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
Adds new live updatable config: uninitialized_connections_semaphore_cpu_concurrency.
It should help to reduce cpu usage by limiting cpu concurrency for new connections. As a last resort when those connections are waiting for initial processing too long (over 1m) they are shed.
New connections_shed and connections_blocked metrics are added for tracking.
Testing:
- manually via simple program creating high number of connection and constantly re-connecting
- added benchmark
Following are benchmark results:
Before:
```
> build/release/test/perf/perf_generic_server --smp=1
170101.41 tps ( 13.1 allocs/op, 0.0 logallocs/op, 7.0 tasks/op, 4695 insns/op, 3178 cycles/op, 0 errors)
[...]
throughput: mean=173850.06 standard-deviation=1844.48 median=174509.66 median-absolute-deviation=874.23 maximum=175087.49 minimum=170588.54
instructions_per_op: mean=4725.59 standard-deviation=13.35 median=4729.38 median-absolute-deviation=12.49 maximum=4738.61 minimum=4709.96
cpu_cycles_per_op: mean=3135.08 standard-deviation=32.13 median=3122.68 median-absolute-deviation=22.29 maximum=3179.38 minimum=3103.15
```
After:
```
> build/release/test/perf/perf_generic_server --smp=1
167373.19 tps ( 13.1 allocs/op, 0.0 logallocs/op, 7.0 tasks/op, 4821 insns/op, 3371 cycles/op, 0 errors)
[...]
throughput:
mean= 171199.55 standard-deviation=2484.58
median= 171667.06 median-absolute-deviation=2087.63
maximum=173689.11 minimum=167904.76
instructions_per_op:
mean= 4801.90 standard-deviation=16.54
median= 4796.78 median-absolute-deviation=9.32
maximum=4830.71 minimum=4789.81
cpu_cycles_per_op:
mean= 3245.26 standard-deviation=32.28
median= 3230.44 median-absolute-deviation=16.52
maximum=3297.39 minimum=3215.62
```
The patch adds around 67 insns/op so it's effect on performance should be negligible.
Fixes: https://github.com/scylladb/scylladb/issues/22844Closesscylladb/scylladb#22828
* github.com:scylladb/scylladb:
transport: move on_connection_close into connection destructor
test: perf: make aggregated_perf_results formatting more human readable
transport: add blocked and shed connection metrics
generic_server: throttle and shed incoming connections according to semaphore limit
generic_server: add data source and sink wrappers bookkeeping network IO
generic_server: coroutinize part of server::do_accepts
test: add benchmark for generic_server
test: perf: add option to count multiple ops per time_parallel iteration
generic_server: add semaphore for limiting new connections concurrency
generic_server: add config to the constructor
generic_server: add on_connection_ready handler
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.
The motivation behind this change to free up disk space as early as possible.
The reason is that snapshot locks the space of all SSTables in the snapshot,
and deleting form the table, for example, by compaction, or tablet migration,
won't free-up their capacity until they are uploaded to object storage and deleted from the snapshot.
This series adds prioritization of deleted sstables in two cases:
First, after the snapshot dir is processed, the list of SSTable generation is cross-referenced with the
list of SSTables presently in the table and any generation that is not in the table is prioritized to
be uploaded earlier.
In addition, a subscription mechanism was added to sstables_manager
and it is used in backup to prioritize SSTables that get deleted from the table directory
during backup.
This is particularly important when backup happens during high disk utilization (e.g. 90%).
Without it, even if the cluster is scaled up and tablets are migrated away from the full nodes
to new nodes, tablet cleanup might not free any space if all the tablet sstables are hardlinked to the
snapshot taken for backup.
