The option is provided by nodetool snapshot
https://docs.scylladb.com/operating-scylla/nodetool-commands/snapshot/
```
nodetool [(-h <host> | --host <host>)] [(-p <port> | --port <port>)]
[(-pp | --print-port)] [(-pw <password> | --password <password>)]
[(-pwf <passwordFilePath> | --password-file <passwordFilePath>)]
[(-u <username> | --username <username>)] snapshot
[(-cf <table> | --column-family <table> | --table <table>)]
[(-kc <kclist> | --kc.list <kclist>)]
[(-sf | --skip-flush)] [(-t <tag> | --tag <tag>)] [--] [<keyspaces...>]
-sf / –skip-flush Do not flush memtables before snapshotting (snapshot will not contain unflushed data)
```
But is currently ignored by scylla-jmx (scylladb/scylla-jmx#167)
and not supported at the api level.
This patch adds support for the option in advance
from the api service level down via snapshot_ctl
to the table class and snapshot implementation.
In addition, a corresponding unit test was added to verify
that taking a snapshot with `skip_flush` does not flush the memtable
(at the table::snapshot level).
Refs #8725Closes#8726
* github.com:scylladb/scylla:
test: database_test: add snapshot_skip_flush_works
api: storage_service/snapshots: support skip-flush option
snapshot: support skip_flush option
table: snapshot: add skip_flush option
api: storage_service/snapshots: add sf (skip_flush) option
Miscellaneous preparatory patches for group 0 discovery.
* scylla-dev/raft-group-0-part-2-v4:
raft: (service) servers map is gid -> server, not sid -> server
system_keyspace: raft.group_id and raft_snapshots.group_id are TIMEUUID
raft: (server) wait for configuration transition to complete
raft: (server) implement raft::server::get_configuration()
raft: (service) don't throw from schema state machine
raft: (service) permit some scylla.raft cells to be empty
raft: (service) properly handle failure to add a server
raft: implement is_transient_error()
Raft Group registry should map Raft Group Id to Raft Server,
not Raft Server ID (which is identical for all groups) to Raft server.
Raft Group 0 ID works as a cluster identifier, so is generated when a
new cluster is created and is shared by all nodes of the same cluster.
Implement a helper to get raft::server by group id.
Consistently throw a new raft_group_not_found exception
if there is no server or rpc for the specified group id.
"
The close path of the multishard combining reader is riddled with
workarounds the fact that the flat mutation reader couldn't wait on
futures when destroyed. Now that we have a close() method that can do
just that, all these workarounds can be removed.
Even more workarounds can be found in tests, where resources like the
reader concurrency semaphore are created separately for each tested
multishard reader and then destroyed after it doesn't need it, so we had
to come up with all sorts of creative and ugly workarounds to keep
these alive until background cleanup is finished.
This series fixes all this. Now, after calling close on the multishard
reader, all resources it used, including the life-cycle policy, the
semaphores created by it can be safely destroyed. This greatly
simplifies the handling of the multishard reader, and makes it much
easier to reason about life-cycle dependencies.
Tests: unit(dev, release:v2, debug:v2,
mutation_reader_test:debug -t test_multishard,
multishard_mutation_query_test:debug,
multishard_combining_reader_as_mutation_source:debug)
"
* 'multishard-combining-reader-close-cleanup/v3' of https://github.com/denesb/scylla:
mutation_reader: reader_lifecycle_policy: remove convenience methods
mutation_reader: multishard_combining_reader: store shard_reader via unique ptr
test/lib/reader_lifecycle_policy: destroy_reader: cleanup context
test/lib/reader_lifecycle_policy: get rid of lifecycle workarounds
test/lib/reader_lifecycle_policy: destroy_reader(): stop the semaphore
test/lib/reader_lifecycle_policy: use a more robust eviction mechanism
reader_concurrency_semaphore: wait for all permits to be destroyed in stop()
test/lib/reader_lifcecycle_policy: fix indentation
mutation_reader: reader_lifecycle_policy::destroy_reader(): require to be called on native shard
reader_lifecycle_policy implementations: fix indentation
mutation_reader: reader_lifecycle_policy::destroy_reader(): de-futurize reader parameter
mutation_reader: shard_reader::close(): wait on the remote reader
multishard_mutation_query: destroy remote parts in the foreground
mutation_reader: shard_reader::close(): close _reader
mutation_reader: reader_lifcecycle_policy::destroy_reader(): remove out-of-date comment
The lifecycle of the reader lifecycle policy and all the resources the
reads use is now enclosed in that of the multishard reader thanks to its
close() method. We can now remove all the workarounds we had in place to
keep different resources as long as background reader cleanup finishes.
