Fix for https://github.com/scylladb/scylladb/pull/24097
The stable branch does not contain the split API reference yet. This change fixes the 404 error raised when accessing the API reference on the stable branch due to the redirect.
Closesscylladb/scylladb#24259
* github.com:scylladb/scylladb:
docs: fix typo
docs: remove API reference redirect
There is a difference how ScyllaDB and Cassandra handle conditional
batches with different IF statements (such as "IF EXISTS" and "IF NOT
EXISTS"). Cassandra tries to detect condition conflicts, and prints
an error instead of silently failing the batch, but in ScyllaDB
we considered this check to be inconsistent and unhelpful, and
decided not to implement it.
In this series, we extend the documentation of the ScyllaDB behaviour
by extending the documents and improving relevant LWT tests.
Fixes: https://github.com/scylladb/scylladb/issues/13011
Backport not needed, only docs and minor tests changes.
Closesscylladb/scylladb#24086
* github.com:scylladb/scylladb:
test: mark difference in handling IFs in LWT as scylla_only
docs: cql: add explicit explanation how mixing IFs works in LWT
docs: lwt: add two missing spaces
The stable branch does not contain the split API reference yet.
This change fixes the 404 error raised when accessing the API reference on the stable branch.
There is a difference how ScyllaDB and Cassandra handle conditional
batches with different IF statements (such as "IF EXISTS" and "IF NOT
EXISTS").
This commit explicitly documents the differences in the behavior.
Refs: #13011
Starting with 2025.1, ScyllaDB versions are no longer called "Enterprise",
but the OS support page still uses that label.
This commit fixes that by replacing "Enterprise" with "ScyllaDB".
This update is required since we've removed "Enterprise" from everywhere else,
including the commands, so having it here is confusing.
Fixes https://github.com/scylladb/scylladb/issues/24179Closesscylladb/scylladb#24181
The non-streaming loading of sstables performs cleanup since recently [1]. For vnodes, unfortunately, cleanup is almost unavoidable, because of the nature of vnodes sharding, even if sstable is already clean. This leads to waste of IO and CPU for nothing. Skipping the cleanup in a smart way is possible, but requires too many changes in the code and in the on-disk data. However, the effort will not help existing SSTables and it's going to be obsoleted by tablets some time soon.
Said that, the easiest way to skip cleanup is the explicit --skip-cleanup option for nodetool and respective skip_cleanup parameter for API handler.
New feature, no backport
fixes#24136
refs #12422 [1]
Closesscylladb/scylladb#24139
* github.com:scylladb/scylladb:
nodetool: Add refresh --skip-cleanup option
api: Introduce skip_cleanup query parameter
distributed_loader: Don't create owned ranges if skip-cleanup is true
code: Push bool skip_cleanup flag around
Documentation for --gather-metric parameter was missing. This functionality can
break regular flow of using test.py, because of possible misconfiguration of
the cgroup on the local machine. Added explanation how to deal with potential
issue of gathering metrics functionality and how to switch it off.
Fixes: https://github.com/scylladb/scylladb/issues/20763Closesscylladb/scylladb#24095
* Rewrite the documentation for the "nodetool restore" command.
* Clarify the relationship between the `--nowait` flag and asynchronous operation.
* Reference the "nodetool task" page for managing background tasks.
Fixes scylladb#21888
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22023
Due to lack of spaces, two example queries were not displayed in the
rendered version of the document.
In result, the `SELECT * FROM movies.nowshowing;` query in the step 6.
returned 6 rows instead of expected 8 rows.
This change resolves an issue where selecting a version from the multiversion dropdown on Markdown pages (e.g. https://docs.scylladb.com/manual/stable/alternator/getting-started.html) incorrectly redirected users to the main page instead of the corresponding versioned page.
The underlying cause was that the `multiversion` extension relies on `source_suffix` to identify available pages for URL mapping. Without this configuration, proper redirection fails for `.md` files.
This fix should be backported to `2025.1` to ensure correct behavior. Otherwise, the fix will only take effect in future releases.
