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In our pre-1.0 API, HTable is considered a light-weight object that consumed by a single thread at a time. The HTablePool class provided a means of sharing multiple HTable instances across a number of threads. As an optimization, HTable managed a "write buffer", accumulating edits and sending a "batch" all at once. By default the batch was sent as the last step in invocations of put(Put) and put(List<Put>). The user could disable the automatic flushing of the write buffer, retaining edits locally and only sending the whole "batch" once the write buffer has filled or when the flushCommits() method in invoked explicitly. Explicit or implicit batch writing was controlled by the setAutoFlushTo(boolean) method. A value of true (the default) had the write buffer flushed at the completion of a call to put(Put) or put(List<Put>). A value of false allowed for explicit buffer management. HTable also exposed the buffer to consumers via getWriteBuffer(). The combination of HTable with setAutoFlushTo(false) and the HTablePool provided a convenient mechanism by which multiple "Put-producing" threads could share a common write buffer. Both HTablePool and HTable are deprecated, and they are officially replaced in The new 1.0 API by Table and BufferedMutator. Table, which replaces HTable, no longer exposes explicit write-buffer management. Instead, explicit buffer management is exposed via BufferedMutator. BufferedMutator is made safe for concurrent use. Where code would previously retrieve and return HTables from an HTablePool, now that code creates and shares a single BufferedMutator instance across all threads. |
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| bin | ||
| conf | ||
| dev-support | ||
| hbase-annotations | ||
| hbase-assembly | ||
| hbase-checkstyle | ||
| hbase-client | ||
| hbase-common | ||
| hbase-examples | ||
| hbase-hadoop-compat | ||
| hbase-hadoop2-compat | ||
| hbase-it | ||
| hbase-native-client | ||
| hbase-prefix-tree | ||
| hbase-protocol | ||
| hbase-rest | ||
| hbase-server | ||
| hbase-shell | ||
| hbase-testing-util | ||
| hbase-thrift | ||
| src/main | ||
| .arcconfig | ||
| .gitattributes | ||
| .gitignore | ||
| CHANGES.txt | ||
| LICENSE.txt | ||
| NOTICE.txt | ||
| README.txt | ||
| pom.xml | ||
README.txt
Apache HBase [1] is an open-source, distributed, versioned, column-oriented store modeled after Google' Bigtable: A Distributed Storage System for Structured Data by Chang et al.[2] Just as Bigtable leverages the distributed data storage provided by the Google File System, HBase provides Bigtable-like capabilities on top of Apache Hadoop [3]. To get started using HBase, the full documentation for this release can be found under the doc/ directory that accompanies this README. Using a browser, open the docs/index.html to view the project home page (or browse to [1]). The hbase 'book' at http://hbase.apache.org/book.html has a 'quick start' section and is where you should being your exploration of the hbase project. The latest HBase can be downloaded from an Apache Mirror [4]. The source code can be found at [5] The HBase issue tracker is at [6] Apache HBase is made available under the Apache License, version 2.0 [7] The HBase mailing lists and archives are listed here [8]. The HBase distribution includes cryptographic software. See the export control notice here [9]. 1. http://hbase.apache.org 2. http://research.google.com/archive/bigtable.html 3. http://hadoop.apache.org 4. http://www.apache.org/dyn/closer.cgi/hbase/ 5. https://hbase.apache.org/source-repository.html 6. https://hbase.apache.org/issue-tracking.html 7. http://hbase.apache.org/license.html 8. http://hbase.apache.org/mail-lists.html 9. https://hbase.apache.org/export_control.html