To return the minimum live timestamp and live row-marker
timestamp across a compaction_group, storage_group, or
table_state.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
When garbage collecting tombstones, we care only
about shadowing of live data. However, currently
we track min/max timestamp of both live and dead
data, but there is no problem with purging tombstones
that shadow dead data (expired or shdowed by other
tombstones in the sstable/memtable).
Also, for shadowable tombstones, we track live row marker timestamps
separately since, if the live row marker timestamp is greater than
a shadowable tombstone timestamp, then the row marker
would shadow the shadowable tombstone thus exposing the cells
in that row, even if their timestasmp may be smaller
than the shadow tombstone's.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Fixes#19960
Write path for sstables/commitlog need to handle the fact that IO extensions can
generate errors, some of which should be considered retry-able, and some that should,
similar to system IO errors, cause the node to go into isolate mode.
One option would of course be for extensions to simply generate std::system_errors,
with system_category and appropriate codes. But this is probably a bad idea, since
it makes it more muddy at which level an error happened, as well as limits the
expressibility of the error.
This adds three distinct types (sharing base) distinguishing permission, availabilty
and configuration errors. These are treated akin to EACCESS, ENOENT and EINVAL in
disk error handler and memtable write loop.
Tests updated to use and verify behaviour.
Closesscylladb/scylladb#19961
If parent_info argument of compaction_manager::perform_compaction
is std::nullopt, then created compaction executor isn't tracked by task
manager. Currently, all compaction operations should by visible in task
manager.
Modify split methods to keep split executor in task manager. Get rid of
the option to bypass task manager.
Closesscylladb/scylladb#19995
* github.com:scylladb/scylladb:
compaction: replace optional<task_info> with task_info param
compaction: keep split executor in task manager
assert() is traditionally disabled in release builds, but not in
scylladb. This hasn't caused problems so far, but the latest abseil
release includes a commit [1] that causes a 1000 insn/op regression when
NDEBUG is not defined.
Clearly, we must move towards a build system where NDEBUG is defined in
release builds. But we can't just define it blindly without vetting
all the assert() calls, as some were written with the expectation that
they are enabled in release mode.
To solve the conundrum, change all assert() calls to a new SCYLLA_ASSERT()
macro in utils/assert.hh. This macro is always defined and is not conditional
on NDEBUG, so we can later (after vetting Seastar) enable NDEBUG in release
mode.
[1] 66ef711d68Closesscylladb/scylladb#20006
compaction_manager::perform_compaction does not create task manager
task for compaction if parent_info is set to std::nullopt. Currently,
we always want to create task manager task for compaction.
Remove optional from task info parameters which start compaction.
Track all compactions with task manager.
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>
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
before this change, when performing memtable_test, we expect that
the memtables of ks.cf is the only memtables being flushed. and
we inject 4 failures in the code path of flush, and wait until 4
of them are triggered. but in the background, `dirty_memory_manager`
performs flush on all tables when necessary. so, the total number of
failures is not necessary the total number of failures triggered
when flushing ks.cf, some of them could be triggered when flushing
system tables. that's why we have sporadict test failures from
this test. as we might check `t.min_memtable_timestamp()` too soon.
after this change, we increase `unspooled_dirty_soft_limit` setting,
in order to disable `dirty_memory_manager`, so that the only flush
is performed by the test.
Fixes#19034
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
before this change, we verify the behavior of design under test using
`BOOST_ASSERT()`, which is a wrapper around `assert()`, so if a test
fails, the test just aborts. this is not very helpful for postmortem
debugging.
after this change, we use `BOOST_REQUIRE` macro for verifying the
behavior, so that Boost.Test prints out the condition if it does not
hold when we test it.
Refs #19034
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.
in this change, we include `fmt/ranges.h` and/or `fmt/std.h`
for formatting the container types, like vector, map
optional and variant using {fmt} instead of the homebrew
formatter based on operator<<.
with this change, the changes adding fmt::formatter and
the changes using ostream formatter explicitly, we are
allowed to drop `FMT_DEPRECATED_OSTREAM` macro.
Refs scylladb#13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
without `FMT_DEPRECATED_OSTREAM` macro, `UUID::to_sstring()` is
implemented using its `fmt::formatter`, which is not available
at the end of this header file where `UUID` is defined. at this moment,
we still use `FMT_DEPRECATED_OSTREAM` and {fmt} v9, so we can
still use `UUID::to_sstring()`, but in {fmt} v10, we cannot.
so, in this change, we change all callers of `UUID::to_sstring()`
to `fmt::to_string()`, so that we don't depend on
`FMT_DEPRECATED_OSTREAM` and {fmt} v9 anymore.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
get0() dates back from the days where Seastar futures carried tuples, and
get0() was a way to get the first (and usually only) element. Now
it's a distraction, and Seastar is likely to deprecate and remove it.
