Previously the test test_interrupt_view_build_shard_registration stopped
the node ungracefully and used commitlog periodic mode to persist the
view build progress in a not very reliable way.
It can happen that due to timing issues, the view build progress is not
persisted, or some of it is persisted in a different ordering than
expected.
To make the test more reliable we change it to stop the node gracefully,
so the commitlog is persisted in a graceful and consistent way, without
using the periodic mode delay. We need to also change the injection for
the shutdown to not get stuck.
Fixes SCYLLADB-1005
Closesscylladb/scylladb#29008
Remove the rest of the code that assumes that either group0 does not exist yet or a cluster is till not upgraded to raft topology. Both of those are not supported any more.
No need to backport since we remove functionality here.
Closesscylladb/scylladb#28841
* github.com:scylladb/scylladb:
service level: remove version 1 service level code
features: move GROUP0_SCHEMA_VERSIONING to deprecated features list
migration_manager: remove unused forward definitions
test: remove unused code
auth: drop auth_migration_listener since it does nothing now
schema: drop schema_registry_entry::maybe_sync() function
schema: drop make_table_deleting_mutations since it should not be needed with raft
schema: remove calculate_schema_digest function
schema: drop recalculate_schema_version function and its uses
migration_manager: drop check for group0_schema_versioning feature
cdc: drop usage of cdc_local table and v1 generation definition
storage_service: no need to add yourself to the topology during reboot since raft state loading already did it
storage_service: remove unused functions
group0: drop with_raft() function from group0_guard since it always returns true now
gossiper: do not gossip TOKENS and CDC_GENERATION_ID any more
gossiper: drop tokens from loaded_endpoint_state
gossiper: remove unused functions
storage_service: do not pass loaded_peer_features to join_topology()
storage_service: remove unused fields from replacement_info
gossiper: drop is_safe_for_restart() function and its use
storage_service: remove unused variables from join_topology
gossiper: remove the code that was only used in gossiper topology
storage_service: drop the check for raft mode from recovery code
cdc: remove legacy code
test: remove unused injection points
auth: remove legacy auth mode and upgrade code
treewide: remove schema pull code since we never pull schema any more
raft topology: drop upgrade_state and its type from the topology state machine since it is not used any longer
group0: hoist the checks for an illegal upgrade into main.cc
api: drop get_topology_upgrade_state and always report upgrade status as done
service_level_controller: drop service level upgrade code
test: drop run_with_raft_recovery parameter to cql_test_env
group0: get rid of group0_upgrade_state
storage_service: drop topology_change_kind as it is no longer needed
storage_service: drop check_ability_to_perform_topology_operation since no upgrades can happen any more
service_storage: remove unused functions
storage_service: remove non raft rebuild code
storage_service: set topology change kind only once
group0: drop in_recovery function and its uses
group0: rename use_raft to maintenance_mode and make it sync
Also remove test_auth_raft_command_split test which is irrelevant since 5ba7d1b116
because it does not use the function that injects max sized command after the
commit.
When we generate view updates, we check whether we can skip the
entire view update if all columns selected by the view are unmodified.
However, for collection columns, we only check if they were unset
before and after the update.
In this patch we add a check for the actual collection contents.
We perform this check for both virtual and non-virtual selections.
When the column is only a virtual column in the view, it would be
enough to check the liveness of each collection cell, however for
that we'd need to deserialize the entire collection anyway, which
should be effectively as expensive as comparing all of its bytes.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-808Closesscylladb/scylladb#28839
* github.com:scylladb/scylladb:
mv: allow skipping view updates when a collection is unmodified
mv: allow skipping view updates if an empty collection remains unset
Currently, the view_update_generator::mutate_MV function acquires a
reference to the keyspace relevant to the operation, then it calls
max_concurrent_for_each and uses that reference inside the lambda passed
to that function. max_concurrent_for_each can preempt and there is no
mechanism that makes sure that the keyspace is alive until the view
updates are generated, so it is possible that the keyspace is freed by
the time the reference is used.
