering only applies to tasks within the same group, which is defined by the {@link #getGroupKey() group key}.
*/
int getOrder();
/**
* An optional, arbitrary set of key/value parameters that the task receives upon execution.
*/
Map getParameters();
/**
* Defines the execution policy of the task, like when the task is scheduled to execute, how many times it should
* execute, etc.
*/
Trigger getTrigger();
}