Testing locally is non-trivial: clone the repository, apply the changes to each relevant branch, set `smv_remote_whitelist` to "", then run `make multiversionpreview`. Afterward, switch between versions in the dropdown to verify behavior. I've tested it locally, so the best next step is to merge and confirm that it works as expected in the live environment.
Closesscylladb/scylladb#23957
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
Update the "How to Switch Snitches" document to indicate that changing
topology (i.e. changing node's DC or rack) while changing the snitch is
no longer supported.
Remove a note which said that switching snitches is not supported with
tablets. It was introduced because of the concern that switching a
snitch might change DC or rack of the node, for which our current tablet
load balancer is completely unprepated. Now that changing DC/rack is
forbidden, there doesn't seem to be anything related to snitches which
could cause trouble for tablets.
Current protocol extension that sends tablet info to drivers only does
that if the driver selects a non-replica coordinator for a routable
request. It works well if some node on the replica list is replaced by
other node, or if some replicas are removed from the list. Driver will
at some point send a request to stale replica, and receive new list in
response.
The issue is with extending the list with new replicas. In that case old
replicas are all still correct, so driver will not select any wrong
replica, and will not receive the new list. As far as I know that only
scenario where this could happen is RF increase.
It could be to some degree worked around in the drivers, but it would
add significant complexity (definitely more than any other invalidations
we introduced) while still not being ideal solution. This scenario
should be rare enough, and the consequences of not handling it minor
enough (new replicas not being used as coordinators) that it does not
warrant driver-side solution. Instead this commit adds info about this
to documentation, advising users to restart applications after replica
lists are extended.
It is worth noting that if new tablet feedback protocol extension is
implemented then this problem goes away. See issue #21664.
Closesscylladb/scylladb#23447
After load-balancer was made capacity-aware it no longer equalizes tablet count per shard, but rather utilization of shard's storage. This makes the old presentation mode not useful in assessing whether balance was reached, since nodes with less capacity will get fewer tablets when in balanced state. This PR adds a new default presentation mode which scales tablet size by its storage utilization so that tablets which have equal shard utilization take equal space on the graph.
To facilitate that, a new virtual table was added: system.load_per_node, which allows the tool to learn about load balancer's view on per-node capacity. It can also serve as a debugging interface to get a view of current balance according to the load-balancer.
Closesscylladb/scylladb#23584
* github.com:scylladb/scylladb:
tablet-mon.py: Add presentation mode which scales tablet size by its storage utilization
tablet-mon.py: Center tablet id text properly in the vertical axis
tablet-mon.py: Show migration stage tag in table mode only when migrating
virtual-tables: Introduce system.load_per_node
virtual_tables: memtable_filling_virtual_table: Propagate permit to execute()
docs: virtual-tables: Fix instructions
service: tablets: Keep load_stats inside tablet_allocator
Currently, when we rebuild a tablet, we stream data from all
replicas. This creates a lot of redundancy, wastes bandwidth
and CPU resources.
In this series, we split the streaming stage of tablet rebuild into
two phases: first we stream tablet's data from only one replica
and then repair the tablet.
Fixes: https://github.com/scylladb/scylladb/issues/17174.
Needs backport to 2025.1 to prevent out of space during streaming
Closesscylladb/scylladb#23187
* github.com:scylladb/scylladb:
test: add test for rebuild with repair
locator: service: move to rebuild_v2 transition if cluster is upgraded
locator: service: add transition to rebuild_repair stage for rebuild_v2
locator: service: add rebuild_repair tablet transition stage
locator: add maybe_get_primary_replica
locator: service: add rebuild_v2 tablet transition kind
gms: add REPAIR_BASED_TABLET_REBUILD cluster feature
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.
Add a new nodetool cluster super-command. Add nodetool
cluster repair command to repair tablet keyspaces.
It uses the new /storage_service/tablets/repair API.
The nodetool cluster repair command allows you to specify
the keyspace and tables to be repaired. A cluster repair of many
tables will request /storage_service/tablets/repair and wait for
the result synchronously for each table.
The nodetool repair command, which was previously used to repair
keyspaces of any type, now repairs only vnode keyspaces.
Fixes: https://github.com/scylladb/scylladb/issues/22409.