Fix the issue by precomputing the necessary information based on the
keyspace reference right away, and then passing that information by
value to the other parts of the code. It turns out that we only need to
know whether the keyspace uses tablets and whether it uses a network
topology strategy.
Fixes: scylladb/scylladb#28925Closesscylladb/scylladb#28928
When we generate view updates, we check whether we can skip the
entire view update if all columns selected by the view are unmodified.
However, for collection columns, we only check if they were unset
before and after the update.
In this patch we add a check for the actual collection contents.
We perform this check for both virtual and non-virtual selections.
When the column is only a virtual column in the view, it would be
enough to check the liveness of each collection cell, however for
that we'd need to deserialize the entire collection anyway, which
should be effectively as expensive as comparing all of its bytes.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-808
Currently, when we generate view updates, we skip the view update if
all columns selected by the view are unchanged in the base table update.
However, this does not apply for collection columns - if the base table
has a collection regular column, we never allow skipping generating
view updates and the reason for that is missing implementation.
We can easily relax this for the case where the collection was missing
before and after the update - in this commit we move the check for
collections after the check for missing cells.
Currently, repair-mode tombstone-gc cannot be used on tables with RF=1. We want to make repair-mode the default for all tablet tables (and more, see https://github.com/scylladb/scylladb/issues/22814), but currently a keyspace created with RF=1 and later altered to RF>1 will end up using timeout-mode tombstone gc. This is because the repair-mode tombstone-gc code relies on repair history to determine the gc-before time for keys/ranges. RF=1 tables cannot run repairs so they will have empty repair history and consequently won't be able to purge tombstones.
This PR solves this by keeping a registry of RF=1 tables and consulting this registry when creating `tombstone_gc_state` objects. If the table is RF=1, tombstone-gc will work as if the table used immediate-mode tombstone-gc. The registry is updated on each replication update. As soon as the table is not RF=1 anymore, the tombstone-gc reverts to the natural repair-mode behaviour.
After this PR, tombstone-gc defaults to repair-mode for all tables, regardless of RF and tablets/vnodes.
Fixes: SCYLLADB-106.
New feature, no backport required.
Closesscylladb/scylladb#22945
* github.com:scylladb/scylladb:
test/{boost,cluster}: add test for tombstone gc mode=repair with RF=1
tombstone_gc: allow use of repair-mode for RF=1 tables
replica/table: update rf=1 table registry in shared tombstone-gc state
tombstone_gc: tombstone_gc_before_getter: consider RF when getting gc before time
tombstone_gc: unpack per_table_history_maps
tombstone_gc: extract _group0_gc_time from per_table_history_map
tombstone_gc: drop tombstone_gc_state(nullptr) ctor and operator bool()
test/lib/random_schema: use timeout-mode tombstone_gc
tombstone_gc_options: add C++ friendly constructor
test: move away from tombstone_gc_state(nullptr) ctor
treewide: move away from tombstone_gc_state(nullptr) ctor
sstable: move away from tombstone_gc_mode::operator bool()
replica/table: add get_tombstone_gc_state()
compaction: use tombstone_gc_state with value semantics
db/row_cache: use tombstone_gc_state with value semantics
tombstone_gc: introduce tombstone_gc_state::for_tests()
When we create a materialized view, we consider 2 cases:
1. the view's primary key contains a column that is not
in the primary key of the base table
2. the view's primary key doesn't contain such a column
In the 2nd case, we add all columns from the base table
to the schema of the view (as virtual columns). As a result,
all of these columns are effectively "selected" in
view_updates::can_skip_view_updates. Same thing happens when
we add new columns to the base table using ALTER.
Because of this, we can never have !column_is_selected and
!has_base_non_pk_columns_in_view_pk at the same time. And
thus, the check (!column_is_selected
&& _base_info.has_base_non_pk_columns_in_view_pk) is always
the same as (!column_is_selected).
Because we immediately return after this check, the tail of
this function is also never reached - all checks after the
(column_is_selected) are affected by this. Also, the condition
(!column_is_selected && base_has_nonexpiring_marker) is always
false at the point it is called. And this in turn makes the
`base_has_nonexpiring_marker` unused, so we delete it as well.
