Severity: low-to-medium
- Remove redundant format() wrapping in debug log at consume_sstable()
(low: one heap allocation per sstable consumed)
- Move get_compactions(filter).size() inside is_enabled() guard in
do_stop_ongoing_compactions() (medium: builds entire compaction vector
just for .size() in log message)
- Guard eager ::format() of descriptor.sstables with is_enabled(debug)
(medium-high: formats entire sstable vector on every minor compaction)
AI-assisted: OpenCode / Claude Opus 4.6
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Dtest failed with:
table - Failed to load SSTable .../me-3gyn_0qwi_313gw2n2y90v2j4fcv-big-Data.db
of origin memtable due to std::runtime_error (Cannot split
.../me-3gyn_0qwi_313gw2n2y90v2j4fcv-big-Data.db because manager has compaction
disabled, reason might be out of space prevention), it will be unlinked...
The reason is that the error above is being triggered when the cause is
shutdown, not out of space prevention. Let's distinguish between the two
cases and log the error with warning level on shutdown.
Fixes https://github.com/scylladb/scylladb/issues/24850.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This pull request adds support for calculation and storing CRC32 digests for all SSTable components.
This change replaces plain file_writer with crc32_digest_file_writer for all SSTable components that should be checksummed. The resulting component digests are stored in the sstable structure
and later persisted to disk as part of the Scylla metadata component during writer::consume_end_of_stream.
Several test cases where introduced to verify expected behaviour.
Additionally, this PR adds new rewrite component mechanism for safe sstable component rewriting.
Previously, rewriting an sstable component (e.g., via rewrite_statistics) created a temporary file that was renamed to the final name after sealing. This allowed crash recovery by simply removing the temporary file on startup.
However, with component digests stored in scylla_metadata (#20100),
replacing a component like Statistics requires atomically updating both the component
and scylla_metadata with the new digest - impossible with POSIX rename.
The new mechanism creates a clone sstable with a fresh generation:
- Hard-links all components from the source except the component being rewritten and scylla_metadata
- Copies original sstable components pointer and recognized components from the source
- Invokes a modifier callback to adjust the new sstable before rewriting
- Writes the modified component along with updated scylla_metadata containing the new digest
- Seals the new sstable with a temporary TOC
- Replaces the old sstable atomically, the same way as it is done in compaction
This is built on the rewrite_sstables compaction framework to support batch operations (e.g., following incremental repair).
In case of any failure durning the whole process, sstable will be automatically deleted on the node startup due to
temporary toc persistence.
Backport is not required, it is a new feature
Fixes https://github.com/scylladb/scylladb/issues/20100, https://github.com/scylladb/scylladb/issues/27453Closesscylladb/scylladb#28338
* github.com:scylladb/scylladb:
docs: document components_digests subcomponent and trailing digest in Scylla.db
sstable_compaction_test: Add tests for perform_component_rewrite
sstable_test: add verification testcases of SSTable components digests persistance
sstables: store digest of all sstable components in scylla metadata
sstables: replace rewrite_statistics with new rewrite component mechanism
sstables: add new rewrite component mechanism for safe sstable component rewriting
compaction: add compaction_group_view method to specify sstable version
sstables: add null_data_sink and serialized_checksum for checksum-only calculation
sstables: extract default write open flags into a constant
sstables: Add write_simple_with_digest for component checksumming
sstables: Extract file writer closing logic into separate methods
sstables: Implement CRC32 digest-only writer
Consider this:
- repair takes the lock holder
- tablet merge filber destories the compaction group and the compaction state
- repair fails
- repair destroy the lock holder
This is observed in the test:
```
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036] Repair 1 out of 1 tablets: table=sec_index.users range=(432345564227567615,504403158265495551] replicas=[0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea:15, 498e354c-1254-4d8d-a565-2f5c6523845a:9, 5208598c-84f0-4526-bb7f-573728592172:28]
...
