The PRUNE MATERALIZED VIEW statement is performed as follows:
1. Perform a range scan of the view table from the view replicas based
on the ranges specified in the statement.
2. While reading the paged scan above, for each view row perform a read
from all base replicas at the corresponding primary key. If a discrepancy
is detected, delete the row in the view table.
When reading multiple rows, this is very slow because for each view row
we need to performe a single row query on multiple replicas.
In this patch we add an option to speed this up by performing many of the
single base row reads concurrently, at the concurrency specified in the
USING CONCURRENCY clause.
Aside from the unit test, I checked manually on a 3-node cluster with 10M rows, using vnodes. There were actually no ghost rows in the test, but we still had to iterate over all view rows and read the corresponding base rows. And actual ghost rows, if there are any, should be a tiny fraction of all rows. I compared concurrencies 1,2,10,100 and the results were:
* Pruning with concurrency 1 took total 1416 seconds
* Pruning with concurrency 2 took total 731 seconds
* Pruning with concurrency 10 took total 234 seconds
* Pruning with concurrency 100 took total 171 seconds
So after a concurrency of 10 or so we're hitting diminishing returns (at least in this setup). At that point we may be no longer bottlenecked by the reads, but by CPU on the shard that's handling the PRUNE
Fixes https://github.com/scylladb/scylladb/issues/27070Closesscylladb/scylladb#27097
* github.com:scylladb/scylladb:
mv: allow setting concurrency in PRUNE MATERIALIZED VIEW
cql: add CONCURRENCY to the USING clause
This patch adds separate group for vector search parameters in the
documentation and fixes small typos and formatting.
Fixes: SCYLLADB-77.
Closesscylladb/scylladb#27385
Even though that `view_building_coordinator::work_on_view_building` has
an `if` at the very beginning which checks whether the currently
processed base table is set, it only prints a message and continues
executing the rest of the function regardless of the result of the
check. However, some of the logic in the function assumes that the
currently processed base table field is set and tries to access the
value of the field. This can lead to the view building coordinator
accessing a disengaged optional, which is undefined behavior.
Fix the function by adding the clearly missing `co_await` to the check.
A regression test is added which checks that the view building state
observer - a different fiber which used to print a weird message due to
erroneus view building coordinator behavior - does not print a warning.
Fixes: scylladb/scylladb#27363Closesscylladb/scylladb#27373
This patch increases the compatibility with DynamoDB Streams by integrating the DynamoDB's event type rules (described in https://github.com/scylladb/scylladb/issues/6918) into Alternator. The main changes are:
- introduce a new flag `alternator_streams_strict_compatibility`, meant as a guard of performance-intensive operations that increase the compatibility with DynamoDB Streams. If enabled, Alternator always performs a RBW before a data-modifying operation, and propagates its result to CDC. Then, the old item is compared to the new one, to determine the mutation type (INSERT vs MODIFY). This option is a no-op for tables with disabled Alternator Streams,
- reduce splitting of simple Alternator mutations,
- correctly distinguish event types described in #6918, except for item deletes. Deleting a missing item with DeleteItem, BatchWriteItem, or a missing field with UpdateItem still emit REMOVEs.
To summarize, the emitted events of the data manipulation operations should be as follows:
- DeleteItem/BatchWriteItem.DeleteItem of existing item: REMOVE (OK)
- DeleteItem of nonexistent item: nothing (OK)
- BatchWriteItem.DeleteItem of nonexistent item: nothing (OK)
- PutItem/UpdateItem/BatchWriteItem.PutItem of existing and not equal item: MODIFY (OK)
- PutItem/UpdateItem/BatchWriteItem.PutItem of existing and equal item: nothing (OK)
- PutItem/UpdateItem/BatchWriteItem.PutItem of nonexistent item: INSERT (OK)
No backport is necessary.
