public static interface Summarizer.Collector
accept(Key, Value)
zero or
more times and then call summarize(Summarizer.StatisticConsumer)
once. After
calling summarize(Summarizer.StatisticConsumer)
, it will not use the
collector again.Modifier and Type | Method and Description |
---|---|
void |
accept(Key k,
Value v)
During compactions, Accumulo passes each Key Value written to the file to this method.
|
void |
summarize(Summarizer.StatisticConsumer sc)
After Accumulo has written some Key Values, it will call this method to generate some
statistics about what was previously passed to
accept(Key, Value) . |
void accept(Key k, Value v)
void summarize(Summarizer.StatisticConsumer sc)
accept(Key, Value)
.
In order for summary data to be useful for decision making about data, it needs to be quickly
accessible. In order to be quickly accessible, it needs to fit in the tablet server cache as
described in TableOperations.summaries(String)
and the compaction strategy
documentation. Therefore its advisable to generate small summaries. If the summary data
generated is too large it will not be stored. The maximum summary size is set using the per
table property table.file.summary.maxSize
. The number of files that exceeded the
summary size is reported by Summary.FileStatistics.getLarge()
.
sc
- Emit statistics to this Object.Copyright © 2011–2019 The Apache Software Foundation. All rights reserved.