The directory utils/ is supposed to contain general-purpose utility
classes and functions, which are either already used across the project,
or are designed to be used across the project.
This patch moves 8 files out of utils/:
utils/advanced_rpc_compressor.hh
utils/advanced_rpc_compressor.cc
utils/advanced_rpc_compressor_protocol.hh
utils/stream_compressor.hh
utils/stream_compressor.cc
utils/dict_trainer.cc
utils/dict_trainer.hh
utils/shared_dict.hh
These 8 files together implement the compression feature of RPC.
None of them are used by any other Scylla component (e.g., sstables have
a different compression), or are ready to be used by another component,
so this patch moves all of them into message/, where RPC is implemented.
Theoretically, we may want in the future to use this cluster of classes
for some other component, but even then, we shouldn't just have these
files individually in utils/ - these are not useful stand-alone
utilities. One cannot use "shared_dict.hh" assuming it is some sort of
general-purpose shared hash table or something - it is completely
specific to compression and zstd, and specifically to its use in those
other classes.
Beyond moving these 8 files, this patch also contains changes to:
1. Fix includes to the 5 moved header files (.hh).
2. Fix configure.py, utils/CMakeLists.txt and message/CMakeLists.txt
for the three moved source files (.cc).
3. In the moved files, change from the "utils::" namespace, to the
"netw::" namespace used by RPC. Also needed to change a bunch
of callers for the new namespace. Also, had to add "utils::"
explicitly in several places which previously assumed the
current namespace is "utils::".
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#25149
`SELECT` commands with SERIAL consistency level are historically allowed for vnode-based views, even though they don't provide linearizability guarantees and in general don't make much sense. In this PR we prohibit LWTs for tablet-based views, but preserve old behavior for vnode-based views for compatibility. Similar logic is applied to CDC log tables.
We also add a general check that disallows colocating a table with another colocated table, since this is not needed for now.
Fixes https://github.com/scylladb/scylladb/issues/26258
backports: not needed (a new feature)
Closesscylladb/scylladb#26284
* github.com:scylladb/scylladb:
cql_test_env.cc: log exception when callback throws
lwt: prohibit for tablet-based views and cdc logs
tablets: disallow chains of colocated tables
database: get_base_table_for_tablet_colocation: extract table_id_by_name lambda
When a test fails inside a do_with_cql_env callback, the logs don’t
make it clear where the failure happened. This is because cql_env
immediately begins shutting down services, which obscures the
original failure.
Some files in compaction/ have using namespace {compaction,sstables}
clauses, some even in headers. This is considered bad practice and
muddies the namespace use. Remove them.
Vector search related implementation moved to a new module vector_search.
As the vector search functionality is going to be extended, it is
better to keep it in a separate module.
Our sstable format selection logic is weird, and hard to follow.
If I'm not misunderstanding, the pieces are:
1. There's the `sstable_format` config entry, which currently
doesn't do anything, but in the past it used to disable
cluster features for versions newer than the specified one.
2. There are deprecated and unused config entries for individual
versions (`enable_sstables_mc_format`, `enable_sstables_md_format`,
etc).
3. There is a cluster feature for each version:
ME_SSTABLE_FORMAT, MD_SSTABLE_FORMAT, etc.
(Currently all sstable version features have been grandfathered,
and aren't checked by the code anymore).
4. There's an entry in `system.scylla_local` which contains the
latest enabled sstable version. (Why? Isn't this directly derived
from cluster features anyway)?
5. There's `sstable_manager::_format` which contains the
sstable version to be used for new writes.
This field is updated by `sstables_format_selector`
based on cluster features and the `system.scylla_local` entry.
I don't see why those pieces are needed. Version selection has the
following constraints:
1. New sstables must be written with a format that supports existing
data. For example, range tombstones with an infinite bound are only
supported by sstables since version "mc". So if a range tombstone
with an infinite bound exists somewhere in the dataset,
the format chosen for new sstables has to be at least as new as "mc".
2. A new format might only be used after a corresponding cluster feature
is enabled. (Otherwise new sstables might become unreadable if they
are sent to another node, or if a node is downgraded).
3. The user should have a way to inhibit format ugprades if he wishes.
So far, constraint (1) has been fulfilled by never using formats older
than the newest format ever enabled on the node. (With an exception
for resharding and reshaping system tables).
Constraint (2) has been fulfilled by calling `sstable_manager::set_format`
only after the corresponsing cluster feature is enabled.
Constraint (3) has been fulfilled by the ability to inhibit cluster
features by setting `sstable_format` by some fixed value.
The main thing I don't like about this whole setup is that it doesn't
let me downgrade the preferred sstable format. After a format is
enabled, there is no way to go back to writing the old format again.
That is no good -- after I make some performance-sensitive changes
in a new format, it might turn out to be a pessimization for the
particular workload, and I want to be able to go back.
This patch aims to give a way to downgrade formats without violating
the constraints. What it does is:
1. The entry in `system.scylla_local` becomes obsolete.
After the patch we no longer update or read it.
