this member function prepares for the backup feature, where the
object to be stored in the object storage is already persisted as a
file on local filesystem. this brings us two benefits:
- with the file, we don't need to accumulate the payloads in memory
and send them in batch, as we do in upload_sink and in
upload_jumbo_sink. this puts less pressure on the memory subsystem.
- with the file, we can read multiple parts in parallel if multpart
upload applies to it, this helps to improve the throughput.
so, this new helper is introduced to help upload an sstable from local
filesystem to the object storage.
Fixes#16287
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
If set, any remaining segment that has data older than this threshold will request flushing, regardless of data pressure. I.e. even a system where nothing happends will after X seconds flush data to free up the commit log.
Related to #15820
The functionality here is to prevent pathological/test cases where a silent system cannot fully process stuff like compaction, GC etc due to things like CL forcing smaller GC windows etc.
Closesscylladb/scylladb#15971
* github.com:scylladb/scylladb:
commitlog: Make max data lifetime runtime-configurable
db::config: Expose commitlog_max_data_lifetime_in_s parameter
commitlog: Add optional max lifetime parameter to cl instance
The SSTable is removed from the reclaimed memory tracking logic only
when its object is deleted. However, there is a risk that the Bloom
filter reloader may attempt to reload the SSTable after it has been
unlinked but before the SSTable object is destroyed. Prevent this by
removing the SSTable from the reclaimed list maintained by the manager
as soon as it is unlinked.
The original logic that updated the memory tracking in
`sstables_manager::deactivate()` is left in place as (a) the variables
have to be updated only when the SSTable object is actually deleted, as
the memory used by the filter is not freed as long as the SSTable is
alive, and (b) the `_reclaimed.erase(*sst)` is still useful during
shutdown, for example, when the SSTable is not unlinked but just
destroyed.
Fixes https://github.com/scylladb/scylladb/issues/19722Closesscylladb/scylladb#19717
* github.com:scylladb/scylladb:
boost/bloom_filter_test: add testcase to verify unlinked sstables are not reloaded
sstables: do not reload components of unlinked sstables
sstables/sstables_manager: introduce on_unlink method
`filesystem_storage` methods frequently call `sync_directory()`, for the sake of flushing (sync'ing) a directory. `sync_directory()` always brackets the sync with open and close, and given that most `sync_directory()` calls target the sstable base directory, those repeated opens and closes are considered wasteful. Rework the `filesystem_storage::_dir` member (from a mere pathname) so that it stand for an `opened_directory` object, which keeps the sstable base directory open, for the purpose of repeated sync'ing.
Resolves#2399.
Closesscylladb/scylladb#19624
* github.com:scylladb/scylladb:
sstables/storage: synch "dst_dir" more leanly in create_links_common()
sstables/storage: close previous directory asynchronously upon dir change
sstables/storage: futurize change_dir_for_test()
sstables/storage: sync through "opened_directory" in filesystem...::move()
sstables/storage: sync through "opened_directory" in the "easy" cases
sstables/storage: introduce "opened_directory" class
Users outside of the token module don't
need to mess with the token::kind.
They can only create key tokens.
Never, minimum or maximum tokens, with a particular
datya value.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
sizeof(dht::token) is only 16 bytes and therefore
it can be passed with 2 registers.
There is no sense in defining minimum_token
and maximum_token out of line, returning a token&
to statically allocated values that require memory
access/copy, while the only call sites that needs
to point to the static min/max tokens are in
dht::ring_position_view.
Instead, they can be defined inline as constexpr
functions and return their const values.
Respectively, define token ctors and methods
as constexpr where applicable (and noexcept while at it
where applicable)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently change_dir_for_test() is synchronous. Make it return a future,
so that we can use async operations in change_dir_for_test() overrides.
Signed-off-by: Laszlo Ersek <laszlo.ersek@scylladb.com>
The SSTable is removed from the reclaimed memory tracking logic only
when its object is deleted. However, there is a risk that the Bloom
filter reloader may attempt to reload the SSTable after it has been
unlinked but before the SSTable object is destroyed. Prevent this by
removing the SSTable from the reclaimed list maintained by the manager
as soon as it is unlinked.