It's worth considering, why did we even have
`base_has_nonexpiring_marker` if it's effectively unused. We
initially introduced it in bd52e05ae2 and we (incorrectly)
used it to allow skipping view updates even if the liveness of
virtual columns changed. Soon after, in 5f85a7a821, we
started categorizing virtual columns as column_is_selected == true
and we moved the liveness checks for virtual columns to the
`if (column_is_selected)` clause, before the `base_has_nonexpiring_marker`
check. We changed this because even if we have a nonexpiring marker
right now, it may be changed in the future, in which case the liveness
of the view row will depend on liveness of the virtual columns and
we'll need to have the view updates from the time the row marker was
nonexpiring.
Closesscylladb/scylladb#28838
It is ambigous, use the appropriate no-gc or gc-all factories instead,
as appropriate.
A special note for mutation::compacted(): according to the comment above
it, it doesn't drop expired tombstones but as it is currently, it
actually does. Change the tombstone gc param for the underlying call to
compact_for_compaction() to uphold the comment. This is used in tests
mostly, so no fallout expected.
Tests are handled in the next commit, to reduce noise.
Two tests in mutation_test.cc have to be updated:
* test_compactor_range_tombstone_spanning_many_pages
has to be updated in this commit, as it uses
mutation_partition::compact_for_query() as well as
compact_for_query(). The test passes default constructed
tombstone_gc() to the latter while the former now uses no-gc
creating a mismatch in tombstone gc behaviour, resulting in test
failure. Update the test to also pass no-gc to compact_for_query().
* test_query_digest similarly uses mutation_partition::query_mutation()
and another compaction method, having to match the no-gc now used in
query_mutation().
Detached migration callbacks (on_create_view, on_update_view, on_drop_view)
can race with view_builder::drain() teardown.
Add a lifetime gate to view_builder and wire callback launches through
_ops_gate.hold() so each detached dispatch future is tracked until it
completes (finally keeps the hold alive). During shutdown, drain()
now waits for all tracked callback work with _ops_gate.close().
This ensures drain does not proceed past callback lifetime while shutdown is in
progress, and ignores only gate_closed_exception at callback entry as the
expected shutdown path.
on_update_view() currently runs its serialized logic inline via with_semaphore()
from a detached callback path, while create/drop already use dedicated async
dispatchers.
Refactor update handling to follow the same pattern:
- add dispatch_update_view(sstring ks_name, sstring view_name)
- move update logic into that coroutine
- acquire the existing view-builder lock via get_or_adopt_view_builder_lock()
- keep existing behavior for missing base/view state
- keep background invocation semantics from on_update_view()
This aligns update/create/drop flow and keeps async lifecycle handling and a first step to fix shutdown issue.
The handler appeared back in c9e710dca3. In this commit it performed the
"core" part of the task -- the do_build_range() method -- inside the
streaming sched group. The setup code looks seemingly was copied from the
view_builder::do_build_step() method and got the explicit switch of the
scheduling group.
The switch looks both -- justified and not. On one hand, it makes it
explict that the activity runs in the streaming scheduling group. On the
other hand, the verb already uses RPC index on 1, which is negotiated to
be run in streaming group anyway. On the "third hand", even though being
explicit the switch happens too late, as there exists a lot of other
activities performed by the handler that seems to also belong to the
same scheduling group, but which is not switched into explicitly.
By and large, it seems better to avoid the explicit switch and rely on
the RPC-level negotiation-based sched group switching.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#28397
In fact, it's partially there already. When view_builder::start() is called is first calls initialization code (the start_in_background() method), then kicks do_build_step() that runs a background fiber to perform build steps. The starting code inherits scheduling group from main(). And the step fiber code needs to run itself in a maintenance scheduling group, so it explicitly grabs one via database->db_config.
This PR mainly gets rid of the call to database::get_streaming_scheduling_group() from do_build_step() as preparation to splitting the streaming scheduling group into parts (see SCYLLADB-351). To make it happen the do_build_step() is patched to inherit its scheduling group from view_builder::start() and the start() itself is called by main from maintenance scheduling group (like for other view building services).
