Jim Paton 1036537c94 Add soft and hard rate limit support
Summary:
This diff adds support for both soft and hard rate limiting. The following changes are included:

1) Options.rate_limit is renamed to Options.hard_rate_limit.
2) Options.rate_limit_delay_milliseconds is renamed to Options.rate_limit_delay_max_milliseconds.
3) Options.soft_rate_limit is added.
4) If the maximum compaction score is > hard_rate_limit and rate_limit_delay_max_milliseconds == 0, then writes are delayed by 1 ms at a time until the max compaction score falls below hard_rate_limit.
5) If the max compaction score is > soft_rate_limit but <= hard_rate_limit, then writes are delayed by 0-1 ms depending on how close we are to hard_rate_limit.
6) Users can disable 4 by setting hard_rate_limit = 0. They can add a limit to the maximum amount of time waited by setting rate_limit_delay_max_milliseconds > 0. Thus, the old behavior can be preserved by setting soft_rate_limit = 0, which is the default.

Test Plan:
make -j32 check
./db_stress

Reviewers: dhruba, haobo, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12003
2013-08-05 15:43:49 -07:00
2013-08-05 15:43:49 -07:00
2012-08-28 11:43:33 -07:00
2012-12-14 14:05:27 -08:00
2012-09-17 10:56:26 -07:00
2013-08-05 15:43:49 -07:00
2013-02-01 11:34:25 -08:00
2013-01-14 18:40:22 -08:00
2013-03-14 16:00:23 -07:00
2013-07-30 08:30:13 -07:00
2013-04-10 17:23:58 -07:00

rocksdb: A persistent key-value store for flash storage
Authors: * The Facebook Database Engineering Team
         * Build on earlier work on leveldb by Sanjay Ghemawat 
           (sanjay@google.com) and Jeff Dean (jeff@google.com)

This code is a library that forms the core building block for a fast
key value server, especially suited for storing data on flash drives.
It has an Log-Stuctured-Merge-Database (LSM) design with flexible tradeoffs
between Write-Amplification-Factor(WAF), Read-Amplification-Factor (RAF)
and Space-Amplification-Factor(SAF). It has multi-threaded compactions,
making it specially suitable for storing multiple terabytes of data in a
single database.

The core of this code has been derived from open-source leveldb.

The code under this directory implements a system for maintaining a
persistent key/value store.

See doc/index.html for more explanation.
See doc/impl.html for a brief overview of the implementation.

The public interface is in include/*.h.  Callers should not include or
rely on the details of any other header files in this package.  Those
internal APIs may be changed without warning.

Guide to header files:

include/db.h
    Main interface to the DB: Start here

include/options.h
    Control over the behavior of an entire database, and also
    control over the behavior of individual reads and writes.

include/comparator.h
    Abstraction for user-specified comparison function.  If you want
    just bytewise comparison of keys, you can use the default comparator,
    but clients can write their own comparator implementations if they
    want custom ordering (e.g. to handle different character
    encodings, etc.)

include/iterator.h
    Interface for iterating over data. You can get an iterator
    from a DB object.

include/write_batch.h
    Interface for atomically applying multiple updates to a database.

include/slice.h
    A simple module for maintaining a pointer and a length into some
    other byte array.

include/status.h
    Status is returned from many of the public interfaces and is used
    to report success and various kinds of errors.

include/env.h
    Abstraction of the OS environment.  A posix implementation of
    this interface is in util/env_posix.cc

include/table_builder.h
    Lower-level modules that most clients probably won't use directly

include/cache.h
    An API for the block cache.

include/compaction_filter.h
    An API for a application filter invoked on every compaction.

include/filter_policy.h
    An API for configuring a bloom filter.

include/memtablerep.h
    An API for implementing a memtable.

include/statistics.h
    An API to retrieve various database statistics.

include/transaction_log_iterator.h
    An API to retrieve transaction logs from a database.


Description
Decentralized cryptocurrency blockchain daemon implementing the XRP Ledger protocol in C++
Readme 2.1 GiB
Languages
C++ 99.4%
CMake 0.5%