Replace with seastar::future::get(), which does the same thing.
Those two members are passed from memtable_list to memtable. Since we
wish to pass them from table, it becomes awkward to pass them as two
separate variables as their contents are specific to memtable internals.
Wrap them in a name that indicates their role (being table-wide shared
data for memtables) and pass them as a unit.
Fixes some typos as found by codespell run on the code.
In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc.
Follow-up commits will take care of them.
Refs: https://github.com/scylladb/scylladb/issues/16255
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
There's one in the utils that creates lw_shared_ptr<memtable> and
applies provided vector of mutations into it. Lots of other test cases
do literally the same by hand.
The make_memtable() assumes that the caller is sitting in the seastar
thread, and all the test cases that can benfit from it already are.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
A memtable object contains two logalloc::allocating_section members
that track memory allocation requirements during reads and writes.
Because these are local to the memtable, each time we seal a memtable
and create a new one, these statistics are forgotten. As a result
we may have to re-learn the typical size of reads and writes, incurring
a small performance penalty.
The solution is to move the allocating_section object to the memtable_list
container. The workload is the same across all memtables of the same
table, so we don't lose discrimination here.
The performance penalty may be increased later if log changes to
memory reserve thresholds including a backtrace, so this reduces the
odds of incurring such a penalty.
Closesscylladb/scylladb#15737
In the next commit, we remove the default value for the
description parameter of migration_manager::announce to avoid
using it in the future. However, many calls to announce in tests
use the default value. We have to change it, but we don't really
care about descriptions in the tests, so we pass the empty string
everywhere.
The migration_manager service is responsible for schema convergence
in the cluster - pushing schema changes to other nodes and pulling
schema when a version mismatch is observed. However, there is also
a part of migration_manager that doesn't really belong there -
creating mutations for schema updates. These are the functions with
prepare_ prefix. They don't modify any state and don't exchange any
messages. They only need to read the local database.
We take these functions out of migration_manager and make them
separate functions to reduce the dependency of other modules
(especially query_processor and CQL statements) on
migration_manager. Since all of these functions only need access
to storage_proxy (or even only replica::database), doing such a
refactor is not complicated. We just have to add one parameter,
either storage_proxy or database and both of them are easily
accessible in the places where these functions are called.
Split long-runing memtable tests.
At a trade-off with verbosity, split these sub-tests for the long
running tests
test_memtable_with_many_versions_conforms_to_mutation_source*.
Refs #13905
Split long running test
test_memtable_with_many_versions_conforms_to_mutation_source to 2 tests
for _plain and _reverse.
Refs #13905
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Closes#14447
In that level no io_priority_class-es exist. Instead, all the IO happens
in the context of current sched-group. File API no longer accepts prio
class argument (and makes io_intent arg mandatory to impls).
So the change consists of
- removing all usage of io_priority_class
- patching file_impl's inheritants to updated API
- priority manager goes away altogether
- IO bandwidth update is performed on respective sched group
- tune-up scylla-gdb.py io_queues command
The first change is huge and was made semi-autimatically by:
- grep io_priority_class | default_priority_class
- remove all calls, found methods' args and class' fields
Patching file_impl-s is smaller, but also mechanical:
- replace io_priority_class& argument with io_intent* one
- pass intent to lower file (if applicatble)
Dropping the priority manager is:
- git-rm .cc and .hh
- sed out all the #include-s
- fix configure.py and cmakefile
The scylla-gdb.py update is a bit hairry -- it needs to use task queues
list for IO classes names and shares, but to detect it should it checks
for the "commitlog" group is present.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#13963
There are several places in tests that either use default_priority_class() explicitly, or use some specific prio class obtained from priority manager. There's currently an ongoing work to remove all priority classes, this set makes the final patch a bit smaller and easier to review. In particular -- in many cases default_priority_class() is implicit and can be avoided by callers. Also, using any prio class by test is excessive, it can go with (implicit) default_priority_class.
ref: #13963Closes#13991
* github.com:scylladb/scylladb:
test, memtable: Use default prio class
test, memtable: Add default value for make_flush_reader() last arg
test, view_build: Use default prio class
test, sstables: Use implicit default prio class in dma_write()
test, sstables: Use default sstable::get_writer()'s prio class arg
Many places call memtable::make_flush_reader() with default priority
class. Make it a default-arg for the method, other reader making methods
of memtable already have it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
As described in https://github.com/scylladb/scylladb/issues/8638,
we're moving away from `SimpleStrategy`, in the future
it will become deprecated.