"
This series introduces a new version of the mutation fragment stream (called v2)
which aims at improving range tombstone handling in the system.
When compacting a mutation fragment stream (e.g. for sstable compaction, data query, repair),
the compactor needs to accumulate range tombstones which are relevant for the yet-to-be-processed range.
See range_tombstone_accumulator. One problem is that it has unbounded memory footprint because the
accumulator needs to keep track of all the tombstoned ranges which are still active.
Another, although more benign, problem is computational complexity needed to maintain that data structure.
The fix is to get rid of the overlap of range tombstones in the mutation fragment stream. In v2 of the
stream, there is no longer a range_tombstone fragment. Deletions of ranges of rows within a given
partition are represented with range_tombstone_change fragments. At any point in the stream there
is a single active clustered tombstone. It is initially equal to the neutral tombstone when the
stream of each partition starts. The range_tombstone_change fragment type signify changes of the
active clustered tombstone. All fragments emitted while a given clustered tombstone is active are
affected by that tombstone. Like with the old range_tombstone fragments, the clustered tombstone
is independent from the partition tombstone carried in partition_start.
The memory needed to compact a stream is now constant, because the compactor needs to only track the
current tombstone. Also, there is no need to expire ranges on each fragment because the stream emits
a fragment when the range ends.
This series doesn't convert all readers to v2. It introduces adaptors which can convert
between v1 and v2 streams. Each mutation source can be constructed with either v1 or v2 stream factory,
but it can be asked any version, performing conversion under the hood if necessary.
In order to guarantee that v1 to v2 conversion produces a well-formed stream, this series needs to
impose a constraint on v1 streams to trim range tombstones to clustering restrictions. Otherwise,
v1->v2 converted could produce range tombstone changes which lie outside query restrictions, making
the stream non-canonical.
The v2 stream is strict about range tombstone trimming. It emits range tombstone changes which reflect
range tombstones trimmed to query restrictions, and fast-forwarding ranges. This makes the stream
more canonical, meaning that for a given set of writes, querying the database should produce the
same stream of fragments for a given restrictions. There is less ambiguity in how the writes
are represented in the fragment stream. It wasn't the case with v1. For example, A given set
of deletions could be produced either as one range_tombstone, or may, split and/or deoverlapped
with other fragments. Making a stream canonical is easier for diff-calculating.
The mc sstable reader was converted to v2 because it seemed like a comparable effort to do that
versus implementing range tombstone trimming in v1.
The classes related to mutation fragment streams were cloned:
flat_mutation_reader_v2, mutation_fragment_v2, related concepts.
Refs #8625. To fully fix#8625 we need to finish the transition and get rid of the converters.
Converters accumulate range tombstones.
