net.opentsdb.core
Interface Query

public interface Query

A query to retreive data from the TSDB.

Method Summary

void	downsample(int interval, Aggregator downsampler) Downsamples the results by specifying a fixed interval between points.
long	getEndTime() Returns the end time of the graph.
long	getStartTime() Returns the start time of the graph.
DataPoints[]	run() Runs this query.
void	setEndTime(long timestamp) Sets the end time of the graph.
void	setStartTime(long timestamp) Sets the start time of the graph.
void	setTimeSeries(String metric, Map<String,String> tags, Aggregator function, boolean rate) Sets the time series to the query.

Method Detail

setStartTime

void setStartTime(long timestamp)

Sets the start time of the graph.

Parameters:

timestamp - The start time, all the data points returned will have a timestamp greater than or equal to this one.

Throws:

IllegalArgumentException - if timestamp is less than or equal to 0, or if it can't fit on 32 bits.

IllegalArgumentException - if timestamp >= getEndTime.

getStartTime

long getStartTime()

Returns the start time of the graph.

Returns:

A strictly positive integer.

Throws:

IllegalStateException - if setStartTime(long) was never called on this instance before.

setEndTime

void setEndTime(long timestamp)

Sets the end time of the graph.

Parameters:

timestamp - The end time, all the data points returned will have a timestamp less than or equal to this one.

Throws:

IllegalArgumentException - if timestamp is less than or equal to 0, or if it can't fit on 32 bits.

IllegalArgumentException - if timestamp <= getStartTime.

getEndTime

long getEndTime()

Returns the end time of the graph.

If setEndTime(long) was never called before, this method will automatically execute setEndTime(System.currentTimeMillis() / 1000) to set the end time.

Returns:

A strictly positive integer.

setTimeSeries

void setTimeSeries(String metric,
                   Map<String,String> tags,
                   Aggregator function,
                   boolean rate)
                   throws NoSuchUniqueName

Sets the time series to the query.

Parameters:

metric - The metric to retreive from the TSDB.

tags - The set of tags of interest.

function - The aggregation function to use.

rate - If true, the rate of the series will be used instead of the actual values.

Throws:

NoSuchUniqueName - if the name of a metric, or a tag name/value does not exist.

downsample

void downsample(int interval,
                Aggregator downsampler)

Downsamples the results by specifying a fixed interval between points.

Technically, downsampling means reducing the sampling interval. Here the idea is similar. Instead of returning every single data point that matched the query, we want one data point per fixed time interval. The way we get this one data point is by aggregating all the data points of that interval together using an Aggregator. This enables you to compute things like the 5-minute average or 10 minute 99th percentile.

Parameters:

interval - Number of seconds wanted between each data point.

downsampler - Aggregation function to use to group data points within an interval.

run

DataPoints[] run()
                 throws org.hbase.async.HBaseException

Runs this query.

Returns:

The data points matched by this query.

Each element in the non-null but possibly empty array returned corresponds to one time series for which some data points have been matched by the query.

Throws:

org.hbase.async.HBaseException - if there was a problem communicating with HBase to perform the search.