public class RrdDb extends Object implements RrdUpdater
RrdDef
) or
from XML file (dumped content of RRDTool's or JRobin's RRD file).
Each RRD is backed with some kind of storage. For example, RRDTool supports only one kind of storage (disk file). On the contrary, JRobin gives you freedom to use other storage (backend) types even to create your own backend types for some special purposes. JRobin by default stores RRD data in files (as RRDTool), but you might choose to store RRD data in memory (this is supported in JRobin), to use java.nio.* instead of java.io.* package for file manipulation (also supported) or to store whole RRDs in the SQL database (you'll have to extend some classes to do this).
Note that JRobin uses binary format different from RRDTool's format. You cannot use this class to manipulate RRD files created with RRDTool. However, if you perform the same sequence of create, update and fetch operations, you will get exactly the same results from JRobin and RRDTool.
You will not be able to use JRobin API if you are not familiar with basic RRDTool concepts. Good place to start is the official RRD tutorial and relevant RRDTool man pages: rrdcreate, rrdupdate, rrdfetch and rrdgraph. For RRDTool's advanced graphing capabilities (RPN extensions), also supported in JRobin, there is an excellent CDEF tutorial.
RrdBackend
,
RrdBackendFactory
Modifier and Type | Field and Description |
---|---|
static String |
PREFIX_RRDTool
prefix to identify external RRDTool file source used in various RrdDb constructors
|
static String |
PREFIX_XML
prefix to identify external XML file source used in various RrdDb constructors
|
(package private) static int |
XML_INITIAL_BUFFER_CAPACITY |
Constructor and Description |
---|
RrdDb(File file) |
RrdDb(File file,
boolean readOnly) |
RrdDb(RrdDef rrdDef)
Constructor used to create new RRD object from the definition.
|
RrdDb(RrdDef rrdDef,
RrdBackendFactory factory)
Constructor used to create new RRD object from the definition object but with a storage
(backend) different from default.
|
RrdDb(String path)
Constructor used to open already existing RRD in R/W mode, with a default storage
(backend) type (file on the disk).
|
RrdDb(String path,
boolean readOnly)
Constructor used to open already existing RRD.
|
RrdDb(String path,
boolean readOnly,
RrdBackendFactory factory)
Constructor used to open already existing RRD backed
with a storage (backend) different from default.
|
RrdDb(String path,
RrdBackendFactory factory)
Constructor used to open already existing RRD in R/W mode with a storage (backend) type
different from default.
|
RrdDb(String rrdPath,
String externalPath)
Constructor used to create RRD files from external file sources.
|
RrdDb(String rrdPath,
String externalPath,
RrdBackendFactory factory)
Constructor used to create RRD files from external file sources with a backend type
different from default.
|
Modifier and Type | Method and Description |
---|---|
(package private) void |
archive(Datasource datasource,
double value,
long numUpdates) |
void |
close()
Closes RRD.
|
boolean |
containsDs(String dsName)
Checks presence of a specific datasource.
|
void |
copyStateTo(RrdUpdater other)
Copies object's internal state to another RrdDb object.
|
FetchRequest |
createFetchRequest(String consolFun,
long fetchStart,
long fetchEnd)
Prepares fetch request to be executed on this RRD.
|
FetchRequest |
createFetchRequest(String consolFun,
long fetchStart,
long fetchEnd,
long resolution)
Prepares fetch request to be executed on this RRD.
|
Sample |
createSample()
Creates new sample with the current timestamp and all data source values set to
'unknown'.
|
Sample |
createSample(long time)
Creates new sample with the given timestamp and all datasource values set to
'unknown'.
|
String |
dump()
Returns string representing complete internal RRD state.
|
void |
dumpXml(OutputStream destination)
Writes the RRD content to OutputStream using XML format.
|
void |
dumpXml(String filename)
Dumps internal RRD state to XML file.
|
String |
exportXml()
This method is just an alias for
getXml method. |
void |
exportXml(OutputStream destination)
This method is just an alias for
dumpXml method. |
void |
exportXml(String filename)
This method is just an alias for
dumpXml(String) method. |
(package private) FetchData |
fetchData(FetchRequest request) |
protected void |
finalize() |
Archive |
findMatchingArchive(FetchRequest request) |
Archive |
findStartMatchArchive(String consolFun,
long startTime,
long resolution)
Finds the archive that best matches to the start time (time period being start-time until now)
and requested resolution.