Refs https://github.com/scylladb/scylladb/pull/26149
Refs https://github.com/scylladb/scylladb/pull/26396
Refs https://github.com/scylladb/scylladb/issues/26382
Fixes https://github.com/scylladb/scylladb/issues/6918
Closes scylladb/scylladb#26121
* github.com:scylladb/scylladb:
test/alternator: Enable the tests failing because of #6918
alternator, cdc: Don't emit events for no-op removes
alternator, cdc: Don't emit an event for equal items
alternator/streams, cdc: Differentiate item replace and item update in CDC
alternator: Change the return type of rmw_operation_return
config: Add alternator_streams_strict_compatibility flag
cdc: Don't split a row marker away from row cells
When we come across a segment truncation, this information may
be helpful to determine when the error occurred exactly and
hint at what code path might've led to it.
Closesscylladb/scylladb#27207
Fixes#24346
When reading, we check for each entry and each chunk, if advancing there
will hit EOF of the segment. However, IFF the last chunk being read has
the last entry _exactly_ matching the chunk size, and the chunk ending
at _exactly_ segment size (preset size, typically 32Mb), we did not check
the position, and instead complained about not being able to read.
This has literally _never_ happened in actual commitlog (that was replayed
at least), but has apparently happened more and more in hints replay.
Fix is simple, just check the file position against size when advancing
said position, i.e. when reading (skipping already does).
v2:
* Added unit test
Closesscylladb/scylladb#27236
The PRUNE MATERALIZED VIEW statement is performed as follows:
1. Perform a range scan of the view table from the view replicas based
on the ranges specified in the statement.
2. While reading the paged scan above, for each view row perform a read
from all base replicas at the corresponding primary key. If a discrepancy
is detected, delete the row in the view table.
When reading multiple rows, this is very slow because for each view row
we need to performe a single row query on multiple replicas.
In this patch we add an option to speed this up by performing many of the
single base row reads concurrently, at the concurrency specified in the
USING CONCURRENCY clause.
Fixes https://github.com/scylladb/scylladb/issues/27070
Previously, the view building coordinator relied on setting each task's state to STARTED and then explicitly removing these state entries once tasks finished, before scheduling new ones. This approach induced a significant number of group0 commits, particularly in large clusters with many nodes and tablets, negatively impacting performance and scalability.
With the update, the coordinator and worker logic has been restructured to operate without maintaining per-task states. Instead, tasks are simply tracked with an aborted boolean flag, which is still essential for certain tablet operations. This change removes much of the coordination complexity, simplifies the view building code, and reduces operational overhead.
In addition, the coordinator now batches reports of finished tasks before making commits. Rather than committing task completions individually, it aggregates them and reports in groups, significantly minimizing the frequency of group0 commits. This new approach is expected to improve efficiency and scalability during materialized view construction, especially in large deployments.
Fixes https://github.com/scylladb/scylladb/issues/26311
This patch needs to be backported to 2025.4.
Closesscylladb/scylladb#26897
* github.com:scylladb/scylladb:
docs/dev/view-building-coordinator: update the docs after recent changes
db/view/view_building: send coordinator's term in the RPC
db/view/view_building_state: replace task's state with `aborted` flag
db/view/view_building_coordinator: batch finished tasks reporting
db/view/view_building_worker: change internal implementation
db/view/view_building_coordinator: change `work_on_tasks` RPC return type
This PR adds support for limiting the maximum shares allocated to a
compaction scheduling class by the compaction controller. It introduces
a new configuration parameter, compaction_max_shares, which, when set
to a non zero value, will cap the shares allocated to compaction jobs.
This PR also exposes the shares computed by the compaction controller
via metrics, for observability purposes.
Fixes https://github.com/scylladb/scylladb/issues/9431
Enhancement. No need to backport.
