com.elastisys.scale.cloudpool.commons.basepool.config.ScaleInConfig Maven / Gradle / Ivy

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Common utility classes for building cloud pools.
There is a newer version: 5.2.3
package com.elastisys.scale.cloudpool.commons.basepool.config;

import static com.google.common.base.Objects.equal;
import static com.google.common.base.Preconditions.checkArgument;

import com.elastisys.scale.cloudpool.commons.scaledown.VictimSelectionPolicy;
import com.elastisys.scale.commons.json.JsonUtils;
import com.google.common.base.Objects;
import com.google.common.collect.Range;

/**
 * The section of a {@link BaseCloudPoolConfig} that describes how to
 * decommission servers (on scale-in).
 *
 * @see BaseCloudPoolConfig
 */
public class ScaleInConfig {
    /** Policy for selecting which server to terminate. */
    private final VictimSelectionPolicy victimSelectionPolicy;

    /**
     * How many seconds prior to the next instance hour an acquired machine
     * instance should be scheduled for termination. This should be set to a
     * conservative and safe value to prevent the machine from being billed for
     * an additional hour. A value of zero is used to specify immediate
     * termination when a scale-down is ordered.
     */
    private final Integer instanceHourMargin;

    /**
     * Creates a new {@link ScaleInConfig}.
     *
     * @param victimSelectionPolicy
     *            Policy for selecting which server to terminate.
     * @param instanceHourMargin
     *            How many seconds prior to the next instance hour an acquired
     *            machine instance should be scheduled for termination. This
     *            should be set to a conservative and safe value to prevent the
     *            machine from being billed for an additional hour. A value of
     *            zero is used to specify immediate termination when a
     *            scale-down is ordered.
     */
    public ScaleInConfig(VictimSelectionPolicy victimSelectionPolicy, int instanceHourMargin) {
        this.victimSelectionPolicy = victimSelectionPolicy;
        this.instanceHourMargin = instanceHourMargin;
    }

    /**
     * Policy for selecting which server to terminate.
     *
     * @return
     */
    public VictimSelectionPolicy getVictimSelectionPolicy() {
        return this.victimSelectionPolicy;
    }

    /**
     * How many seconds prior to the next instance hour an acquired machine
     * instance should be scheduled for termination. This should be set to a
     * conservative and safe value to prevent the machine from being billed for
     * an additional hour. A value of zero is used to specify immediate
     * termination when a scale-down is ordered.
     *
     * @return
     */
    public Integer getInstanceHourMargin() {
        return this.instanceHourMargin;
    }

    public void validate() throws IllegalArgumentException {
        checkArgument(this.victimSelectionPolicy != null, "victim selection policy cannot be null");
        checkArgument(Range.closedOpen(0, 3600).contains(this.instanceHourMargin),
                "instance hour margin must be in interval [0, 3600)");
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(this.victimSelectionPolicy, this.instanceHourMargin);
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof ScaleInConfig) {
            ScaleInConfig that = (ScaleInConfig) obj;
            return equal(this.victimSelectionPolicy, that.victimSelectionPolicy)
                    && equal(this.instanceHourMargin, that.instanceHourMargin);
        }
        return false;
    }

    @Override
    public String toString() {
        return JsonUtils.toPrettyString(JsonUtils.toJson(this));
    }
}