Currently, while stopping the compaction_manager, we stop task_manager
compaction module and concurrently run compaction_manager::really_do_stop.
really_do_stop stops and waits for all task_executors that are kept
in compaction_manager::_tasks, but nothing ensures that no more tasks will
be added there. Due to leftover tasks, we trigger on_fatal_internal_error.
Modify the order of compaction_manager::stop. After the change, we stop
compaction tasks in the following order:
- abort module abort source;
- close module gate in the background;
- stop_ongoing_compactions (kept in compaction_manager::_tasks);
- wait until module gate is closed.
Check module abort source before creating compaction executor and
adding it to _tasks.
Thanks to the above, we can be sure that:
- after module::stop there will be no tasks in _tasks;
- compaction_manager::stop aborts all tasks; we don't wait for any whole
compaction to finish.
Fixes: https://github.com/scylladb/scylladb/issues/25806.
Fixes shutdown bug; Needs backports to all version
- (cherry picked from commit 17707d0e6b)
- (cherry picked from commit 97c77d7cd5)
Parent PR: #25885Closesscylladb/scylladb#26222
* github.com:scylladb/scylladb:
compaction: move _tasks check
compaction: stop compaction module in really_do_stop
In compaction_manager::really_do_stop we check whether _tasks list
is empty after the compactions are stopped. However, a new task may
still sneak in, causing the assertion failure. Such a task won't
be there for long - module::make_task will fail as the module is
already stopped.
Move the assertion, that checks if _tasks is empty, after the
compaction_states' gates are closed.
Fixes: #25806.
(cherry picked from commit 97c77d7cd5)
Currently, compaction::task_manager_module is stopped in compaction_manager::stop,
concurrently to really_do_stop. We can't predict the order of the two.
Do not set _task_manager_module to nullptr at stop, because
compaction_manager::really_do_stop() may be called before the actual
shutdown, while other components still try to use it.
compaction::task_manager_module does not keep a pointer to compaction_manager,
so we won't end up with memory leak.
Stop compaction module in really_do_stop, after ongoing compactions
are stopped.
It's a preparation for further patches.
(cherry picked from commit 17707d0e6b)
compaction/scrub: register sstables for compaction before validation
When `scrub --validate` runs, it collects all candidate sstables at the
start and validates them one by one in separate compaction tasks.
However, scrub in validate mode does not register these sstables for
compaction, which allows regular compaction to pick them up and
potentially compact them away before validation begins. This leads to
scrub failures because the sstables can no longer be found.
This patch fixes the issue by first disabling compaction, collecting the
sstables, and then registering them for compaction before starting
validation. This ensures that the enqueued sstables remain available for
the entire duration of the scrub validation task.
Fixes#23363
This reported scrub failure occurs on all versions that have the
checksum/digest validation feature for uncompressed sstables.
So, backport it to older versions.
- (cherry picked from commit 84f2e99c05)
- (cherry picked from commit 7cdda510ee)
Parent PR: #26034Closesscylladb/scylladb#26097
* github.com:scylladb/scylladb:
compaction/scrub: register sstables for compaction before validation
compaction/scrub: handle exceptions when moving invalid sstables to quarantine
The `drain` method, cancels all running compactions and moves the
compaction manager into the disabled state. To move it back to
the enabled state, the `enable` method shall be called.
This, however, throws an assertion error as the submission time is
not cancelled and re-enabling the manager tries to arm the armed timer.
Thus, cancel the timer, when calling the drain method to disable
the compaction manager.
Fixes https://github.com/scylladb/scylladb/issues/24504
All versions are affected. So it's a good candidate for a backport.
Closesscylladb/scylladb#24505
(cherry picked from commit a9a53d9178)
Closesscylladb/scylladb#24589
When `scrub --validate` runs, it collects all candidate sstables at the
start and validates them one by one in separate compaction tasks.
However, scrub in validate mode does not register these sstables for
compaction, which allows regular compaction to pick them up and
potentially compact them away before validation begins. This leads to
scrub failures because the sstables can no longer be found.
This patch fixes the issue by first disabling compaction, collecting the
sstables, and then registering them for compaction before starting
validation. This ensures that the enqueued sstables remain available for
the entire duration of the scrub validation task.