Tests:
- unit [dev]
"
* tag 'flat_mutation_reader_range_tombstone_split-v3.2' of github.com:tgrabiec/scylla: (26 commits)
tests: mutation_source_test: Run tests with conversions inserted in the middle
tests: mutation_source_tests: Unroll run_flat_mutation_reader_tests()
tests: Add tests for flat_mutation_reader_v2
flat_mutation_reader: Update the doc to reflect range tombstone trimming
sstables: Switch the mx reader to flat_mutation_reader_v2
row_cache: Emit range tombstone adjacent to upper bound of population range
tests: sstables: Fix test assertions to not expect more than they should
flat_mutation_reader: Trim range tombstones in make_flat_mutation_reader_from_fragments()
clustering_ranges_walker: Emit range tombstone changes while walking
tests: flat_mutation_reader_assertions_v2: Adapt to the v2 stream
Clone flat_reader_assertions into flat_reader_assertions_v2
test: lib: simple_schema: Reuse new_tombstone()
test: lib: simple_schema: Accept tombstone in delete_range()
mutation_source: Introduce make_reader_v2()
partition_snapshot_flat_reader: Trim range tombstones to query ranges
mutation_partition: Trim range tombstones to query ranges
sstables: reader: Inline specialization of sstable_mutation_reader
sstables: k_l: reader: Trim range tombstones to query ranges
clustering_ranges_walker: Introduce split_tombstone()
position_range: Introduce contains() check for ranges
...
The one was added to smothly switch tri-comparing stuff from int
to strong-ordering. As for today only tests still need it and the
conversion is pretty simple, plus operator<<(ostream&) for the
std::strong_ordering type.
* xemul/br-remove-int-or-strong-ordering-2:
util: Drop int_or_strong_ordering concept
tests: Switch total-order-check onto strong_ordering
to_string: Add formatter for strong_ordering
tests: Return strong-ordering from tri-comparators
The main difficulty was in making sure that emitted range tombstone
changes reflect range tombstones trimmed to clustering restrictions.
This is handled by mutation_fragment_filter and
clustering_ranges_walker. They return a list of range_tombstone_change
fragments to emit for each hop as the reader walks over the clustering
domain.
Tests which were using a normalizing reader expected range tombstones
to be split around rows. Drop this an adjust the tests accoridngly. No
reader splits range tombstones around rows now.
Cache populating reader was emitting the row entry which stands for
the upper bound of the population range, but did not emit range
tombstones for the clustering range corresponding to:
[ before(key), after(key) ).
This surfaces after sstable readers are changed to trim emitted range
tombstones to the fast-forwarding range. Before, it didn't cause
problems, because that range tombstone part would be emitted as part
of the sstable read.
The fix is to drop the optimization which pushes the row after
population is done, and let the regular handling for
copy_from_cache_to_buffer() take care of emitting the row and
tombstones for the remaining range.
A unit test is added which covers population from all sstable
versions.
Before this patch, the tests expected readers to emit range tombstones
which are outside clustering restrictions. Readers do not have to emit
range tombstones outside clustering restrictions, so fix tests to only
expect the part which overlaps with query ranges.
This is a preparatory patch before changing readers to trim range
tombstones to clustering ranges.
Incremental selection may not work properly for LCS and ICS due to an
use-after-free bug in partitioned set which came into existence after
compound set was introduced.
The use-after-free happens because partitioned set wasn't taking into
account that the next position can become the current position in the
next iteration, which will be used by all selectors managed by
compound set. So if next position is freed, when it were being used
as current position, subsequent selectors would find the current
position freed, making them produce incorrect results.
Fix this by moving ownership of next pos from incremental_selector_impl
to incremental_selector, which makes it more robust as the latter knows
better when the selection is done with the next pos. incremental_selector
will still return ring_position_view to avoid copies.
Fixes#8802.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20210611130957.156712-1-raphaelsc@scylladb.com>
In #8772, an assert validating first token <= last token
failed in leveled_manifest::overlapping.
It is unclear how we got to that state, so add validation
in sstable::set_first_and_last_keys() that the to-be-set
first and last keys are well ordered.
Otherwise, throw malformed_sstable_exception.
set_first_and_last_keys is called both on the write path
from the sstable writer before the sstable is sealed,
and on the open/load path via update_info_for_opened_data().
This series also fixes issues with unit tests with
regards to first/last keys so they won't fail the
validation.
