update_history can take a long time compared to compaction, as a call
issued on shard S1 can be handled on shard S2. If the other shard is
under heavy load, we may unnecessarily block kicking off a new
compaction. Normally it isn't a problem, as compactions aren't super
frequent, but there were edge cases where the described behaviour caused
compaction to fail to keep up with excessive flushing, leading to too
many sstables on disk and OOM during a read.
There is no need to wait with next compaction until history is updated,
so release the weight earlier to remove unnecessary serialization.
Compaction is marked as finished as soon as sstables are compacted
(without waiting for history update).
Let's also use generation_type for compaction ancestors, so once we
support something other than integer for SSTable generation, we
won't have discrepancy about what the generation type is.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
coroutine::parallel_for_each avoids an allocation and is therefore preferred. The lifetime
of the function object is less ambiguous, and so it is safer. Replace all eligible
occurences (i.e. caller is a coroutine).
One case (storage_service::node_ops_cmd_heartbeat_updater()) needed a little extra
attention since there was a handle_exception() continuation attached. It is converted
to a try/catch.
Closes#10699
The messages only dumps the last sealed fragment, but it should dump
all the output fragments replacing the exhausted input ones.
Let's print origin of output fragments, so we can differ between
files with compaction and garbage-collection origin.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20220524232232.119520-1-raphaelsc@scylladb.com>
Off-strategy works on maintenance sstable set using maintenance
scheduling group, whereas "in-strategy" works on main sstable set
and uses compaction group.
Today, it can happen that off-strategy has to wait for an "in-strategy"
maintenance compaction, e.g. cleanup, to complete before getting
a chance to run. But that's not desired behavior as off-strategy uses
maintenance group, and its candidates don't add to the backlog that
influences "in-strategy" bandwidth. Therefore, "in-strategy" and
off-strategy should be decoupled, with off-strategy having its own
semaphore for guaranteeing serialization across tables.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#10595
Reapply: "disable_auto_compaction: stop ongoing compactions"
This is a reapplication of a former commit
4affa801a5 which was reverted by
8e8dc2c930.
This commit is a fixed version of the original where a call to the
compaction_manager constructor accidentally issued (`compaction_manager()`)
instead a call to retrieve a compaction manager reference
(`get_compaction_manager()`), we don't use this function because it
doesn't exist anymore - it existed at the time the patch was written
bu was removed in 9066224cf4 later on,
instead, we just use the private table member _compaction_manager which refs
the compaction manager.
The explanation for the bad effect is probably that a `this` pointer
capture down the call chain, resulted in a use after free which had
an unknown effect on the system. (memory corruption at startup).
Test: unit (dev,debug)
write performance test as the one used to find the bug.
A screenshot of the performance test can be found at
https://github.com/scylladb/scylla/issues/10146/#issuecomment-1129578381
Fixes https://github.com/scylladb/scylla/issues/9313
Refs https://github.com/scylladb/scylla/issues/10146
For completeness, the original commit message was:
The api call disables new regular compaction jobs from starting
but it doesn't wait for ongoing compaction to stop and so it's
much less useful.
Returning after stopping regular compaction jobs and waiting
for them to stop guarantees that no regular compactions job are
running when nodetool disableautocompaction returns successfully.
Signed-off-by: Eliran Sinvani <eliransin@scylladb.com>
Closes#10597
* github.com:scylladb/scylla:
compaction_manager: Make invoking the empty constructor more explicit
Reapply: "disable_auto_compaction: stop ongoing compactions"
The compaction manager's empty constructor is supposed to be invoked
only in testing environment, however, it is easy to invoke it by mistake
from production code.
Here we add a more verbose constructor and making the default compaction
private, the verbose compiler need to be invoked with a tag
for_testing_tag, this will ensure that this constructor will be invoked
only when intended.
The unit tests were changed according to this new paradigm.
Tests: unit (dev)
Signed-off-by: Eliran Sinvani <eliransin@scylladb.com>
Today, aborting a maintenance compaction like major, which is waiting for
its turn to run, can take lots of time because compaction manager will
only be able to bail out the task once it gets the "permit" from the
serialization mechanism, i.e. semaphore. Meaning that the command that
started the task will only complete after all this time waiting for
the "permit".
To allow a pending maintenance compaction to be quickly aborted, we
can use the abortable variant of get_units(). So when user submits an
abortion request, get_units() will be able to return earlier through
the abort exception.
