Package org.apache.accumulo.core.summary

Class Gatherer

java.lang.Object

org.apache.accumulo.core.summary.Gatherer

public class Gatherer
extends Object

This class implements using multiple tservers to gather summaries. Below is a rough outline of the RPC process.

1. Clients pick a random tserver and make an RPC to remotely execute gather(ExecutorService).
2. gather(ExecutorService) will call make RPC calls to multiple tservers to remotely execute processPartition(ExecutorService, int, int)
3. processPartition(ExecutorService, int, int) will make RPC calls to multiple tserver to remotely execute
4. processFiles(FileSystemResolver, Map, BlockCache, BlockCache, Cache, ExecutorService)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Gatherer.FileSystemResolver
static class	Gatherer.RowRange

Constructor Summary

Constructors

Constructor	Description
Gatherer(ClientContext context, TSummaryRequest request, AccumuloConfiguration tableConfig, CryptoService cryptoService)

Method Summary

Modifier and Type	Method	Description
Future<SummaryCollection>	gather(ExecutorService es)
Future<SummaryCollection>	processFiles(Gatherer.FileSystemResolver volMgr, Map<String,List<TRowRange>> files, BlockCache summaryCache, BlockCache indexCache, com.google.common.cache.Cache<String,Long> fileLenCache, ExecutorService srp)	This method will read summaries from a set of files.
Future<SummaryCollection>	processPartition(ExecutorService execSrv, int modulus, int remainder)	This methods reads a subset of file paths into memory and groups them by location.

Methods inherited from class java.lang.Object

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

Constructor Detail

Gatherer

public Gatherer(ClientContext context,
                TSummaryRequest request,
                AccumuloConfiguration tableConfig,
                CryptoService cryptoService)

Method Detail

processPartition

public Future<SummaryCollection> processPartition(ExecutorService execSrv,
                                                  int modulus,
                                                  int remainder)

This methods reads a subset of file paths into memory and groups them by location. Then it request summaries for files from each location/tablet server.

processFiles

public Future<SummaryCollection> processFiles(Gatherer.FileSystemResolver volMgr,
                                              Map<String,List<TRowRange>> files,
                                              BlockCache summaryCache,
                                              BlockCache indexCache,
                                              com.google.common.cache.Cache<String,Long> fileLenCache,
                                              ExecutorService srp)

This method will read summaries from a set of files.

gather

public Future<SummaryCollection> gather(ExecutorService es)