Refs #8772
Test: unit(dev)
DTest: next-gating(dev), materialized_views_test:TestMaterializedViews.interrupt_build_process_and_resharding_half_to_max_test(debug)
* tag 'validate-first-and-last-keys-ordering-v1':
sstable: validate first and last keys ordering
test: lib: reusable_sst: save unexpected errors
test: sstable_datafile_test: stcs_reshape_test: use token_generation_for_current_shard
test: sstable_test: define primary key in schema for compressed sstable
* scylla-dev/raft-group-0-part-1-rebase:
raft: (service) pass Raft service into storage_service
raft: (service) add comments for boot steps
raft: add ordering for raft::server_address based on id
raft: (internal) simplify construction of tagged_id
raft: (internal) tagged_id minor improvements
Raft group 0 initialization and configuration changes
should be integrated with Scylla cluster assembly,
happening when starting the storage service and joining
the cluster. Prepare for this.
Since Raft service depends on query processor, and query
processor depends on storage service, to break a dependency
loop split Raft initialization into two steps: starting
an under-constructed instance of "sharded" Raft service,
accepting an under-constructed instance of "sharded"
query_processor, and then passed into storage service start
function, and then the local state of Raft groups from system
tables once query processor starts.
Consistently abbreviate raft_services instance raft_svcs, as
is the convention at Scylla.
Update the tests.
Introduce a syntax helper tagged_id::create_random_id(),
used to create a new Raft server or group id.
Provide a default ordering for tagged ids, for use
in Raft leader discovery, which selects the smallest
id for leader.
This helper uses int_or_strong_ordering to facilitate vector
ordering checks. The rework is straightforward.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Indexed select statements fetch primary key information from
their internal materialized views and then use it to query
the base table. Unfortunately, the current mechanism for retrieving
base table rows makes it easy to overwhelm the replicas with unbounded
concurrency - the number of concurrent ops is increased exponentially
until a short read is encountered, but it's not enough to cap the
concurrency - if data is fetched row-by-row, then short reads usually
don't occur and as a result it's easy to see concurrency of 1M or
higher. In order to avoid overloading the replicas, the concurrency
of indexed queries is now capped at 4096 and additionally throttled
if enough results are already fetched. For paged queries it means that
the query returns as soon as 1MB of data is ready, and for unpaged ones
the concurrency will no longer be doubled as soon as the previous
iteration fetched 1MB of results.
The fixed 4096 value can be subject to debate, its reasoning is as follows:
for 2KiB rows, so moderately large but not huge, they result in
fetching 10MB of data, which is the granularity used by replicas.
For 200B rows, which is rather small, the result would still be
around 1MB.
At the same time, 4096 separate tasks also means 4096 allocations,
so increasing the number also strains the allocator.
Fixes#8799
Tests: unit(release),
manual: observing metrics of modified index_paging_test
Closes#8814
* github.com:scylladb/scylla:
cql3: limit the transitional result size for indexed queries
cql3: return indexed pages after 1MB worth of data
cql3: limit the concurrency of indexed statements
Unpaged indexed queries already have a concurrency limit of 4096,
but now the concurrency is further limited by previous number of bytes
fetched. Once this number reached 1MB, the concurrency will not be
increased in consecutive queries to avoid overload.
Eliminate not used includes and replace some more includes
with forward declarations where appropriate.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Fixes#8773
When refactored for cdc, properties -> extensions merge
was modified so it did not handle _removal_ (i.e. an
extension function returning null -> no entry in new map).
This causes certain enterprise extensions to not be able
to disable themselves.
Fixed by filtering existing extensions by property keywords.
Unit test added.
Closes#8774
Also drop a single violation in transport/server.cc. This helps
prevent dead code from piling up.
Three functions in row_cache_test that are not used in debug mode
are moved near their user, and under the same ifdef, to avoid triggering
the error.
Closes#8767
Currently the test is using "first_key", "last_key"
literals for the first and last keys and expects them
to sort properly with the murmur3 partitioner.
