There's yet another -test-env -- the alternator- one -- which needs
gossiper. It now uses global reference, but can grab gossiper reference
from the cql-test-env which partitipates in initialization.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Seastar is an external library from Scylla's point of view so
we should use the angle bracket #include style. Most of the source
follows this, this patch fixes a few stragglers.
Also fix cases of #include which reached out to seastar's directory
tree directly, via #include "seastar/include/sesatar/..." to
just refer to <seastar/...>.
Closes#10433
And adjust callers. The factory functions just sprinkle upgrade_to_v2()
on returned readers for now.
One test in row_cache_test.cc had to be disabled, because the upgrade to
v2 wrapper we now have over cache readers doesn't allow it to directly
control the reader's buffer size and so the test fails. There is a FIXME
left in the test code and the test will be re-enabled once a native v2
reader implementation allows us to get rid of the upgrade wrapper.
Measure performance of the single-mutation reader:
make_flat_mutation_reader_from_mutation_v2.
Comparable to the `one_row` case that consumes the
single mutation using the multi-mutatio reader:
make_flat_mutation_reader_from_mutations_v2
perf_mutation_readers shows ~20-30% improvement of
make_flat_mutation_reader_from_mutation_v2
the same single mutation, just given as a single-item vector
to make_flat_mutation_reader_from_mutations_v2.
test iterations median mad min max
Before:
combined.one_row 720118 825.668ns 1.020ns 824.648ns 827.750ns
After:
combined.one_mutation 881482 751.157ns 0.397ns 750.211ns 751.912ns
combined.one_row 843270 756.553ns 0.303ns 755.889ns 757.911ns
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Adds sub-template for time_parallel with templated result type + optional
per-iteration post-process func. Idea is that Res may be a subtype of
perf_result, with additional stats, initiated on init, and post-process
function can fix up and apply stats -> we can add stats to result.
In most files it was unused. We should move these to the patch which
moved out the last interesting reader from mutation_reader.hh (and added
the corresponding new header include) but its probably not worth the
effort.
Some other files still relied on mutation_reader.hh to provide reader
concurrency semaphore and some other misc reader related definitions.
"
Cleanup compaction works by rewriting all sstables that need clean up, one at
a time.
This approach can cause bad write amplification because the output data is
being made incrementally available for regular compaction.
Cleanup is a long operation on large data sets, and while it's happening,
new data can be written to buckets, triggering regular compaction.
Cleanup fighting for resources with regular compaction is a known problem.
With cleanup adding one file at a time to buckets, regular may require multiple
rounds to compact the data in a given bucket B, producing bad writeamp.
To fix this problem, cleanup will be made bucket aware. As each compaction
strategy has its own definition of bucket, strategies will implement their
own method to retrieve cleanup jobs. The method will be implemented such that
all files in a bucket B will be cleaned up together, and on completion,
they'll be made available for regular at once.
For STCS / ICS, a bucket is a size tier.
For TWCS, a bucket is a window.
For LCS, a bucket is a level.
In this way, writeamp problem is fixed as regular won't have to perform
multiple rounds to compact the data in a given bucket. Additionally, cleanup
will now be able to deduplicate data and will become way more efficient at
garbage collecting expired data.
The space requirement shouldn't be an issue, as compacting an entire bucket
happens during regular compaction anyway.
With leveled strategy, compacting an entire level is also not a problem because
files in a level L don't overlap and therefore incremental compaction is
employed to limit the space requirement.
By the time being, only STCS cleanup was made bucket aware. The others will be
using a default method, where one file is cleaned up at a time. Making cleanup
of other strategies bucket aware is relatively easy now and will be done soon.
Refs #10097.
"
* 'cleanup-compaction-revamp/v3' of https://github.com/raphaelsc/scylla:
test: sstable_compaction_test: Add test for strategy cleanup method
compaction: STCS: Implement cleanup strategy
compaction_manager: Wire cleanup task into the strategy cleanup method
compaction_strategy: Allow strategies to define their own cleanup strategy
compaction: Introduce compaction_descriptor::sstables_size
compaction: Move decision of garbage collection from strategy to task type
Based on perf_simple_query, just bashes data into CL using
normal distribution min/max data chunk size, allowing direct
freeing of segments, _but_ delayed by a normal dist as well,
to "simulate" secondary delay in data persistance.
Needs more stuff.