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: Started to repair 1 out of 1 tables in keyspace=sec_index, table=users, table_id=ea2072d0-ccd9-11f0-8dba-c5ab01bffb77, repair_reason=repair
repair - Enable incremental repair for table=sec_index.users range=(432345564227567615,504403158265495551]
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: get_sync_boundary: got error from node=0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea, keyspace=sec_index, table=users, range=(432345564227567615,504403158265495551], error=seastar::rpc::remote_verb_error (Compaction state for table [0x60f008fa34c0] not found)
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge
....
scylla[10793] Segmentation fault on shard 28, in scheduling group streaming
```
The rwlock in compaction_state could be destroyed before the lock holder
of the rwlock is destroyed. This causes user after free when the lock
the holder is destroyed.
To fix it, users of repair lock will now be waited when a compaction
group is being stopped.
That way, compaction group - which controls the lifetime of rwlock -
cannot be destroyed while the lock is held.
Additionally, the merge completion fiber - that might remove groups -
is properly serialized with incremental repair.
The issue can be reproduced using sanitize build consistently and can not
be reproduced after the fix.
Fixes#27365Closesscylladb/scylladb#28823
* github.com:scylladb/scylladb:
repair: Fix rwlock in compaction_state and lock holder lifecycle
repair: Prevent repair lock holder leakage after table drop
Consider this:
- repair takes the lock holder
- tablet merge filber destories the compaction group and the compaction state
- repair fails
- repair destroy the lock holder
This is observed in the test:
```
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036] Repair 1 out of 1 tablets: table=sec_index.users range=(432345564227567615,504403158265495551] replicas=[0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea:15, 498e354c-1254-4d8d-a565-2f5c6523845a:9, 5208598c-84f0-4526-bb7f-573728592172:28]
...
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: Started to repair 1 out of 1 tables in keyspace=sec_index, table=users, table_id=ea2072d0-ccd9-11f0-8dba-c5ab01bffb77, repair_reason=repair
repair - Enable incremental repair for table=sec_index.users range=(432345564227567615,504403158265495551]
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: get_sync_boundary: got error from node=0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea, keyspace=sec_index, table=users, range=(432345564227567615,504403158265495551], error=seastar::rpc::remote_verb_error (Compaction state for table [0x60f008fa34c0] not found)
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge
....
scylla[10793] Segmentation fault on shard 28, in scheduling group streaming
```
The rwlock in compaction_state could be destroyed before the lock holder
of the rwlock is destroyed. This causes user after free when the lock
the holder is destroyed.
To fix it, users of repair lock will now be waited when a compaction
group is being stopped.
That way, compaction group - which controls the lifetime of rwlock -
cannot be destroyed while the lock is held.
Additionally, the merge completion fiber - that might remove groups -
is properly serialized with incremental repair.
The issue can be reproduced using sanitize build consistently and can not
be reproduced after the fix.
Fixes#27365
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Split the chained inject_parameter().value_or() expression into two
separate named variables for clarity.
Use condition_variable::when() instead of wait(). when() is the
coroutine-native API, designed specifically for co_await contexts —
it avoids the heap allocation of a promise_waiter that wait() uses,
and instead uses a stack-based awaiter.
Closesscylladb/scylladb#28824
Previously, rewriting an sstable component (e.g., via rewrite_statistics) created a temporary file that was renamed
to the final name after sealing. This allows crash recovery by simply removing the temporary file on startup.
However, this approach won't work once component digests are stored in scylla_metadata,
as replacing a component like Statistics will require atomically updating both the component
and scylla_metadata with the new digest—impossible with POSIX rename.
The new mechanism creates a clone sstable with a fresh generation:
- Hard-links all components from the source except the component being rewritten and scylla metadata if update_sstable_id is true
- Copies original sstable components pointer and recognized components from the source
- Invokes a modifier callback to adjust the new sstable before rewriting
- Writes the modified component. If update_sstable_id is true, reads scylla metadata, generates new sstable_id and rewrites it.
- Seals the new sstable with a temporary TOC
- Replaces the old sstable atomically, the same way as it is done in compaction
This is built on the rewrite_sstables compaction framework to support batch operations (e.g., following incremental repair).
In case of any failure during the whole process, sstable will be automatically deleted on the node startup due to
temporary toc persistence.
