rocksdb/hdfs
Dhruba Borthakur 1ca0584345 This is the mega-patch multi-threaded compaction
published in https://reviews.facebook.net/D5997.

Summary:
This patch allows compaction to occur in multiple background threads
concurrently.

If a manual compaction is issued, the system falls back to a
single-compaction-thread model. This is done to ensure correctess
and simplicity of code. When the manual compaction is finished,
the system resumes its concurrent-compaction mode automatically.

The updates to the manifest are done via group-commit approach.

Test Plan: run db_bench
2012-10-19 14:00:53 -07:00
..
README Create leveldb server via Thrift. 2012-07-07 09:42:39 -07:00
env_hdfs.h This is the mega-patch multi-threaded compaction 2012-10-19 14:00:53 -07:00
hdfs.h Make Leveldb save data into HDFS files. You have to set USE_HDFS in your environment variable to compile leveldb with HDFS support. 2012-06-14 00:29:01 -07:00
libhdfs.a Add libhdfs.a to the build process. 2012-08-29 15:21:56 -07:00

README

This directory contains the hdfs extensions needed to make leveldb store
files in HDFS.

The hdfs.h file is copied from the Apache Hadoop 1.0 source code. 
It defines the libhdfs library
(http://hadoop.apache.org/common/docs/r0.20.2/libhdfs.html) to access 
data in HDFS.  The libhdfs.a is copied from the Apache Hadoop 1.0 build. 
It implements the API defined in hdfs.h. If your hadoop cluster is running
a different hadoop release, then install these two files manually from your
hadoop distribution and then recompile leveldb.

The env_hdfs.h file defines the leveldb objects that are needed to talk to an
underlying filesystem. 

If you want to compile leveldb with hdfs support, please set the following
enviroment variables appropriately:
   USE_HDFS=1
   JAVA_HOME=/usr/local/jdk-6u22-64
   LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/jdk-6u22-64/jre/lib/amd64/server:/usr/local/jdk-6u22-64/jre/lib/amd64/:./snappy/libs
   make clean all db_bench

To run dbbench,
  set CLASSPATH to include your hadoop distribution
  db_bench --hdfs="hdfs://hbaseudbperf001.snc1.facebook.com:9000"