Fixes#23363
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 7cdda510ee)
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
In validate mode, scrub moves invalid sstables into the quarantine
folder. If validation fails because the sstable files are missing from
disk, there is nothing to move, and the quarantine step will throw an
exception. Handle such exceptions so scrub can return a proper
compaction_result instead of propagating the exception to the caller.
This will help the testcase for #23363 to reliably determine if the
scrub has failed or not.
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 84f2e99c05)
Interval map is very susceptible to quadratic space behavior when
it's flooded with many entries overlapping all (or most of)
intervals, since each such entry will have presence on all
intervals it overlaps with.
A trigger we observed was memtable flush storm, which creates many
small "L0" sstables that spans roughly the entire token range.
Since we cannot rely on insertion order, solution will be about
storing sstables with such wide ranges in a vector (unleveled).
There should be no consequence for single-key reads, since upper
layer applies an additional filtering based on token of key being
queried.
And for range scans, there can be an increase in memory usage,
but not significant because the sstables span an wide range and
would have been selected in the combined reader if the range of
scan overlaps with them.
Anyway, this is a protection against storm of memtable flushes
and shouldn't be the common scenario.
It works both with tablets and vnodes, by adjusting the token
range spanned by compaction group accordingly.
Fixes#23634.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
(cherry picked from commit c77f710a0c)
This will be useful for feeding token range owned by compaction group
into sstable set.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
(cherry picked from commit 21d1e78457)
This provides a way for compaction layer to know compaction group's
token range. It will be important for sstable set impl to know
the token range of underlying group.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
(cherry picked from commit 59dad2121f)
Convert tasks::task_manager::task::impl::release_resources() to a coroutine
to prepare for upcoming changes that will implement asynchronous resource
release.
This is a preparatory refactoring that enables future coroutine-based
implementation of resource cleanup logic.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
(cherry picked from commit 4c1f1baab4)
Replace remaining uses of boost::adaptors::transformed with std::views::transform
to reduce Boost dependencies, following the migration pattern established in
bab12e3a. This change addresses recently merged code that reintroduced Boost
header dependencies through boost::adaptors::transformed usage.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22365
now that we are allowed to use C++23. we now have the luxury of using
`std::views::reverse`.
- replace `boost::adaptors::transformed` with `std::views::transform`
- remove unused `#include <boost/range/adaptor/reversed.hpp>`
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
ICS is a compaction strategy that inherits size tiered properties --
therefore it's write optimized too -- but fixes its space overhead of
100% due to input files being only released on completion. That's
achieved with the concept of sstable run (similar in concept to LCS
levels) which breaks a large sstable into fixed-size chunks (1G by
default), known as run fragments. ICS picks similar-sized runs
for compaction, and fragments of those runs can be released
incrementally as they're compacted, reducing the space overhead
to about (number_of_input_runs * 1G). This allows user to increase
storage density of nodes (from 50% to ~80%), reducing the cost of
ownership.
NOTE: test_system_schema_version_is_stable adjusted to account for batchlog
using IncrementalCompactionStrategy
contains:
compaction/: added incremental_compaction_strategy.cc (.hh), incremental_backlog_tracker.cc (.hh)
compaction/CMakeLists.txt: include ICS cc files
configure.py: changes for ICS files, includes test
db/legacy_schema_migrator.cc / db/schema_tables.cc: fallback to ICS when strategy is not supported
db/system_keyspace: pick ICS for some system tables
schema/schema.hh: ICS becomes default
test/boost: Add incremental_compaction_test.cc
test/boost/sstable_compaction_test.cc: ICS related changes
test/cqlpy/test_compaction_strategy_validation.py: ICS related changes
docs/architecture/compaction/compaction-strategies.rst: changes to ICS section
docs/cql/compaction.rst: changes to ICS section
docs/cql/ddl.rst: adds reference to ICS options
docs/getting-started/system-requirements.rst: updates sentence mentioning ICS
docs/kb/compaction.rst: changes to ICS section
docs/kb/garbage-collection-ics.rst: add file
docs/kb/index.rst: add reference to <garbage-collection-ics>
docs/operating-scylla/procedures/tips/production-readiness.rst: add ICS section
some relevant commits throughout the ICS history:
commit 434b97699b39c570d0d849d372bf64f418e5c692
Merge: 105586f747 30250749b8
Author: Paweł Dziepak <pdziepak@scylladb.com>
Date: Tue Mar 12 12:14:23 2019 +0000
Merge "Introduce Incremental Compaction Strategy (ICS)" from Raphael
"
Introduce new compaction strategy which is essentially like size tiered
but will work with the existing incremental compaction. Thus incremental
compaction strategy.