Also it does that for all generated sstables
which is less interesting for reshape.
Use token_generation_for_current_shard to
generate random, properly ordered keys.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Otherwise, the primary_key will be considered as composite,
as its length does not equal 1. That hampers token caluclation
when decorating the dirst and last keys in the summary file.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
This patch is not backward compatible with its original,
but it's considered fine, since the original workload types were not
yet part of any release.
The changes include:
- instead of using 'unspecified' for declaring that there's no workload
type for a particular service level, NULL is used for that purpose;
NULL is the standard way of representing lack of data
- introducing a delete marker, which accompanies NULL and makes it
possible to distinguish between wanting to forcibly reset a workload
type to unspecified and not wanting to change the previous value
- updating the tests accordingly
These changes come in as a single patch, because they're intertwined
with each other and the tests for workload types are already in place;
an attempt to split them proved to be more complicated than it's worth.
Tests: unit(release)
Closes#8763
Compaction manager can start tons of compaction of fully expired sstable in
parallel, which may consume a significant amount of resources.
This problem is caused by weight being released too early in compaction, after
data is all compacted but before table is called to update its state, like
replacing sstables and so on.
Fully expired sstables aren't actually compacted, so the following can happen:
- compaction 1 starts for expired sst A with weight W, but there's nothing to
be compacted, so weight W is released, then calls table to update state.
- compaction 2 starts for expired sst B with weight W, but there's nothing to
be compacted, so weight W is released, then calls table to update state.
- compaction 3 starts for expired sst C with weight W, but there's nothing to
be compacted, so weight W is released, then calls table to update state.
- compaction 1 is done updating table state, so it finally completes and
releases all the resources.
- compaction 2 is done updating table state, so it finally completes and
releases all the resources.
- compaction 3 is done updating table state, so it finally completes and
releases all the resources.
This happens because, with expired sstable, compaction will release weight
faster than it will update table state, as there's nothing to be compacted.
With my reproducer, it's very easy to reach 50 parallel compactions on a single
shard, but that number can be easily worse depending on the amount of sstables
with fully expired data, across all tables. This high parallelism can happen
only with a couple of tables, if there are many time windows with expired data,
as they can be compacted in parallel.
Prior to 55a8b6e3c9, weight was released earlier in compaction, before
last sstable was sealed, but right now, there's no need to release weight
earlier. Weight can be released in a much simpler way, after the compaction is
actually done. So such compactions will be serialized from now on.
Fixes#8710.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20210527165443.165198-1-raphaelsc@scylladb.com>
[avi: drop now unneeded storage_service_for_tests]
user_defined_function_test fails sporadically in debug mode
due to lua timeout. Raise the timeout to avoid the failure, but
not so much that the test that expects timout becomes too slow.
Fixes#8746.
Closes#8747
This is another boring patch.
One of schema constructors has been deprecated for many years now but
was used in several places anyway. Usage of this constructor could
lead to data corruption when using MX sstables because this constructor
does not set schema version. MX reading/writing code depends on schema
version.
This patch replaces all the places the deprecated constructor is used
with schema_builder equivalent. The schema_builder sets the schema
version correctly.
Fixes#8507
Test: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <4beabc8c942ebf2c1f9b09cfab7668777ce5b384.1622357125.git.piotr@scylladb.com>
Reopening #8286 since the token metadata fix that allows `Everywhere` strategy tables to work with RBO (#8536) has been merged.
---
Currently when a node wants to create and broadcast a new CDC generation
it performs the following steps:
1. choose the generation's stream IDs and mapping (how this is done is
irrelevant for the current discussion)
2. choose the generation's timestamp by taking the current time
(according to its local clock) and adding 2 * ring_delay
3. insert the generation's data (mapping and stream IDs) into
system_distributed.cdc_generation_descriptions, using the
generation's timestamp as the partition key (we call this table
the "old internal table" below)
4. insert the generation's timestamp into the "CDC_STREAMS_TIMESTAMP"
application state.