As far as I understand, the purpose of this entry is to prevent
unwanted format downgrades (which is something cluster features
are designed for) and it's updated if and only if relevant
cluster features are updated. So there's no reason to have it,
we can just directly use cluster features.
2. `sstable_format_selector` gets deleted.
Without the `system.scylla_local` around, it's just a glorified
feature listener.
3. The format selection logic is moved into `sstable_manager`.
It already sees the `db::config` and the `gms::feature_service`.
For the foreseeable future, the knowledge of enabled cluster features
and current config should be enough information to pick the right formats.
4. The `sstable_format` entry in `db::config` is no longer intended to
inhibit cluster features. Instead, it is intended to select the
format for new sstables, and it becomes live-updatable.
5. Instead of writing new sstables with "highest supported" format,
(which used to be set by `sstables_format_selector`) we write
them with the "preferred" format, which is determined by
`sstable_manager` based on the combination of enabled features
and the current value of `sstable_format`.
Closesscylladb/scylladb#26092
[avi: Pavel found the reason for the scylla_local entry -
it predates stable storage for cluster features]
The latter is recommended in seastar, and the former was left as
compatibility alias. Latest seastar explicitly marks it as deprecated so
once the submodule is updated, compilation logs will explode.
Most of the patch is generated with
for f in $(git grep -l '\<distributed<[A-Za-z0-9:_]*>') ; do sed -e 's/\<distributed<\([A-Za-z0-9:_]*\)>/sharded<\1>/g' -i $f; done
for f in $(git grep -l distributed.hh); do sed -e 's/distributed.hh/sharded.hh/' -i $f ; done
and a small manual change in test/perf/perf.hh
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#26136
Similarly to view builder, view building worker needs to be drained
in `storage_service::do_drain()`.
Storage service drain is happening at the same beginning of shutdown
procedure. Before this patch, the worker was still building views
after the storage service was drained and this caused errors like:
`Error applying view update to (named_gate_closed_exception)` and
`locator::no_such_tablet_map`.
Fixesscylladb/scylladb#25908Closesscylladb/scylladb#25984
When a scaling out is delayed or fails, it is crucial to ensure that clusters remain operational
and recoverable even under extreme conditions. To achieve this, the following proactive measures
are implemented:
- reject writes
- includes: inserts, updates, deletes, counter updates, hints, read+repair and lwt writes
- applicable to: user tables, views, CDC log, audit, cql tracing
- stop running compactions/repairs and prevent from starting new ones
- reject incoming tablet migrations
The aforementioned mechanisms are automatically enabled when node's disk utilization reaches
the critical level (default: 98%) and disabled when the utilization drop below the threshold.
Apart from that, the series add tests that require mounted volumes to simulate out of space.
The paths to the volumes can be provided using the a pytest argument, i.e. `--space-limited-dirs`.
When not provided, tests are skipped.
Test scenarios:
1. Start a cluster and write data until one of the nodes reaches 90% of the disk utilization
2. Perform an **operation** that would take the nodes over 100%
3. The nodes should not exceed the critical disk utilization (98% by default)
4. Scale out the cluster by adding one node per rack
5. Retry or wait for the **operation** from step 2
The **operation** is: writing data, running compactions, building materialized views, running repair,
migrating tablets (caused by RF change, decommission).
The test is successful, if no nodes run out of space, the **operation** from step 2 is
aborted/paused/timed out and the **operation** from step 5 is successful.
`perf-simple-query --smp 1 -m 1G` results obtained for fixed 400MHz frequency:
Read path (before)
```
instructions_per_op:
mean= 39661.51 standard-deviation=34.53
median= 39655.39 median-absolute-deviation=23.33
maximum=39708.71 minimum=39622.61
```
Read path (after)
```
instructions_per_op:
mean= 39691.68 standard-deviation=34.54
median= 39683.14 median-absolute-deviation=11.94
maximum=39749.32 minimum=39656.63
```
Write path (before):
```
instructions_per_op:
mean= 50942.86 standard-deviation=97.69
median= 50974.11 median-absolute-deviation=34.25
maximum=51019.23 minimum=50771.60
```
Write path (after):
```
instructions_per_op:
mean= 51000.15 standard-deviation=115.04
median= 51043.93 median-absolute-deviation=52.19
maximum=51065.81 minimum=50795.00
```
Fixes: https://github.com/scylladb/scylladb/issues/14067
Refs: https://github.com/scylladb/scylladb/issues/2871
No backport, as it is a new feature.
Closesscylladb/scylladb#23917
* github.com:scylladb/scylladb:
tests/cluster: Add new storage tests
test/scylla_cluster: Override workdir when passed via cmdline
streaming: Reject incoming migrations
storage_service: extend locator::load_stats to collect per-node critical disk utilization flag
repair_service: Add a facility to disable the service
compaction_manager: Subscribe to out of space controller
compaction_manager: Replace enabled/disabled states with running state
database: Add critical_disk_utilization mode database can be moved to
disk_space_monitor: add subscription API for threshold-based disk space monitoring
docs: Add feature documentation
config: Add critical_disk_utilization_level option
replica/exceptions: Add a new custom replica exception
This patch introduces `view_building_coordinator`, a single entity within whole cluster responsible for building tablet-based views.