The original logic that updated the memory tracking in
`sstables_manager::deactivate()` is left in place as (a) the variables
have to be updated only when the SSTable object is actually deleted, as
the memory used by the filter is not freed as long as the SSTable is
alive, and (b) the `_reclaimed.erase(*sst)` is still useful during
shutdown, for example, when the SSTable is not unlinked but just
destroyed.
Fixes#19722
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
This PR adds support for aborting index reads from within `index_consume_entry_context::consume_input` when the server is being stopped. The abort source is now propagated down to the `index_consume_entry_context`, making it available for `consume_input` to check if an abort has been requested. If an abort is detected, `consume_input` will throw an exception to stop the index read operation.
Closesscylladb/scylladb#19453
* github.com:scylladb/scylladb:
test/boost: test abort behaviour during index read
sstables/index_reader: stop consuming index when abort has been requested
sstables::index_consume_entry_context: store abort_source
sstable: drop old filter only after the new filter is built during rebuild
sstables/sstables_manager: store abort_source in sstable_manager
replica/database: pass abort_source to database constructor
Added a new boost test, index_reader_test, with a testcase to verifyi
the abort behaviour during an index read using
index_consume_entry_context.
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
There are two schemas associated with a sstable writer:
the sstable's schema (i.e. the schema of the table at the time when the
sstable object was created), and the writer's schema (equal to the schema
of the reader which is feeding into the writer).
It's easy to mix up the two and break something as a result.
The writer's schema is needed to correctly interpret and serialize the data
passing through the writer, and to populate the on-disk metadata about the
on-disk schema.
The sstables's schema is used to configure some parameters for newly created
sstable, such as bloom filter false positive ratio, or compression.
This series fixes the known mixups between the two — when setting up compression,
and when setting up the bloom filters.
Fixes#16065
The bug is present in all supported versions, so the patch has to be backported to all of them.
Closesscylladb/scylladb#19695
* github.com:scylladb/scylladb:
sstables/mx/writer: when creating local_compression, use the sstables's schema, not the writer's
sstables/mx/writer: when creating filter, use the sstables's schema, not the writer's
sstables: for i_filter downcasts, use dynamic_cast instead of static_cast
```
DEBUG 2024-07-03 00:59:58,291 [shard 0:main] compaction_manager - Compaction task 0x51800002a480 for table tests.3 compaction_group=0 [0x503000062050]: switch_state: none -> pending: pending=2 active=0 done=0 errors=0
DEBUG 2024-07-03 01:00:02,868 [shard 0:main] compaction - Checking droppable sstables in tests.3, candidates=0
DEBUG 2024-07-03 01:00:02,868 [shard 0:main] compaction - time_window_compaction_strategy::newest_bucket:
now 1720314000000000
buckets = {
key=1720314000000000, size=2
key=1720310400000000, size=2
1720314000000000: GMT: Sunday, July 7, 2024 1:00:00 AM
1720310400000000: GMT: Sunday, July 7, 2024 12:00:00 AM
```
the test failed to complete when ran across different clock hours, as it
expected all sstables produced to belong to same window of 1h size.
let's fix it by reusing timestamps, so it's always consistent.
Fixes#13280.
Fixes#18564.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#19749
There are two schema's associated with a sstable writer:
the sstable's schema (i.e. the schema of the table at the time when the
sstable object was created), and the writer's schema (equal to the schema
of the reader which is feeding into the writer).
It's easy to mix up the two and break something as a result.
The writer's schema is needed to correctly interpret and serialize the data
passing through the writer, and to populate the on-disk metadata about the
on-disk schema.
The sstables's schema is used to configure some parameters for newly created
sstable, such as bloom filter false positive ratio, or compression.
The problem fixed by this patch is that the writer was wrongly creating
the compressor objects based on its own schema, but using them based
based on the sstable's schema the sstable's schema.
This patch forces the writer to use the sstable's schema for both.
There are two schema's associated with a sstable writer:
the sstable's schema (i.e. the schema of the table at the time when the
sstable object was created), and the writer's schema (equal to the schema
of the reader which is feeding into the writer).
It's easy to mix up the two and break something as a result.
The writer's schema is needed to correctly interpret and serialize the data
passing through the writer, and to populate the on-disk metadata about the
on-disk schema.
The sstables's schema is used to configure some parameters for newly created
sstable, such as bloom filter false positive ratio, or compression.
The problem fixed by this patch is that the writer was wrongly creating
the filter based on its own schema, while the layer outside the writer
was interpreting it as if it was created with the sstable's schema.