The timestamp spreads epidemically through the gossip protocol. When
nodes see the timestamp, they retrieve the generation data from the
old internal table.
Unfortunately, due to the schema of the old internal table, where
the entire generation data is stored in a single cell, step 3 may fail for
sufficiently large generations (there is a size threshold for which step
3 will always fail - retrying the operation won't help). Also the old
internal table lies in the system_distributed keyspace that uses
SimpleStrategy with replication factor 3, which is also problematic; for
example, when nodes restart, they must reach at least 2 out of these 3
specific replicas in order to retrieve the current generation (we write
and read the generation data with QUORUM, unless we're a single-node
cluster, where we use ONE). Until this happens, a restarting
node can't coordinate writes to CDC-enabled tables. It would be better
if the node could access the last known generation locally.
The commit introduces a new table for broadcasting generation data with
the following properties:
- it uses a better schema that stores the data in multiple rows, each
of manageable size
- it resides in a new keyspace that uses EverywhereStrategy so the
data will be written to every node in the cluster that has a token in
the token ring
- the data will be written using CL=ALL and read using CL=ONE; thanks
to this, restarting node won't have to communicate with other nodes
to retrieve the data of the last known generation. Note that writing
with CL=ALL does not reduce availability: creating a new generation
*requires* all nodes to be available anyway, because they must learn
about the generation before their clocks go past the generation's
timestamp; if they don't, partitions won't be mapped to stream IDs
consistently across the cluster
- the partition key is no longer the generation's timestamp. Because it
was that way in the old internal table, it forced the algorithm to
choose the timestamp *before* the generation data was inserted into
the table. What if the inserting took a long time? It increased the
chance that nodes would learn about the generation too late (after
their clocks moved past its timestamp). With the new schema we will
first insert the generation data using a randomly generated UUID as
the partition key, *then* choose the timestamp, then gossip both the
timestamp and the UUID.
Observe that after a node learns about a generation broadcasted using
this new method through gossip it will retrieve its data very quickly
since it's one of the replicas and it can use CL=ONE as it was
written using CL=ALL.
The generation's timestamp and the UUID mentioned in the last point form
a "generation identifier" for this new generation. For passing these new
identifiers around, we introduce the cdc::generation_id_v2 type.
Fixes#7961.
---
For optimal review experience it is best to first read the updated design notes (you can read them rendered here: https://github.com/kbr-/scylla/blob/cdc-gen-table/docs/design-notes/cdc.md), specifically the ["Generation switching"](https://github.com/kbr-/scylla/blob/cdc-gen-table/docs/design-notes/cdc.md#generation-switching) section followed by the ["Internal generation descriptions table V1 and upgrade procedure"](https://github.com/kbr-/scylla/blob/cdc-gen-table/docs/design-notes/cdc.md#internal-generation-descriptions-table-v1-and-upgrade-procedure) section, then read the commits in topological order.
dtest gating run (dev): https://jenkins.scylladb.com/job/scylla-master/job/byo/job/byo_build_tests_dtest/1160/
unit tests (dev) passed locally
Closes#8643
* github.com:scylladb/scylla:
docs: update cdc.md with info about the new internal table
sys_dist_ks: don't create old CDC generations table on service initialization
sys_dist_ks: rename all_tables() to ensured_tables()
cdc: when creating new generations, use format v2 if possible
main: pass feature_service to cdc::generation_service
gms: introduce CDC_GENERATIONS_V2 feature
cdc: introduce retrieve_generation_data
test: cdc: include new generations table in permissions test
sys_dist_ks: increase timeout for create_cdc_desc
sys_dist_ks: new table for exchanging CDC generations
tree-wide: introduce cdc::generation_id_v2
This draft extends and obsoletes #8123 by introducing a way of determining the workload type from service level parameters, and then using this context to qualify requests for shedding.