The view building coordinator takes slightly different approach than the existing node-local view builder. The whole process is split into smaller view building tasks, one per each tablet replica of the base table.
The coordinator builds one base table at a time and it can choose another when all views of currently processing base table are built.
The tasks are started by setting `STARTED` state and they are executed by node-local view building worker. The tasks are scheduled in a way, that each shard processes only one tablet at a time (multiple tasks can be started for a shard on a node because a table can have multiple views but then all tasks have the same base table and tablet (last_token)). Once the coordinator starts the tasks, it sends `work_on_view_building_tasks` RPC to start the tasks and receive their results.
This RPC is resilient to RPC failure or raft leader change, meaning if one RPC call started a batch of tasks but then failed (for instance the raft leader was changed and caller aborted waiting for the response), next RPC call will attach itself to the already started batch.
The coordinator plugs into handling tablet operations (migration/resize/RF change) and adjusts its tasks accordingly. At the start of each tablet operation, the coordinator aborts necessary view building tasks to prevent https://github.com/scylladb/scylladb/issues/21564. Then, new adjusted tasks are created at the end of the operation.
If the operation fails at any moment, aborted tasks are rollback.
The view building coordinator can also handle staging sstables using process_staging view building tasks. We do this because we don't want to start generating view updates from a staging sstable prematurely, before the writes are directed to the new replica (https://github.com/scylladb/scylladb/issues/19149).
For detailed description check: `docs/dev/view-building-coordinator.md`
Fixes https://github.com/scylladb/scylladb/issues/22288
Fixes https://github.com/scylladb/scylladb/issues/19149
Fixes https://github.com/scylladb/scylladb/issues/21564
Fixes https://github.com/scylladb/scylladb/issues/17603
Fixes https://github.com/scylladb/scylladb/issues/22586
Fixes https://github.com/scylladb/scylladb/issues/18826
Fixes https://github.com/scylladb/scylladb/issues/23930
---
This PR is reimplementation of https://github.com/scylladb/scylladb/pull/21942Closesscylladb/scylladb#23760
* github.com:scylladb/scylladb:
test/cluster: add view build status tests
test/cluster: add view building coordinator tests
utils/error_injection: allow to abort `injection_handler::wait_for_message()`
test: adjust existing tests
utils/error_injection: add injection with `sleep_abortable()`
db/view/view_builder: ignore `no_such_keyspace` exception
docs/dev: add view building coordinator documentation
db/view/view_building_worker: work on `process_staging` tasks
db/view/view_building_worker: register staging sstable to view building coordinator when needed
db/view/view_building_worker: discover staging sstables
db/view/view_building_worker: add method to register staging sstable
db/view/view_update_generator: add method to process staging sstables instantly
db/view/view_update_generator: extract generating updates from staging sstables to a method
db/view/view_update_generator: ignore tablet-based sstables
db/view/view_building_coordinator: update view build status on node join/left
db/view/view_building_coordinator: handle tablet operations
db/view: add view building task mutation builder
service/topology_coordinator: run view building coordinator
db/view: introduce `view_building_coordinator`
db/view/view_building_worker: update built views locally
db/view: introduce `view_building_worker`
db/view: extract common view building functionalities
db/view: prepare to create abstract `view_consumer`
message/messaging_service: add `work_on_view_building_tasks` RPC
service/topology_coordinator: make `term_changed_error` public
db/schema_tables: create/cleanup tasks when an index is created/dropped
service/migration_manager: cleanup view building state on drop keyspace
service/migration_manager: cleanup view building state on drop view
service/migration_manager: create view building tasks on create view
test/boost: enable proxy remote in some tests
service/migration_manager: pass `storage_proxy` to `prepare_keyspace_drop_announcement()`
service/migration_manager: coroutinize `prepare_new_view_announcement()`
service/storage_proxy: expose references to `system_keyspace` and `view_building_state_machine`
service: reload `view_building_state_machine` on group0 apply()
service/vb_coordinator: add currently processing base
db/system_keyspace: move `get_scylla_local_mutation()` up
db/system_keyspace: add `view_building_tasks` table
db/view: add view_building_state and views_state
db/system_keyspace: add method to get view build status map
db/view: extract `system.view_build_status_v2` cql statements to system_keyspace
db/system_keyspace: move `internal_system_query_state()` function earlier
db/view: ignore tablet-based views in `view_builder`
gms/feature_service: add VIEW_BUILDING_COORDINATOR feature
When database operates in the critical disk utilization mode, all
mutation writes including inserts, updates, deletes, counter updates,
hints, read+repair, lwt writes) to user tables and other associated
with them tables like views, CDC log, audit are rejected, with a clear
error exception returned.
The mode is meant to be used with the disk space monitor in order
to prevent any user writes when node's disk utilization is too high.