We should remove all uses of it and replace them
with `NetworkTopologyStrategy`.
This change replaces `SimpleStrategy` with
`NetworkTopologyStrategy` in all unit tests,
or at least in the ones where it was reasonable to do so.
Some of the tests were written explicitly to test the
`SimpleStrategy` strategy, or changing the keyspace from
`SimpleStrategy` to `NetworkTopologyStrategy`.
These tests were left intact.
It's still a feature that is supported,
even if it's slowly getting deprecated.
The typical way to use `NetworkTopologyStrategy` is
to specify a replication factor for each datacenter.
This could be a bit cumbersome, we would have to fetch
the list of datacenters, set the repfactors, etc.
Luckily there is another way - we can just specify
a replication factor to use for or each existing
datacenter, like this:
```cql
CREATE KEYSPACE {} WITH REPLICATION =
{'class' : 'NetworkTopologyStrategy', 'replication_factor' : 1};
```
This makes the change rather straightforward - just replace all
instances of `'SimpleStrategy'', with `'NetworkTopologyStrategy'`.
Refs: https://github.com/scylladb/scylladb/issues/8638
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
Closes#13990
without C++23 `std::ranges::repeat_view`, it'd be cumbersume to
implement a loop without dummy variable. this change helps to
silence following warning:
```
test/boost/memtable_test.cc:1135:26: error: unused variable 'value' [-Werror,-Wunused-variable]
for (int value : boost::irange<int>(0, num_flushes)) {
^
```
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Schema related files are moved there. This excludes schema files that
also interact with mutations, because the mutation module depends on
the schema. Those files will have to go into a separate module.
Closes#12858
We currently have two method families to generate partition keys:
* make_keys() in test/lib/simple_schema.hh
* token_generation_for_shard() in test/lib/sstable_utils.hh
Both work only for schemas with a single partition key column of `text` type and both generate keys of fixed size.
This is very restrictive and simplistic. Tests, which wanted anything more complicated than that had to rely on open-coded key generation.
Also, many tests started to rely on the simplistic nature of these keys, in particular two tests started failing because the new key generation method generated keys of varying size:
* sstable_compaction_test.sstable_run_based_compaction_test
* sstable_mutation_test.test_key_count_estimation
These two tests seems to depend on generated keys all being of the same size. This makes some sense in the case of the key count estimation test, but makes no sense at all to me in the case of the sstable run test.
Closes#12657
* github.com:scylladb/scylladb:
test/lib/sstable_utils: remove now unused token_generation_for_shard() and friends
test/lib/simple_schema: remove now unused make_keys() and friends
test: migrate to tests::generate_partition_key[s]()
test/lib/test_services: add table_for_tests::make_default_schema()
test/lib: add key_utils.hh
test/lib/random_schema.hh: value_generator: add min_size_in_bytes
This series switches memtable and cache to use a new representation for mutation data,
called `mutation_partition_v2`. In this representation, range tombstone information is stored
in the same tree as rows, attached to row entries. Each entry has a new tombstone field,
which represents range tombstone part which applies to the interval between this entry and
the previous one. See docs/dev/mvcc.md for more details about the format.
The transient mutation object still uses the old model in order to avoid work needed to adapt
old code to the new model. It may also be a good idea to live with two models, since the
transient mutation has different requirements and thus different trade-offs can be made.
Transient mutation doesn't need to support eviction and strong exception guarantees,
so its algorithms and in-memory representation can be simpler.
This allows us to incrementally evict range tombstone information. Before this series,
range tombstones were accumulated and evicted only when the whole partition entry was evicted. This
could lead to inefficient use of cache memory.
Another advantage of the new representation is that reads don't have to lookup
range tombstone information in a different tree while reading. This leads to simpler
and more efficient readers.
There are several disadvantages too. Firstly, rows_entry is now larger by 16 bytes.
Secondly, update algorithms are more complex because they need to deoverlap range tombstone
information. Also, to handle preemption and provide strong exception guarantees, update
algorithms may need to allocate sentinel entries, which adds complexity and reduces performance.
The memtable reader was changed to use the same cursor implementation
which cache uses, for improved code reuse and reducing risk of bugs
due to discrepancy of algorithms which deal with MVCC.
