org.opennms.netmgt.rrd
Class RrdUtils

java.lang.Object
  org.opennms.netmgt.rrd.RrdUtils

public class RrdUtils
extends java.lang.Object

Provides static methods for interacting with round robin files. Supports JNI and JRobin based files and provides queuing for managing differences in collection speed and disk write speed. This behaviour is implemented using the Strategy pattern with a different RrdStrategy for JRobin and JNI as well as a Strategy that provides Queueing on top of either one. The following System properties select which strategy is in use.

 
  org.opennms.rrd.usejni: (defaults to true)
   true - use the existing RRDTool code via the JNI interface @see JniRrdStrategy
   false - use the pure java JRobin interface @see JRobinRrdStrategy
  
  org.opennms.rrd.usequeue: (defaults to true)
    use the queueing that allows collection to occur even though the disks are
    keeping up. @see QueuingRrdStrategy  
  
  
 

Constructor Summary

RrdUtils()

Method Summary

static java.io.InputStream	createGraph(java.lang.String command, java.io.File workDir) Creates an InputStream representing the bytes of a graph created from round robin data.
static boolean	createRRD(java.lang.String creator, java.lang.String directory, java.lang.String rrdName, int step, java.util.List dataSources, java.util.List rraList)
static boolean	createRRD(java.lang.String creator, java.lang.String directory, java.lang.String dsName, int step, java.lang.String dsType, int dsHeartbeat, java.lang.String dsMin, java.lang.String dsMax, java.util.List rraList) Create a round robin database file.
static java.lang.Double	fetchLastValue(java.lang.String rrdFile, int interval) This method issues an round robin fetch command to retrieve the last value of the datasource stored in the specified RRD file.
static java.lang.Double	fetchLastValueInRange(java.lang.String rrdFile, int interval, int range) This method issues an round robing fetch command to retrieve the last value of the datasource stored in the specified RRD file within given tolerance (which should be a multiple of the RRD interval).
static java.lang.String	getExtension()
static RrdStrategy	getStrategy()
static void	graphicsInitialize()
static void	initialize() Initializes the underlying round robin system and sets up the appropriate strategy.
static void	setStrategy(RrdStrategy strategy)
static void	updateRRD(java.lang.String owner, java.lang.String repositoryDir, java.lang.String rrdName, long timestamp, java.lang.String val) Add datapoints to a round robin database.
static void	updateRRD(java.lang.String owner, java.lang.String repositoryDir, java.lang.String rrdName, java.lang.String val) Add datapoints to a round robin database using the current system time as the timestamp for the values

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RrdUtils

public RrdUtils()

Method Detail

getStrategy

public static RrdStrategy getStrategy()

setStrategy

public static void setStrategy(RrdStrategy strategy)

initialize

public static void initialize()
                       throws RrdException

Initializes the underlying round robin system and sets up the appropriate strategy. The strategies are currently selected using System properties. This creates the appropriate RrdStrategy and calls its initialize method

Throws:

RrdException

graphicsInitialize

public static void graphicsInitialize()
                               throws RrdException

Throws:

RrdException

createRRD

public static boolean createRRD(java.lang.String creator,
                                java.lang.String directory,
                                java.lang.String dsName,
                                int step,
                                java.lang.String dsType,
                                int dsHeartbeat,
                                java.lang.String dsMin,
                                java.lang.String dsMax,
                                java.util.List rraList)
                         throws RrdException

Create a round robin database file. See the man page for rrdtool create for definitions of each of these.

Parameters:

creator - - A string representing who is creating this file for use in log msgs

directory - - The directory to create the file in

dsName - - The datasource name for use in the round robin database

step - - the step for the database

dsType - - the type for the datasource

dsHeartbeat - - the heartbeat for the datasouce

dsMin - - the minimum allowable value for the datasource

dsMax - - the maximum allowable value for the datasouce

rraList - - a List of the round robin archives to create in the database

Returns:

true if the file was actually created, false otherwise

Throws:

RrdException

createRRD

public static boolean createRRD(java.lang.String creator,
                                java.lang.String directory,
                                java.lang.String rrdName,
                                int step,
                                java.util.List dataSources,
                                java.util.List rraList)
                         throws RrdException

Throws:

RrdException

updateRRD

public static void updateRRD(java.lang.String owner,
                             java.lang.String repositoryDir,
                             java.lang.String rrdName,
                             java.lang.String val)
                      throws RrdException

Add datapoints to a round robin database using the current system time as the timestamp for the values

Parameters:

owner - the owner of the file. This is used in log messages

repositoryDir - the directory the file resides in

rrdName - the name for the rrd file.

val - a colon separated list of values representing the updates for datasources for this rrd

Throws:

RrdException

updateRRD

public static void updateRRD(java.lang.String owner,
                             java.lang.String repositoryDir,
                             java.lang.String rrdName,
                             long timestamp,
                             java.lang.String val)
                      throws RrdException

Add datapoints to a round robin database.

Parameters:

owner - the owner of the file. This is used in log messages

repositoryDir - the directory the file resides in

rrdName - the name for the rrd file.

timestamp - the timestamp in millis to use for the rrd update (this gets rounded to the nearest second)

val - a colon separated list of values representing the updates for datasources for this rrd

Throws:

RrdException

fetchLastValue

public static java.lang.Double fetchLastValue(java.lang.String rrdFile,
                                              int interval)
                                       throws java.lang.NumberFormatException,
                                              RrdException

This method issues an round robin fetch command to retrieve the last value of the datasource stored in the specified RRD file. The retrieved value returned to the caller. NOTE: This method assumes that each RRD file contains a single datasource.

Parameters:

rrdFile - RRD file from which to fetch the data.

interval - Thresholding interval (should equal RRD step size)

Returns:

Retrived datasource value as a java.lang.Double

Throws:

java.lang.NumberFormatException - if the retrieved value fails to convert to a double

RrdException

fetchLastValueInRange

public static java.lang.Double fetchLastValueInRange(java.lang.String rrdFile,
                                                     int interval,
                                                     int range)
                                              throws java.lang.NumberFormatException,
                                                     RrdException

This method issues an round robing fetch command to retrieve the last value of the datasource stored in the specified RRD file within given tolerance (which should be a multiple of the RRD interval). This is useful If you are not entirely sure when an RRD might have been updated, but you want to retrieve the last value which is not NaN NOTE: This method assumes that each RRD file contains a single datasource.

Parameters:

rrdFile - RRD file from which to fetch the data.

interval - Thresholding interval (should equal RRD step size)

Returns:

Retrived datasource value as a java.lang.Double

Throws:

java.lang.NumberFormatException - if the retrieved value fails to convert to a double

RrdException

createGraph

public static java.io.InputStream createGraph(java.lang.String command,
                                              java.io.File workDir)
                                       throws java.io.IOException,
                                              RrdException

Creates an InputStream representing the bytes of a graph created from round robin data. It accepts an rrdtool graph command. The underlying implementation converts this command to a format appropriate for it .

Parameters:

command - the command needed to create the graph

workDir - the directory that all referenced files are relative to

Returns:

an input stream representing the bytes of a graph image as a PNG file

Throws:

java.io.IOException - if an IOError occurs

RrdException - if an RRD error occurs

getExtension

public static java.lang.String getExtension()