Introduce the `subscribe` method to disk_space_monitor, allowing clients to
register callbacks triggered when disk utilization crosses a configurable
threshold.
The API supports flexible trigger options, including notifications on threshold
crossing and direction (above/below). This enables more granular and efficient
disk space monitoring for consumers.
Change return type of `check_needs_view_update_path()`. Instead of
retrning bool which tells whether to use staging directory (and register
to `view_update_generator`) or use normal directory.
Now the function returns enum with possible values:
- `normal_directory` - use normal directory for the sstable
- `staging_directly_to_generator` - use staging directory and register
to `view_update_generator`
- `staging_managed_by_vbc` - use staging directory but don't register it
to `view_update_generator` but create view building tasks for
later
The third option is new, it's used when the table has any view which is
in building process currrently. In this case, registering it to `view_update_generator`
prematurely may lead to base-view inconsistency
(for example when a replica is in a pending state).
The state may be also reloaded on `topology_change` or `mixed_change`
because topology coordinator may change view building tasks during
tablet operations.
The new service, `auth_integration`, has taken over the responsibility
over managing effective service levels from `service_level_controller`.
However, before these changes, it still accessed `auth::service` via
the service level controller. Let's change that.
Note that we also remove a check that `auth::service` has been
initialized. It's not necessary anymore because the lifetime of
`auth_integration` is strictly nested within the lifetime of `auth::service`.
In actuality, `service_level_controller` should lose its reference to
`auth::service` completely. All of the management over effective service
levels has already been moved to `auth_integration`. However, the
referernce is still needed when dropping a distributed service level
because we need to update the corresponding attribute for relevant
roles.
That should not lead to invalid accesses, though. Dropping a service level
should not be possible when `auth::service` is not initialized.
We introduce a new type, `auth_integration`, that will be used internally
by `service_level_controller`. Its purpose is to take over the responsibility
over managing effective service levels.
The main problem of the current implementation of service level controller
is its dependency on `auth::service` whose lifetime is strictly nested
within the lifetime of service level controller. That may and already have
led to invalid memory accesses; for an example, see issue
scylladb/scylladb#24792.
Our strategy is to split service level controller into smaller parts and
ensure that we access `auth::service` only when it's valid to do so.
This commit is the first step towards that.
We don't change anything in the logic yet, just add the new type. Further
adjustments will be made in following commits.
When the configuration option `rf_rack_valid_keyspaces` is enabled and there
is an RF-rack-invalid keyspace, starting a node fails. However, when the
configuration option is disabled, but there still is a keyspace that violates
the condition, we'd like Scylla to print a warning informing the user about
the fact. That's what happens in this commit.
We provide a validation test.
Remove support for generating numerical sstable generation for new sstables.
Loading such sstables is still supported but new sstables are always created with a uuid generation.
This is possible since:
* All live versions (since 5.4 / f014ccf369) now support uuid sstable generations.
* The `uuid_sstable_identifiers_enabled` config option (that is unused from version 2025.2 / 6da758d74c) controls only the use of uuid generations when creating new sstables. SSTables with uuid generations should still be properly loaded by older versions, even if `uuid_sstable_identifiers_enabled` is set to `false`.
Fixes#24248
* Enhancement, no backport needed
Closesscylladb/scylladb#24512
* github.com:scylladb/scylladb:
streaming: stream_blob: use the table sstable_generation_generator
replica: distributed_loader: process_upload_dir: use the table sstable_generation_generator
sstables: sstable_generation_generator: stop tracking highest generation
replica: table: get rid of update_sstables_known_generation
sstables: sstable_directory: stop tracking highest_generation
replica: distributed_loader: stop tracking highest_generation
sstables: sstable_generation: get rid of uuid_identifiers bool class
sstables_manager: drop uuid_sstable_identifiers
feature_service: move UUID_SSTABLE_IDENTIFIERS to supported_feature_set
test: cql_query_test: add test_sstable_load_mixed_generation_type
test: sstable_datafile_test: move copy_directory helper to test/lib/test_utils
test: database_test: move table_dir helper to test/lib/test_utils
Instead of storing it partially in tombstone_gc and partially in an
external map. Move all external parts into the new
shared_tombstone_gc_state. This new class is responsible for
keeping and updating the repair history. tombstone_gc_state just keeps
const pointers to the shared state as before and is only responsible for
querying the tombstone gc before times.
This separation makes the code easier to follow and also enables further
patching of tombstone_gc_state.
Previously, `raft_group0::abort()` was called in `storage_service::do_drain` (introduced in #24418) to stop the group0 Raft server before destroying local storage. This was necessary because `raft::server` depends on storage (via `raft_sys_table_storage` and `group0_state_machine`).
However, this caused issues: services like `sstable_dict_autotrainer` and `auth::service`, which use `group0_client` but are not stopped by `storage_service`, could trigger use-after-free if `raft_group0` was destroyed too early. This can happen both during normal shutdown and when 'nodetool drain' is used.
