org.opennms.netmgt.rrd.rrdtool

Class JniRrdStrategy

java.lang.Object

org.opennms.netmgt.rrd.rrdtool.AbstractJniRrdStrategy<JniRrdStrategy.CreateCommand,StringBuffer>

org.opennms.netmgt.rrd.rrdtool.JniRrdStrategy

All Implemented Interfaces:

RrdStrategy<JniRrdStrategy.CreateCommand,StringBuffer>

public class JniRrdStrategy
extends AbstractJniRrdStrategy<JniRrdStrategy.CreateCommand,StringBuffer>

Provides an rrdtool based implementation of RrdStrategy. It uses the existing JNI based single-threaded interface to write the rrdtool compatible RRD files. The JNI interface takes command-like arguments and doesn't provide open files so the the Objects used to represent open files are really partial command strings See the individual methods for more details

Version:

$Id: $

Author:

ranger

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JniRrdStrategy.CreateCommand

Constructor Summary

Constructors

Constructor and Description
JniRrdStrategy() Initialized the JNI Interface

Method Summary

Modifier and Type	Method and Description
void	closeFile(StringBuffer rrd) The 'closes' the rrd file.
JniRrdStrategy.CreateCommand	createDefinition(String creator, String directory, String rrdName, int step, List<RrdDataSource> dataSources, List<String> rraList) Create a round robin database definition from the supplied parameters.
void	createFile(JniRrdStrategy.CreateCommand createCommand) Creates a the rrd file from the rrdDefinition.
Double	fetchLastValue(String rrdFile, String ds, int interval) Fetches the last value from the round robin database with the given name.
Double	fetchLastValue(String rrdFile, String ds, String consolidationFunction, int interval) Fetches the last value from the round robin database with the given name.
Double	fetchLastValueInRange(String rrdFile, String ds, int interval, int range) Fetches the last value from the round robin database with the given name within a time range.
Properties	getConfigurationProperties() getConfigurationProperties
StringBuffer	openFile(String fileName) Opens the round robin database with the supplied name.
void	setConfigurationProperties(Properties configurationParameters) setConfigurationProperties
void	updateFile(StringBuffer rrd, String owner, String data) Updates the supplied round robin database with the given timestamp:value point

Methods inherited from class org.opennms.netmgt.rrd.rrdtool.AbstractJniRrdStrategy

createGraph, createGraphReturnDetails, getDefaultFileExtension, getGraphLeftOffset, getGraphRightOffset, getGraphTopOffsetWithText, getStats, promoteEnqueuedFiles

Methods inherited from class java.lang.Object

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

Constructor Detail

JniRrdStrategy

public JniRrdStrategy()
               throws Exception

Initialized the JNI Interface

Throws:

Exception - if any.

Method Detail

getConfigurationProperties

public Properties getConfigurationProperties()

getConfigurationProperties

Returns:

a Properties object.

setConfigurationProperties

public void setConfigurationProperties(Properties configurationParameters)

setConfigurationProperties

Parameters:

configurationParameters - a Properties object.

closeFile

public void closeFile(StringBuffer rrd)
               throws Exception

The 'closes' the rrd file. This is where the actual work of writing the RRD files takes place. The passed in rrd is actually an rrd command string containing updates. This method executes this command.

Parameters:

rrd - a StringBuffer object.

Throws:

Exception - if any.

createDefinition

public JniRrdStrategy.CreateCommand createDefinition(String creator,
                                                     String directory,
                                                     String rrdName,
                                                     int step,
                                                     List<RrdDataSource> dataSources,
                                                     List<String> rraList)
                                              throws Exception

Create a round robin database definition from the supplied parameters. This definition is used in the createFile call to create the actual file.

Parameters:

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

directory - - The directory to create the file in

rrdName - - The name to use for the round robin database

step - - the step for the database

dataSources - - the data sources to use for round robin database

rraList - - a List of the round robin archives to create in the database. defines after which time the data is condensed to a defined lower step

Returns:

an object representing the definition of an round robin database. Can be null if the database exists already.

Throws:

Exception - If an error occurs while creating the definition

createFile

public void createFile(JniRrdStrategy.CreateCommand createCommand)
                throws Exception

Creates a the rrd file from the rrdDefinition. Since this definition is really just the create command string it just executes it.

Parameters:

createCommand - a String object.

Throws:

Exception - if any.

openFile

public StringBuffer openFile(String fileName)
                      throws Exception

Opens the round robin database with the supplied name. It is assumed the name refers to a round robin database appropriate for this strategy implementation The 'opens' the given rrd file. In actuality since the JNI interface does not provide files that may be open, this constructs the beginning portion of the rrd command to update the file.

Parameters:

fileName - the name of the associated rrd file

Returns:

an open rrd reference that can by used in calls to updateFile and closeFile

Throws:

Exception - if an error occurs opening the file

updateFile

public void updateFile(StringBuffer rrd,
                       String owner,
                       String data)
                throws Exception

Updates the supplied round robin database with the given timestamp:value point This 'updates' the given rrd file by providing data. Since the JNI interface does not provide files that can be open, this just appends the data to the command string constructed so far. The data is not immediately written to the file since this would eliminate the possibility of getting performance benefit by doing more than one write per open. The updates are all performed at once in the closeFile method.

Parameters:

rrd - an rrd object created using openFile

owner - the owner of the rrd

data - a string of the form :

Throws:

Exception - if an error occurs updating the file

fetchLastValue

public Double fetchLastValue(String rrdFile,
                             String ds,
                             int interval)
                      throws NumberFormatException,
                             RrdException

Fetches the last value from the round robin database with the given name. The interval passed in should be the interval associated with the round robin database. Fetches the last value directly from the rrd file using the JNI Interface.

Parameters:

rrdFile - a name the represents a round robin database

ds - a name the represents a data source to be used

interval - a step interval of the round robin database

Returns:

The last value as a Double (if the last value didn't exist returns a Double.NaN)

Throws:

NumberFormatException - if any.

RrdException - if any.

fetchLastValue

public Double fetchLastValue(String rrdFile,
                             String ds,
                             String consolidationFunction,
                             int interval)

Fetches the last value from the round robin database with the given name. The interval passed in should be the interval associated with the round robin database.

Parameters:

rrdFile - a name the represents a round robin database

ds - a name the represents a data source to be used

consolidationFunction - a String object.

interval - a step interval of the round robin database

Returns:

The last value as a Double (if the last value didn't exist returns a Double.NaN)

fetchLastValueInRange

public Double fetchLastValueInRange(String rrdFile,
                                    String ds,
                                    int interval,
                                    int range)
                             throws NumberFormatException,
                                    RrdException

Fetches the last value from the round robin database with the given name within a time range. The interval passed in should be the interval associated with the round robin database. The range should be the amount of "lag" acceptable for an update to be considered valid. Range must be a multiple of the RRD interval.

Parameters:

rrdFile - a name the represents a round robin database

ds - a name the represents a data source to be used

interval - a step interval of the round robin database

range - an acceptable range for which the last value will be returned

Returns:

The last value as a Double (if the last value didn't exist returns a Double.NaN)

Throws:

NumberFormatException - if any.

RrdException - if any.