io.cdap.cdap.api.dataset.lib

Class CounterTimeseriesTable

java.lang.Object

io.cdap.cdap.api.dataset.lib.AbstractDataset

io.cdap.cdap.api.dataset.lib.CounterTimeseriesTable

All Implemented Interfaces:

Dataset, MeteredDataset, Closeable, AutoCloseable, org.apache.tephra.TransactionAware

public class CounterTimeseriesTable
extends AbstractDataset

A Dataset for incrementing counts over time periods. This Dataset provides an extension to TimeseriesTable for long values and provides increment methods for counting.

For more information on choosing values for rowPartitionIntervalSize and tag usage, please see the TimeseriesTable class description.

See Also:

TimeseriesTable

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CounterTimeseriesTable.Counter Defines an object for counters in CounterTimeseriesTable.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ATTR_TIME_INTERVAL_TO_STORE_PER_ROW
static long	DEFAULT_TIME_INTERVAL_PER_ROW See TimeseriesTable javadoc for description.
static int	MAX_ROWS_TO_SCAN_PER_READ Limit on the number of rows to scan per read.
protected Table	table
static String	TYPE Type name

Constructor Summary

Constructors

Constructor and Description
CounterTimeseriesTable(DatasetSpecification spec, Table table) Creates an instance of the DataSet.

Method Summary

Modifier and Type	Method and Description
long	increment(byte[] counter, long amount, long timestamp, byte[]... tags) Increments the value for a counter for a row and timestamp.
Iterator<CounterTimeseriesTable.Counter>	read(byte[] counter, long startTime, long endTime, byte[]... tags) Reads entries for a given time range and returns an Iterator.
Iterator<CounterTimeseriesTable.Counter>	read(byte[] counter, long startTime, long endTime, int offset, int limit, byte[]... tags) Reads entries for a given time range and returns an Iterator.
void	set(byte[] counter, long value, long timestamp, byte[]... tags) Set the value for a counter.

Methods inherited from class io.cdap.cdap.api.dataset.lib.AbstractDataset

close, commitTx, getName, getTransactionAwareName, getTxChanges, postTxCommit, rollbackTx, setMetricsCollector, startTx, toString, updateTx

Methods inherited from class java.lang.Object

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

Field Detail

TYPE

public static final String TYPE

Type name

See Also:

Constant Field Values

ATTR_TIME_INTERVAL_TO_STORE_PER_ROW

public static final String ATTR_TIME_INTERVAL_TO_STORE_PER_ROW

See Also:

Constant Field Values

DEFAULT_TIME_INTERVAL_PER_ROW

public static final long DEFAULT_TIME_INTERVAL_PER_ROW

See TimeseriesTable javadoc for description.

MAX_ROWS_TO_SCAN_PER_READ

public static final int MAX_ROWS_TO_SCAN_PER_READ

Limit on the number of rows to scan per read.

See Also:

Constant Field Values

table

protected final Table table

Constructor Detail

CounterTimeseriesTable

public CounterTimeseriesTable(DatasetSpecification spec,
                              Table table)

Creates an instance of the DataSet.

Method Detail

increment

public long increment(byte[] counter,
                      long amount,
                      long timestamp,
                      byte[]... tags)

Increments the value for a counter for a row and timestamp.

Parameters:

counter - the name of the counter to increment

amount - the amount to increment by

timestamp - timestamp of the entry

tags - optional list of tags associated with the counter. See TimeseriesTable class description for more details.

Returns:

value of the entry after increment

set

public void set(byte[] counter,
                long value,
                long timestamp,
                byte[]... tags)

Set the value for a counter.

Parameters:

counter - the name of the counter to set

value - the value to set

timestamp - timestamp of the entry

tags - optional list of tags associated with the counter. See TimeseriesTable class description for more details.

read

public Iterator<CounterTimeseriesTable.Counter> read(byte[] counter,
                                                     long startTime,
                                                     long endTime,
                                                     byte[]... tags)

Reads entries for a given time range and returns an Iterator. NOTE: A limit is placed on the max number of time intervals to be scanned during a read, as defined by MAX_ROWS_TO_SCAN_PER_READ.

Parameters:

counter - name of the counter to read

startTime - defines start of the time range to read, inclusive

endTime - defines end of the time range to read, inclusive

tags - a set of tags which entries returned must contain. Tags for entries are defined at write-time and an entry is only returned if it contains all of these tags.

Returns:

an iterator over entries that satisfy provided conditions

read

public Iterator<CounterTimeseriesTable.Counter> read(byte[] counter,
                                                     long startTime,
                                                     long endTime,
                                                     int offset,
                                                     int limit,
                                                     byte[]... tags)

Reads entries for a given time range and returns an Iterator. Provides the same functionality as read(byte[], long, long, byte[]...) but accepts additional parameters for pagination purposes.

Parameters:

counter - name of the counter to read

startTime - defines start of the time range to read, inclusive

endTime - defines end of the time range to read, inclusive

offset - the number of initial entries to ignore and not add to the results

limit - upper limit on number of results returned. If limit is exceeded, the first limit results are returned.

tags - a set of tags which entries returned must contain. Tags for entries are defined at write-time and an entry is only returned if it contains all of these tags.

Returns:

an iterator over entries that satisfy provided conditions