Refs #10485.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#10581
After fcb8d040 ("treewide: use Software Package Data Exchange
(SPDX) license identifiers"), many dual-licensed files were
left with empty comments on top. Remove them to avoid visual
noise.
Closes#10562
No functional changes intended - this series is quite verbose,
but after it's in, it should be considerably easier to change
the type of SSTable generations to something else - e.g. a string
or timeUUID.
Closes#10533
propagate_replacement() is an internal function that shouldn't be in
the public interface. No one besides an unit test for incremental
compaction needs it. In the future, I want to revisit incremental
compaction unit test to stop using it and only rely on public
interfaces
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20220506171647.81063-1-raphaelsc@scylladb.com>
Dtest triggers the problem by:
1) creating table with LCS
2) disabling regular compaction
3) writing a few sstables
4) running maintenance compaction, e.g. cleanup
Once the maintenance compaction completes, disengaged optional _last_compacted_keys
triggers an exception in notify_completion().
_last_compacted_keys is used by regular for its round-robin file picking
policy. It stores the last compacted key for each level. Meaning it's
irrelevant for any other compaction type.
Regular compaction is responsible for initializing it when it runs for
the first time to pick files. But with it disabled, notify_completion()
will find it uninitialized, therefore resulting in bad_optional_access.
To fix this, the procedure is skipped if _last_compacted_keys is
disengaged. Regular compaction, once re-enabled, will be able to
fill _last_compacted_keys by looking at metadata of the files.
compaction_test.py::TestCompaction::test_disable_autocompaction_doesnt_
block_user_initiated_compactions[CLEANUP-LeveledCompactionStrategy]
now passes.
Fixes#10378.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#10508
SSTable was moved into descriptor, so on failure, it couldn't be used
without resulting in a segfault. Fix it by not moving sst, and changing
signature to make it explicit we don't want to move the content.
Fixes#10505.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#10506
"
Today, both operations are picking the highest level as the ideal level for
placing the output, but the size of input should be used instead.
The formula for calculating the ideal level is:
ceil(log base(fan_out) of (total_input_size / max_fragment_size))
where fan_out = 10 by default,
total_input_size = total size of input data and
max_fragment_size = maximum size for fragment (160M by default)
such that 20 fragments will be placed at level 2, as level 1
capacity is 10 fragments only.
By placing the output in the incorrect level, tons of backlog will be generated
for LCS because it will either have to promote or demote fragments until the
levels are properly balanced.
"
* 'optimize_lcs_major_and_reshape/v2' of https://github.com/raphaelsc/scylla:
compaction: LCS: avoid needless work post major compaction completion
compaction: LCS: avoid needless work post reshape completion
compaction: LCS: extract calculation of ideal level for input
compaction: LCS: Fix off-by-one in formula used to calculate ideal level
That's done by picking the ideal level for the input, such
that LCS won't have to either promote or demote data, because
the output level is not the best candidate for having the
size of the output data.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
That's done by picking the ideal level for reshape input, such
that LCS won't have to either promote or demote data, because
the output level is not the best candidate for having the
size of the output data.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
ideal level is calculated as:
ceil(log base10 of ((input_size + max_fragment_size - 1) / max_fragment_size))
such that 20 fragments will be placed at level 2, as level 1
capacity is 10 fragments only.
The goal of extracting it is that the formula will be useful for
major in addition to reshape.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
To calculate ideal level, we use the formula:
log 10 (input_size / max_fragment_size)
input_size / max_fragment_size is calculating number of fragments.
the problem is that the calculation can miss the last fragment, so
wrong level may be picked if last fragment would cause the target
level to exceed its capacity.
To fix it, let's tweak the formula to:
log 10 ((input_size + max_fragment_size - 1) / max_fragment_size)
such that the actual # of fragments will be calculated.
If wrong level is picked, it can cause unnecessary writeamp as,
LCS will later have to promote data into the next level.
Problem spotted by Benny Halevy.
Fixes#10458.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
flat_mutation_reader make_scrubbing_reader no longer exists
and there is no need to include flat_mutation_reader.hh
nor forward declare the class.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
We filter only on the parittion key, so it doesn't matter,
but we want to get rid of flat_mutation_reader v1.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
_estimated_remaining_tasks gets updated via get_next_non_expired_sstables ->
get_compaction_candidates, but otherwise if we return earlier from
get_sstables_for_compaction, it does not get updated and may go out of sync.
