rocksdb/hdfs
Andrew Kryczka 6cc9aef162 New API for background work in single thread pool
Summary:
Previously users could set `max_background_flushes=0` to force rocksdb to use a single thread pool for both background flushes and compactions. That'll no longer be possible since I'm going to deprecate `max_background_flushes` and `max_background_compactions` in favor of a single option. This diff introduces a new way to force a single thread pool: when high-pri pool has zero threads, all background jobs will be submitted to low-pri pool.

Note the majority of the code change is adding `Env::GetBackgroundThreads()`, which is necessary to check whether the user has provided a zero-sized thread pool.
Closes https://github.com/facebook/rocksdb/pull/2204

Differential Revision: D4936256

Pulled By: ajkr

fbshipit-source-id: 929a07a0c0705f7766f5339cd013ff74e90d6e01
2017-05-23 11:12:27 -07:00
..
env_hdfs.h New API for background work in single thread pool 2017-05-23 11:12:27 -07:00
README using java7 in runtime for hdfs env (#1072) 2016-04-12 00:08:26 -04:00
setup.sh hdfs cleanup and compile test against CDH 4.4. 2014-05-20 17:22:12 -04:00

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

It has been compiled and testing against CDH 4.4 (2.0.0+1475-1.cdh4.4.0.p0.23~precise-cdh4.4.0).

The configuration assumes that packages libhdfs0, libhdfs0-dev are 
installed which basically means that hdfs.h is in /usr/include and libhdfs in /usr/lib

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

If you want to compile rocksdb with hdfs support, please set the following
environment variables appropriately (also defined in setup.sh for convenience)
   USE_HDFS=1
   JAVA_HOME=/usr/local/jdk-7u79-64
   LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/jdk-7u79-64/jre/lib/amd64/server:/usr/local/jdk-7u79-64/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"