Some baseline measurements on master:
--min-flush-delay-in-ms 10 --max-flush-delay-in-ms 200
--commitlog-use-hard-size-limit true
--commitlog-total-space-in-mb 10000 --min-data-size 160 --max-data-size 1024
--smp1
median 2065648.59 tps ( 1.1 allocs/op, 0.0 tasks/op, 1482 insns/op)
median absolute deviation: 48752.44
maximum: 2161987.06
minimum: 1984267.90
--min-data-size 256 --max-data-size 16384
median 269385.25 tps ( 2.2 allocs/op, 0.7 tasks/op, 3244 insns/op)
median absolute deviation: 15719.13
maximum: 323574.43
minimum: 228206.28
--min-data-size 4096 --max-data-size 61440
median 67734.22 tps ( 6.4 allocs/op, 2.9 tasks/op, 9153 insns/op)
median absolute deviation: 2070.93
maximum: 82833.17
minimum: 61473.57
--min-data-size 61440 --max-data-size 1843200
median 2281.37 tps ( 79.7 allocs/op, 43.5 tasks/op, 202963 insns/op)
median absolute deviation: 128.87
maximum: 3143.84
minimum: 2140.80
--min-data-size 368640 --max-data-size 6144000
median 679.76 tps (225.5 allocs/op, 116.3 tasks/op, 662700 insns/op)
median absolute deviation: 39.30
maximum: 1148.95
minimum: 586.86
Actual throughput obviously meaningless, as it is run on my slow
machine, but IPS might be relevant.
Note that transaction throughput plummets as we increase median data
sizes above ~200k, since we then more or less always end up replacing
buffers in every call.
Closes#10230
For compaction to be able to purge expired data, like tombstones, a
sstable set snapshot is set in the compaction descriptor.
That's a decision that belongs to task type. For example, all regular
compaction enable GC, whereas scrub for example doesn't for safety
reasons.
The problem is that the decision is being made by every instantiation
of compaction_descriptor in the strategies, which is both unnecessary
and also adds lots of boilerplate to the code, making it hard to
understand and work with.
As sstable set snapshot is an implementation detail, a new method
is being added to compaction_descriptor to make the intention
clearer, making the interface easier to understand.
can_purge_tombstones, used previously by rewrite task only, is being
reused for communicating GC intention into task::compact_sstables().
The boilerplate was a pain when adding a new strategy method for
the ongoing work on cleanup, described by issue #10097.
Another benefit is that we'll now only create a set snapshot when
compaction will really run. Before, it could happen that the snapshot
would be discarded if the compaction attempt had to be postponed,
which is a waste of cpu cycles.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
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
Memtables are a replica-side entity, and so are moved to the
replica module and namespace.
Memtables are also used outside the replica, in two places:
- in some virtual tables; this is also in some way inside the replica,
(virtual readers are installed at the replica level, not the
cooordinator), so I don't consider it a layering violation
- in many sstable unit tests, as a convenient way to create sstables
with known input. This is a layering violation.
We could make memtables their own module, but I think this is wrong.
Memtables are deeply tied into replica memory management, and trying
to make them a low-level primitive (at a lower level than sstables) will
be difficult. Not least because memtables use sstables. Instead, we
should have a memtable-like thing that doesn't support merging and
doesn't have all other funky memtable stuff, and instead replace
the uses of memtables in sstable tests with some kind of
make_flat_mutation_reader_from_unsorted_mutations() that does
the sorting that is the reason for the use of memtables in tests (and
live with the layering violation meanwhile).
Test: unit (dev)
Closes#10120
Initialize it to "md" until ME format support is
complete (i.e. storing originating host id in sstable stats metadata
is implemented), so at present there is no observable change by
default.
Also declare "enable_sstables_md_format" unused -- the idea, going
forward, being that only "sstable_format" controls the written sstable
file format and that no more per-format enablement config options
shall be added.
Signed-off-by: Michael Livshin <michael.livshin@scylladb.com>
After the mechanical change in fcb8d040e8
("treewide: use Software Package Data Exchange (SPDX) license identifiers"),
a few stray license blurbs or fragments thereof remain. In two cases
these were extra blurbs in code generators intended for the generated code,
in others they were just missed by the script.
Clean them up, adding an SPDX license identifier where needed.
Closes#10072
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
seastar::later() was recently deprecated and replaced with two
alternatives: a cheap seastar::yield() and an expensive (but more
powerful) seastar::check_for_io_immediately(), that corresponds to
the original later().
This patch replaces all later() calls with the weaker yield(). In
all cases except one, it's unambiguously correct. In one case
(test/perf scheduling_latency_measurer::stop()) it's not so ambiguous,
since check_for_io_immediately() will additionally force a poll and
so will cause more work to be done (but no additional tasks to be
executed). However, I think that any measurement that relies on
the measuring the work on the last tick to be inaccurate (you need
thousands of ticks to get any amount of confidence in the
measurement) that in the end it doesn't matter what we pick.
Tests: unit (dev)
Closes#9904
Move replica-oriented classes to the replica namespace. The main
classes moved are ::database, ::keyspace, and ::table, but a few
ancillary classes are also moved. There are certainly classes that
should be moved but aren't (like distributed_loader) but we have
to start somewhere.
References are adjusted treewide. In many cases, it is obvious that
a call site should not access the replica (but the data_dictionary
instead), but that is left for separate work.
scylla-gdb.py is adjusted to look for both the new and old names.