This patch forces the writer to pick the filter's parameters based on the
sstable's schema instead.
It was added to make integration of storage groups easier, but it's
complicated since it's another source of truth and we could have
problems if it becomes inconsistent with the group map.
Fixes#18506.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
If set, any remaining segment that has data older than this threshold
will request flushing, regardless of data pressure. I.e. even a system
where nothing happends will after X seconds flush data to free up the
commit log.
apply_monotonically() is run with reclaim disabled. So with some bad luck,
sentinel insertion might fail with bad_alloc even on a perfectly healthy node.
We can't deal with the failure of sentinel insertion, so this will result in a
crash.
This patch prevents the spurious OOM by reserving some memory (1 LSA segment)
and only making it available right before the critical allocations.
Fixes https://github.com/scylladb/scylladb/issues/19552Closesscylladb/scylladb#19617
* github.com:scylladb/scylladb:
mutation_partition_v2: in apply_monotonically(), avoid bad_alloc on sentinel insertion
logalloc: add hold_reserve
logalloc: generalize refill_emergency_reserve()
for better debugging experience.
before this change, we have
```
fatal error: in "sstable_directory_test_generation_sanity": critical check sst->generation() == sst1->generation() has failed
```
after this change, we have
```
fatal error: in "sstable_directory_test_generation_sanity": critical
check sst->generation() == sst1->generation() has failed [3ghm_0ntw_29vj625yegw7jodysc != 3ghm_0ntw_29vj625yegw7jodysd]
```
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#19639
mutation_partition_v2::apply_monotonically() needs to perform some allocations
in a destructor, to ensure that the invariants of the data structure are
restored before returning. But it is usually called with reclaiming disabled,
so the allocations might fail even in a perfectly healthy node with plenty of
reclaimable memory.
This patch adds a mechanism which allows to reserve some LSA memory (by
asking the allocator to keep it unused) and make it available for allocation
right when we need to guarantee allocation success.
The reader concurrency semaphore restricts the concurrency of reads that require CPU (intention: they read from the cache) to 1, meaning that if there is even a single active read which declares that it needs just CPU to proceed, no new read is admitted. This is meant to keep the concurrency of reads in the cache at 1. The idea is that concurrency in the cache is not useful: it just leads to the reactor rotating between these reads, all of the finishing later then they could if they were the only active read in the cache.
This was observed to backfire in the case where there reads from a single table are mostly very fast, but on some keys are very slow (hint: collection full of tombstones). In this case the slow read keeps up the fast reads in the queue, increasing the 99th percentile latencies significantly.
This series proposes to fix this, by making the CPU concurrency configurable. We don't like tunables like this and this is not a proper fix, but a workaround. The proper fix would be to allow to cut any page early, but we cannot cut a page in the middle of a row. We could maybe have a way of detecting slow reads and excluding them from the CPU concurrency. This would be a heuristic and it would be hard to get right. So in this series a robust and simple configurable is offered, which can be used on those few clusters which do suffer from the too strict concurrency limit. We have seen it in very few cases so far, so this doesn't seem to be wide-spread.
Fixes: https://github.com/scylladb/scylladb/issues/19017
This fixes a regression introduced in 5.0, so we have to backport to all currently supported releases
Closesscylladb/scylladb#19018
* github.com:scylladb/scylladb:
test/boost/reader_concurrency_semaphore_test: add test for live-configurable cpu concurrenc Please enter the commit message for your changes. Lines starting
test/boost/reader_concurrency_semaphore_test: hoist require_can_admit
reader_concurrency_semaphore: wire in the configurable cpu concurrency
reader_concurrency_semaphore: add cpu_concurrency constructor parameter
db/config: introduce reader_concurrency_semahore_cpu_concurrency
This short series enhances utils::chunked_vector so it could be used more easily to convert dht::partition_range_vector to chunked_vector, for example.
- utils: chunked_vector: document invalidation of iterators on move
- utils: chunked_vector: add ctor from std::initializer_list
- utils: chunked_vector: add ctor from a single value
No backport required
Closesscylladb/scylladb#19462
* github.com:scylladb/scylladb:
chunked_vector_test: add tests for value-initialization constructor
utils: chunked_vector: add ctor from std::initializer_list
utils: chunked_vector: document invalidation of iterators on move
The bloom filters are built with partition estimates because the actual
partition count might not be available in all cases. If the estimate is
inaccurate, the bloom filters might end up being too large or too small
compared to their optimal sizes. This PR rebuilds bloom filters with
inaccurate partition estimates using the actual partition count before
the filter is written to disk. A bloom filter is considered to have an
inaccurate estimate if its false positive rate based on the current
bitmap size is either less than 75% or more than 125% of the configured
false positive rate.