This PR reworks the shutdown logic:
* Introduces `abort_and_drain()`, which aborts the server and waits for background tasks to finish, but keeps the server object alive. Clients will see `raft::stopped_error` if they try to access group0 after this method is called.
* Final destruction now happens in `abort_and_destroy()`, called later from `main.cc`, ensuring safe cleanup.
The `raft_server_for_group::aborted` is changed to a `shared_future`, as it is now awaited in both abort methods.
Node startup can fail before reaching `storage_service`, in which case `drain_on_shutdown()` and `abort_and_drain()` are never called. To ensure proper cleanup, `raft_group0` deinitialization logic must be included in both `abort_and_drain()` and `abort_and_destroy()`.
Refs #25115Fixes#24625
Backport: the changes are complicated and not safe to backport, we'll backport a revert of the original patch (#24418) in a separate PR.
Closesscylladb/scylladb#25151
* https://github.com/scylladb/scylladb:
raft_group0: split shutdown into abort_and_drain and destroy
Revert "main.cc: fix group0 shutdown order"
Nowadays the way to configure an internal service is
1. service declares its config struct
2. caller (main/test/tool) fills the respective config with values it wants
3. the service is started with the config passed by value
The feature service code behaves likewise, but provides a helper method to create its config out of db::config. This PR moves this helper out of gms code, so that it doesn't mess with system-wide db::config and only needs its own small struct feature_config.
For the reference: similar changes with other services: #23705 , #20174 , #19166Closesscylladb/scylladb#25118
* github.com:scylladb/scylladb:
gms,init: Move get_disabled_features_from_db_config() from gms
code: Update callers generating feature service config
gms: Make feature_config a simple struct
gms: Split feature_config_from_db_config() into two
Previously, raft_group0::abort() was called in
storage_service::do_drain (introduced in #24418) to
stop the group0 Raft server before destroying local storage.
This was necessary because raft::server depends on storage
(via raft_sys_table_storage and group0_state_machine).
However, this caused issues: services like
sstable_dict_autotrainer and auth::service, which use
group0_client but are not stopped by storage_service,
could trigger use-after-free if raft_group0 was destroyed
too early. This can happen both during normal shutdown
and when 'nodetool drain' is used.
This commit reworks the shutdown logic:
* Introduces abort_and_drain(), which aborts the server
and waits for background tasks to finish, but keeps the
server object alive. Clients will see raft::stopped_error if
they try to access group0 after abort_and_drain().
* Final destruction happens in a separate method destroy(),
called later from main.cc.
The raft_server_for_group::aborted is changed to a
shared_future -- abort_server now returns a future so that
we can wait for it in abort_and_drain(), it should return
the future from the previous abort_server call, which can
happen in the on_background_error callback.
Node startup can fail before reaching storage_service,
in which case ss.drain_on_shutdown() and abort_and_drain()
are never called. To ensure proper cleanup,
abort_and_drain() is called from main.cc before destroy().
Clients of raft_group_registry are expected to call
destroy_server() for the servers they own. Currently,
the only such client is raft_group0, which satisfies
this requirement. As a result,
raft_group_registry::stop_servers() is no longer needed.
Instead, raft_group_registry::stop() now verifies that all
servers have been properly destroyed.
If any remain, it calls on_internal_error().
The call to drain_on_shutdown() in cql_test_env.cc
appears redundant. The only source of raft::server
instances in raft_group_registry is group0_service, and
if group0_service.start() succeeds, both abort_and_drain()
and destroy() are guaranteed to be called during shutdown.
We call paxos_store::ensure_initialized in the beginning of
storage_proxy::cas to create a paxos state table for a user table if
it doesn't exist. When the LWT coordinator sends RPCs to replicas,
some of them may not yet have the paxos schema. In
paxos_store::get_paxos_state_schema we just wait for them to appear,
or throw 'no_such_column_family' if the base table was dropped.
Introduce paxos_store abstraction to isolate Paxos state access.
Prepares for supporting either system.paxos or a co-located
table as the storage backend.
Instead of requesting it from gms code, create it "by hand" with the
help of get_disabled_features_from_db_config() method. This is how other
services are configured by main/tools/testing code.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Analysis of customer stalls revealed that the function `detail::hash_with_salt` (invoked by `passwords::check`) often blocks the reactor. Internally, this function uses the external `crypt_r` function to compute password hashes, which is CPU-intensive.
This PR addresses the issue in two ways:
1) `sha-512` is now the only password hashing scheme for new passwords (it was already the common-case).
2) `passwords::check` is moved to a dedicated alien thread.
Regarding point 1: before this change, the following hashing schemes were supported by `identify_best_supported_scheme()`: bcrypt_y, bcrypt_a, SHA-512, SHA-256, and MD5. The reason for this was that the `crypt_r` function used for password hashing comes from an external library (currently `libxcrypt`), and the supported hashing algorithms vary depending on the library in use. However:
- The bcrypt schemes never worked properly because their prefixes lack the required round count (e.g. `$2y$` instead of `$2y$05$`). Moreover, bcrypt is slower than SHA-512, so it not good idea to fix or use it.