|
int |
getArcCount()
Returns the number of RRA arcihves defined in the file
|
Archive |
getArchive(int arcIndex)
Returns Archive object for the given archive index.
|
Archive |
getArchive(String consolFun,
int steps)
Returns Archive object with the given consolidation function and the number
of steps.
|
(package private) Archive[] |
getArchives() |
int |
getArcIndex(String consolFun,
int steps)
Returns index of Archive object with the given consolidation function and the number
of steps.
|
byte[] |
getBytes()
Returns an array of bytes representing the whole RRD.
|
String |
getCanonicalPath()
Returns canonical path to the underlying RRD file.
|
Datasource |
getDatasource(int dsIndex)
Returns Datasource object for the given datasource index.
|
Datasource |
getDatasource(String dsName)
Returns Datasource object corresponding to the given datasource name.
|
(package private) Datasource[] |
getDatasources() |
int |
getDsCount()
Returns the number of datasources defined in the file
|
int |
getDsIndex(String dsName)
Returns internal index number for the given datasource name.
|
String[] |
getDsNames()
Returns an array of datasource names defined in RRD.
|
Header |
getHeader()
Returns RRD header.
|
String |
getInfo() |
long |
getLastArchiveUpdateTime()
Returns the last time when some of the archives in this RRD was updated.
|
double |
getLastDatasourceValue(String dsName)
Returns the last stored value for the given datasource.
|
double[] |
getLastDatasourceValues()
Returns an array of last datasource values.
|
long |
getLastUpdateTime()
Returns time of last update operation as timestamp (in seconds).
|
String |
getPath()
Returns path to this RRD.
|
RrdAllocator |
getRrdAllocator()
Required to implement RrdUpdater interface.
|
RrdBackend |
getRrdBackend()
Returns backend object for this RRD which performs actual I/O operations.
|
RrdDef |
getRrdDef()
Returns RRD definition object which can be used to create new RRD
with the same creation parameters but with no data in it.
|
String |
getXml()
Returns string representing internal RRD state in XML format.
|
boolean |
isClosed()
Returns true if the RRD is closed.
|
static void |
main(String[] args) |
static void |
setDefaultFactory(String factoryName)
Sets default backend factory to be used.
|
void |
setInfo(String info) |
(package private) void |
store(Sample sample) |
String |
toString() |
public static final String PREFIX_XML
public static final String PREFIX_RRDTool
static final int XML_INITIAL_BUFFER_CAPACITY
public RrdDb(RrdDef rrdDef) throws RrdException, IOException
RrdBackendFactory.setDefaultFactory(String)
method call.
New RRD file structure is specified with an object of class
RrdDef
. The underlying RRD storage is created as soon
as the constructor returns.
Typical scenario:
// create new RRD definition RrdDef def = new RrdDef("test.rrd", 300); def.addDatasource("input", DsTypes.DT_COUNTER, 600, 0, Double.NaN); def.addDatasource("output", DsTypes.DT_COUNTER, 600, 0, Double.NaN); def.addArchive(ConsolFuns.CF_AVERAGE, 0.5, 1, 600); def.addArchive(ConsolFuns.CF_AVERAGE, 0.5, 6, 700); def.addArchive(ConsolFuns.CF_AVERAGE, 0.5, 24, 797); def.addArchive(ConsolFuns.CF_AVERAGE, 0.5, 288, 775); def.addArchive(ConsolFuns.CF_MAX, 0.5, 1, 600); def.addArchive(ConsolFuns.CF_MAX, 0.5, 6, 700); def.addArchive(ConsolFuns.CF_MAX, 0.5, 24, 797); def.addArchive(ConsolFuns.CF_MAX, 0.5, 288, 775); // RRD definition is now completed, create the database! RrdDb rrd = new RrdDb(def); // new RRD file has been created on your disk
rrdDef
- Object describing the structure of the new RRD file.IOException
- Thrown in case of I/O error.RrdException
- Thrown if invalid RrdDef object is supplied.public RrdDb(RrdDef rrdDef, RrdBackendFactory factory) throws RrdException, IOException
JRobin uses factories to create RRD backend objecs. There are three different backend factories supplied with JRobin, and each factory has its unique name:
For example, to create RRD in memory, use the following code:
RrdBackendFactory factory = RrdBackendFactory.getFactory("MEMORY"); RrdDb rrdDb = new RrdDb(rrdDef, factory); rrdDb.close();
New RRD file structure is specified with an object of class
RrdDef
. The underlying RRD storage is created as soon
as the constructor returns.