This prepares the infrastructure for component digests. Once digests are introduced in scylla_metadata
this mechanism will be extended to also rewrite scylla metadata with the updated digest alongside the modified component, ensuring atomic updates of both.
The futurization refactoring in 9d3755f276 ("replica: Futurize
retrieval of sstable sets in compaction_group_view") changed
maybe_wait_for_sstable_count_reduction() from a single predicated
wait:
```
co_await cstate.compaction_done.wait([..] {
return num_runs_for_compaction() <= threshold
|| !can_perform_regular_compaction(t);
});
```
to a while loop with a predicated wait:
```
while (can_perform_regular_compaction(t)
&& co_await num_runs_for_compaction() > threshold) {
co_await cstate.compaction_done.wait([this, &t] {
return !can_perform_regular_compaction(t);
});
}
```
This was necessary because num_runs_for_compaction() became a
coroutine (returns future<size_t>) and can no longer be called
inside a condition_variable predicate (which must be synchronous).
However, the inner wait's predicate — !can_perform_regular_compaction(t)
— only returns true when compaction is disabled or the table is being
removed. During normal operation, every signal() from compaction_done
wakes the waiter, the predicate returns false, and the waiter
immediately goes back to sleep without ever re-checking the outer
while loop's num_runs_for_compaction() condition.
This causes memtable flushes to hang forever in
maybe_wait_for_sstable_count_reduction() whenever the sstable run
count exceeds the threshold, because completed compactions signal
compaction_done but the signal is swallowed by the predicate.
Fix by replacing the predicated wait with a bare wait(), so that
any signal (including from completed compactions) causes the outer
while loop to re-evaluate num_runs_for_compaction().
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-610Closesscylladb/scylladb#28801
This is a problem caught after removing split from
add_sstable_and_update_cache(), which was used by
intra node migration when loading new sstables
into the destination shard.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
If manager has been disabled due to out of space prevention, it's
important to throw an exception rather than silently not
splitting the new sstable.
Not splitting a sstable when needed can cause correctness issue
when finalizing split later.
It's better to fail the writer (e.g. repair one) which will be
retried than making caller think everything succeeded.
The new replica::table::add_new_sstable_and_update_cache() will
now unlink the new sstable on failure, so the table dir will
not be left with sstables not loaded.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This is crucial with MVs, since the splitting must preserve the state of
the original sstable. We want the sstable to be in staging dir, so it's
excluded when calculating the diff for performing pushes to view
replicas.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Since the function must only be used on new sstables, it should
be renamed to something describing its usage should be restricted.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Add support for the new configuration parameter `compaction_max_shares`,
and update the compaction manager to pass it down to the compaction
controller when it changes. The shares allocated to compaction jobs will
be limited by this new parameter.
Fixes#9431
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
Introduce an updateable value `max_shares` to compaction manager's
config. Also add a method `update_max_shares()` that applies the latest
`max_shares` value to the compaction controller’s `max_shares`. This new
variable will be connected to a config parameter in the next patch.
Refs #9431
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
Add a `max_shares` constructor parameter to compaction_controller to
allow configuring the maximum output of the control points at
construction time. The constructor now calls `set_max_shares()` with the
provided max_shares value. The subsequent commits will wire this value
to a new configuration option.
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
When auto compaction is disabled, all ongoing compactions, including
major compactions, are stopped. However, major compactions should not be
stopped, since the disable request applies only to regular auto
compactions.
This patch fixes the issue by tagging major compaction tasks with the
newly introduced `compaction_type::MajorCompaction`. Since
`table::disable_auto_compaction()` already requests the compaction
manager to stop only tasks of type `compaction_type::Compaction`, major
compactions will no longer be stopped.
Fixes#24501
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
This PR introduces support for a new scrub option: `--drop-unfixable-sstables`, which enables the dropping of corrupted SSTables during scrub only in segregate mode. The patch includes implementation, validation, and set of tests to ensure correct behavior and error handling.