New feature (nested scheduling group), not backporting
Closesscylladb/scylladb#28386
* github.com:scylladb/scylladb:
view_builder: Start background in maintenance group
view_builder: Wake-up step fiber with condition variable
Currently view_builder::start() is called in default scheduling group.
Once it initializes itself, it wakes up the step fiber that explicitly
switches to maintenance scheduling group.
This explicit switch made sence before previous patch, when the fiber
was implemented as a serialized action. Now the fiber starts directly
from .start() method and can inherit scheduling group from it.
Said that, main code calls view_builder::start() in maintenance
scheduling group killing two birds with one stone. First, the step fiber
no longer needs borrow its scheduling group indirectly via database.
Second, the start_in_background() code itself runs in a more suitable
scheduling group.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
View builder runs a background fiber that perform build steps. To kick
the fiber it uses serizlized action, but it's an overkill -- nobody
waits for the action to finish, but on stop, when it's joined.
This patch uses condition variable to kick the fiber, and starts it
instantly, in the place where serialized action was first kicked.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
There are few places that use raft_group0_client as a way to get to system_keyspace. Mostly they can live without it -- either the needed reference is already at hand, or it's (ab)used to get to the database reference. The only place that really needs the system keyspace is the state merger code that needs last state ID. For that, the explicit helper method is added to group0_client.
Refining API between components, not backporting
Closesscylladb/scylladb#28387
* github.com:scylladb/scylladb:
raft_group0_client: Dont export system keyspace
raft_group0_client: Add and use get_last_group0_state_id()
group0_state_machine: Call ensure_group0_sched() with data_dictionary
view_building_worker: Use its own system_keyspace& reference
When building with `--disable-precompiled-header`, view.cc failed to
compile due to missing <seastar/coroutine/all.hh> include, which provides
`coroutine::all`.
The problem doesn't manifest when precompiled headers are used, which is
the default. So that's likely why it was missed by the CI.
Adding the explicit include fixes the build.
Fixes: scylladb/scylladb#28378
Ref: scylladb/scylladb#28093
No backport: This problem is only present in master.
Closesscylladb/scylladb#28379
Some code in the worker need to mess with system_keyspace&. While
there's a reference on it from the worker object, it gets one via
group0 -> group0_client, which is a bit an overkill.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
db: view: refactor semaphore usage in create/drop view paths
Refactor the construction and usage of semaphore units in the create and drop view flows.
The previous semaphore handling was hard to follow (as noted while working on https://github.com/scylladb/scylladb/pull/27929), so this change restructures unit creation and movement to follow a clearer and symmetric pattern across shards.
The semaphore usage model is now documented with a detailed in-code comment to make the intended behavior and invariants explicit.
As part of the refactor, the control flow is modernized by replacing continuation-based logic with coroutine-style code, improving readability and maintainability.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-250
backport: not required, this is a refactor
Closesscylladb/scylladb#28093
* github.com:scylladb/scylladb:
db: view: extend try/catch scope in handle_create_view_local The try/catch region is extended to cover step functions and inner helpers, which may throw or abort during view creation. This change is safe because we are just swolowing more parts that may throw due to semaphore abortion or any other abortion request, and doesnt change the logic
db: view: refine create/drop coroutine signatures Refactor the create/drop coroutine interfaces to accept parameters as const references, enabling a clearer workflow and safer data flow.
db: view: switch from continuations to coroutines Refactor the flow and style of create and drop view to use coroutines instead of continuations. This simplifies the logic, improves readability, and makes the code easier to maintain and extend. This commit also utilizes the get_view_builder_units function that was added in the previous commit. this commit also introduces a new alisasing for optional unit type for simpler and more readable functions that use this type
db: view: introduce helper to acquire or reuse semaphore units Introduce a small helper that acquires semaphore units when needed or reuses units provided by the caller. This centralizes semaphore handling, simplifies the current logic, and enables refactoring the view create/drop path to a coroutine-based implementation instead of continuation-style code.
db: view: add detailed comments on semaphore bookkeeping and serialized create/drop on shard 0
The try/catch region is extended to cover step functions and inner helpers,
which may throw or abort during view creation.