NOTE: Replaces PR https://github.com/scylladb/scylladb/pull/26696
Ran a test in which the backlog raised the need for max shares (normalized backlog above normalization_factor), and played with different values for new option compaction_max_shares to see it works (500, 1000, 2000, 250, 50)
Closesscylladb/scylladb#27024
* github.com:scylladb/scylladb:
db/config: introduce new config parameter `compaction_max_shares`
compaction_manager:config: introduce max_shares
compaction_controller: add configurable maximum shares
compaction_controller: introduce `set_max_shares()`
To avoid case when an old coordinator (which hasn't been stopped yet)
dictates what should be done, add raft term to the `work_on_view_building_tasks`
RPC.
The worker needs to check if the term matches the current term from raft
server, and deny the request when the term is bad.
After previous commits, we can drop entire task's state and replace it
with single boolean flag, which determines if a task was aborted.
Once a task was aborted, it cannot get resurrected to a normal state.
In previous implementation to execute view building tasks, the
coordinator needed to firstly set their states to `STARTED`
and then it needed to remove them before it could start the next ones.
This logic required a lot of group0 commits, especially in large
clusters with higher number of nodes and big tablet count.
After previous commit to the view building worker, the coordinator
can start view building tasks without setting the `STARTED` state
and deleting finished tasks.
This patch adjusts the coordinator to save finished tasks locally,
so it can continue to execute next ones and the finished tasks are
periodically removed from the group0 by `finished_task_gc_fiber()`.
Add support for the new configuration parameter `compaction_max_shares`,
and update the compaction manager to pass it down to the compaction
controller when it changes. The shares allocated to compaction jobs will
be limited by this new parameter.
Fixes#9431
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
When migrating tablet size during the end_migration tablet transition stage, we need the pending and leaving replica hosts. The leaving and pending replicas are gathered in objects of type std::optional<tablet_replica> and are not checked if they contain a value before dereferencing which could cause an exception in the topology coordinator.
This patch adds a check for leaving and pending replicas, and only performs the tablet size migration if neither are empty.
This bug was introduced in 10f07fb95a
This change also adds the ability to create a tablet size in load_stats during end_migration stage of a tablet rebuild. We compute the new tablet size from by averaging the tablet sizes of the existing replicas.
This change also adds the virtual table tablet_sizes which contains tablet sizes of all the replicas of all the tablets in the cluster.
A version containing this bug has not yet been released, so a backport is not needed.
Closesscylladb/scylladb#27118
* github.com:scylladb/scylladb:
test: add tests for tablet size migration during end_migration
virtual_table: add tablet_sizes virtual table
load_stats: update tablet sizes after migration or rebuild
This commit doesn't change the logic behind the view building worker but
it changes how the worker is executing view building tasks.
Previously, the worker had a state only on shard0 and it was reacting to
changes in group0 state. When it noticed some tasks were moved to
`STARTED` state, the worker was creating a batch for it on the shard0
state.
The RPC call was used only to start the batch and to get its result.
Now, the main logic of batch management was moved to the RPC call
handler.
The worker has a local state on each shard and the state
contains:
- unique ptr to the batch
- set of completed tasks
- information for which views the base table was flushed
So currently, each batch lives on a shard where it has its work to do
exclusively. This eliminates a need to do a synchronization between
shard0 and work shard, which was a painful point in previous
implementation.
The worker still reacts to changes in group0 view building state, but
currently it's only used to observe whether any view building tasks was
aborted by setting `ABORTED` state.
To prepare for further changes to drop the view building task state,
the worker ignores `IDLE` and `STARTED` states completely.
During the initial implementation of the view builing coordinator,
we decided that if a view building task fails locally on the worker
(example reason: view update's target replica is not available),
the worker will retry this work instead of reporting a failure to the
coordinator.
However, we left return type of the RPC, which was telling if a task was
finished successfully or aborted.
But the worker doesn't need to report that a task was aborted, because
it's the coordinator, who decides to abort a task.
So, this commit changes the return type to list of UUIDs of completed
tasks.
Previously length of the returned vector needed to be the same as length
of the vector sent in the request.