Fixes#19060
Backport is not required, it is a new feature
Closesscylladb/scylladb#26579
* github.com:scylladb/scylladb:
sstable_compaction_test: add segregate mode tests for drop-unfixable-sstables option
test/nodetool: add scrub drop-unfixable-sstables option testcase
scrub: add support for dropping unfixable sstables in segregate mode
This patch adds a new flag `drop-unfixable-sstables` to the scrub operation
in segregate mode, allowing to automatically drop SSTables that
cannot be fixed during scrub. It also includes API support of the 'drop_unfixable_sstables'
paramater and validation to ensure this flag is not enabled in other modes rather than segragate.
The method `maybe_wait_for_sstable_count_reduction()`, when retrieving
the list of sstables for a possible compaction, holds a reference to the
compaction strategy. If the strategy is updated during execution, it can
cause a use after free issue. To prevent this, hold a copy of the
compaction strategy so it isn’t yanked away during the method’s
execution.
Refs #26546
Refs #25913
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
sstables/exceptions.hh still hosts some compaction specific exception
types. Move them over to the new compaction/exceptions.hh, to make the
compaction module more self-contained.
The namespace usage in this directory is very inconsistent, with files
and classes scattered in:
* global namespace
* namespace compaction
* namespace sstables
With cases, where all three used in the same file. This code used to
live in sstables/ and some of it still retains namespace sstables as a
heritage of that time. The mismatch between the dir (future module) and
the namespace used is confusing, so finish the migration and move all
code in compaction/ to namespace compaction too.
This patch, although large, is mechanic and only the following kind of
changes are made:
* replace namespace sstable {} with namespace compaction {}
* add namespace compaction {}
* drop/add sstables::
* drop/add compaction::
* move around forward-declarations so they are in the correct namespace
context
This refactoring revealed some awkward leftover coupling between
sstables and compaction, in sstables/sstable_set.cc, where the
make_sstable_set() methods of compaction strategies are implemented.
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.
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.
Our sstable format selection logic is weird, and hard to follow.
If I'm not misunderstanding, the pieces are:
1. There's the `sstable_format` config entry, which currently
doesn't do anything, but in the past it used to disable
cluster features for versions newer than the specified one.
2. There are deprecated and unused config entries for individual
versions (`enable_sstables_mc_format`, `enable_sstables_md_format`,
etc).
3. There is a cluster feature for each version:
ME_SSTABLE_FORMAT, MD_SSTABLE_FORMAT, etc.
(Currently all sstable version features have been grandfathered,
and aren't checked by the code anymore).
4. There's an entry in `system.scylla_local` which contains the
latest enabled sstable version. (Why? Isn't this directly derived
from cluster features anyway)?
5. There's `sstable_manager::_format` which contains the
sstable version to be used for new writes.
This field is updated by `sstables_format_selector`
based on cluster features and the `system.scylla_local` entry.
I don't see why those pieces are needed. Version selection has the
following constraints:
1. New sstables must be written with a format that supports existing
data. For example, range tombstones with an infinite bound are only
supported by sstables since version "mc". So if a range tombstone
with an infinite bound exists somewhere in the dataset,
the format chosen for new sstables has to be at least as new as "mc".
2. A new format might only be used after a corresponding cluster feature
is enabled. (Otherwise new sstables might become unreadable if they
are sent to another node, or if a node is downgraded).
3. The user should have a way to inhibit format ugprades if he wishes.
So far, constraint (1) has been fulfilled by never using formats older
than the newest format ever enabled on the node. (With an exception
for resharding and reshaping system tables).
Constraint (2) has been fulfilled by calling `sstable_manager::set_format`
only after the corresponsing cluster feature is enabled.
Constraint (3) has been fulfilled by the ability to inhibit cluster
features by setting `sstable_format` by some fixed value.
The main thing I don't like about this whole setup is that it doesn't
let me downgrade the preferred sstable format. After a format is
enabled, there is no way to go back to writing the old format again.
That is no good -- after I make some performance-sensitive changes
in a new format, it might turn out to be a pessimization for the
particular workload, and I want to be able to go back.