Fixes#19049
A manual test was run to check the impact of rebuild on compaction.
Table definition used : CREATE TABLE scylla_bench.simple_table (id int PRIMARY KEY);
Setup : 3 billion random rows with id in the range [0, 1e8) were inserted as batches of 5 rows into scylla_bench.simple_table via 80 threads.
Compaction statistics :
scylla_bench.simple_table :
(a) Total number of compactions : `1501`
(b) Total time spent in compaction : `9h58m47.269s`
(c) Number of compactions which rebuilt bloom filters : `16`
(d) Total time taken by these 16 compactions which rebuilt bloom filters : `2h55m11.89s`
(e) Total time spent by these 16 compactions to rebuild bloom filters : `8m6.221s` which is
- `4.63%` of the total time taken by the compactions which rebuilt filters (d)
- `1.35%` of the total compaction time (b).
(f) Total bytes saved by rebuilding filters : `388 MB`
system.compaction_history :
(a) Total number of compactions : `77`
(b) Total time spent in compaction : `21.24s`
(c) Number of compactions which rebuilt bloom filters : `74`
(d) Time taken by these 74 compactions which rebuilt bloom filters : `20.48s`
(e) Time spent by these 74 compactions to rebuild bloom filters : `377ms` which is
- `1.84%` of the total time taken by the compactions which rebuilt filters (d)
- `1.77%` of the total compaction time (b).
(f) Total bytes saved by rebuilding filters : `20 kB`
The following tables also had compactions and the bloom filter was rebuilt in all those compactions.
However, the time taken for every rebuild was observed as 0ms from the logs as it completed within a microsecond :
system.raft :
(a) Total number of compactions : `2`
(b) Total time spent in compaction : `106ms`
(c) Total bytes saved by rebuilding filters : `960 B`
system_schema.tables :
(a) Total number of compactions : `1`
(b) Total time spent in compaction : `25ms`
(c) Total bytes saved by rebuilding filter : `312 B`
system.topology :
(a) Total number of compactions : `1`
(b) Total time spent in compaction : `25ms`
(c) Total bytes saved by rebuilding filter : `320 B`
Closesscylladb/scylladb#19190
* github.com:scylladb/scylladb:
bloom_filter_test: add testcase to verify filter rebuilds
test/boost: move bloom filter tests from sstable_datafile_test into a new file
sstables/mx/writer: rebuild bloom filters with bad partition estimates
sstables/mx/writer: add variable to track number of partitions consumed
sstable: introduce sstable::maybe_rebuild_filter_from_index()
sstable: add method to return filter format for the given sstable version
utils/i_filter: introduce get_filter_size()
since we've switched almost all callers of the operator<< to {fmt},
let's drop the unused operator<<:s.
the callers in alternator/streams.cc is updated to use `fmt::print()`
to format the `bytes` instances.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#19448
this change was created in the same spirit of ebff5f5d.
despite that we include Seastar as a submodule, Seastar is not a
part of scylla project. so we'd better include its headers using
brackets.
ebff5f5d addressed this cosmetic issue a while back. but probably
clangd's header-insertion helped some of contributor to insert
the missing headers with `"`. so this style of `include` returned
to the tree with these new changes.
unfortunately, clangd does not allow us to configure the style
of `include` at the time of writing.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#19406
This patch adds a check if aggregation query is doing single-partition read and if so, makes the query to not use forward_service and do not parallelize the request.
Fixesscylladb/scylladb#19349Closesscylladb/scylladb#19350
* github.com:scylladb/scylladb:
test/boost/cql_query_test: add test for single-partition aggregation
cql3/select_statement: do not parallelize single-partition aggregations
flat_mutation_reader_v2 was introduced in a pair of commits in 2021:
e3309322c3 "Clone flat_mutation_reader related classes into v2 variants"
08b5773c12 "Adapt flat_mutation_reader_v2 to the new version of the API"
as a replacement for flat_mutation_reader, using range_tombstone_change
instead of range_tombstone to represent represent range tombstones. See
those commits for more information.