* Enhancement, no backport needed
Closesscylladb/scylladb#23241
* github.com:scylladb/scylladb:
db: snapshot: backup_task: prioritize sstables deleted during upload
sstables_manager: add subscriptions
db: snapshot: backup_task: limit concurrency
sstables: directory_semaphore: expose get_units
db: snapshot: backup_task: add sharded sstables_manager
database: expose get_sstables_manager(schema)
db: snapshot: backup_task: do_backup: prioritize sstables that are already deleted from the table
db: snapshot-ctl: pass table_id to backup_task
db: snapshot-ctl: expose sharded db() getter
db: snapshot: backup_task: do_backup: organize components by sstable generation
db: snapshot: coroutinize backup_task
db: snapshot: backup_task: refactor backup_file out of uploads_worker
db: snapshot: backup_task: refactor uploads_worker out of do_backup
db: snapshot: backup_task: process_snapshot_dir: initialize total progress
utils/s3: upload_progress: init members to 0
db: snapshot: backup_task: do_backup: refactor process_snapshot_dir
db: snapshot: backup_task: keep expection as member
subscribe on each shard's sstables_manager to get
callback notifications and keep the generation numbers
of deleted sstables in a vector so they can be prioritized
first to free up their disk space as soon as possible.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Otherwise, once all the background tasks are created
we have no way to reorder the queue.
Fixes#23239
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Get a reference to the table's sstables_manager
on each shard. This will be used be later patches
to limit concurrency and to subscribe for notifications.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Detect SSTables that are already deleted from the table
in process_snapshot_dir when their number_of_links is equal to 1.
Note that the SSTable may be hard-linked by more than one snapshot,
so even after it is deleted from the table, its number of links
would be greater than one. In that case, however, uploading it
earlier won't help to free-up its capacity since it is still held
by other snapshots.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
To be used by the following patches to get
to the table's sstables_manager for concurrency
control and for notifications (TBD).
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Do not rely on the snapshot directory listing order.
This will become useful for prioritizing unlinked
sstables in a following patch.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Let do_backup deal only with the high level coordination.
A future patch will follow this structure to run
uploads_worker on each shard.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Now we can calculate advance how much data we intend to upload
before we start uploading it.
This will be used also later when uploading in parallel
on all shards, so we can collect the progress from all
shards in get_progress().
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Do preliminary listing of the snapshot dir.
While at it, simplify the loop as follows:
The optional directory_entry returned by snapshot_dir_lister.get()
can be checked as part of the loop condition expression,
and with that, error handling can be simplified and moved
out of the loop body.
A followup patch will organize the component files
by their sstable generation.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
db: snapshot: backup_task: process_snapshot_dir: simplify loop
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
The cache should not garbage-collect tombstone which cover data in the
memtable. Add overlap checks (get_max_purgeable) to garbage collection
to detect tombstones which cover data in the memtable and to prevent
their garbage collection.
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
"
The series makes endpoint state map in the gossiper addressable by host
id instead of ips. The transition has implication outside of the
gossiper as well. Gossiper based topology operations are affected by
this change since they assume that the mapping is ip based.
On wire protocol is not affected by the change as maps that are sent by
the gossiper protocol remain ip based. If old node sends two different
entries for the same host id the one with newer generation is applied.
If new node has two ids that are mapped to the same ip the newer one is
added to the outgoing map.
Interoperability was verified manually by running mixed cluster.
The series concludes the conversion of the system to be host id based.
"
* 'gleb/gossipper-endpoint-map-to-host-id-v2' of github.com:scylladb/scylla-dev:
gossiper: make examine_gossiper private
gossiper: rename get_nodes_with_host_id to get_node_ip
treewide: drop id parameter from gossiper::for_each_endpoint_state
treewide: move gossiper to index nodes by host id
gossiper: drop ip from replicate function parameters
gossiper: drop ip from apply_new_states parameters
gossiper: drop address from handle_major_state_change parameter list
gossiper: pass rpc::client_info to gossiper_shutdown verb handler
gossiper: add try_get_host_id function
gossiper: add ip to endpoint_state
serialization: fix std::map de-serializer to not invoke value's default constructor
gossiper: drop template from wait_alive_helper function
gossiper: move get_supported_features and its users to host id
storage_service: make candidates_for_removal host id based
gossiper: use peers table to detect address change
storage_service: use std::views::keys instead of std::views::transform that returns a key
gossiper: move _pending_mark_alive_endpoints to host id
gossiper: do not allow to assassinate endpoint in raft topology mode
gossiper: fix indentation after previous patch
gossiper: do not allow to assassinate non existing endpoint
the option of `uuid_sstable_identifier_enabled` was introduced in
f014ccf3 . the first version which has this change was 5.4, and
6.1 has been branched. during the discussion of backup and restore,
we realized that we've been taking efforts to address problems which
could have been addressed with the sstable with UUID-based identifier.