No we can drop this restriction and the RPC handler return list of UUIDs
of completed tasks (subset of vector sent in the request).
This change is required to drop `STARTED` state in next commits.
Since Scylla 2025.4 wasn't released yet and we're going to merge this
patch before releasing, no RPC versioning or cluster feature is needed.
This commit introduces TLS encryption support for vector store connections.
A new configuration option is added:
- vector_store_encryption_options.truststore: path to the trust store file
To enable secure connections, use the https:// scheme in the
vector_store_primary_uri/vector_store_secondary_uri configuration options.
Fixes: VECTOR-327
Remove the FIXME comment for re-enabling caching of the large tables
since the tables are used infrequently [1].
[1] : github.com/scylladb/scylladb/pull/26789#issuecomment-3477540364
Fixes#26032
Signed-off-by: Gautam Menghani <gautam.opensource@gmail.com>
Closesscylladb/scylladb#26789
Add precompiled header support to CMakeLists.txt and configure.py -
it improves compilation time by approximately 10%.
New header `stdafx.hh` is added, don't include it manually -
the compiler will include it for you. The header contains includes from
external libraries used by Scylla - seastar, standard library,
linux headers and zlib.
The feature is enabled by default, use CMake option `Scylla_USE_PRECOMPILED_HEADER`
or configure.py --disable-precompiled-header to disable.
The feature should be disabled, when trying to check headers - otherwise
you might get false negatives on missing includes from seastar / abseil and so on.
Note: following configuration needs to be added to ccache.conf:
sloppiness = pch_defines,time_macros,include_file_mtime,include_file_ctime
Closesscylladb/scylladb#26617
This change adds support for secondary vector store clients, typically
located in different availability zones. Secondary clients serve as
fallback targets when all primary clients are unavailable.
New configuration option allows specifying secondary client addresses
and ports.
Fixes: VECTOR-187
Closesscylladb/scylladb#26484
This patch adds a metric for pre-compression size of sstable files.
This patch adds a per-table metric
`scylla_column_family_total_disk_space_before_compression`,
which measures the hypothetical total size of sstables on disk,
if Data.db was replaced with an uncompressed equivalent.
As for the implementation:
Before the patch, tables and sstable sets are already tracking their total physical file size.
Whenever sstables are added or removed, the size delta is propagated from the sstable up through sstable sets into table_stats.
To implement the new metric, we turn the size delta that is getting passed around from a one-dimensional to a two-dimensional value, which includes both the physical and the pre-compression size.
New functionality, no backport needed.
Closesscylladb/scylladb#26996
* github.com:scylladb/scylladb:
replica/table: add a metric for hypothetical total file size without compression
replica/table: keep track of total pre-compression file size
This reverts commit 43738298be.
This commit causes instability in dtests. Several non-gating dtests
started failing, as well as some gating ones, see #27047.
Closesscylladb/scylladb#27067Fixes#27047
…played
Currently, if flushing hints falls within the repair cache timeout, then the flush_time is set to batchlog_manager::_last_replay. _last_replay is updated on each replay, even if some batches weren't replayed. Due to that, we risk the data resurrection.
Update _last_replay only if all batches were replayed.
Fixes: https://github.com/scylladb/scylladb/issues/24415.
Needs backport to all live versions.
Closesscylladb/scylladb#26793
* github.com:scylladb/scylladb:
test: extend test_batchlog_replay_failure_during_repair
db: batchlog_manager: update _last_replay only if all batches were replayed
This PR fixes staging stables handling by view building coordinator in case of intra-node tablet migration or tablet merge.
To support tablet merge, the worker stores the sstables grouped only be `table_id`, instead of `(table_id, last_token)` pair.
There shouldn't be that many staging sstables, so selecting relevant for each `process_staging` task is fine.
For the intra-node migration support, the patch adds methods to load migrated sstables on the destination shard and to cleanup them on source shard.