rrdDef
- RRD definition objectfactory
- The factory which will be used to create storage for this RRDRrdException
- Thrown if invalid factory or definition is suppliedIOException
- Thrown in case of I/O errorRrdBackendFactory
public RrdDb(String path, boolean readOnly) throws IOException, RrdException
path
- Path to existing RRD.readOnly
- Should be set to false
if you want to update
the underlying RRD. If you want just to fetch data from the RRD file
(read-only access), specify true
. If you try to update RRD file
open in read-only mode (m_readOnly
set to true
),
IOException
will be thrown.IOException
- Thrown in case of I/O error.RrdException
- Thrown in case of JRobin specific error.public RrdDb(String path, boolean readOnly, RrdBackendFactory factory) throws FileNotFoundException, IOException, RrdException
path
- Path to existing RRD.readOnly
- Should be set to false
if you want to update
the underlying RRD. If you want just to fetch data from the RRD file
(read-only access), specify true
. If you try to update RRD file
open in read-only mode (m_readOnly
set to true
),
IOException
will be thrown.factory
- Backend factory which will be used for this RRD.FileNotFoundException
- Thrown if the requested file does not exist.IOException
- Thrown in case of general I/O error (bad RRD file, for example).RrdException
- Thrown in case of JRobin specific error.RrdBackendFactory
public RrdDb(String path) throws IOException, RrdException
Constructor used to open already existing RRD in R/W mode, with a default storage (backend) type (file on the disk).
path
- Path to existing RRD.IOException
- Thrown in case of I/O error.RrdException
- Thrown in case of JRobin specific error.public RrdDb(String path, RrdBackendFactory factory) throws IOException, RrdException
Constructor used to open already existing RRD in R/W mode with a storage (backend) type different from default.
path
- Path to existing RRD.factory
- Backend factory used to create this RRD.IOException
- Thrown in case of I/O error.RrdException
- Thrown in case of JRobin specific error.RrdBackendFactory
public RrdDb(String rrdPath, String externalPath) throws IOException, RrdException, RrdException
rrdtool dump
command).
Newly created RRD will be backed with a default storage (backend) type (file on the disk).
JRobin and RRDTool use the same format for XML dump and this constructor should be used to (re)create JRobin RRD files from XML dumps. First, dump the content of a RRDTool RRD file (use command line):
rrdtool dump original.rrd > original.xml
Than, use the file original.xml
to create JRobin RRD file named
copy.rrd
:
RrdDb rrd = new RrdDb("copy.rrd", "original.xml");
or:
RrdDb rrd = new RrdDb("copy.rrd", "xml:/original.xml");
See documentation for dumpXml()
method
to see how to convert JRobin files to RRDTool's format.
To read RRDTool files directly, specify rrdtool:/
prefix in the
externalPath
argument. For example, to create JRobin compatible file named
copy.rrd
from the file original.rrd
created with RRDTool, use
the following code:
RrdDb rrd = new RrdDb("copy.rrd", "rrdtool:/original.rrd");
Note that the prefix xml:/
or rrdtool:/
is necessary to distinguish
between XML and RRDTool's binary sources. If no prefix is supplied, XML format is assumed.
rrdPath
- Path to a RRD file which will be createdexternalPath
- Path to an external file which should be imported, with an optional
xml:/
or rrdtool:/
prefix.IOException
- Thrown in case of I/O errorRrdException
- Thrown in case of JRobin specific errorpublic RrdDb(String rrdPath, String externalPath, RrdBackendFactory factory) throws IOException, RrdException
rrdtool dump
command).
JRobin and RRDTool use the same format for XML dump and this constructor should be used to (re)create JRobin RRD files from XML dumps. First, dump the content of a RRDTool RRD file (use command line):
rrdtool dump original.rrd > original.xml
Than, use the file original.xml
to create JRobin RRD file named
copy.rrd
:
RrdDb rrd = new RrdDb("copy.rrd", "original.xml");
or:
RrdDb rrd = new RrdDb("copy.rrd", "xml:/original.xml");
See documentation for dumpXml()
method
to see how to convert JRobin files to RRDTool's format.