The rough idea is that when the admission queue in the CQL server is hit, it might make more sense to start shedding surplus requests instead of accumulating them on the semaphore. The assumption that interactive workloads are more interested in the success rate of as many requests as possible, and hanging on a semaphore reduces the chances for a request to succeed. Thus, it may make sense to shed some requests to reduce the load on this coordinator and let the existing requests to finish.
It's a draft, because I only performed local guided tests. #8123 was followed by some experiments on a multinode cluster which I want to rerun first.
Closes#8680
* github.com:scylladb/scylla:
test: add a case for conflicting workload types
cql-pytest: add basic tests for service level workload types
docs: describe workload types for service levels
sys_dist_ks: fix redundant parsing in get_service_level
sys_dist_ks: make get_service_level exception-safe
transport: start shedding requests during potential overload
client_state: hook workload type from service levels
cql3: add listing service level workload type
cql3: add persisting service level workload type
qos: add workload_type service level parameter
The purpose of the class in question is to start sharded storage
service to make its global instance alive. I don't know when exactly
it happened but no code that instantiates this wrapper really needs
the global storage service.
Ref: #2795
tests: unit(dev), perf_sstable(dev)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210526170454.15795-1-xemul@scylladb.com>
This warning triggers when a range for ("for (auto x : range)") causes
non-trivial copies, prompting the developer to replace with a capture
by reference. A few minor violations in the test suite are corrected.
Closes#8699
Fixes#8270
If we have an allocation pattern where we leave large parts of segments "wasted" (typically because the segment has empty space, but cannot hold the mutation being added), we can have a disk usage that is below threshold, yet still get a disk _footprint_ that is over limit causing new segment allocation to stall.
We need to take a few things into account:
1.) Need to include wasted space in the threshold check. Whether or not disk is actually used does not matter here.
2.) If we stall a segment alloc, we should just flush immediately. No point in waiting for the timer task.
3.) Need to adjust the thresholds a bit. Depending on sizes, we should probably consider start flushing once we've used up space enough to be in the last available segment, so a new one is hopefully available by the time we hit the limit.
Also fix edge case (for tests), when we have too few segment to have an active one (i.e. need flush everything).
Closes#8695
* github.com:scylladb/scylla:
commitlog_test: Add test case for usage/disk size threshold mismatch
commitlog: Flush all segments if we only have one.
commitlog: Always force flush if segment allocation is waiting
commitlog: Include segment wasted (slack) size in footprint check
commitlog: Adjust (lower) usage threshold
The old table won't be created in clusters that are bootstrapped after
this commit. It will stay in clusters that were upgraded from a version
before this commit.
Note that a fully upgraded cluster doesn't automatically create a new
generation in the new format. Even if the last generation was created
before the upgrade, the cluster will keep using it.
A new generation will be created in the new format when either:
1. a new node bootstraps (in the new version),
2. or the user runs checkAndRepairCdcStreams, which has a new check: if
the current generation uses the old format, the command will decide
that repair is needed, even if the generation is completely fine
otherwise (also in the new version).
During upgrade, while the CDC_GENERATIONS_V2 feature is still not
enabled, the user may still bootstrap a node in the old version of
Scylla or run checkAndRepairCdcStreams on a not-yet-upgraded node. In
that case a new generation will be created in the old format,
using the old table definitions.
test_phased_barrier_reassignment has a timeout to prevent the test from
hanging on failure, but it occastionally triggers in debug mode since
the timeout is quite low (1ms). Increase the timeout to prevent false
positives. Since the timeout only expires if the test fails, it will
have no impact on execution time.
Ref #8613Closes#8692
Off-strategy compaction on a table using STCS is slow because of
the needless write amplification of 2. That's because STCS reshape
isn't taking advantage of the fact that sstables produced by
a repair-based operation are disjoint. So the ~256 input sstables
were compacted (in batches of 32) into larger sstables, which in
turn were compacted into even larger ones. That write amp is very
significant on large data sets, making the whole operation 2x
slower.
Fixes#8449.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20210524213426.196407-1-raphaelsc@scylladb.com>
