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From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Trivial Update of "Hbase/HbaseArchitecture" by stack
Date Thu, 16 Aug 2007 16:39:08 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Lucene-hadoop Wiki" for change notification.

The following page has been changed by stack:
http://wiki.apache.org/lucene-hadoop/Hbase/HbaseArchitecture

The comment on the change is:
More purging of deprecated HClient

------------------------------------------------------------------------------
   * [#datamodel Data Model]
    * [#conceptual Conceptual View]
    * [#physical Physical Storage View]
-  * [#client HClient Client API]
+  * [#client Client API]
    * [#scanner Scanner API]
   * [#hregion HRegion (Tablet) Server]
   * [#master HBase Master Server]
@@ -166, +166 @@

  [[Anchor(scanner)]]
  == Scanner API ==
  
+ To obtain a scanner, a Cursor-like row 'iterator' that must be closed, [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HTable.html#HTable(org.apache.hadoop.conf.Configuration,%20org.apache.hadoop.io.Text)
instantiate an HTable], and then invoke  [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HTable.html#obtainScanner(org.apache.hadoop.io.Text[],%20org.apache.hadoop.io.Text)
obtainScanner].  This method returns an [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HScannerInterface.html
HScannerInterface] against which you call [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HScannerInterface.html#next(org.apache.hadoop.hbase.HStoreKey,%20java.util.SortedMap)
next] and ultimately [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HScannerInterface.h
 tml#close() close].
- To obtain a scanner, a 'iterator' that must be closed, [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HClient.html#openTable(org.apache.hadoop.io.Text)
open the table], and use [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HClient.html#obtainScanner(org.apache.hadoop.io.Text%5B%5D,%20org.apache.hadoop.io.Text)
obtainScanner].
- 
- Then use the [http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Nightly/javadoc/org/apache/hadoop/hbase/HScannerInterface.html
scanner API]
  
  [[Anchor(hregion)]]
  = HRegion (Tablet) Server =
@@ -360, +358 @@

  the ROOT and META upon startup, and serving the location of the ROOT
  HRegion.
  
- The HClient is fairly complicated, and often needs to navigate the
+ The HBase client is fairly complicated, and often needs to navigate the
  ROOT and META HRegions when serving a user's request to scan a
  specific user table. If an H!RegionServer is unavailable or it does not
- have an HRegion it should have, the HClient will wait and retry. At
+ have an HRegion it should have, the client will wait and retry. At
  startup or in case of a recent H!RegionServer failure, the correct
  mapping info from HRegion to H!RegionServer may not always be
  available.
@@ -377, +375 @@

   1. The set of current H!RegionServers is known only to the HMaster
   1. The mapping between HRegions and H!RegionServers is stored in two special HRegions,
which are allocated to H!RegionServers like any other.
   1. The ROOT HRegion is a special one, the location of which the HMaster always knows.
-  1. It's the HClient's responsibility to navigate all this.
+  1. It's the client's responsibility to navigate all this.
  
  [[Anchor(status)]]
  = Current Status =

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