It works like size tiered, but each element composing a tier is a sstable
run, meaning that the compaction strategy will look for N similar-sized
sstable runs to compact, not just individual sstables.
Parameters:
* "sstable_size_in_mb": defines the maximum sstable (fragment) size
composing
a sstable run, which impacts directly the disk space requirement which is
improved with incremental compaction.
The lower the value the lower the space requirement for compaction because
fragments involved will be released more frequently.
* all others available in size tiered compaction strategy
HOWTO
=====
To change an existing table to use it, do:
ALTER TABLE mykeyspace.mytable WITH compaction =
{'class' : 'IncrementalCompactionStrategy'};
Set fragment size:
ALTER TABLE mykeyspace.mytable WITH compaction =
{'class' : 'IncrementalCompactionStrategy', 'sstable_size_in_mb' : 1000 }
"
commit 94ef3cd29a196bedbbeb8707e20fe78a197f30a1
Merge: dca89ce7a5 e08ef3e1a3
Author: Avi Kivity <avi@scylladb.com>
Date: Tue Sep 8 11:31:52 2020 +0300
Merge "Add feature to limit space amplification in Incremental Compaction" from Raphael
"
A new option, space_amplification_goal (SAG), is being added to ICS. This option
will allow ICS user to set a goal on the space amplification (SA). It's not
supposed to be an upper bound on the space amplification, but rather, a goal.
This new option will be disabled by default as it doesn't benefit write-only
(no overwrites) workloads and could hurt severely the write performance.
The strategy is free to delay triggering this new behavior, in order to
increase overall compaction efficiency.
The graph below shows how this feature works in practice for different values
of space_amplification_goal:
https://user-images.githubusercontent.com/1409139/89347544-60b7b980-d681-11ea-87ab-e2fdc3ecb9f0.png
When strategy finds space amplification crossed space_amplification_goal, it
will work on reducing the SA by doing a cross-tier compaction on the two
largest tiers. This feature works only on the two largest tiers, because taking
into account others, could hurt the compaction efficiency which is based on
the fact that the more similar-sized sstables are compacted together the higher
the compaction efficiency will be.
With SAG enabled, min_threshold only plays an important role on the smallest
tiers, given that the second-largest tier could be compacted into the largest
tier for a space_amplification_goal value < 2.
By making the options space_amplification_goal and min_threshold independent,
user will be able to tune write amplification and space amplification, based on
the needs. The lower the space_amplification_goal the higher the write
amplification, but by increasing the min threshold, the write amplification
can be decreased to a desired amount.
"
commit 7d90911c5fb3fa891ad64a62147c3a6ca26d61b1
Author: Raphael S. Carvalho <raphaelsc@scylladb.com>
Date: Sat Oct 16 13:41:46 2021 -0300
compaction: ICS: Add garbage collection
Today, ICS lacks an approach to persist expired tombstones in a timely manner,
which is a problem because accumulation of tombstones are known to affecting
latency considerably.
For an expired tombstone to be purged, it has to reach the top of the LSM tree
and hope that older overlapping data wasn't introduced at the bottom.
The condition are there and must be satisfied to avoid data resurrection.
STCS, today, has an inefficient garbage collection approach because it only
picks a single sstable, which satisfies the tombstone density threshold and
file staleness. That's a problem because overlapping data either on same tier
or smaller tiers will prevent tombstones from being purged. Also, nothing is
done to push the tombstones to the top of the tree, for the conditions to be
eventually satisfied.