- SHA-256 and SHA-512 both belong to the SHA-2 family. Libraries that support one almost always support the other, so it’s very unlikely to find SHA-256 without SHA-512.
- MD5 is no longer considered secure for password hashing.
Regarding point 2: the `passwords::check` call now runs on a shared alien thread created at database startup. An `std::mutex` synchronizes that thread with the shards. In theory this could introduce a frequent lock contention, but in practice each shard handles only a few hundred new connections per second—even during storms. There is already `_conns_cpu_concurrency_semaphore` in `generic_server` limits the number of concurrent connection handlers.
Fixes https://github.com/scylladb/scylladb/issues/24524
Backport not needed, as it is a new feature.
Closesscylladb/scylladb#24924
* github.com:scylladb/scylladb:
main: utils: add thread names to alien workers
auth: move passwords::check call to alien thread
test: wait for 3 clients with given username in test_service_level_api
auth: refactor password checking in password_authenticator
auth: make SHA-512 the only password hashing scheme for new passwords
auth: whitespace change in identify_best_supported_scheme()
auth: require scheme as parameter for `generate_salt`
auth: check password hashing scheme support on authenticator start
This commit adds a call to `pthread_setname_np` in
`alien_worker::spawn`, so each alien worker thread receives a
descriptive name. This makes debugging, monitoring, and performance
analysis easier by allowing alien workers to be clearly identified
in tools such as `perf`.
Analysis of customer stalls showed that the `detail::hash_with_salt`
function, called from `passwords::check`, often blocks the reactor.
This function internally uses the `crypt_r` function from an external
library to compute password hashes, which is a CPU-intensive operation.
To prevent such reactor stalls, this commit moves the
`passwords::check` call to a dedicated alien thread. This thread is
created at system startup and is shared by all shards.
Within the alien thread, an `std::mutex` synchronizes access between
the thread and the shards. While this could theoretically cause
frequent lock contentions, in practice, even during connection storms,
the number of new connections per second per shard is limited
(typically hundreds per second). Additionally, the
`_conns_cpu_concurrency_semaphore` in `generic_server` ensures that not
too many connections are processed at once.
Fixesscylladb/scylladb#24524
This change is preparing ground for state update unification for raft bound subsystems. It introduces schema_applier which in the future will become generic interface for applying mutations in raft.
Pulling database::apply() out of schema merging code will allow to batch changes to subsystems. Future generic code will first call prepare() on all implementations, then single database::apply() and then update() on all implementations, then on each shard it will call commit() for all implementations, without preemption so that the change is observed as atomic across all subsystems, and then post_commit().
Backport: no, it's a new feature
Fixes: https://github.com/scylladb/scylladb/issues/19649
Fixes https://github.com/scylladb/scylladb/issues/24531Closesscylladb/scylladb#24886
[avi: adjust for std::vector<mutations> -> utils::chunked_vector<mutations>]
* github.com:scylladb/scylladb:
test: add type creation to test_snapshot
storage_service: always wake up load balancer on update tablet metadata
db: schema_applier: call destroy also when exception occurs
db: replica: simplify seeding ERM during shema change
db: remove cleanup from add_column_family
db: abort on exception during schema commit phase
db: make user defined types changes atomic
replica: db: make keyspace schema changes atomic
db: atomically apply changes to tables and views
replica: make truncate_table_on_all_shards get whole schema from table_shards
service: split update_tablet_metadata into two phases
service: pull out update_tablet_metadata from migration_listener
db: service: add store_service dependency to schema_applier
service: simplify load_tablet_metadata and update_tablet_metadata
db: don't perform move on tablet_hint reference
replica: split add_column_family_and_make_directory into steps
replica: db: split drop_table into steps
db: don't move map references in merge_tables_and_views()
db: introduce commit_on_shard function
db: access types during schema merge via special storage
replica: make non-preemptive keyspace create/update/delete functions public
replica: split update keyspace into two phases
replica: split creating keyspace into two functions
db: rename create_keyspace_from_schema_partition
db: decouple functions and aggregates schema change notification from merging code
db: store functions and aggregates change batch in schema_applier
db: decouple tables and views schema change notifications from merging code
db: store tables and views schema diff in schema_applier
db: decouple user type schema change notifications from types merging code
service: unify keyspace notification functions arguments
db: replica: decouple keyspace schema change notifications to a separate function
db: add class encapsulating schema merging
There is already implicit logical dependency via migration_notifier
but in the next commits we'll be moving store_service out from it
as we need better control (i.e. return a value from the call).
This patch is a part of vector_store_client sharded service
implementation for a communication with vector-store service.
It adds a `services/vector_store_client.{cc|hh}` sharded service and a
configuration parameter `vector_store_uri` with a
`http://vector-store.dns.name:port` format. If there will be an error
during parsing that parameter there will be an exception during
construction.
For the future unit testing purposes the patch adds
`vector_store_client_tester` as a way to inject mockup functionality.
