std::function<> requires the functor it wraps to be copyable, which is
an unnecessarily strict requirement. To relax this, we use
noncopyable_function<> instead. Since the former seems to lack some
disambiguation magic of the latter, we add `_v1` and `_v2` postfixes to
manually disambiguate.
The flat_mutation_reader files were conflated and contained multiple
readers, which were not strictly necessary. Splitting optimizes both
iterative compilation times, as touching rarely used readers doesn't
recompile large chunks of codebase. Total compilation times are also
improved, as the size of flat_mutation_reader.hh and
flat_mutation_reader_v2.hh have been reduced and those files are
included by many file in the codebase.
With changes
real 29m14.051s
user 168m39.071s
sys 5m13.443s
Without changes
real 30m36.203s
user 175m43.354s
sys 5m26.376s
Closes#10194
The underlying implementation behind the v1 and v2 variants if said
methods is the same, but we want to move to using the v2 variant in the
test as the v1 variant is going away soon.
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
Just a facade using converters behind the scenes. The actual segregator
is not worth migrating to v2 while mutation and the flushing readers
don't have a v2 versions. Still, migrating all users to a v2 API allows
the conversion to happen at a single point where more work is necessary,
instead of scattered around all the users.
We leave the v1 version in place to aid incremental migration to the v2
one.
The gc_grace_seconds is a very fragile and broken design inherited from
Cassandra. Deleted data can be resurrected if cluster wide repair is not
performed within gc_grace_seconds. This design pushes the job of making
the database consistency to the user. In practice, it is very hard to
guarantee repair is performed within gc_grace_seconds all the time. For
example, repair workload has the lowest priority in the system which can
be slowed down by the higher priority workload, so that there is no
guarantee when a repair can finish. A gc_grace_seconds value that is
used to work might not work after data volume grows in a cluster. Users
might want to avoid running repair during a specific period where
latency is the top priority for their business.
To solve this problem, an automatic mechanism to protect data
resurrection is proposed and implemented. The main idea is to remove the
tombstone only after the range that covers the tombstone is repaired.
In this patch, a new table option tombstone_gc is added. The option is
used to configure tombstone gc mode. For example:
1) GC a tombstone after gc_grace_seconds
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'timeout'} ;
This is the default mode. If no tombstone_gc option is specified by the
user. The old gc_grace_seconds based gc will be used.
2) Never GC a tombstone
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'disabled'};
3) GC a tombstone immediately
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'immediate'};
4) GC a tombstone after repair
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'repair'};
In addition to the 'mode' option, another option 'propagation_delay_in_seconds'
is added. It defines the max time a write could possibly delay before it
eventually arrives at a node.
A new gossip feature TOMBSTONE_GC_OPTIONS is added. The new tombstone_gc
option can only be used after the whole cluster supports the new
feature. A mixed cluster works with no problem.
Tests: compaction_test.py, ninja test
Fixes#3560
[avi: resolve conflicts vs data_dictionary]
Add schema parameter so that:
* Caller has better control over schema -- especially relevant for
reverse reads where it is not possible to follow the convention of
passing the query schema which is reversed compared to that of the
mutations.
* Now that we don't depend on the mutations for the schema, we can lift
the restriction on mutations not being empty: this leads to safer
code. When the mutations parameter is empty, an empty reader is
created.
Add "make_" prefix to follow convention of similar reader factory
functions.
Tests: unit(dev)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20211115155614.363663-1-bdenes@scylladb.com>
Test both methods: the "old" disk-based one and the recently added
in-memory one, with different configurations and also add additional
checks to ensure they don't loose data.
Recently we observed an OOM caused by the partition based splitting
writer going crazy, creating 1.7K buckets while scrubbing an especially
broken sstable. To avoid situations like that in the future, this patch
provides a max limit for the number of live buckets. When the number of
buckets reach this number, the largest bucket is closed and replaced by
a bucket. This will end up creating more output sstables during scrub
overall, but now they won't all be written at the same time causing
insane memory pressure and possibly OOM.
Scrub compaction sets this limit to 100, the same limit the TWCS's
timestamp based splitting writer uses (implemented through the
classifier -
time_window_compaction_strategy::max_data_segregation_window_count).
Fixes: #9400
Tests: unit(dev)
Closes#9401
Add a new segregator which segregates a stream, potentially containing
duplicate or even out-of-order partitions, into multiple output streams,
such that each output stream has strictly monotonic partitions.
This segregator will be used by a new scrub compaction mode which is
meant to fix sstables containing duplicate or out-of-order data.
`with_closeable` simplifies scoped use of
flat_mutation_reader, making sure to always close
the reader after use.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
bucket_writer::close waits for the _consumer_fut.
It is called both after consume_end_of_stream()
and after abort().
_consumer_fut is expected to return an exception
on the abort path. Wait for it and drop any exception
so it won't be abandoned as seen in #7904.
With that moved to close() time, consume_end_of_stream
doesn't need to return a future and is made void
all the way in the stack. This is ok since
queue_reader_handle::push_end_of_stream is synchronous too.
Added a unit test that aborts the reader consumer
during `segregate_by_timestamp`, reproducing the
Exceptional future ignored issue without the fix.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Consolidate shard_based_splitting_writer::shard_writer
and timestamp_based_splitting_writer::bucket_writer
common code into mutation_writer::bucket_writer.
This provides a common place to handle consume_end_of_stream()
and abort(), and in particular the handling of the underlying
_conmsumer_fut.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
We want to start tracking the memory consumption of mutation fragments.
For this we need schema and permit during construction, and on each
modification, so the memory consumption can be recalculated and pass to
the permit.
In this patch we just add the new parameters and go through the insane
churn of updating all call sites. They will be used in the next patch.
Not used yet, this patch does all the churn of propagating a permit
to each impl.
In the next patch we will use it to track to track the memory
consumption of `_buffer`.
random_schema already has a _schema field which in turn
has a get_partitioner() function. Store partitioner
in random_schema is redundant.
At the moment all uses of random_schema are based on
default partitioner so it is not necessary to set it
explicitly. If in the future we need random_schema to
work with other partitioners we will add the constructor
back and fix the creation of _schema to contain it. It's
not needed now though.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
1. Move tests to test (using singular seems to be a convention
in the rest of the code base)
2. Move boost tests to test/boost, other
(non-boost) unit tests to test/unit, tests which are
expected to be run manually to test/manual.
Update configure.py and test.py with new paths to tests.
