phanther/rubix

Cache File System optimized for columnar formats and object stores

RubiX

RubiX is a light-weight data caching framework that can be used by Big-Data engines. RubiX can be extended to support any engine that accesses data in cloud stores using Hadoop FileSystem interface via plugins. Using the same plugins, RubiX can also be extended to be used with any cloud store

Usecase

RubiX provides disk or in-memory caching of data, which would otherwise be accessed over network when it resides in cloud store, thereby improving performance.

Supported Engines and Cloud Stores

• Presto: Amazon S3 is supported
• Hadoop-1: Any engine using hadoop-1, e.g. Hive can utilize RubiX. Amazon S3 is supported

How to use it

RubiX has two components: a BookKeeper server and a FileSystem implementation that an engine should use.

List of things to be done to use RubiX are:

1. Start the BookKeeper server. It can be started via hadoop jar command, e.g.:

hadoop jar rubix-bookkeeper-1.0.jar com.qubole.rubix.bookkeeper.BookKeeperServer

2. Engine side changes:
   To use RubiX, you need to place the appropriate jars in the classpath and configure Engines to use RubiX filesystem to access the cloud store. Sections below show how to get started on RubiX with supported plugins

Using RubiX with Presto

1. Place rubix-bookkeeper.jar, rubix-core.jar, rubix-presto.jar in presto/plugin/hive-hadoop2/ directory.
   All these jars are packaged in rubix-presto.tar under assembly module
2. Configuration changes
   i. Set configuration to use RubiX filesystem in Presto.
   ii. Set "hive.force-local-scheduling=true" in hive.properties
3. Start/Re-start the Presto server

Using RubiX with Hive

1. Add RubiX jars: rubix-bookkeeper.jar, rubix-core.jar, rubix-hadoop1 either to hadoop/lib directly or via add jar command.
   All these jars are packaged in rubix-hadoop1.tar under assembly module
2. Configuration changes: Use following configs to start using RubiX
   fs.s3n.impl=com.qubole.rubix.hadoop1.CachingNativeS3FileSystem
   fs.s3.impl=com.qubole.rubix.hadoop1.CachingNativeS3FileSystem

Configurations

BookKeeper server configurations

These configurations are to be providing as hadoop configs while started the BookKeeper server

Configuration	Default	Description
hadoop.cache.data.bookkeeper.port	8899	The port on which BookKeeper server will listen
hadoop.cache.data.bookkeeper.max-threads	unbounded	Maximum number of threads BookKeeper can launch
hadoop.cache.data.block-size	1048576	The size in bytes in which the file is logically divided internally. Higher value means lesser space requirement for metadata but can cause reading of more additional data than needed
hadoop.cache.data.dirprefix.list	/media/ephemeral	Prefixes for paths of directories used to store cached data. Final paths created by appending suffix in range [0, 5] followed by fcache.
hadoop.cache.data.fullness.percentage	80	Percentage of total disk space to use for caching and backing files are deleted in an LRU way.
hadoop.cache.data.expiration	unbounded	How long data is kept in cache

FileSystem configurations

These configurations need to be provided by the engine which is going to use RubiX

Configuration	Default	Description
hadoop.cache.data.enabled	true	Control using cache or not
hadoop.cache.data.strict.mode	false	By default RubiX tries not to fail read requests if there are some errors and tries to fallback to reading directly from remote source. Setting this config to true will fail read request if there were errors in RubiX.
hadoop.cache.data.location.blacklist	empty	Regex blacklisting locations that should not be cached

Monitoring

Client side monitoring is set up right now, stats are published to MBean named rubix:name=stats

Engines which provide interface to view jmx stats can see these stats. E.g. in Presto you can run this query to see the stats:

presto:default> select * from jmx.jmx."rubix:name=stats";
    node     | cachedreads | extrareadfromremote |      hitrate       |      missrate      |   readfromcache    |  readfromremote   | remotereads | warmuppenalty 
-------------+-------------+---------------------+--------------------+--------------------+--------------------+-------------------+-------------+---------------
 presto-vbox |          25 |  1.7881784439086914 | 0.5681818181818182 | 0.4318181818181818 | 18.379225730895996 | 18.55983543395996 |          19 |             0 
(1 row)

Building

mvn clean install

Note that you will need thrift-0.9.0 installed

Need Help?

You can post your queries to https://groups.google.com/forum/#!forum/rubix-users