This change is safe because we are just swolowing more parts that may throw due to semaphore abortion
or any other abortion request, and doesnt change the logic
Refactor the flow and style of create and drop view to use coroutines instead of continuations.
This simplifies the logic, improves readability, and makes the code
easier to maintain and extend. This commit also utilizes the get_view_builder_units function that was added in the previous commit.
this commit also introduces a new alisasing for optional unit type for simpler and more readable functions that use this type
Introduce a small helper that acquires semaphore units when needed or
reuses units provided by the caller.
This centralizes semaphore handling, simplifies the current logic, and
enables refactoring the view create/drop path to a coroutine-based
implementation instead of continuation-style code.
The function assert_rf_rack_valid_keyspace uses the exception type
std::invalid_argument when the RF-rack validation fails. Document it and
change all callers to catch this specific exception type when checking
for RF-rack validation failures, so that other exception types can be
propagated properly.
The last remining tables in the v3 keyspace are those that are genuinely
distinct -- added by Cassandra 3.0 or >= ScyllaDB 2.0.
Move these out of the v3 keyspace too, with this the v3 keyspace is
defunct and removed.
Create and drop view operations are currently performed on all shards, and their execution is not fully serialized. On slower processors this can lead to interleavings that leave stale entries in `system.scylla_views_build`
A problematic sequence looks like this:
* `on_create_view()` runs on shard 0 → entries for shard 0 and shard 1 are created
* `on_drop_view()` runs on shard 0 → entry for shard 0 is removed
* `on_create_view()` runs on shard 1 → entries for shard 0 and shard 1 are created again
* `on_drop_view()` runs on shard 1 → entry for shard 1 is removed, while the shard 0 entry remains
This results in a leftover row in `system.scylla_views_builds_in_progress`, causing `view_build_test.cc` to get stuck indefinitely in an eventual state and eventually be terminated by CI.
This patch fixes the issue by fully serializing all view create and drop operations through shard 0. Shard 0 becomes the single execution point and notifies other shards to perform their work in order. Requests originating.
new process:
- view_builder::on_create_view(...) runs only on shard 0 and kicks off dispatch_create_view(...) in the background.
- dispatch_create_view(...) (shard 0) first checks should_ignore_tablet_keyspace(...) and returns early if needed.
- dispatch_create_view(...) calls handle_seed_view_build_progress(...) on shard 0. That:
- writes the global “build progress” row across all shards via _sys_ks.register_view_for_building_for_all_shards(...).
- After seeding, dispatch_create_view(...) broadcasts to all shards with container().invoke_on_all(...).
- Each shard runs handle_create_view_local(...), which:
- waits for pending base writes/streams, flushes the base,
- resets the reader to the current token and adds the new view,
- handles errors and triggers _build_step to continue processing.
Drop view
- view_builder::on_drop_view(...) runs only on shard 0 and kicks off dispatch_drop_view(...) in the background.
- dispatch_drop_view(...) (shard 0) first checks should_ignore_tablet_keyspace(...) and returns early if needed.
- It broadcasts handle_drop_view_local(...) to all shards with invoke_on_all(...).
- Each shard runs handle_drop_view_local(...), which:
- removes the view from local build state (_base_to_build_step and _built_views) by scanning existing steps,
- ignores missing keyspace cases.
- After all shards finish local cleanup, shard 0 runs handle_drop_view_global_cleanup(...), which:
- removes global build progress, built‑view state, and view build status in system tables,
Shutdown
- drain() waits on _view_notification_sem before _sem so in‑flight dispatches finish before bookkeeping is halted.
In addition, the test is adjusted to remove the long eventual wait (596.52s / 30 iterations) and instead rely on the default wait of 17 iterations (~4.37 minutes), eliminating unnecessary delays while preserving correctness.
Fixes: https://github.com/scylladb/scylladb/issues/27898
Backport: not required as the problem happens on master
Closesscylladb/scylladb#27929
Allow creating materialized views and secondary indexes in a tablets keyspace only if it's RF-rack-valid, and enforce RF-rack-validity while the keyspace has views by restricting some operations:
* Altering a keyspace's RF if it would make the keyspace RF-rack-invalid
* Adding a node in a new rack
* Removing / Decommissioning the last node in a rack
Previously the config option `rf_rack_valid_keyspaces` was required for creating views. We now remove this restriction - it's not needed because we always maintain RF-rack-validity for keyspaces with views.
