Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
Enable creating shared_ptr<BaseClass> in nonstatic_class_registry
using BaseClass::ptr_type and use that for
abstract_replication_strategy.
While at it, also clean up compressor with that respect
to define compressor::ptr_type as shared_ptr<compressor>
thus simplifying compressor_registry.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Cassandra 3.0 deprecated the 'sstable_compression' attribute and added
'class' as a replacement. Follow by supporting both.
The SSTABLE_COMPRESSION variable is renamed to SSTABLE_COMPRESSION_DEPRECATED
to detect all uses and prevent future misuse.
To prevent old-version nodes from seeing the new name, the
compression_parameters class preserves the key name when it is
constructed from an options map, and emits the same key name when
asked to generate an options map.
Existing unit tests are modified to use the new name, and a test
is added to ensure the old name is still supported.
Fixes#8948.
Closes#8949
Replace stdx::optional and stdx::string_view with the C++ std
counterparts.
Some instances of boost::variant were also replaced with std::variant,
namely those that called seastar::visit.
Scylla now requires GCC 8 to compile.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20190108111141.5369-1-duarte@scylladb.com>
This patch adds compatibility for Cassandra's "chunk_size_in_kb", as
well as it keeps Scylla's "chunk_size_kb" compression parameter.
Fixes#3669
Tests: unit (release)
v2: use variable instead of array
v3: fix commited files
Signed-off-by: Juliana Oliveira <juliana@scylladb.com>
Message-Id: <20181211215840.GA7379@shenzou.localdomain>
Make a "compressor" an actual class, that can be implemented and
registered via class registry.
For "common" compressors, the objects will be shared, but complex
implementors can be semi-stateful.
sstable compression is split into two parts: The "static" config
which is shared across shards, and a "local" one, which holds
a compressor pointer. The latter is encapsulated, along with
actual compressed data writers, in sstables/compress.cc.
For compression (write), compression writer is instansiated
with the settings active in table metadata.
For decompression (read), compression reader is instansiated
with the settings stored in sstable metadata, which can
differ from the currently active table metadata.
v2:
* Structured patch sets differently (dependencies)
* Added more comments/api descs
* Added patch to move all sstable compression into compress.cc,
effectively separating top-level virtual compressor object
from sstable io knowledge
v3:
* Rebased
v4:
* Moved all sstable compression logic/knowledge into
compress.cc (local compression). Merged the two patches
(separation just confuses reader).
The CQL 3.1 documentation specifies that for disabling compression,
users should use an empty string:
ALTER TABLE mytable WITH COMPRESSION = {'sstable_compression': ''};
However, Cassandra also accepts the absence of the sstable_compression
option to disable compression. The patch 7c28ed prevented this behavior
in Scylla, which this patch aims to fix.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <1478639499-4183-1-git-send-email-duarte@scylladb.com>
This patch extracts the definition of the default compressor into the
compression_parameters class, so that the table and view creation
statements don't have to explicitly deal with it.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Following Cassandra, our default sstable compression chunk size is 64 KB.
The big downside of this default size is that small reads need to read
and uncompress a large chunk, around 32 KB (if compression halves the data
size). In this patch we switch the default chunk size to 4 KB, which allows
faster small reads (the report in issue #1337 was of a 60-fold speedup...).
Since commit 2f56577, large reads will not be signficantly slowed down by
changing to a small chunk size. The remaining potential downside of this
change is lowering of the compression ratio because of the smaller chunks
individually compressed. However, experimentation shows that the compression
ratio is hurt somewhat, but not dramatically, by lowering the chunk size:
A recent survey of Cassandra compression in
https://www.percona.com/blog/2016/03/09/evaluating-database-compression-methods/
reports a compression ratio of 2 for 64 KB chunks, vs. 1.75 for 4 KB chunks.
My own test on a cassandra-stress workload (whose data is relatively hard
to compress), showed compression ratio 1.25 for 64 KB chunk, vs. 1.23 for
4 KB chunks.
Also remember that if a user wants to control the chunk length for a
particular table, he can - the 64 KB or 4 KB sizes are just the default.
Fixes#1337
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <1467063335-12096-1-git-send-email-nyh@scylladb.com>
Passing a single enum specifying a compressor type around is not enough,
since there are other compression options user may want to specify.
Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>
The field compressor is about saying which compressor algorithm
must be used in compression of sstable data file.
This is a small step towards compressed sstable data file.
Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