Remaining work:
- performance optimizations to apply_monotonically() to avoid regressions
- performance testing
- preemption support in apply_to_incomplete (cache update from memtable)
Fixes#2578Fixes#3288Fixes#10587Closes#12048
* github.com:scylladb/scylladb:
test: mvcc: Extend some scenarios with exhaustive consistency checks on eviction
test: mvcc: Extract mvcc_container::allocate_in_region()
row_cache, lru: Introduce evict_shallow()
test: mvcc: Avoid copies of mutation under failure injection
test: mvcc: Add missing logalloc::reclaim_lock to test_apply_is_atomic
mutation_partition_v2: Avoid full scan when applying mutation to non-evictable
Pass is_evictable to apply()
tests: mutation_partition_v2: Introduce test_external_memory_usage_v2 mirroring the test for v1
tests: mutation: Fix test_external_memory_usage() to not measure mutation object footprint
tests: mutation_partition_v2: Add test for exception safety of mutation merging
tests: Add tests for the mutation_partition_v2 model
mutation_partition_v2: Implement compact()
cache_tracker: Extract insert(mutation_partition_v2&)
mvcc, mutation_partition: Document guarantees in case merging succeeds
mutation_partition_v2: Accept arbitrary preemption source in apply_monotonically()
mutation_partition_v2: Simplify get_continuity()
row_cache: Distinguish dummy insertion site in trace log
db: Use mutation_partition_v2 in mvcc
range_tombstone_change_merger: Introduce peek()
readers: Extract range_tombstone_change_merger
mvcc: partition_snapshot_row_cursor: Handle non-evictable snapshots
mvcc: partition_snapshot_row_cursor: Support digest calculation
mutation_partition_v2: Store range tombstones together with rows
db: Introduce mutation_partition_v2
doc: Introduce docs/dev/mvcc.md
db: cache_tracker: Introduce insert() variant which positions before existing entry in the LRU
db: Print range_tombstone bounds as position_in_partition
test: memtable_test: Relax test_segment_migration_during_flush
test: cache_flat_mutation_reader: Avoid timestamp clash
test: cache_flat_mutation_reader_test: Use monotonic timestamps when inserting rows
test: mvcc: Fix sporadic failures due to compact_for_compaction()
test: lib: random_mutation_generator: Produce partition tombstone less often
test: lib: random_utils: Introduce with_probability()
test: lib: Improve error message in has_same_continuity()
test: mvcc: mvcc_container: Avoid UB in tracker() getter when there is no tracker
test: mvcc: Insert entries in the tracker
test: mvcc_test: Do not set dummy::no on non-clustering rows
mutation_partition: Print full position in error report in append_clustered_row()
db: mutation_cleaner: Extract make_region_space_guard()
position_in_partition: Optimize equality check
mvcc: Fix version merging state resetting
mutation_partition: apply_resume: Mark operator bool() as explicit
We have enabled the command line options without changing a
single line of code, we only had to replace old include
with scylla_test_case.hh.
Next step is to add x-log-compaction-groups options, which will
determine the number of compaction groups to be used by all
instantiations of replica::table.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
With compaction groups, automatic flushing may not pick the user
table. Fix it by using explicit flush.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Use the newly introduced key generation facilities, instead of the the
old inflexible alternatives and hand-rolled code.
Most of the migrations are mechanic, but there are two tests that
were tricky to migrate:
* sstable_compaction_test.sstable_run_based_compaction_test
* sstable_mutation_test.test_key_count_estimation
These two tests seems to depend on generated keys all being of the same
size. This makes some sense in the case of the key count estimation
test, but makes no sense at all to me in the case of the sstable run
test.
Partition version merging can now insert sentinels, which may
temporarily increase unspooled memory. It is no longer true that
unspooled monotonically decreases, which the test verified. Relax it,
and only verify that unspooled is smaller than real dirty.
active_memtable() was fine to a single group, but with multiple groups,
there will be one active memtable per group. Let's change the
interface to reflect that.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The latter is pretty popular test/lib header that disseminates the
former one over whole lot of unit tests. The former, in turn, naturally
includes sstables.hh thus making tons of unrelated tests depend on
sstables class unused by them.
However, simple removal doesn't work, becase of local_shard_only bool
class definition in sstable_utils.hh used in simple_schema.hh. This
thing, in turn, is used in keys making helpers that don't belong to
sstable utils, so these are moved into simple_schema as well.
When done, this affects the mutation_source_test.hh, which needs the
local_shard_only bool class (and helps spreading the sstables.hh
throughout more unrelated tests) and a bunch of .cc test sources that
used sstable_utils.hh to indirectly include various headers of their
demand.