The restrictions are relevant only for keyspaces with numerical RF. Keyspace with rack-list-based RF are always RF-rack-valid.
Fixesscylladb/scylladb#23345
Fixes https://github.com/scylladb/scylladb/issues/26820
backport to relevant versions for materialized views with tablets since it depends on rf-rack validity
Closesscylladb/scylladb#26354
* github.com:scylladb/scylladb:
docs: update RF-rack restrictions
cql3: don't apply RF-rack restrictions on vector indexes
cql3: add warning when creating mv/index with tablets about rf-rack
service/tablet_allocator: always allow tablet merge of tables with views
locator: extend rf-rack validation for rack lists
test: test rf-rack validity when creating keyspace during node ops
locator: fix rf-rack validation during node join/remove
test: test topology restrictions for views with tablets
test: add test_topology_ops_with_rf_rack_valid
topology coordinator: restrict node join/remove to preserve RF-rack validity
topology coordinator: add validation to node remove
locator: extend rf-rack validation functions
view: change validate_view_keyspace to allow MVs if RF=Racks
db: enforce rf-rack-validity for keyspaces with views
replica/db: add enforce_rf_rack_validity_for_keyspace helper
db: remove enforce parameter from check_rf_rack_validity
test: adjust test to not break rf-rack validity
Call discover_staging_sstables in view_update_generator::start() instead
of in the constructor, because the constructor is called during
initialization before sstables are loaded.
The initialization order was changed in 5d1f74b86a and caused this
regression. It means the view update generator won't discover staging
sstables on startup and view updates won't be generated for them. It
also causes issues in sstable cleanup.
view_update_generator::start() is called in a later stage of the
initialization, after sstable loading, so do the discovery of staging
sstables there.
Fixesscylladb/scylladb#27956Closesscylladb/scylladb#27970
This patch consists of a few smaller follow-ups to the view building worker:
- catch general execption in staging task registrator
- remove unnecessary CV broadcast
- don't pollute function context with conditionally compiled variable
- avoid creating a copy of tasks map
- fix some typos
Refs https://github.com/scylladb/scylladb/issues/25929
Refs https://github.com/scylladb/scylladb/pull/26897
This PR doesn't fix any bugs but recently we're backporting some PRs to 2025.4, so let's also backport this one to avoid painful conflicts.
Closesscylladb/scylladb#26558
* github.com:scylladb/scylladb:
docs/dev/view-building-coordinator: fix typos
db/view/view_building_worker: remove unnnecessary empty lines
db/view/view_building_worker: fix typo
db/view/view_building_worker: avoid creating a copy of tasks map
db/view/view_building_worker: wrap conditionally compiled code in a scope
db/view/view_building_worker: remove unnecessary CV broadcast
db/view/view_building_worker: catch general execption in staging task registrator
The function validate_view_keyspace checks if a keyspace is eligible for
having materialized views, and it is used for validation when creating a
MV or a MV-based index.
Previously, it was required that the rf_rack_valid_keyspaces option is
set in order for tablets-based keyspaces to be considered eligible, and
the RF-rack condition was enforced when the option is set.
Instead of this, we change the validation to allow MVs in a keyspace if
the RF-rack condition is satisfied for the keyspace - regardless of the
config option.
We remove the config validation for views on startup that validates the
option `rf_rack_valid_keyspaces` is set if there are any views with
tablets, since this is not required anymore.
We can do this without worrying about upgrades because this change will
be effective from 2025.4 where MVs with tablets are first out of
experimental phase.
We update the test for MV and index restrictions in tablets keyspaces
according to the new requirements.
* Create MV/index: previously the test checked that it's allowed only if
the config option `rf_rack_valid_keyspaces` is set. This is changed
now so it's always allowed to create MV/index if the keyspace is
RF-rack-valid. Update the test to verify that we can create MV/index
when the keyspace is RF-rack-valid, even if the rf_rack option is not
set, and verify that it fails when the keyspace is RF-rack-invalid.