The patch should be backported to 2025.4
Fixes https://github.com/scylladb/scylladb/issues/26244Closesscylladb/scylladb#26454
* github.com:scylladb/scylladb:
service/storage_service: migrate staging sstables in view building worker during intra-node migration
db/view/view_building_worker: support sstables intra-node migration
db/view_building_worker: fix indent
db/view/view_building_worker: don't organize staging sstables by last token
Modify test_batchlog_replay_failure_during_repair to also check
that there isn't data resurrection if flushing hints falls within
the repair cache timeout.
This PR refactors excluded nodes handling for tablets and topology. For tablets a dedicated variable `topology::excluded_tablet_nodes` is introduced, for topology operations a method get_excluded_nodes() is inlined into topology_coordinator and renamed to `get_excluded_nodes_for_topology_request`.
The PR improves codes readability and efficiency, no behavior changes.
backport: this is a refactoring/optimization, no need to backport
Closesscylladb/scylladb#26907
* https://github.com/scylladb/scylladb:
topology_coordinator: drop unused exec_global_command overload
topology_coordinator: rename get_excluded_nodes -> get_excluded_nodes_for_topology_request
topology_state_machine: inline get_excluded_nodes
messaging_service: simplify and optimize ban_host
storage_service: topology_state_load: extract topology variable
topology_coordinator: excluded_tablet_nodes -> ignored_nodes
topology_state_machine: add excluded_tablet_nodes field
Remove bootstrap and decomission from allowed_repair_based_node_ops.
Using RBNO over streaming for these operations has no benefits, as they
are not exposed to the out-of-date replica problem that replace,
removenode and rebuild are.
On top of that, RBNO is known to have problems with empty user tables.
Using streaming for boostrap and decomission is safe and faster
than RBNO in all condition, especially when the table is small.
One test needs adjustment as it relies on RBNO being used for all node
ops.
Fixes: #24664Closesscylladb/scylladb#26330
The view building coordinator manages the process by sending RPC
requests to all nodes in the cluster, instructing them what to do.
If processing that message fails, the coordinator decides if it
wants to retry it or (temporarily) abandon the work.
An example of the latter scenario could be if one of the target nodes
dies and any attempts to communicate with it would fail.
Unfortunately, the current approach to it is not perfect and may result
in a storm of warnings, effectively clogging the logs. As an example,
take a look at scylladb/scylladb#26686: the gossiper failed to mark
one of the dead nodes as DOWN fast enough, and it resulted in a warning storm.
To prevent situations like that, we implement a form of backoff.
If processing an RPC message fails, we postpone finishing the task for
a second. That should reduce the number of messages in the logs and avoid
retries that are likely to fail as well.
We provide a reproducer test.
Fixesscylladb/scylladb#26686
Backport: impact on the user. We should backport it to 2025.4.
Closesscylladb/scylladb#26729
* github.com:scylladb/scylladb:
tet/cluster/mv: Clean up test_backoff_when_node_fails_task_rpc
db/view/view_building_coordinator: Rate limit logging failed RPC
db/view: Add backoff when RPC fails
The view building coordinator sends tasks in form of RPC messages
to other nodes in the cluster. If processing that RPC fails, the
coordinator logs the error.
However, since tasks are per replica (so per shard), it may happen
that we end up with a large number of similar messages, e.g. if the
target node has died, because every shard will fail to process its
RPC message. It might become even worse in the case of a network
partition.
To mitigate that, we rate limit the logging by 1 seconds.
We extend the test `test_backoff_when_node_fails_task_rpc` so that
it allows the view building coordinator to have multiple tablet
replica targets. If not for rate limiting the warning messages,
we should start getting more of them, potentially leading to
a test failure.
The view building coordinator manages the process of view building
by sending RPC requests to all nodes in the cluster, instructing them
what to do. If processing that message fails, the coordinator decides
if it wants to retry it or (temporarily) abandon the work.
An example of the latter scenario could be if one of the target nodes
dies and any attempts to communicate with it would fail.