Needs backport to 2025.1 that introduces the new tablet repair API
Closesscylladb/scylladb#22905
* github.com:scylladb/scylladb:
docs: nodetool: update repair and add tablet-repair docs
test: nodetool: add tests for cluster repair command
nodetool: add cluster repair command
nodetool: repair: extract getting hosts and dcs to functions
nodetool: repair: warn about repairing tablet keyspaces
nodetool: repair: move keyspace_uses_tablets function
Modify write_both_read_old and streaming stages in rebuild_v2 transition
kind: write_both_read_old moves to rebuild_repair stage and streaming stage
streams data only from one replica.
Currently, in the streaming stage of rebuild tablet transition,
we stream tablet data from all replicas.
This patch series splits the streaming stage into two phases:
- repair phase, where we repair the tablet;
- streaming phase, where we stream tablet data from one replica.
To differentiate the two streaming methods, a new tablet transition
kind - rebuild_v2 - is added.
The transtions and stages for rebuild_v2 transition kind will be
added in the following patches.
This series add a new config option: `tablets_mode_for_new_keyspaces` that replaces the existing
`enable_tablets` option. It can be set to the following values:
disabled: New keyspaces use vnodes by default, unless enabled by the tablets={'enabled':true} option
enabled: New keyspaces use tablets by default, unless disabled by the tablets={'disabled':true} option
enforced: New keyspaces must use tablets. Tablets cannot be disabled using the CREATE KEYSPACE option
`tablets_mode_for_new_keyspaces=disabled` or `tablets_mode_for_new_keyspaces=enabled` control whether
tablets are disabled or enabled by default for new keyspaces, respectively.
In either cases, tablets can be opted-in or out using the `tablets={'enabled':...}`
keyspace option, when the keyspace is created.
`tablets_mode_for_new_keyspaces=enforced` enables tablets by default for new keyspaces,
like `tablets_mode_for_new_keyspaces=enabled`.
However, it does not allow to opt-out when creating
new keyspaces by setting `tablets = {'enabled': false}`
Refs scylladb/scylla-enterprise#4355
* Requires backport to 2025.1
Closesscylladb/scylladb#22273
* github.com:scylladb/scylladb:
boost/tablets_test: verify failure to create keyspace with tablets and non network replication strategy
tablets: enforce tablets using tablets_mode_for_new_keyspaces=enforced config option
db/config: add tablets_mode_for_new_keyspaces option
Add a size check for BatchItemWrite command - if the item count is
bigger than configuration value `alternator_maximum_batch_write_size`,
an error will be raised and no modification will happen.
This is done to synchronize with DynamoDB, where maximum size of
BatchItemWrite is 25. To avoid complaints from clients, who use
our feature of BatchWriteItem being limitless we set default value
to 100.
Fixes#5057Closesscylladb/scylladb#23232
Move `object_storage.yaml` endpoints to `scylla.yaml`
This change also removes the `object_storage.yaml` file
altogether and adds tests for fetching the endpoints
via the `v2/config/object_storage_endpoints` REST api.
Also, `object_storage_config_file` options is moved to a deprecated state as it's no longer needed.
This PR depends on #22951, the reviewers should review patch 393e1ac0ec066475ca94094265a5f88dbbdb1a1f
Refs https://github.com/scylladb/scylladb/issues/22428Closesscylladb/scylladb#22952
* github.com:scylladb/scylladb:
Remove db::config::object_storage_config
Move `object_storage.yaml` endpoints to `scylla.yaml`
This PR extends Scylla's SSTable compression with the ability to use compression dictionaries shared across compression chunks. This involves several changes:
- We refactor `compression_parameters` and friends (`compressor`, `sstables::local_compression`, `sstables::compression`) to prepare for making the construction of `compressor`s asynchronous, to enable sharing pieces of compressors (the dictionaries) across shards.
- We introduce the notion of "hidden compression options" which are written to `CompressionInfo.db` and used to construct decompressors, like regular options, but don't appear in the schema. (We later stuff the SSTable's dictionary into `CompressionInfo.db` using a sequence of such options).
- We add a cluster feature which guards the creation of dictionary-compressed SSTables.