This service will be used by the select statements for the Vector search
indexes (see VS-46). For this reason I've added vector_store_client
service in the query processor.
Reference: VS-47 VS-45
Before this change, `mapreduce_service` used `_shared_token_metadata`
to get the topology. However, the token was used in a part of the code
that already had its own ERM with its own metadata token. Moreover,
as mapreduce_service's token and ERM's token are not guaranteed to be
the same, inconsistencies could occur.
Therefore, this commit removes `_shared_token_metadata` and its usage.
We've adjusted all of the Boost tests so they respect the invariant
enforced by the `rf_rack_valid_keyspaces` configuration option, or
explicitly disabled the option in those that turned out to be more
problematic and will require more attention. Thanks to that, we can
now enable it by default in the test suite.
Currently, stream_manager is initialized after storage_service and
so it is stopped before the storage_service is. In its stop method
storage_service accesses stream_manager which is uninitialized
at a time.
Move stream_manager initialization over the storage_service initialization.
Fixes: #23207.
Closesscylladb/scylladb#24008
We don't want each shard to have its own copy of each dictionary.
It would unnecessary pressure on cache and memory.
Instead, we want to share dictionaries between shards.
Before this commit, all dictionaries live on shard 0.
All other shards borrow foreign shared pointers from shard 0.
There's a problem with this setup: dictionary blobs receive many random
accesses. If shard 0 is on a remote NUMA node, this could pose
a performance problem.
Therefore, for each dictionary, we would like to have one copy per NUMA node,
not one copy per the entire machine. And each shard should use the copy
belonging to its own NUMA node. This is the main goal of this patch.
There is another issue with putting all dicts on shard 0: it eats
an assymetric amount of memory from shard 0.
This commit spreads the ownership of dicts over all shards within
the NUMA group, to make the situation more symmetric.
(Dict owner is decided based on the hash of dict contents).
It should be noted that the last part isn't necessarily a good thing,
though.
While it makes the situation more symmetric within each node,
it makes it less symmetric across the cluster, if different node
sizes are present.
If dicts occupy 1% of memory on each shard of a 100-shard node,
then the same dicts would occupy 100% of memory on a 1-shard node.
So for the sake of cluster-wide symmetry, we might later want to consider
e.g. making the memory limit for dictionaries inversely proportional
to the number of shards.
Changing DC or rack on a node which was already bootstrapped is, in
case of vnodes, very unsafe (almost guaranteed to cause data loss or
unavailability), and is outright not supported if the cluster has
a tablet-backed keyspaces. Moreover, the possibility of doing that
makes it impossible to uphold some of the invariants promised by
the RF-rack-valid flag, which is eventually going to become
unconditionally enabled.
Get rid of the above problems by removing the possibility of changing
the DC / rack of a node. A node will now fail to start if its snitch
reports a different DC or rack than the one that was reported during the
first boot.
Fixes: scylladb/scylladb#23278Fixes: scylladb/scylladb#22869
Marking for backport to 2025.1, as this is a necessary part of the RF-rack-valid saga
Closesscylladb/scylladb#23800
* github.com:scylladb/scylladb:
doc: changing topology when changing snitches is no longer supported
test: cluster: introduce test_no_dc_rack_change
storage_service: don't update DC/rack in update_topology_with_local_metadata
main: make dc and rack immutable after bootstrap
test: cluster: remove test_snitch_change
Changing DC or rack on a node which was already bootstrapped is, in
case of vnodes, very unsafe (almost guaranteed to cause data loss or
unavailability), and is outright not supported if the cluster has
a tablet-backed keyspaces. Moreover, the possibility of doing that
makes it impossible to uphold some of the invariants promised by
the RF-rack-valid flag, which is eventually going to become
unconditionally enabled.
Get rid of the above problems by removing the possibility of changing
the DC / rack of a node. A node will now fail to start if its snitch
reports a different DC or rack than the one that was reported during the
first boot.
Fixes: scylladb/scylladb#23278
Can be used to query per-node stats about load as seen by the load
balancer.
In particular, node's capacity will be used by tablet-mon.py to
scale tablet columns so that equal height is equal node utilization.
Before this patch, `system.dicts` contains only one dictionary, for RPC
compression, with the fixed name "general".
In later parts of this series, we will add more dictionaries to
system.dicts, one per table, for SSTable compression.
To enable that, this patch adjusts the callback mechanism for group0's `write_mutations`
command, so that the mutation callbacks for group0-managed tables can see which
partition keys were affected. This way, the callbacks can query only the
modified partitions instead of doing a full scan. (This is necessary to
prevent quadratic behaviours.)
For now, only the `system.dicts` callback uses the partition keys.
Create a `sstable_compressor_factory_impl` in `scylla_main`,
and pipe it through constructors into `sstables_manager`.
In next commits, the factory available through the `sstables_manager`
will be used to create compressors for SSTable readers and writers.
