65 lines
2.5 KiB
Text
65 lines
2.5 KiB
Text
bLSM initial release
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====================
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This is an initial release of bLSM, which is scheduled to appear in
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Sigmod 2012. bLSM is a general-purpose log structured merge tree that
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targets highly-available, scalable, key-value storage systems.
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We have been careful to minimize the number of seeks performed by read
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and scan optimizations, and have introduced a new spring-and-gear "level
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scheduler" that bounds write latencies.
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The implementation is currently geared toward performance testing, and
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has a number of limitations that we plan to address in short order:
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* Recovery does not work until after enough data has been inserted to
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start filling disk with data.
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* bLSM does not take advantage of write skew to reduce write
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amplification. As a side effect, certain heavily skewed workloads will
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lead to unacceptably write latencies. We plan to address this by
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partitioning the state on disk, and scheduling merges based on the heat of
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each partition.
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In the mean time, feel free to drop me a line at sears@cs.berkeley.edu
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Licensing
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=========
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bLSM uses several 3rd party open source libraries and tools.
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This file summarizes the tools used, their purpose, and the licenses
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under which they're released. Portions of bLSM are based upon Stasis'
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"Rose" LSM-Tree implementation.
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http://code.google.com/p/stasis/source/browse/trunk/benchmarks/rose.cpp
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Except as specifically stated below, the 3rd party software packages
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listed below are not distributed as part of this project, but instead
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are separately downloaded from the respective provider and built on
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the developer’s machine as a pre-build step.
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bLSM relies upon Stasis, a transactional storage library written and
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maintained by the authors of bLSM.
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TCL/TK license (BSD-style)
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http://code.google.com/p/stasis/source/browse/trunk/COPYING
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http://code.google.com/p/stasis/
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bLSM includes an example MapKeeper-compatible storage server, which
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relies upon the MapKeeper prototocol specification, which we also
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maintain:
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https://github.com/m1ch1/mapkeeper
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Apache 2.0 license: https://github.com/m1ch1/mapkeeper/blob/master/LICENSE.txt
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The generated MapKeeper files (and, therefore the bLSM MapKeeper
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bindings) also require Thrift and Boost.
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Thrift is a serialization and RPC framework:
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http://thrift.apache.org/
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Apache 2.0 license: http://svn.apache.org/viewvc/thrift/trunk/LICENSE?view=markup
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Boost is a collection of utility libraries for C++:
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http://www.boost.org/
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Boost Software License: http://www.boost.org/users/license.html
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