After patching, sstables.hh touches 2x times less tests. As a side
effect the sstables_manager.hh also becomes 2x times less dependent
on by tests.
Continuation of 9bdea110a6
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#12240
The "virtual dirty" term is not very informative. "Virtual" means
"not real", but it doesn't say in which way it isn't real.
In this case, virtual dirty refers to real dirty memory, minus
the portion of memtables that has been written to disk (but not
yet sealed - in that case it would not be dirty in the first
place).
I chose to call "the portion of memtables that has been written
to disk" as "spooled memory". At least the unique term will cause
people to look it up and may be easier to remember. From that
we have "unspooled memory".
I plan to further change the accounting to account for spooled memory
rather than unspooled, as that is a more natural term, but that is left
for later.
The documentation, config item, and metrics are adjusted. The config
item is practically unused so it isn't worth keeping compatibility here.
The test simulates a situation where 2 threads issue flushes to 2
tables. Both issue small flushes, but one has injected reactor stalls.
This can lead to a situation where lots of small sstables accumulate on
disk, and, if compaction never has a chance to keep up, resources can be
exhausted.
(cherry picked from commit b5684aa96d)
(cherry picked from commit 25407a7e41)
Now that memtable flush error handling was moved entirely
to table::seal_active_memtable, we don't need to notify_soft_pressure
to keep retry going. The inifinite retry loop should
eventually either succeed or die (by isolating the node or aborting)
on its own.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
This reverts commit aa8f135f64, reversing
changes made to 9a88bc260c. The patch
causes hangs during flush.
Also reverts parts of 411231da75 that impacted the unit test.
Fixes#10897.
There is a bug introduced in e74c3c8 (4.6.0) which makes memtable
reader skip one a range tombstone for a certain pattern of deletions
and under certain sequence of events.
_rt_stream contains the result of deoverlapping range tombstones which
had the same position, which were sipped from all the versions. The
result of deoverlapping may produce a range tombstone which starts
later, at the same position as a more recent tombstone which has not
been sipped from the partition version yet. If we consume the old
range tombstone from _rt_stream and then refresh the iterators, the
refresh will skip over the newer tombstone.
The fix is to drop the logic which drains _rt_stream so that
_rt_stream is always merged with partition versions.
For the problem to trigger, there have to be multiple MVCC versions
(at least 2) which contain deletions of the following form:
[a, c] @ t0
[a, b) @ t1, [b, d] @ t2
c > b
The proper sequence for such versions is (assuming d > c):
[a, b) @ t1,
[b, d] @ t2
Due to the bug, the reader will produce:
[a, b) @ t1,
[b, c] @ t0
The reader also needs to be preempted right before processing [b, d] @
t2 and iterators need to get invalidated so that
lsa_partition_reader::do_refresh_state() is called and it skips over
[b, d] @ t2. Otherwise, the reader will emit [b, d] @ t2 later. If it
does emit the proper range tombstone, it's possible that it will violate
fragment order in the stream if _rt_stream accumulated remainders
(possible with 3 MVCC versions).
The problem goes away once MVCC versions merge.
Fixes#10913Fixes#10830Closes#10914
When memtable receives a tombstone it can happen under some workloads
that it covers data which is still in the memtable. Some workloads may
insert and delete data within a short time frame. We could reduce the
rate of memtable flushes if we eagerly drop tombstoned data.
One workload which benefits is the raft log. It stores a row for each
uncommitted raft entry. When entries are committed they are
deleted. So the live set is expected to be short under normal
conditions.
Fixes#652.
Closes#10807
* github.com:scylladb/scylla:
memtable: Add counters for tombstone compaction
memtable, cache: Eagerly compact data with tombstones
memtable: Subtract from flushed memory when cleaning
mvcc: Introduce apply_resume to hold state for partition version merging
test: mutation: Compare against compacted mutations
compacting_reader: Drop irrelevant tombstones
mutation_partition: Extract deletable_row::compact_and_expire()
mvcc: Apply mutations in memtable with preemption enabled
test: memtable: Make failed_flush_prevents_writes() immune to background merging
Before the change, the test artificiallu set the soft pressure
condition hoping that the background flusher will flush the
memtable. It won't happen if by the time the background flusher runs
the LSA region is updated and soft pressure (which is not really
there) is lifted. Once apply() becomes preemptibe, backgroun partition
version merging can lift the soft pressure, making the memtable flush
not occur and making the test fail.
Fix by triggering soft pressure on retries.
Fixes#10801
Refs #10793
(cherry picked from commit 0e78ad50ea)
Closes#10802