The transition was incremental; the last use of the original
flat_mutation_reader was removed in 2022 in commit
026f8cc1e7 "db: Use mutation_partition_v2 in mvcc"
In turn, flat_mutation_reader was introduced in 2017 in commit
748205ca75 "Introduce flat_mutation_reader"
To transition from a mutation_reader that nested rows within
a partition in a separate stream, to a flat reader that streamed
partitions and rows in the same stream.
Here, we reclaim the original name and rename the awkward
flat_mutation_reader_v2 to mutation_reader.
Note that mutation_fragment_v2 remains since we still use the original
for compatibilty, sometimes.
Some notes about the transition:
- files were also renamed. In one case (flat_mutation_reader_test.cc), the
rename target already existed, so we rename to
mutation_reader_another_test.cc.
- a namespace 'mutation_reader' with two definitions existed (in
mutation_reader_fwd.hh). Its contents was folded into the mutation_reader
class. As a result, a few #includes had to be adjusted.
Closesscylladb/scylladb#19356
Normally, the space overhead for TWCS is 1/N, where is number of windows. But during off-strategy, the overhead is 100% because input sstables cannot be released earlier.
Reshaping a TWCS table that takes ~50% of available space can result in system running out of space.
That's fixed by restricting every TWCS off-strategy job to 10% of free space in disk. Tables that aren't big will not be penalized with increased write amplification, as all input (disjoint) sstables can still be compacted in a single round.
Fixes#16514.
Closesscylladb/scylladb#18137
* github.com:scylladb/scylladb:
compaction: Reduce twcs off-strategy space overhead to 10% of free space
compaction: wire storage free space into reshape procedure
sstables: Allow to get free space from underlying storage
replica: don't expose compaction_group to reshape task
since we've switched almost all callers of the operator<< to {fmt}, let's drop the unused operator<<:s.
there are more occurrences of unused operator<< in the tree, but let's do the cleanup piecemeal.
---
this is a cleanup, so no need to backport
Closesscylladb/scylladb#19346
* github.com:scylladb/scylladb:
types: remove unused operator<<
node_ops: remove unused operator<<
lang: remove unused operator<<
gms: remove unused operator<<
dht: remove unused operator<<
test: do not use operator<< for std::optional
Before these changes, compilation was failing with the following
error:
In file included from test/boost/hint_test.cc:12:
/usr/include/fmt/ranges.h:298:7: error: no member named 'parse' in 'fmt::formatter<db::hints::sync_point::host_id_or_addr>'
298 | f.parse(ctx);
| ~ ^
We add the missing callback.
Closesscylladb/scylladb#19375
Replace the reserve_partial loop in large_bitset constructor with a new function - reserve_gently() that can reserve memory without stalling by repeatedly calling reserve_partial() method of the passed container.
Closesscylladb/scylladb#19361
* github.com:scylladb/scylladb:
utils/large_bitset: replace reserve_partial with utils::reserve_gently
utils/stall_free: introduce reserve_gently
Add reserve_gently() that can reserve memory without stalling by
repeatedly calling reserve_partial() method of the passed container.
Update the comments of existing reserve_partial() methods to mention
this newly introduced reserve_gently() wrapper.
Also, add test to verify the functionality.
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
in 94cdfcaa94, we added commitlog_cleanup_test to `configure.py`,
but didn't add it to the CMake building system.
in this change, let's add it to the CMake building system.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#19314
Making the count resources on the maintenance (streaming) semaphore live update via config. This will allow us to improve repair speed on mixed-shard clusters, where we suspect that reader trashing -- due to the combination of high number of readers on each shard and very conservative reader count limit (10) -- is the main cause of the slowness.
Making this count limit confgurable allows us to start experimenting with this fix, without committing to a count limit increase (or removal), addressing the pain in the field.
Refs: #18269
No OSS backport needed.
Closesscylladb/scylladb#19248
* github.com:scylladb/scylladb:
replica/database: wire in maintenance_reader_concurrency_semaphore_count_limit
db/config: introduce maintenance_reader_concurrency_semaphore_count_limit
reader_concurrency_semaphore: make count parameter live-update
since we've switched almost all callers of the operator<< to {fmt},
let's drop the unused operator<<:s.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