Unfortunately, the current approach to it is not perfect and may result
in a storm of warnings, effectively clogging the logs. As an example,
take a look at scylladb/scylladb#26686: the gossiper failed to mark
one of the dead nodes as DOWN fast enough, and it resulted in a warning storm.
To prevent situations like that, we implement a form of backoff.
If processing an RPC message fails, we postpone finishing the task for
a second. That should reduce the number of messages in the logs and avoid
retries that are likely to fail as well.
We provide a reproducer test: it fails before this commit and succeeds
with it.
Fixesscylladb/scylladb#26686
Currently, if flushing hints falls within the repair cache timeout,
then the flush_time is set to batchlog_manager::_last_replay.
_last_replay is updated on each replay, even if some batches weren't
replayed. Due to that, we risk the data resurrection.
Update _last_replay only if all batches were replayed.
Fixes: https://github.com/scylladb/scylladb/issues/24415.
When generating CDC log mutations for some base mutation, use a CDC schema that is compatible with the base schema.
The compatible CDC schema has for every base column a corresponding CDC column with the same name. If using a non-compatible schema, we may encounter a situation, especially during ALTER, that we have a mutation with a base column set with some value, but the CDC schema doesn't have a column by that name. This would cause the user request to fail with an error.
We add to the schema object a schema_ptr that for CDC-enabled tables points to the schema object of the CDC table that is compatible with the schema. It is set by the schema merge algorithm when creating the schema for a table that is created or altered. We use the fact that a base table and its CDC table are created and altered in the same group0 operation, and this way we can find and set the cdc schema for a base table.
When transporting the base schema as a frozen schema between shards, we transport with it the frozen cdc schema as well.
The patch starts with a series of refactoring commits that make extending the frozen schema easier and cleans up some duplication in the code about the frozen schema. We combine the two types `frozen_schema_with_base_info` and `view_schema_and_base_info` to a single type `extended_frozen_schema` that holds a frozen schema with additional data that is not part of the schema mutations but needs to be transported with it to unfreeze it - base_info, and the frozen cdc schema which is added in a later commit.
Fixes https://github.com/scylladb/scylladb/issues/26405
backport not needed - enhancement
Closesscylladb/scylladb#24960
* github.com:scylladb/scylladb:
test: cdc: test cdc compatible schema
cdc: use compatiable cdc schema
db: schema_applier: create schema with pointer to CDC schema
db: schema_applier: extract cdc tables
schema: add pointer to CDC schema
schema_registry: remove base_info from global_schema_ptr
schema_registry: use extended_frozen_schema in schema load
schema_registry: replace frozen_schema+base_info with extended_frozen_schema
frozen_schema: extract info from schema_ptr in the constructor
frozen_schema: rename frozen_schema_with_base_info to extended_frozen_schema
Every table and sstable set keeps track of the total file size
of contained sstables.
Due to a feature request, we also want to keep track of the hypothetical
file size if Data files were uncompressed, to add a metric that
shows the compression ratio of sstables.
We achieve this by replacing the relevant `uint_64 bytes_on_disk`
counters everywhere with a struct that contains both the actual
(post-compression) size and the hypothetical pre-compression size.
This patch isn't supposed to change any observable behavior.
In the next patch, we will use these changes to add a new metric.
The topology_coordinator::is_excluded() creates a temporary hash
map for each call. This is probably not a performance problem since
left_nodes_rs contains only those left nodes that are referenced
from tablet replicas, this happens temporarily while e.g. a replaced
node is being rebuilt. On the other hand, why not just have a
dedicated field in the topology_state_machine, then this code wouldn't
look suspicious.
There was a problem with staging sstables after tablet merge.
Let's say there were 2 tablets and tablet 1 (lower last token)
had an staging sstable. Then a tablet merge occured, so there is only
one tablet now (higher last token).
But entries in `_staging_sstables`, which are grouped by last token, are
never adjusted.
