/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Sep 30, 2010
*/
package com.bigdata.bop.cost;
import java.io.Serializable;
/**
* A cost model of the disk.
*
* @todo Develop disk models for SAS,SATA,SSD and various RAID configurations,
* including the #of spindles in the RAID array.
* @todo Develop disk models for SAN, NAS, NFS, parallel file systems, etc.
* @todo Conditionally copy the desired disk model parameters into the fields
* above to see the performance estimates for a given configuration.
* @todo The scattered and sustained write rates can be estimated from the
* transfer rate. However, SCSI does much better than SATA when it can
* reorder the writes for improved locality.
*/
public class DiskCostModel implements Serializable {
/**
* @todo should be either Externalizable and explicitly managed versioning
* or Serializable with a public interface for versioning.
*/
private static final long serialVersionUID = 1L;
public static final DiskCostModel DEFAULT = new DiskCostModel(10d, 41943040);
/**
* The average disk seek time (milliseconds).
*/
final public double seekTime;
/**
* The average disk transfer rate (megabytes per second).
*/
final public double transferRate;
/**
*
* @param seekTime
* The average disk seek time (milliseconds).
* @param transferRate
* The average disk transfer rate (megabytes per second).
*/
public DiskCostModel(double seekTime, double transferRate) {
this.seekTime = seekTime;
this.transferRate = transferRate;
}
}