Due to incremental compaction, ICS can more easily have an effecient GC by
doing cross-tier compaction of relevant tiers.
The trigger will be file staleness and tombstone density, which threshold
values can be configured by tombstone_compaction_interval and
tombstone_threshold, respectively.
If ICS finds a tier which meets both conditions, then that tier and the
larger[1] *and* closest-in-size[2] tier will be compacted together.
[1]: A larger tier is picked because we want tombstones to eventually reach the
top of the tree.
[2]: It also has to be the closest-in-size tier as the smaller the size
difference the higher the efficiency of the compaction. We want to minimize
write amplification as much as possible.
The staleness condition is there to prevent the same file from being picked
over and over again in a short interval.
With this approach, ICS will be continuously working to purge garbage while
not hurting overall efficiency on a steady state, as same-tier compactions are
prioritized.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20211016164146.38010-1-raphaelsc@scylladb.com>
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#22063
now that we are allowed to use C++23. we now have the luxury of using
`std::ranges::to`.
in this change, we:
- replace `boost::copy_range` to `std::ranges::to`
- remove unused `#include` of boost headers
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21880
now that we are allowed to use C++23. we now have the luxury of using
`std::views::transform`.
in this change, we:
- replace `boost::adaptors::transformed` with `std::views::transform`
- use `fmt::join()` when appropriate where `boost::algorithm::join()`
is not applicable to a range view returned by `std::view::transform`.
- use `std::ranges::fold_left()` to accumulate the range returned by
`std::view::transform`
- use `std::ranges::fold_left()` to get the maximum element in the
range returned by `std::view::transform`
- use `std::ranges::min()` to get the minimal element in the range
returned by `std::view::transform`
- use `std::ranges::equal()` to compare the range views returned
by `std::view::transform`
- remove unused `#include <boost/range/adaptor/transformed.hpp>`
- use `std::ranges::subrange()` instead of `boost::make_iterator_range()`,
to feed `std::views::transform()` a view range.
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
limitations:
there are still a couple places where we are still using
`boost::adaptors::transformed` due to the lack of a C++23 alternative
for `boost::join()` and `boost::adaptors::uniqued`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21700
these unused includes are identified by clang-include-cleaner. after
auditing the source files, all of the reports have been confirmed.
please note, because `mutation/mutation.hh` does not include
`seastar/coroutine/maybe_yield.hh` anymore, and quite a few source
files were relying on this header to bring in the declaration of
`maybe_yield()`, we have to include this header in the places where
this symbol is used. the same applies to `seastar/core/when_all.hh`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
tombstone_gc.hh is relatively lightweight and is used in many places,
but it includes the heavyweight boost/icl/interval_map.hh. Lighten
the load for its users by wrapping lw_shared_ptr<some icl map type>
in a forward-declared class. Define the class in a new header
tombstone_gc-internals.hh, to be used by the two translation units
that need it.
Ref #1.
Closesscylladb/scylladb#21706
When users start an operation asynchronously with API, they are expected to check the operation's status. Hence, the status should be kept in task manager for reasonable time after the operation is done. The operations that are started internally usually don't need to stay in task manager for that long.
Add api_task_ttl that will be used for tasks started with API. By default it's 1 hour. The time for which non-API tasks stay in task manager isn't changed.
Fixes: #21499.
Refs: #21425.
No backport needed - previous versions may use task_ttl
Closesscylladb/scylladb#21505
* github.com:scylladb/scylladb:
test: add test to check user_task_ttl
tasks: api: move make_task method
docs: nodetool: update backup and restore commands docs
docs: update task manager docs
nodetool: add nodetool tasks user-ttl command
node_ops: use user task ttl for node ops virtual task
tasks: use user_task_ttl for tasks started by user
api: task_manager: add /task_manager/user_ttl to get and set user task ttl
tasks: add task_manager::task::is_user_task method
tasks: keep updateable_value of task_ttl in task manager
db: config: add user_task_ttl_seconds named value
Modernize the codebase by replacing Boost range adaptors with C++23 standard library views,
reducing external dependencies and leveraging modern C++ language features.
