Remove pices related to Riak, clean up other things.

This commit is contained in:
Gregory Burd 2012-06-19 15:00:48 +01:00
parent 30fd2ded4c
commit 8f8cda0776

View file

@ -1,11 +1,13 @@
# HanoiDB Ordered Key/Value Storage
# HanoiDB Indexed Key/Value Storage
HanoiDB implements an ordered key/value storage engine, implemented
using "doubling sizes" persistent ordered sets of key/value pairs,
much like LevelDB.
Here's the bullet list:
HanoiDB implements an indexed, key/value storage engine. The primary index is
a log-structured merge tree (LSM-BTree) implemented using "doubling sizes"
persistent ordered sets of key/value pairs, similar is some regards to
[LevelDB](http://code.google.com/p/leveldb/). HanoiDB includes a visualizer
which when used to watch a living database resembles the "Towers of Hanoi"
puzzle game, which inspired the name of this database.
## Features
- Insert, Delete and Read all have worst case *O*(log<sub>2</sub>(*N*)) latency.
- Incremental space reclaimation: The cost of evicting stale key/values
is amortized into insertion
@ -14,20 +16,25 @@ Here's the bullet list:
- Operations-friendly "append-only" storage
- allows you to backup live system
- crash-recovery is very fast and the logic is straight forward
- All data subject to CRC32 checksums
- Supports efficient range queries
- all data subject to CRC32 checksums
- data can be compressed on disk to save space
- Efficient range queries
- Riak secondary indexing
- Fast key and bucket listing
- Uses bloom filters to avoid unnecessary lookups on disk
- Time-based expiry of data
- configure the database to expire data older than n seconds
- specify a lifetime in seconds for any particular key/value pair
- Efficient resource utilization
- Doesn't store all keys in memory
- Uses a modest number of file descriptors proportional to the number of levels
- IO is generally balanced between random and sequential
- Low CPU overhead
- doesn't store all keys in memory
- uses a modest number of file descriptors proportional to the number of levels
- I/O is generally balanced between random and sequential
- low CPU overhead
- ~2000 lines of pure Erlang code in src/*.erl
HanoiDB is developed by Trifork, a Riak expert solutions provider. You're most
welcome to contact us if you want help optimizing your Riak setup.
HanoiDB is developed by Trifork, a Riak expert solutions provider, and Basho
Technologies, makers of Riak. HanoiDB can be used in Riak via the
`riak_kv_tower_backend` repository.
### Configuration options
@ -40,7 +47,7 @@ Put these values in your `app.config` in the `hanoidb` section
%% Enable/disable on-disk compression.
%%
{compress, none | gzip},
%% Expire (automatically delete) entries after N seconds.
%% When this value is 0 (zero), entries never expire.
%%
@ -76,20 +83,3 @@ Put these values in your `app.config` in the `hanoidb` section
{merge_strategy, fast | predictable}
]},
```
### How to deploy HanoiDB as a Riak/KV backend
This storage engine can function as an alternative backend for Basho's Riak/KV.
You can deploy `hanoidb` into a Riak devrel cluster using the `enable-hanoidb`
script. Clone the `riak` repo, change your working directory to it, and then
execute the `enable-hanoidb` script. It adds `hanoidb` as a dependency, runs `make
all devrel`, and then modifies the configuration settings of the resulting dev
nodes to use the hanoidb storage backend.
1. `git clone git://github.com/basho/riak.git`
1. `mkdir riak/deps`
1. `cd riak/deps`
1. `git clone git://github.com/basho/hanoidb.git`
1. `cd ..`
1. `./deps/hanoidb/enable-hanoidb`