Since there shouldn't be thousands of sstables, we can just hold list of
sstables per table and filter necessary entries when doing
`process_staging` view building task.
We have a configuration option "tablets_mode_for_new_keyspaces" which
determines whether new keyspaces should use tablets or vnodes.
For some reason, this configuration parameter was never marked live-
updatable, so in this patch we add flag. No other changes are needed -
the existing code that uses this flag always uses it through the
up-to-date configuration.
In the previous patches we start to honor tablets_mode_for_new_keyspaces
also in Alternator CreateTable, and we wanted to test this but couldn't
do this in test/alternator because the option was not live-updatable.
Now that it will be, we'll be able to test this feature in
test/alternator.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
When we build a materialized view we read the entire base table from start to
end to generate all required view udpates. If a view is created while another view
is being built on the same base table, this is optimized - we start generating
view udpates for the new view from the base table rows that we're currently
reading, and we read the missed initial range again after the previous view
finishes building.
The view building progress is only updated after generating view updates for
some read partitions. However, there are scenarios where we'll generate no
view updates for the entire read range. If this was not handled we could
end up in an infinite view building loop like we did in https://github.com/scylladb/scylladb/issues/17293
To handle this, we mark the view as built if the reader generated no partitions.
However, this is not always the correct conclusion. Another scenario where
the reader won't encounter any partitions is when view building is interrupted,
and then we perform a reshard. In this scenario, we set the reader for all
shards to the last unbuilt token for an existing partition before the reshard.
However, this partition may not exist on a shard after reshard, and if there
are also no partitions with higher tokens, the reader will generate no partitions
even though it hasn't finished view building.
Additionally, we already have a check that prevents infinite view building loops
without taking the partitions generated by the reader into account. At the end
of stream, before looping back to the start, we advance current_key to the end
of the built range and check for built views in that range. This handles the case
where the entire range is empty - the conditions for a built view are:
1. the "next_token" is no greater than "first_token" (the view building process
looped back, so we've built all tokens above "first_token")
2. the "current_token" is no less than "first_token" (after looping back, we've
built all tokens below "first_token")
If the range is empty, we'll pass these conditions on an empty range after advancing
"current_key" to the end because:
1. after looping back, "next_token" will be set to `dht::minimum_token`
2. "current_key" will be set to `dht::ring_position::max()`
In this patch we remove the check for partitions generated by the reader. This fixes
the issue with resharding and it does not resurrect the issue with infinite view building
that the check was introduced for.
Fixes https://github.com/scylladb/scylladb/issues/26523Closesscylladb/scylladb#26635
An Alternator user was recently "bit" when switching `alternator_enforce_authorization` from "false" to "true": ְְְAfter the configuration change, all application requests suddenly failed because unbeknownst to the user, their application used incorrect secret keys.
This series introduces a solution for users who want to **safely** switch `alternator_enforce_authorization` from "false" to "true": Before switching from "false" to "true", the user can temporarily switch a new option, `alternator_warn_authorization`, to true. In this "warn" mode, authentication and authorization errors are counted in metrics (`scylla_alternator_authentication_failures` and `scylla_alternator_authorization_failures`) and logged as WARNings, but the user's application continues to work. The user can use these metrics or log messages to learn of errors in their application's setup, fix them, and only do the switch of `alternator_enforce_authorization` when the metrics or log messages show there are no more errors.
The first patch is the implementation of the the feature - the new configuration option, the metrics and the log messages, the second patch is a test for the new feature, and the third patch is documentation recommending how to use the warn mode and the associated metrics or log messages to safely switch `alternaor_enforce_authorization` from false to true.
Fixes#25308
This is a feature that users need, so it should probably be backported to live branches.