To read RRDTool files directly, specify rrdtool:/
prefix in the
externalPath
argument. For example, to create JRobin compatible file named
copy.rrd
from the file original.rrd
created with RRDTool, use
the following code:
RrdDb rrd = new RrdDb("copy.rrd", "rrdtool:/original.rrd");
Note that the prefix xml:/
or rrdtool:/
is necessary to distinguish
between XML and RRDTool's binary sources. If no prefix is supplied, XML format is assumed.
rrdPath
- Path to RRD which will be createdexternalPath
- Path to an external file which should be imported, with an optional
xml:/
or rrdtool:/
prefix.factory
- Backend factory which will be used to create storage (backend) for this RRD.IOException
- Thrown in case of I/O errorRrdException
- Thrown in case of JRobin specific errorRrdBackendFactory
public RrdDb(File file) throws IOException, RrdException
IOException
RrdException
public RrdDb(File file, boolean readOnly) throws IOException, RrdException
IOException
RrdException
public void close() throws IOException
IOException
- Thrown in case of I/O related error.public boolean isClosed()
public Header getHeader()
public Datasource getDatasource(int dsIndex)
dsIndex
- Datasource index (zero based)public Archive getArchive(int arcIndex)
arcIndex
- Archive index (zero based)public String[] getDsNames() throws IOException
IOException
- Thrown in case of I/O error.public Sample createSample(long time) throws IOException
Sample
object to specify
datasource values for the given timestamp. See documentation for
Sample
for an explanation how to do this.
Once populated with data source values, call Sample's
update()
method to actually
store sample in the RRD associated with it.
time
- Sample timestamp rounded to the nearest second (without milliseconds).IOException
- Thrown in case of I/O error.public Sample createSample() throws IOException
Sample
object to specify
datasource values for the current timestamp. See documentation for
Sample
for an explanation how to do this.
Once populated with data source values, call Sample's
update()
method to actually
store sample in the RRD associated with it.
IOException
- Thrown in case of I/O error.public FetchRequest createFetchRequest(String consolFun, long fetchStart, long fetchEnd, long resolution) throws RrdException
Prepares fetch request to be executed on this RRD. Use returned
FetchRequest
object and its fetchData()
method to actually fetch data from the RRD file.
consolFun
- Consolidation function to be used in fetch request. Allowed values are
"AVERAGE", "MIN", "MAX" and "LAST" (these constants are conveniently defined in the
ConsolFuns
class).fetchStart
- Starting timestamp for fetch request.fetchEnd
- Ending timestamp for fetch request.resolution
- Fetch resolution (see RRDTool's
rrdfetch man page for an
explanation of this parameter.RrdException
- In case of JRobin related error (invalid consolidation function or
invalid time span).public FetchRequest createFetchRequest(String consolFun, long fetchStart, long fetchEnd) throws RrdException
Prepares fetch request to be executed on this RRD. Use returned
FetchRequest
object and its fetchData()
method to actually fetch data from this RRD. Data will be fetched with the smallest
possible resolution (see RRDTool's
rrdfetch man page
for the explanation of the resolution parameter).
consolFun
- Consolidation function to be used in fetch request. Allowed values are
"AVERAGE", "MIN", "MAX" and "LAST" (these constants are conveniently defined in the
ConsolFuns
class).fetchStart
- Starting timestamp for fetch request.fetchEnd
- Ending timestamp for fetch request.RrdException
- In case of JRobin related error (invalid consolidation function or
invalid time span).void store(Sample sample) throws IOException, RrdException
IOException
RrdException
FetchData fetchData(FetchRequest request) throws IOException, RrdException
IOException
RrdException
public Archive findMatchingArchive(FetchRequest request) throws RrdException, IOException
RrdException
IOException
public Archive findStartMatchArchive(String consolFun, long startTime, long resolution) throws IOException
consolFun
- Consolidation function of the datasource.startTime
- Start time of the time period in seconds.resolution
- Requested fetch resolution.IOException
- Thrown in case of I/O related error.public String dump() throws IOException
Returns string representing complete internal RRD state. The returned
string can be printed to stdout
and/or used for debugging purposes.
