diff --git a/CHANGES.txt b/CHANGES.txt index 7dceeecb127..ca26637919d 100644 --- a/CHANGES.txt +++ b/CHANGES.txt @@ -137,6 +137,8 @@ Release 0.91.0 - Unreleased in a synchronized function (Liyin Tang via Stack) HBASE-3710 Book.xml - fill out descriptions of metrics (Doug Meil via Stack) + HBASE-3738 Book.xml - expanding Architecture Client section + (Doug Meil via Stack) TASK HBASE-3559 Move report of split to master OFF the heartbeat channel diff --git a/src/docbkx/book.xml b/src/docbkx/book.xml index 0643176cda0..2c886b58dbf 100644 --- a/src/docbkx/book.xml +++ b/src/docbkx/book.xml @@ -707,8 +707,38 @@ throws InterruptedException, IOException { Administrative functions are handled through HBaseAdmin - For connection configuration information, see the configuration section. - +
Connections + For connection configuration information, see the configuration section. + + HTable +instances are not thread-safe. When creating HTable instances, it is advisable to use the same HBaseConfiguration +instance. This will ensure sharing of zookeeper and socket instances to the region servers +which is usually what you want. For example, this is preferred: + HBaseConfiguration conf = HBaseConfiguration.create(); +HTable table1 = new HTable(conf, "myTable"); +HTable table2 = new HTable(conf, "myTable"); + a s opposed to this: + HBaseConfiguration conf1 = HBaseConfiguration.create(); +HTable table1 = new HTable(conf1, "myTable"); +HBaseConfiguration conf2 = HBaseConfiguration.create(); +HTable table2 = new HTable(conf2, "myTable"); + For more information about how connections are handled in the HBase client, + see HConnectionManager. + +
+
WriteBuffer and Batch Methods + If autoflush is turned off on HTable, + Puts are sent to region servers when the writebuffer + is filled. The writebuffer is 2MB by default. Before an HTable instance is + discarded, either close() or + flushCommits() should be invoked so Puts + will not be lost. + + For fine-grained control of batching of + Puts or Deletes, + see the batch methods on HTable. + +