Closesscylladb/scylladb#25457
* github.com:scylladb/scylladb:
docs/alternator: explain alternator_warn_authorization
test/alternator: tests for new auth failure metrics and log messages
alternator: add alternator_warn_authorization config
Recent seastar update deprecated in/out streams usage pattern when a stream is default constructed early and them move-assigned with the proper one (see scylladb/seastar#3051). This PR fixes few places in Scylla that still use one.
Adopting newer seastar API, no need to backport
Closesscylladb/scylladb#26747
* github.com:scylladb/scylladb:
commitlog: Remove unused work::r stream variable
ec2_snitch: Fix indentation after previous patch
ec2_snitch: Coroutinize the aws_api_call_once()
sstable: Construct output_stream for data instantly
test: Don't reuse on-stack input stream
`sstable_compression_user_table_options` allows configuring a node-global SSTable compression algorithm for user tables via scylla.yaml. The current default is LZ4Compressor (inherited from Cassandra).
Make LZ4WithDictsCompressor the new default. Metrics from real datasets in the field have shown significant improvements in compression ratios.
If the dictionary compression feature is not enabled in the cluster (e.g., during an upgrade), fall back to the `LZ4Compressor`. Once the feature is enabled, flip the default back to the dictionary compressor using with a listener callback.
Fixes#26610.
Closesscylladb/scylladb#26697
* github.com:scylladb/scylladb:
test/cluster: Add test for default SSTable compressor
db/config: Change default SSTable compressor to LZ4WithDictsCompressor
db/config: Deprecate sstable_compression_dictionaries_allow_in_ddl
boost/cql_query_test: Get expected compressor from config
use utils::chunked_vector instead of std::vector to store cdc stream
sets for tablets.
a cdc stream set usually represents all streams for a specific table and
timestamp, and has a stream id per each tablet of the table. each stream
id is represented by 16 bytes. thus the vector could require quite large
contiguous allocations for a table that has many tablets. change it to
chunked_vector to avoid large contiguous allocations.
Fixesscylladb/scylladb#26791Closesscylladb/scylladb#26792
`sstable_compression_user_table_options` allows configuring a
node-global SSTable compression algorithm for user tables via
scylla.yaml. The current default is `LZ4Compressor` (inherited from
Cassandra).
Make `LZ4WithDictsCompressor` the new default. Metrics from real datasets
in the field have shown significant improvements in compression ratios.
If the dictionary compression feature is not enabled in the cluster
(e.g., during an upgrade), fall back to the `LZ4Compressor`. Once the
feature is enabled, flip the default back to the dictionary compressor
using with a listener callback.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
With this flag enabled, Alternator Streams produces more accurate event
types:
- nop operations (i.e. replacing an item with an identical one, deleting
a nonexistent item) don't produce an event,
- updates of an existing item produce a MODIFY event, instead of INSERT,
- etc.
This flag affects the internal behaviour of some operations, i.e.
Alternator may select a preimage and propagate it to CDC (in contrary to
CDC making the request), or do extra item comparisons (i.e. compare the
existing item with the new one). These operations may be costly, and
users that don't use Streams won't need them.
This flag is live-updatable. An operation reads this flag once, and uses
its value for the entire operation.
The option is a knob that allows to reject dictionary-aware compressors
in the validation stage of CREATE/ALTER statements, and in the
validation of `sstable_compression_user_table_options`. It was
introduced in 7d26d3c7cb to allow the admins of Scylla Cloud to
selectively enable it in certain clusters. For more details, check:
https://github.com/scylladb/scylla-enterprise/issues/5435
As of this series, we want to start offering dictionary compression as
the default option in all clusters, i.e., treat it as a generally
available feature. This makes the knob redundant.
Additionally, making dictionary compression the default choice in
`sstable_compression_user_table_options` creates an awkward dependency
with the knob (disabling the knob should cause
`sstable_compression_user_table_options` to fall back to a non-dict
compressor as default). That may not be very clear to the end user.
For these reasons, mark the option as "Deprecated", remove all relevant
tests, and adjust the business logic as if dictionary compression is
always available.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