This patch aims to give a way to downgrade formats without violating
the constraints. What it does is:
1. The entry in `system.scylla_local` becomes obsolete.
After the patch we no longer update or read it.
As far as I understand, the purpose of this entry is to prevent
unwanted format downgrades (which is something cluster features
are designed for) and it's updated if and only if relevant
cluster features are updated. So there's no reason to have it,
we can just directly use cluster features.
2. `sstable_format_selector` gets deleted.
Without the `system.scylla_local` around, it's just a glorified
feature listener.
3. The format selection logic is moved into `sstable_manager`.
It already sees the `db::config` and the `gms::feature_service`.
For the foreseeable future, the knowledge of enabled cluster features
and current config should be enough information to pick the right formats.
4. The `sstable_format` entry in `db::config` is no longer intended to
inhibit cluster features. Instead, it is intended to select the
format for new sstables, and it becomes live-updatable.
5. Instead of writing new sstables with "highest supported" format,
(which used to be set by `sstables_format_selector`) we write
them with the "preferred" format, which is determined by
`sstable_manager` based on the combination of enabled features
and the current value of `sstable_format`.
Closesscylladb/scylladb#26092
[avi: Pavel found the reason for the scylla_local entry -
it predates stable storage for cluster features]
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.
Closesscylladb/scylladb#26034
* github.com:scylladb/scylladb:
compaction/scrub: register sstables for compaction before validation
compaction/scrub: handle exceptions when moving invalid sstables to quarantine
The compaction_manager::stop_compaction() method internally walks the
list of tasks and compares each task's compacting_table (which is
compaction group view pointer) with the given one. In case this
stop_compaction() method is called via API for a specific table, the
method walks the list of tasks for every compaction group from the
table, thus resulting in nr_groups * nr_tasks complexity. Not terrible,
but not nice either.
The proposal is to pass filtering function into the inner
do_stop_ongoing_compactions() method. Some users will pass a simple
"return true" lambda, but those that need to stop compactions for a
specitif table (e.g. -- the API handler) will effectively walk the
list of tasks once comparing the given compaction group's schema with
the target table one (spoiler: eventually this place will also be
simplified not to mess with replica::table at all).
One ugliness with the change is the way "scope" for logging message is
collected. If all tasks belong to the same table, then "for table ..."
is printed in logs. With the change the scope is no longer known
instantly and is evaluated dynamically while walking the list of tasks.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#25846
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>
The interface suggests the whole sstable cleanup is aborted with
'nodetool stop CLEANUP', but it is currently stopping only the
ongoing cleanup task, and the compaction manager will retry the
task since the error is not propagated all the way back to the
caller. With raft topology, the coordinator should retry it though
since cleanup became mandatory with automatic cleanup. So it's
only fixing the usage where cleanup is issued manually.
The stop exception is only propagated to the caller of cleanup.
When stopping tasks during shutdown, the exception is swallowed
and the error only returned to the caller.
Fixes#20823.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#24996
Using a single state variable to keep track whether compaction
manager is enabled/disabled is insufficient, as multiple services
may independently request compactions to be disabled.
To address this, a counter is introduced to record how many times
the compaction manager has been drained. The manager is considered
enabled only when this counter reaches zero.
Introducing a counter, enabled and disabled states become obsolete.
So they are replaced with a single running state.
The central idea of incremental repair is to allow repair participants
to select and repair only a portion of the dataset to speed up the
repair process. All repair participants must utilize an identical
selection method to repair and synchronize the same selected dataset.
There are two primary selection methods: time-based and file-based. The
time-based method selects data within a specified time frame. It is
versatile but it is less efficient because it requires reading all of
the dataset and omitting data beyond the time frame. The file-based
method selects data from unrepaired SSTables and is more efficient
because it allows the entire SSTable to be omitted. This document patch
implements the file-based selection method.
Incremental repair will only be supported for tablet tables; it will not
be supported for vnode tables. On one hand, the legacy vnode is less
important to support. On the other hand, the incremental repair for
vnode is much harder to implement. With vnodes, a SSTalbe could contain
data for multiple vnode ranges. When a given vnode range is repaired,
only a portion of the SSTable is repaired. This complicates the
manipulation of SSTables significantly during both repair and
compaction. With tablets, an entire tablet is repaired so that a
sstable is either fully repaired or not repaired which is a huge
simplification.