The database, keyspace, and table classes represent the replica-only
part of the objects after which they are named. Reading from a table
doesn't give you the full data, just the replica's view, and it is not
consistent since reconciliation is applied on the coordinator.
As a first step in acknowledging this, move the related files to
a replica/ subdirectory.
The test case assumed int32 partition key, but
scylla_bench_large_part_ds1 has int64 partition key. This resulted in
no results to be returned by the reader.
Fixs by introducing a partition key factory on the data source level.
Message-Id: <20220105150550.67951-1-tgrabiec@scylladb.com>
Make compaction procedure switch to table_state. Only function in
compaction.cc still directly using table is
get_fully_expired_sstables(T,...), but subsequently we'll make it
switch to table_state and then we can finally stop including database.hh
in the compaction code.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
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>
That's intended to fix a bad layer violation as table was given the
responsibility of disabling compaction for a given table T, but that
logic clearly belongs to compaction_manager instead.
Additionally, gate will be used instead of counter, as former provides
manager with a way to synchronize with functions running under
run_with_compaction_disabled. so remove() can wait for their
termination.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
there's no need for wrapping compaction_data in shared_ptr, also
let's kill unused params in create_compaction_data to simplify
its creation.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
So the compaction perf of different compaction strategies can be
compared. Data timestamps are diversified such that they fall into four
different bucket if TWCS is used, in order to be able to stress the
timestamp based splitting code path.
Closes#9488
gcc complains about comparing a signed loop induction variable
with an unsigned limit, or comparing an expected value and measured
value. Fix by using unsigned throughout, except in one case where
the signed value was needed for the data_value constructor.
compaction_info must only contain info data to be exported to the
outside world, whereas compaction_data will contain data for
controlling compaction behavior and stats which change as
compaction progresses.
This separation makes the interface clearer, also allowing for
future improvements like removing direct references to table
in compaction.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Today, compaction is calling compaction manager to register / deregister
the compaction_info created by it.
This is a layer violation because manager sits one layer above
compaction, so manager should be responsible for managing compaction
info.
From now on, compaction_info will be created and managed by
compaction_manager. compaction will only have a reference to info,
which it can use to update the world about compaction progress.
This will allow compaction_manager to be simplified as info can be
coupled with its respective task, allowing duplication to be removed
and layer violation to be fixed.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
There are now 231 translation units that indirectly include commitlog.hh
due to the need to have access to db::commitlog::force_sync.
Move that type to a new file commitlog_types.hh and make it available
without access to the commitlog class.
This reduces the number of translation units that depend on commitlog.hh
to 84, improving compile time.
"This series removes layer violation in compaction, and also
simplifies compaction manager and how it interacts with compaction
procedure."
* 'compaction_manager_layer_violation_fix/v3' of github.com:raphaelsc/scylla:
compaction: split compaction info and data for control
compaction_manager: use task when stopping a given compaction type
compaction: remove start_size and end_size from compaction_info
compaction_manager: introduce helpers for task
compaction_manager: introduce explicit ctor for task
compaction: kill sstables field in compaction_info
compaction: kill table pointer in compaction_info
compaction: simplify procedure to stop ongoing compactions
compaction: move management of compaction_info to compaction_manager
compaction: move output run id from compaction_info into task
compaction_info must only contain info data to be exported to the
outside world, whereas compaction_data will contain data for
controlling compaction behavior and stats which change as
compaction progresses.
This separation makes the interface clearer, also allowing for
future improvements like removing direct references to table
in compaction.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Today, compaction is calling compaction manager to register / deregister
the compaction_info created by it.
This is a layer violation because manager sits one layer above
compaction, so manager should be responsible for managing compaction
info.
From now on, compaction_info will be created and managed by
compaction_manager. compaction will only have a reference to info,
which it can use to update the world about compaction progress.
This will allow compaction_manager to be simplified as info can be
coupled with its respective task, allowing duplication to be removed
and layer violation to be fixed.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This needs to add forward declarations of the gossiper class and
re-include some other headers here and there.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This was a global variable that was potentially modified from a
performance benchmark. It would modify the behavior of `index_reader`
in certain scenarios.
Remove the variable so we can specify the behavior of `index_reader`
functions without relying on anything other than what's passed into the
constructor and the function parameters.
This warning can catch a virtual function that thinks it
overrides another, but doesn't, because the two functions
have different signatures. This isn't very likely since most
of our virtual functions override pure virtuals, but it's
still worth having.
Enable the warning and fix numerous violations.
Closes#9347
The default values for the fields of this class didn't make much sense,
and the default constructor was used only in a single place so removing
it is trivial.
It's safer when the user is forced to supply the limits.
Some state accessors called get_local_gossiper(); this is removed
and replaced with a parameter. Some callers (redis, alternators)
now have the gossiper passed as a parameter during initialization
so they can use the adjusted API.