* Alter: Add a new test to verify that while a keyspace has views, it
can't be altered to become RF-rack-invalid.
With the introduction of rack-lists and the reliance of materialized views on them, the `get_view_natural_endpoint` function can be greatly simplified. When using tablets, instead of doing any index-matching, we can now pair base tables with views only in the same rack.
In this series we remove no longer needed code and reorganize the needed code for better clarity.
After the changes, the `get_view_natural_endpoint` function goes down from 245 lines to 85 lines, while the whole pairing-related text goes down from 346 lines to 239 lines.
Fixes https://github.com/scylladb/scylladb/issues/26313Closesscylladb/scylladb#27383
* github.com:scylladb/scylladb:
mv: replace the simple/complex rack-aware pairing with exact rack matching
mv: split out vnode pairing code from get_view_natural_endpoint
mv: unify self-pairing and rack-aware pairing into one bool
mv: remove the workaround for left nodes when sending view updates
The code creates a local variable, so it's better to wrap it in a local
scope, to the conditionally compiled variable doesn't pollute the
external scope.
After scylladb/scylladb#26897 was merged, the worker doesn't use the
view building state machine CV to manage lifetime of batches, so the
broadcast is not needed.
In case of general exception in `view_building_worker::create_staging_sstable_tasks()`,
catch it, print it with error level and sleep 1s before retrying.
This will allow for the registrator to retry its work in case of failure
and it should be easier to detect any bugs in the method.
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
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
When the initial version of rack-aware pairing was introduced, materialized
views with tablets were still experimental. Since then, we decided that
we'll only allow materialized views in clusters where the base table and
the view are replicated on the same racks, with one replica of each tablet
on each rack.
This allows us to remove almost all logic from our base-view pairing. The
only check for the paired view replica is now whether it's in the same
rack as the base replica sending the update.
In this patch we replace the simple and complex rack-aware pairing with
the simple check above.
Because of this, we have to remove a test case from network_topology_strategy_test
which was testing complex pairing. The tested topology is not supported
for views with tablets (or is unlikely to be supported, as it's a random test),
so there's no use keeping the test.
The test case for simple rack aware pairing was kept, but now we only test
the case where each rack has one replica, not multiple.
Additionally, we split finding of an unpaired replica to a separate function
and partially rewrite it without reusing the helper stuctures that were
present when calculating the simple and complex rack-aware pairing.
We only look for an unpaired replica if we couldn't find a paired replica
ourselves or if the number of view replicas didn't match the base replicas.
If an unpaired replica appears while these conditions pass, we won't send
an extra update, but that would be a new bug altogether, because we only
expect the unpaired replica to appear during RF changes, so when these
conditions aren't fulfilled.
Fixes https://github.com/scylladb/scylladb/issues/26313
To avoid repeatedly checking whether we're using tablets and having
to use unnecesarily flexible code fitting both cases, we split out
the base-view pairing code for the case of vnodes to another function.
The get_view_natural_endpoint will now have only common steps,
a call to that function, and steps specific to tablets.
We always use "legacy self pairing" when not using tablets, and
the "rack aware pairing" has been enabled in every version where
views with tablets isn't experimental. So in practice, instead
of checking these variables we can just look at whether the
table uses tablets.
At one point, the get_view_natural_endpoint was using IP for the
view update (and hint) destinations, but the hint code was using
host_id for the destinations. When a node left, we could no longer
have a mapping for a IP to host_id and when trying to store a hint
for this IP, we'd crash.
We worked around this issue by dropping the view update completely
if the target is in the "left" state.
Since then, we also moved to host_id's in the view update code, so
there's no longer any translation needed when storing the hints.
Additionally, we now drain hints not when entering the "left" state,
but when the node actually stops owning tokens.
Because of that, the workaround is not needed anymore, so we remove
it in this commit.
The existing test_mv_tablets_empty_ip case verifies that indeed, we
do not crash in the original problematic scenario.
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
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.