Key Changes:
- Replace `boost::adaptors::filtered` with `std::views::filter`
- Remove `#include <boost/range/adaptor/filtered.hpp>`
- Utilize standard library range views
Motivation:
- Reduce project's external dependency footprint
- Leverage standard library's range and view capabilities
- Improve long-term code maintainability
- Align with modern C++ best practices
Implementation Challenges and Considerations:
1. Range Conversion and Move Semantics
- `std::ranges::to` adaptor requires rvalue references
- Necessitated updates to variable and parameter constness
- Example: `cql3/restrictions/statement_restrictions.cc` modified to remove `const`
from `common` to enable efficient range conversion
2. Range Iteration and Mutation
- Range views may mutate internal state during iteration
- Cannot pass ranges by const reference in some scenarios
- Solution: Pass ranges by rvalue reference to explicitly indicate
state invalidation
Limitations:
- One instance of `boost::adaptors::filtered` temporarily preserved
due to lack of a C++23 alternative for `boost::join()`
- A comprehensive replacement will be addressed in a follow-up change
This change is part of our ongoing effort to modernize the codebase,
reducing external dependencies and adopting modern C++ practices.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21648
This PR enables compaction tasks to verify the integrity of the input data through checksum and digest checks. The mechanism for integrity checking was introduced in previous PRs (#20207, #20720) as a built-in functionality of the input streams. This PR integrates this mechanism with compaction. The change applies to all compaction types and covers both compressed and uncompressed SSTables adhering to the 3.x format. If a compaction task reads only part of an SSTable, then only the per-chunk checksums are verified, not the digest.
The PR consists of:
* Changes to mx readers to support integrity checking. The kl readers, considered as compatibility-only, were left unchanged. Also, integrity checking on single-partition reversed reads (`data_consume_reversed_partition()`) remains unsupported by mx readers as this is not used in compaction.
* Changes to `sstable` and `sstable_set` APIs to allow toggling integrity checks for mx readers.
* Activation of integrity checking for all compaction types.
* Tests for all compaction types with corrupted SSTables.
Integrity checks come at a cost. For uncompressed SSTables, the cost is the loading of the CRC and Digest components from disk, and the calculation of checksums and digest from the actual data. For compressed SSTables, checksums are stored in-place and they are being checked already on all reads, so the only extra cost is the loading and calculation of the digest. The measurements show a ~5% regression in compaction performance for uncompressed SSTables, and a negligible regression for compressed SSTables.
Command: `perf-sstable --smp=1 --cpuset=1 --poll-mode --mode=compaction --iterations=1000 --partitions 10000 --sstables=1 --key_size=4096 --num_columns=15 --column_size={32, 1024, 3500, 7000, 14500}`
Uncompressed SSTables:
```
+--------------+-----------------------+----------------------+------------+
| SSTable Size | No Integrity (p/sec) | Integrity (p/sec) | Regression |
+--------------+-----------------------+----------------------+------------+
| 50 MiB | 65175.59 +- 80.82 | 61814.63 +- 72.88 | 5.16% |
| 200 MiB | 41795.10 +- 60.39 | 39686.28 +- 45.05 | 5.05% |
| 500 MiB | 21087.41 +- 30.72 | 20092.93 +- 25.05 | 4.72% |
| 1 GiB | 12781.64 +- 21.77 | 12233.94 +- 21.71 | 4.29% |
| 2 GiB | 6629.99 +- 9.40 | 6377.13 +- 8.28 | 3.81% |
+--------------+-----------------------+----------------------+------------+
```
Compressed SSTables:
```
+--------------+-----------------------+----------------------+------------+
| SSTable Size | No Integrity (p/sec) | Integrity (p/sec) | Regression |
+--------------+-----------------------+----------------------+------------+
| 50 MiB | 53975.05 +- 63.18 | 53825.93 +- 62.28 | 0.28% |
| 200 MiB | 28687.94 +- 26.58 | 28689.41 +- 26.91 | 0% |
| 500 MiB | 13865.35 +- 15.50 | 13790.41 +- 14.88 | 0.54% |
| 1 GiB | 7858.10 +- 7.71 | 7829.75 +- 9.66 | 0.36% |
| 2 GiB | 4023.11 +- 2.43 | 4010.54 +- 2.55 | 0.31% |
+--------------+-----------------------+----------------------+------------+
(p/sec = partitions/sec)
```
Refs #19071.