IOException
- Thrown in case of I/O related error.void archive(Datasource datasource, double value, long numUpdates) throws IOException, RrdException
IOException
RrdException
public int getDsIndex(String dsName) throws RrdException, IOException
Returns internal index number for the given datasource name. This index is heavily used by jrobin.graph package and has no value outside of it.
dsName
- Data source name.RrdException
- Thrown in case of JRobin related error (invalid data source name,
for example)IOException
- Thrown in case of I/O error.public boolean containsDs(String dsName) throws IOException
dsName
- Datasource name to checktrue
if datasource is present in this RRD, false
otherwiseIOException
- Thrown in case of I/O error.Datasource[] getDatasources()
Archive[] getArchives()
public void dumpXml(OutputStream destination) throws IOException
destination
- Output stream to receive XML dataIOException
- Thrown in case of I/O related errorpublic void exportXml(OutputStream destination) throws IOException
dumpXml
method.destination
- Output stream to receive XML dataIOException
- Thrown in case of I/O related errorpublic String getXml() throws IOException, RrdException
IOException
- Thrown in case of I/O related errorRrdException
- Thrown in case of JRobin specific errorpublic String exportXml() throws IOException, RrdException
getXml
method.IOException
- Thrown in case of I/O related errorRrdException
- Thrown in case of JRobin specific errorpublic void dumpXml(String filename) throws IOException, RrdException
Suppose that you have a JRobin RRD file original.rrd
and you want
to convert it to RRDTool format. First, execute the following java code:
RrdDb rrd = new RrdDb("original.rrd");
rrd.dumpXml("original.xml");
Use original.xml
file to create the corresponding RRDTool file
(from your command line):
rrdtool restore copy.rrd original.xml
filename
- Path to XML file which will be created.IOException
- Thrown in case of I/O related error.RrdException
- Thrown in case of JRobin related error.public void exportXml(String filename) throws IOException, RrdException
dumpXml(String)
method.filename
- Path to XML file which will be created.IOException
- Thrown in case of I/O related errorRrdException
- Thrown in case of JRobin specific errorpublic long getLastUpdateTime() throws IOException
IOException
- Thrown in case of I/O related errorpublic RrdDef getRrdDef() throws RrdException, IOException
Example:
RrdDb rrd1 = new RrdDb("original.rrd"); RrdDef def = rrd1.getRrdDef(); // fix path def.setPath("empty_copy.rrd"); // create new RRD file RrdDb rrd2 = new RrdDb(def);
IOException
- Thrown in case of I/O related error.RrdException
- Thrown in case of JRobin specific error.protected void finalize() throws Throwable
public void copyStateTo(RrdUpdater other) throws IOException, RrdException
copyStateTo
in interface RrdUpdater
other
- New RrdDb object to copy state toIOException
- Thrown in case of I/O errorRrdException
- Thrown if supplied argument is not a compatible RrdDb objectpublic Datasource getDatasource(String dsName) throws IOException
dsName
- Datasource nameIOException
- Thrown in case of I/O errorpublic int getArcIndex(String consolFun, int steps) throws RrdException, IOException
consolFun
- Consolidation functionsteps
- Number of archive stepsIOException
- Thrown in case of I/O errorRrdException
- Thrown if no such archive could be foundpublic Archive getArchive(String consolFun, int steps) throws IOException
consolFun
- Consolidation functionsteps
- Number of archive stepsIOException
- Thrown in case of I/O errorpublic String getCanonicalPath() throws IOException
IOException
- Thrown in case of I/O error or if the underlying backend is
not derived from RrdFileBackend.public String getPath()
public RrdBackend getRrdBackend()
getRrdBackend
in interface RrdUpdater
public RrdAllocator getRrdAllocator()
getRrdAllocator
in interface RrdUpdater
public byte[] getBytes() throws IOException
IOException
- Thrown in case of I/O related error.public static void setDefaultFactory(String factoryName) throws RrdException
RrdBackendFactory.setDefaultFactory(java.lang.String)
.factoryName
- Name of the backend factory to be set as default.RrdException
- Thrown if invalid factory name is supplied, or not called
before the first backend object (before the first RrdDb object) is created.public double[] getLastDatasourceValues() throws IOException
IOException
- Thrown in case of I/O errorpublic double getLastDatasourceValue(String dsName) throws IOException, RrdException
dsName
- Datasource nameIOException
- Thrown in case of I/O errorRrdException
- Thrown if no datasource in this RrdDb matches the given datasource namepublic int getDsCount()
public int getArcCount()
public long getLastArchiveUpdateTime() throws IOException
getLastUpdateTime()
since RRD file can be updated without updating any of
the archives.IOException
- Thrown in case of I/O errorpublic String getInfo() throws IOException
IOException
public void setInfo(String info) throws IOException
IOException
public static void main(String[] args)