When a node is started with the option `rf_rack_valid_keyspaces`
enabled, the initialization will fail if there is an RF-rack-invalid
keyspace. We want to force the user to adjust their existing
keyspaces when upgrading to 2025.* so that the invariant that
every keyspace is RF-rack-valid is always satisfied.
Fixesscylladb/scylladb#23300
This series adds an async guard to system_keyspace operations
and adds a deferred action to stop the system_keyspace in main() before destroying the service.
This helps to make sure that sys_ks is unplugged from its users and that all async operations using it are drained once it's stopped.
* Enhancement, no backport needed
Closesscylladb/scylladb#23113
* github.com:scylladb/scylladb:
main: stop system keyspace
system_keyspace: call shutdown from stop
system_keyspace: shutdown: allow calling more than once
database, compaction_manager, large_data_handler: use pluggable<system_keysapce>
utils: add class pluggable
"
This is series starts conversion of the gossiper to use host ids to
index nodes. It does not touch the main map yet, but converts a lot of
internal code to host id. There are also some unrelated cleanups that
were done while working on the series. On of which is dropping code
related to old shadow round. We replaced shadow round with explicit
GOSSIP_GET_ENDPOINT_STATES verb in cd7d64f588
which is in scylla-4.3.0, so there should be no compatibility problem.
We already dropped a lot of old shadow round code in previous patches
anyway.
I tested manually that old and new node can co-exist in the same
cluster,
"
* 'gleb/gossiper-host-id-v2' of github.com:scylladb/scylla-dev: (33 commits)
gossiper: drop unneeded code
gossiper: move _expire_time_endpoint_map to host_id
gossiper: move _just_removed_endpoints to host id
gossiper: drop unused get_msg_addr function
messaging_service: change connection dropping notification to pass host id only
messaging_service: pass host id to remove_rpc_client in down notification
treewide: pass host id to endpoint_lifecycle_subscriber
treewide: drop endpoint life cycle subscribers that do nothing
load_meter: move to host id
treewide: use host id directly in endpoint state change subscribers
treewide: pass host id to endpoint state change subscribers
gossiper: drop deprecated unsafe_assassinate_endpoint operation
storage_service: drop unused code in handle_state_removed
treewide: drop endpoint state change subscribers that do nothing
gossiper: drop ip address from handle_echo_msg and simplify code since host_id is now mandatory
gossiper: start using host ids to send messages earlier
messaging_service: add temporary address map entry on incoming connection
topology_coordinator: notify about IP change from sync_raft_topology_nodes as well
treewide: move everyone to use host id based gossiper::is_alive and drop ip based one
storage_proxy: drop unused template
...
Before this patch, the load balancer was equalizing tablet count per
shard, so it achieved balance assuming that:
1) tablets have the same size
2) shards have the same capacity
That can cause imbalance of utilization if shards have different
capacity, which can happen in heterogeneous clusters with different
instance types. One of the causes for capacity difference is that
larger instances run with fewer shards due to vCPUs being dedicated to
IRQ handling. This makes those shards have more disk capacity, and
more CPU power.
After this patch, the load balancer equalizes shard's storage
utilization, so it no longer assumes that shards have the same
capacity. It still assumes that each tablet has equal size. So it's a
middle step towards full size-aware balancing.
One consequence is that to be able to balance, the load balancer need
to know about every node's capacity, which is collected with the same
RPC which collects load_stats for average tablet size. This is not a
significant set back because migrations cannot proceed anyway if nodes
are down due to barriers. We could make intra-node migration
scheduling work without capacity information, but it's pointless due
to above, so not implemented.
Also, per-shard goal for tablet count is still the same for all nodes in the cluster,
so nodes with less capacity will be below limit and nodes with more capacity will
be slightly above limit. This shouldn't be a significant problem in practice, we could
compensate for this by increasing the limit.
Refs #23042Closesscylladb/scylladb#23079
* github.com:scylladb/scylladb:
tablets: Make load balancing capacity-aware
topology_coordinator: Fix confusing log message
topology_coordinator: Refresh load stats after adding a new node
topology_coordinator: Allow capacity stats to be refreshed with some nodes down
topology_coordinator: Refactor load status refreshing so that it can be triggered from multiple places
test: boost: tablets_test: Always provide capacity in load_stats
test: perf_load_balancing: Set node capacity
test: perf_load_balancing: Convert to topology_builder
config, disk_space_monitor: Allow overriding capacity via config
storage_service, tablets: Collect per-node capacity in load_stats
We want to move to use host ids as soon as possible. Currently it is
possible only after the full gossiper exchange (because only at this
point gossiper state is added and with it address map entry). To make it
possible to move to host ids earlier this patch adds address map entries
on incoming communication during CLIENT_ID verb processing. The patch
also adds generation to CLIENT_ID to use it when address map is updated.
It is done so that older gossiper entries can be overwritten with newer
mapping in case of IP change.
Intended for testing, or hot-fixing out-of-space issues in production.
Tablet load balancer uses this information for determining per-shard load
so reducing capacity will cause tablets to be migrated away from the node.