New feature, no backport is needed.
Closesscylladb/scylladb#21153
* github.com:scylladb/scylladb:
test: Add test for compaction with corrupted SSTables
compaction: Enable integrity checks for all compaction types
sstables: Add integrity option to factories for sstable_set readers
sstables: Add integrity option to sstable::make_reader()
sstables: Add integrity option to mx::make_reader()
sstables: Load checksums and digests in mx full-scan reader
sstables: Add integrity option to data_consume_single_partition()
sstables: Disengage integrity_check from sstable class
sstables: Allow data sources to disable digest check
Compaction tasks create mutation readers to read SSTables from disk.
Each compaction type defines its own reader creation logic by
implementing the pure virtual function `compaction::make_sstable_reader()`.
Modify all implementations of `make_sstable_reader()` to enable
integrity checking on the created readers. This way, all compaction
tasks will be able to detect corruption issues on the compacting
SSTables.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
Split compaction divides the partitions in an existing sstable into two
groups and writes them into two new sstables, which replace the original
one. The partition count from the original sstable is used as an
estimate when writing the new ones, but this estimate is not accurate as
the partitions are split between the two new sstables and each will
contain only a portion of the original partition count. This also causes
the bloom filters to be rebuilt at the end of compaction, as they were
initially built with inaccurate estimates.
Fix this by using a better estimate for the output sstables based on the
token ranges written to them.
Fixes scylladb#20253
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
we don't use `std::list` in compaction/compaction_manager.hh, neither
is this header responsible for exposing the declarations in `<list>`.
so let's stop `#include` this header.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21436
now that we are allowed to use C++23. we now have the luxury of using
`std::ranges::any_of`.
in this change, we replace `boost::algorithm::any_of` with
`std::ranges::any_of`
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
The current condition that consults the compaction manager
state for awaiting `_stop_future` works since _stop_future
is assigned after the state is set to `stopped`, but it is
incidental. What matters is that `_stop_future` is engaged.
While at it, exchange _stop_future with a ready future
so that stop() can be safely called multiple times.
And dropped the superfluous co_return.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
stop_ongoing_compactions now ignores any errors returned
by tasks, and it should leave no task left behind.
Assert that here, before the compaction_manager is destroyed.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
stop() methods, like destructors must always succeed,
and returning errors from them is futile as there is
nothing else we can do with them but continue with shutdown.
Leaked errors on the stop path may cause termination
on shutdown, when called in a deferred action destructor.
Fixesscylladb/scylladb#21298
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Stopped tasks currently linger in _tasks until the fiber that created
the task is scheduled again and unlinks the task. This window between
stop and remove prevents reliable checks for empty _tasks list after all
tasks are stopped.
Unlink the task early so really_do_stop() can safely check for an empty
_tasks list (next patch).
_tasks is currently std::list<shared_ptr<compaction_task_executor>>, but
it has no role in keeping the instances alive, this is done by the
fibers which create the task (and pin a shared ptr instance).
This lends itself to an intrusive list, avoiding that extra
allocation upon push_back().
Using an intrusive list also makes it simpler and much cheaper (O(1) vs.
O(N)) to remove tasks from the _tasks list. This will be made use of in
the next patch.
Code using _task has to be updated because the value_type changes from
shared_ptr<compaction_task_executor> to compaction_task_executor&.
This pattern is -- if requested (by test) suspend code execution until requestor (the test) explicitly wakes it up. For that the injected place should inject a lambda that is called with so called "handler" at hand and try to read message from the handler. In many cases the inner lambda additionally prints a message into logs that tests waits upon to make sure injection was stepped on. In the end of the day this "breakpoint" is injected like
```
co_await inject("foo", [] (auto& handler) {
log.info("foo waiting");
co_await handler.wait_for_message(timeout);
});
```
This PR makes breakpoints shorter and more unified, like this
```
co_await inject("foo", wait_for_message(timeout));
```
where `wait_for_message` is a wrapper structure used to pick new `inject()` overload.