This patch uses the repaired_at from sstables::statistics component to
mark a sstable as repaired. It uses a virtual clock as the repair
timestamp, i.e., using a monotonically increasing number for the
repaired_at field of a SSTable and sstables_repaired_at column in
system.tablets table. Notice that when a sstable is not repaired, the
repaired_at field will be set to the default value 0 by default. The
being_repaired in memory field of a SSTable is used to explicitly mark
that a SSTable is being selected. The following variables are used for
incremental repair:
The repaired_at on disk field of a SSTable is used.
- A 64-bit number increases sequentially
The sstables_repaired_at is added to the system.tablets table.
- repaired_at <= sstables_repaired_at means the sstable is repaired
The being_repaired in memory field of a SSTable is added.
- A repair UUID tells which sstable has participated in the repair
Initial test results:
1) Medium dataset results
Node amount: 3
Instance type: i4i.2xlarge
Disk usage per node: ~500GB
Cluster pre-populated with ~500GB of data before starting repairs job.
Results for Repair Timings:
The regular repair run took 210 mins.
Incremental repair 1st run took 183 mins, 2nd and 3rd runs took around 48s
The speedup is: 183 mins / 48s = 228X
2) Small dataset results
Node amount: 3
Instance type: i4i.2xlarge
Disk usage per node: ~167GB
Cluster pre-populated with ~167GB of data before starting the repairs job.
Regular repair 1st run took 110s, 2nd and 3rd runs took 110s.
Incremental repair 1st run took 110 seconds, 2nd and 3rd run took 1.5 seconds.
The speedup is: 110s / 1.5s = 73X
3) Large dataset results
Node amount: 6
Instance type: i4i.2xlarge, 3 racks
50% of base load, 50% read/write
Dataset == Sum of data on each node
Dataset Non-incremental repair (minutes)
1.3 TiB 31:07
3.5 TiB 25:10
5.0 TiB 19:03
6.3 TiB 31:42
Dataset Incremental repair (minutes)
1.3 TiB 24:32
3.0 TiB 13:06
4.0 TiB 5:23
4.8 TiB 7:14
5.6 TiB 3:58
6.3 TiB 7:33
7.0 TiB 6:55
Fixes#22472Closesscylladb/scylladb#24291
* github.com:scylladb/scylladb:
replica: Introduce get_compaction_reenablers_and_lock_holders_for_repair
compaction: Move compaction_reenabler to compaction_reenabler.hh
topology_coordinator: Make rpc::remote_verb_error to warning level
repair: Add metrics for sstable bytes read and skipped from sstables
test.py: Disable incremental for test_tombstone_gc_for_streaming_and_repair
test.py: Add tests for tablet incremental repair
repair: Add tablet incremental repair support
compaction: Add tablet incremental repair support
feature_service: Add TABLET_INCREMENTAL_REPAIR feature
tablet_allocator: Add tablet_force_tablet_count_increase and decrease
repair: Add incremental helpers
sstable: Add being_repaired to sstable
sstables: Add set_repaired_at to metadata_collector
mutation_compactor: Introduce add operator to compaction_stats
tablet: Add sstables_repaired_at to system.tablets table
test: Fix drain api in task_manager_client.py
This patch addes incremental_repair support in compaction.
- The sstables are split into repaired and unrepaired set.
- Repaired and unrepaired set compact sperately.
- The repaired_at from sstable and sstables_repaired_at from
system.tablets table are used to decide if a sstable is repaired or
not.
- Different compactions tasks, e.g., minor, major, scrub, split, are
serialized with tablet repair.
Instead of storing it partially in tombstone_gc and partially in an
external map. Move all external parts into the new
shared_tombstone_gc_state. This new class is responsible for
keeping and updating the repair history. tombstone_gc_state just keeps
const pointers to the shared state as before and is only responsible for
querying the tombstone gc before times.