Refs #10418
(to be closed when the fix reaches branch-4.6)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#10419
With off-strategy, we no longer need LCS explicitly switching to STCS
mode, and even without off-strategy, the dynamic fan-in approach
in compaction manager will cause LCS to automatically switch to
STCS under heavy write load.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20220411181322.192830-1-raphaelsc@scylladb.com>
Bucket awareness in cleanup was introduced in a69d98c3d0.
STCS and TWCS already support it, and now LCS will receive it.
The goal of bucket awareness is to reduce writeamp in cleanup,
therefore reducing operation time. Additionally, garbage collection
becomes more efficient as shadowed data can now be potentially
compacted with the data that shadows it, assuming they're on
the same level.
The implementation for LCS is simple. Will reuse the procedure
for STCS for returning jobs in level 0. And one job will be
returned for each non-empty level > 0. What allows us to do it
is our incremental selection approach used in compaction,
that sets a limit on memory usage and disk space requirement.
Fixes#10097.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20220331173417.211257-1-raphaelsc@scylladb.com>
If exception is caught while updating backlog tracker, the backlog
tracker will be disabled for the underlying table, potentially
causing compaction to fall behind.
That being said, let's raise the log level to error, to give it
its due importance and allow tests to detect the problem.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20220330151421.49054-1-raphaelsc@scylladb.com>
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.
"
Quoting patch 3/4:
"This continues the work in a69d98c3d0,
by implementing the cleanup method in TWCS to make it bucket aware.
Till now, the default impl was used which cleanups on file at a
time, starting from the smallest.
The cleanup strategy for TWCS is simple. It's simply calling the
size tiered cleanup method for each bucket, so there will be
one job for each tier in each window.
The next strategies to receive this improvement are LCS and ICS
(the latter one being only available in enterprise).
Refs #10097."
** Simply put, the goal is to reduce writeamp when performing cleanup
on a TWCS table, therefore reducing the operation time. **
tests: unit(dev).
"
* 'twcs_cleanup_bucket_aware/v1' of https://github.com/raphaelsc/scylla:
tests: sstable_compaction_test: Add test for TWCS' bucket-aware cleanup
compaction: TWCS: Implement cleanup method for bucket awareness
compaction: TWCS: change get_buckets() signature to work with const qualified functions
compaction_strategy: get_cleanup_compaction_jobs: accept candidates by value
With v2 having individual bounds of range tombstone as separate
fragments, out-of-order fragments become more difficult to handle,
especially in the presence of active range tombstone.
Scrub in both SKIP and SEGREGATE mode closes the partition on
seeing the first invalid fragment (SEGREAGE re-opens it immediately).
If there is an active range tombstone, scrub now also has to take care
of closing said tombstone when closing the partition. In a normal stream
it could just use the last position-in-partition to create a closing
bound. But when out-of-order fragments are on the table this is not
possible: the closing bound may be found later in the stream, with a
position smaller than that of the current position-in-partition.
To prevent extending range tombstone changes like that, Scrub now aborts
the compaction on the first invalid fragment seen *inside* an active
range tombstone.
Fixing a v2 stream with range tombstone changes is definitely possible,
but non-trivial, so we defer it until there is demand for it.
This series also makes the mutation fragment stream validator check for
open range tombstones on partition-end and adds a comprehensive
test-suite for the validator.
Fixes: #10168
Tests: unit(dev)
* scrub-rtc-handling-fix/v2 of github.com/denesb/scylla.git:
compaction/compaction: abort scrub when attempting to rectify stream with active tombstone
test/boost/mutation_test: add test for mutation_fragment_stream_validator
mutation_fragment_stream_validator: validate range tombstone changes
This continues the work in a69d98c3d0,
by implementing the cleanup method in TWCS to make it bucket aware.
Till now, the default impl was used which cleanups on file at a
time, starting from the smallest.
The cleanup strategy for TWCS is simple. It's simply calling the
size tiered cleanup method for each bucket, so there will be
one job for each tier in each window.
The next strategies to receive this improvement are LCS and ICS
(the latter one being only available in enterprise).
Refs #10097.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Then caller can decide whether to copy or move candidate set into the
function. cleanup_sstables_compaction_task can move candidates as
it's no longer needed once it retrieves all descriptors.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