Closesscylladb/scylladb#21342
* github.com:scylladb/scylladb:
sstables: Use inject(wait_for_message_overload)
treewide,error_injection: Use inject(wait_for_message) and fix tests
treewide,error_injection: Use inject(wait_for_message) overload
error_injection: Add inject() overload with wait_for_message wrapper
When a compaction_group is removed via `compaction_manager::remove`,
it is erase from `_compaction_state`, and therefore compaction
is definitely not enabled on it.
This triggers an internal error if tablets are cleaned up
during drop/truncate, which checks that compaction is disabled
in all compaction groups.
Note that the callers of `compaction_disabled` aren't really
interested in compaction being actively disabled on the
compaction_group, but rather if it's enabled or not.
A follow-up patch can be consider to reverse the logic
and expose `compaction_enabled` rather than `compaction_disabled`.
Fixesscylladb/scylladb#20060
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closesscylladb/scylladb#21378
Many places want to inject a handler that waits for external kick. Now
there's convenience inject() method overload for this. It will result in
extra messages in logs, but so far no code/test cares about it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Add documentation to clarify the purpose and behavior of
make_interpose_consumer() in the compaction_strategy_impl class. This
method is crucial for building layered processing pipelines but its
semantics were previously undocumented.
The added documentation explains how:
- It decorates end consumers with additional processing steps
- It enables construction of processing pipelines
- The original consumer's semantics are preserved
This improves code maintainability by making the pipeline construction
pattern more apparent to developers.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21336
now that we are allowed to use C++23. we now have the luxury of using
`std::views::values`.
in this change, we:
- replace `boost::adaptors::map_values` with `std::views::values`
- update affected code to work with `std::views::values`
- the places where we use `boost::join()` are not changed, because
we cannot use `std::views::concat` yet. this helper is only
available in C++26.
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21265
Currently, running the `nodetool compactionhistory` command or using the rest api `curl -X GET --header "Accept: application/json" "http://localhost:10000/compaction_manager/compaction_history"` return compaction history without the `row_merged` field.
The series computes rows merged during compaction and provides this information to users via both the nodetool command and the rest api. The `rows_merged` field contains information on merged clustering keys across multiple sstable files. For instance, compacting two sstables of a table consisting of 7 rows where two rows are part of the both sstables, the output would have the following format: {1: 5, 2: 2}.
No backport is required. It extends the existing compaction history output.
Fixes https://github.com/scylladb/scylladb/issues/666Closesscylladb/scylladb#20481
* github.com:scylladb/scylladb:
test/rest_api: Add tests for compactionhistory
nodetool: Add rows merged stats into compactionhistory output
compaction: Update compaction history with collected histogram
compaction: Remove const qualifier from methods creating sstable readers
sstable_set: Add optional statistics to make_local_shard_sstable_reader
make_combined_reader: Add optional parameter, combined_reader_statistics
reader_selector: Extend with maximum reader count
mutation_fragment_merger: Create histogram while consuming mutation fragment batches
A new field has been added to the compaction_stats structure to hold
collected combined reader statistics. The struct is than used to update
the compaction_history table.
Compaction classes start mutate their internal members to be used
in methods setup_sstable_reader and make_sstable_reader creating
sstable reades that are marked as const.
Remove the const qualifier from these methods. Even though it made
sense initially to mark them as const, it is no longer applicable.
the log.hh under the root of the tree was created keep the backward
compatibility when seastar was extracted into a separate library.
so log.hh should belong to `utils` directory, as it is based solely
on seastar, and can be used all subsystems.
in this change, we move log.hh into utils/log.hh to that it is more
modularized. and this also improves the readability, when one see
`#include "utils/log.hh"`, it is obvious that this source file
needs the logging system, instead of its own log facility -- please
note, we do have two other `log.hh` in the tree.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
since chrono allows dividion between durations with different units. let
use it instead for rounding down to the nearest multiple of the window
size, for better readability.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#20476
This includes way too much, including <boost/regex.hpp>, which is huge.
Drop includes of adaptors.hpp and replace by what is needed.
Closesscylladb/scylladb#21187