see also #10459 which is the issue which proposed to implement UUID-v1
based sstable identifier.
now that two major releases passed, we should have the luxury to mark
this option "unused". this option which was previously introduced to
keep the backward compatibility, and to allow user to opt-out of the
feature for some reasons.
so in this change, mark the option unused, so that if any user still
sets this option with command line, they will get a clear error. but
we still parse and handle this setting in `scylla.yaml`, so that this
option is still respected for existing settings, and for existing tests,
which are not yet prepared for the uuid-based sstable identifiers.
Refs #10459Fixes#20337
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#20341
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`
Add a fiber responsible for periodic re-training of compression dictionaries
(for tables which opted into dict-aware compression).
As of this patch, it works like this:
every `$tick_period` (15 minutes), if we are the current Raft leader,
we check for dict-aware tables which have no dict, or a dict older
than `$retrain_period`.
For those tables, if they have enough data (>1GiB) for a training,
we train a new dict and check if it's significantly better
than the current one (provides ratio smaller than 95% of current ratio),
and if so, we update the dict.
Adds a helper method which queries the creation timestamp
of a given dict in `system.dicts`.
We will later use the age of the current SSTable compression dict
to decide if another training should be done already.
When a table is dropped, its corresponding dictionary in `system.dicts`
-- if any -- should be deleted, otherwise it will remain forever as
garbage.
This commit implements such cleanup.
Extend the `system.dicts` helper for querying and modifying
`system.dicts` with an ability to use names other than "general".
We will use that in later commits to publish dictionaries for SSTable compression.
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.
That map became redundant once we added
object_storage_endpoints in the config, this patch removes
it and switches all the user code to use the new option.
Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>
This patch changes gossiper to index nodes by host ids instead of ips.
The main data structure that changes is _endpoint_state_map, but this
results in a lot of changes since everything that uses the map directly
or indirectly has to be changed. The big victim of this outside of the
gossiper itself is topology over gossiper code. It works on IPs and
assumes the gossiper does the same and both need to be changed together.
Changes to other subsystems are much smaller since they already mostly
work on host ids anyway.
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>
The new option deprecates the existing `enable_tablets` option.
It will be extended in the next patch with a 3rd value: "enforced"
while will enable tablets by default for new keyspace but
without the posibility to opt out using the `tablets = {'enabled':
false}` keyspace schema option.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
This PR is an introductory step towards enforcing
RF-rack-valid keyspaces in Scylla.
The scope of changes:
* defining RF-rack-valid keyspaces,
* introducing a configuration option enforcing RF-rack-valid
keyspaces,
* restricting the CREATE and ALTER KEYSPACE statements
so that they never lead to RF-rack invalid keyspaces,
* during the initialization of a node, it verifies that all existing
keyspaces are RF-rack-valid. If not, the initialization fails.
We provide tests verifying that the changes behave as intended.
---
Note that there are a number of things that still need to be implemented.
That includes, for instance, restricting topology operations too.
---
Implementation strategy (going beyond the scope of this PR):
1. Introduce the new configuration option `rf_rack_valid_keyspaces`.
2. Start enforcing RF-rack-validity in keyspaces if the option is enabled.
3. Adjust the tests: in the tree and out of it. Explicitly enable the option in all tests.
4. Once the tests have been adjusted, change the default value of the option to enabled.
5. Stop explicitly enabling the option in tests.
6. Get rid of the option.
---
Fixesscylladb/scylladb#20356Fixesscylladb/scylladb#23276Fixesscylladb/scylladb#23300
---
Backport: this is part of the requirements for releasing 2025.1.
Closesscylladb/scylladb#23138
* github.com:scylladb/scylladb:
main: Refuse to start node when RF-rack-invalid keyspace exists
cql3: Ensure that CREATE and ALTER never lead to RF-rack-invalid keyspaces
db/config: Introduce RF-rack-valid keyspaces