This separation makes the code easier to follow and also enables further
patching of tombstone_gc_state.
This will allow upcoming work to gently produce a sstable set for
each compaction group view. Example: repaired and unrepaired.
Locking strategy for compaction's sstable selection:
Since sstable retrieval path became futurized, tasks in compaction
manager will now hold the write lock (compaction_state::lock)
when retrieving the sstable list, feeding them into compaction
strategy, and finally registering selected sstables as compacting.
The last step prevents another concurrent task from picking the
same sstable. Previously, all those steps were atomic, but
we have seen stall in that area in large installations, so
futurization of that area would come sooner or later.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Since there will be only one physical sstable set, it makes sense to move
backlog tracker to replica::compaction_group. With incremental repair,
it still makes sense to compute backlog accounting both logical sets,
since the compound backlog influences the overall read amplification,
and the total backlog across repaired and unrepaired sets can help
driving decisions like giving up on incremental repair when unrepaired
set is almost as large as the repaired set, causing an amplification
of 2.
Also it's needed for correctness because a sstable can move quickly
across the logical sets, and having one tracker for each logical
set could cause the sstable to not be erased in the old set it
belonged to;
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Since table_state is a view to a compaction group, it makes sense
to rename it as so.
With upcoming incremental repair, each replica::compaction_group
will be actually two compaction groups, so there will be two
views for each replica::compaction_group.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This tells "cleanup" (done via try_perform_cleanup) and prepares the
ground for more callers (see next patch)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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
Currently, the `system.compaction_history` table miss information like the type of compaction (cleanup, major, resharding, etc), the sstable generations involved (in and out), shard's id the compaction was triggered on and statistics on purged tombstones to be collected during compaction.
The series extends the table with the following columns:
- "compaction_type" (text)
- "shard_id" (int)
- "sstables_in" (list<sstableinfo_type>)
- "sstables_out" (list<sstableinfo_type>)
- "total_tombstone_purge_attempt" (long)
- "total_tombstone_purge_failure_due_to_overlapping_with_memtable" (long)
- "total_tombstone_purge_failure_due_to_overlapping_with_uncompacting_sstable" (long)
with a user defined type `sstableinfo_type` that holds the information about sstable file
- generation (uuid)
- origin (text)
- size (long)
Additional statistics stored in the compaction_history have been incorporated in the API `/compaction_manager/compaction_history` and the `nodetool compactionhistory` command.
No backport is required. It extends the existing compaction history output.
Fixes https://github.com/scylladb/scylladb/issues/3791Closesscylladb/scylladb#21288
* github.com:scylladb/scylladb:
nodetool: Refactor of compactionhistory_operation
nodetool: Add more stats into compactionhistory output
api/compaction_manager: Extend compaction_history api
compaction: Collect tombstone purge stats during compaction
compacting_reader: Extend to accept tombstone purge statistics
mutation_compactor: Collect tombstone purge attempts
compaction_garbage_collector: Extend return type of max_purgeable_fn
compaction: Extend compaction_result to collect more information
system_keyspace: Upgrade compaction_history table
system_keyspace: Create UDT: sstableinfo_type
system_keyspace: Extract compaction_history struct
system_keyspace: Squeeze update_compaction_history parameters
compaction/compaction_manager: update_history accepts compaction_result as rvalue
Collect tombstone purge statistics like
+ total number of purge attempts
+ number of purge failures due to data overlapping with memtables
+ number of purge failures due to data overlapping with non-compacting
sstables
and expose them in the compaction_stats structure.
The conversion is unnecessary and likely dates back from before the
split between interval and wrapped_interval. It gets in the way
of making the conversion explicit.
Closesscylladb/scylladb#24164
Move the compaction_history_entry struct to a seperate file. The intent
of this change is to later re-use it in scylla-nodetool as it currently
defines its own structure that is very similar.
Since the number of statistics inserted into compaction_history
table grows in time, the number of parameters in the method
update_compaction_history grows as well.
So instead, let's re-use the already existing compaction_history_entry
structure to populate data from the compaction_manager to the
system table.