- We introduce a central "compressor factory" (one instance shared by all shards), which from this point onward is used to construct all `compressor` objects (one per SSTable) used to process the SSTables. When constructing a compressor for writing, it uses the "current"/"recommended" dictionary (which is passed to the factory from the actively-observed contents of the group0-managed `system.dicts`). When constructing a compressor for reading, it uses the dictionary written in the hidden compression options in CompressionInfo.db. And it keeps dictionaries deduplicated, so that each unique live dictionary blob has only one instance in memory, shared across shards.
- We teach the relevant `lz4` and `zstd` compressor wrappers about the dictionaries.
- We add a HTTP API call which samples pieces of the given table (i.e. the Data.db files) from across the cluster, trains a dictionary on it, and publishes it via `system.dicts` as the new current dictionary for that table. (And we add some RPC verbs to support that).
- We add a HTTP API call which estimates the impact of various available compression configurations on the compression ratio.
- We add an autotrainer fiber which periodically retrains dicts for dict-aware tables and publishes them if they seem to be a significant improvement.
Known imperfections:
- The factory currently keeps one dictionary instance on the entire node, but we probably want one copy per NUMA node. I didn't do that because exposing NUMA knowledge to Scylla seems to require some changes in Seastar first.
New feature, no backporting involved.
Closesscylladb/scylladb#23025
* github.com:scylladb/scylladb:
docs: add user-facing documentation for SSTable compression with shared dicts
docs/dev: add sstable-compression-dicts.md
test: add test_sstable_compression_dictionaries_autotrain.py
test: add test_sstable_compression_dictionaries_basic.py
test/pylib/rest_client: add `keyspace_upgrade_sstables` helper
main: run a sstable_dict_autotrainer
api: add the estimate_compression_ratios API call
dict_autotrainer: introduce sstable_dict_autotrainer
db/system_keyspace: add query_dict_timestamp
compress: add ZstdWithDictsCompressor and LZ4WithDictsCompressor
main: clean up sstable compression dicts after table drops
sstables/compress: discard hidden compression options after the decompressor is created
compress: change compressor_ptr from shared_ptr to unique_ptr
api: add the retrain_dict API call
storage_service: add some dict-related routines
main: in compression_dict_updated_callback, recognize and use SSTable compression dicts
storage_service: add do_sample_sstables()
messaging_service: add SAMPLE_SSTABLES and ESTIMATE_SSTABLE_VOLUME verbs
db/system_keyspace: let `system.dicts` helpers be used for dicts other than the RPC compression dict
raft/group0_state_machine: on `system.dicts` mutations, pass the affected partitition keys to the callback
database: add sample_data_files()
database: add take_sstable_set_snapshot()
compress: teach `lz4_processor` about dictionaries
compress: teach `zstd_processor` about dictionaries
sstables: delegate compressor creation to the compressor factory
sstables: plug an `sstable_compressor_factory` into `sstables_manager`
sstables: introduce sstable_compressor_factory
utils/hashers: add get_sha256()
gms/feature_service: add the SSTABLE_COMPRESSION_DICTS cluster feature
compress: add hidden dictionary options
compress: remove `compression_parameters::get_compressor()`
sstables/compress: remove get_sstable_compressor()
sstables/compress: move ownership of `compressor` to `sstable::compression`
compress: remove compressor::option_names()
compress: clean up the constructor of zstd_processor
compress: squash zstd.cc into compress.cc
sstables/compress: break the dependency of `compression_parameters` on `compressor`
compress.hh: switch compressor::name() from an instance member to a virtual call
bytes: adapt fmt_hex to std::span<const std::byte>
This change also removes the `object_storage.yaml` file
altogether and adds tests for fetching the endpoints
via the `v2/config/object_storage_endpoints` REST api.
Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>
`tablets_mode_for_new_keyspaces=enforced` enables tablets by default for
new keyspaces, like `tablets_mode_for_new_keyspaces=enabled`.
However, it does not allow to opt-out when creating
new keyspaces by setting `tablets = {'enabled': false}`.
Refs scylladb/scylla-enterprise#4355
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
