Commit 62458b8e4f introduced the enforcement of EXECUTE permissions of functions in cql select. However, according to the reference in #12869, the permissions should be enforced only on UDFs and UDAs.
The code does not distinguish between the two so the permissions are also unintenionally enforced also on native function. This commit introduce the distinction and only enforces the permissions on non native functions.
Fixes#16526
Manually verified (before and after change) with the reproducer supplied in #16526 and also with some the `min` and `max` native functions.
Also added test that checks for regression on native functions execution and verified that it fails on authorization before
the fix and passes after the fix.
Closesscylladb/scylladb#16556
* github.com:scylladb/scylladb:
test.py: Add test for native functions permissions
select statement: verify EXECUTE permissions only for non native functions
This short series fixes a regression from Scylla 5.2 to Scylla 5.4 in "SELECT * GROUP BY" - this query was supposed to return just a single row from each partition (the first one in clustering order), but after the expression rewrite started to wrongly return all rows.
The series also includes a regression test that verifies that this query works doesn't work correctly before this series, but works with this patch - and also works as expected in Scylla 5.2 and in Cassadra.
Fixes#16531.
Closesscylladb/scylladb#16559
* github.com:scylladb/scylladb:
test/cql-pytest: check that most aggregators don't take "*"
cql-pytest: add reproducer for GROUP BY regression
cql: fix regression in SELECT * GROUP BY
Although you can "SELECT COUNT(*)", this has special handling in the CQL
parser (it is converted into a special row-counting request) and you can't
give "*" to other aggregators - e.g., "SELECT SUM(*)". This patch includes
a simple test that confirms this.
I wanted to check this in relation to the previous patch, which did,
sort of, a "SELECT $$first$$(*)" - a syntax which this test shows
wouldn't have actually worked if we tried it.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
test/cql-pytest/test_group_by.py has tests that verifies that requests
like
SELECT p,c1,c2,v FROM tbl WHERE p=0 GROUP BY p
work as expected - the "GROUP BY p" means in this case that we should
only return the first row in the p=0 partition.
As a user discovered, it turns out that the almost identical request:
SELECT * FROM tbl WHERE p=0 GROUP BY p
Doesn't work the same - before the fix in the previous patch, it
erroneously returned all rows in p=0, not just the first one.
The test in this patch demonstrates this - it fails on Scylla 5.4,
passes on Scylla 5.2 and on Cassandra - and passes when the fix
from the previous patch is used.
This patch includes another tiny test, to check the interaction of GROUP BY
with filtering. This second test passes on Scylla - but I want it in
anyway because it is yet another interaction that might break (the
user that reported #16531 also had filtering, and I was worried it might
have been related).
Refs #16531
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Check that the initial_tablets appears in system_schema.scylla_keyspaces
if turned on explicitly
Check that it's possible to change initial_tablets with ALTER KEYSPACE
Check that changing r.s. from simple to network-topology doesn't
activate tablets
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The option is kepd in DDL, but is _not_ stored in
system_schema.keyspaces. Instead, it's removed from the provided options
and kept in scylla_keyspaces table in its own column. All the places
that had optional initial_tablets disengaged now set this value up the
way the find appropriate.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Now all the callers have it at hands (spoiler: not yet initialized, but
still) so the params can also have it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The object in question fully describes the keyspace to be created and,
among other things, contains replication strategy options. Next patches
move the "initial_tablets" option out of those options and keep it
separately, so the ks metadata should also carry this option separately.
This patch is _just_ extending the metadata creation API, in fact the
new field is unused (write-only) so all the places that need to provide
this data keep it disengaged and are explicitly marked with FIXME
comment. Next patches will fix that.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Previous patch added params to r.s. classes' constructors, but callers
don't construct those directly, instead they use the create_r.s.()
wrapper. This patch adds params to the wrapper too.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
When replication strategy class is created caller parr const reference
on the config options which is, in turn, a map<string, string>. In the
future r.s. classes will need to get "scylla specific" info along with
legacy options and this patch prepares for that by passing more generic
params argument into constructor. Currently the only inhabitant of the
new params is the legacy options.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This switch is currently possible, but results in not supported keyspace state
Closesscylladb/scylladb#16513
* github.com:scylladb/scylladb:
test: Add a test that switching between vnodes and tablets is banned
cql3/statements: Don't allow switching between vnode and per-table replication strategies
cql3/statements: Keep local keyspace variable in alter_keyspace_statement::validate
Before this series, materialized views already work correctly on keyspaces with tablets, but secondary indexes do not. The goal of these series is make CQL secondary indexes fully supported on tablets:
1. First we need to make CREATE INDEX work with tablets (it didn't before this series). Fixes#16396.
2. Then we need to keep the promise that our documentation makes - that **local** secondary index should be synchronously updated - Fixes#16371.
As you can see in the patches below, and as was expected already in the design phase, the code changes needed to make indexes support tablets were minimal. But writing reliable tests for these issues was the biggest effort that went into this series.
Closesscylladb/scylladb#16436
* github.com:scylladb/scylladb:
secondary-index, tablets: ensure that LSI are synchronous
test: add missing "tags" schema extension to cql_test_env
mv, test: fix delay_before_remote_view_update injection point
secondary index: fix view creation when using tablets
The test test_many_partitions is very slow, as it tests a slow scan over
a lot of partitions. This was observed to time out on the slower ARM
machines, making the test flaky. To prevent this, create an
extra-patient cql connection with a 10 minutes timeout for the scan
itself.
This is a follow-up to fb9379edf1, which
attempted to fix this, but didn't patch all the places doing slow scans.
This patch fixes the other scan, the one actually observed to time-out
in CI.
Fixes: #16145Closesscylladb/scylladb#16370
In other words, print more user-friendly messages, and avoid crashing.
Specifically:
* Don't crash when attempting to load schema tables from configured data-dir, while configuration does not have any configured data-directories.
* Detect the case where schema mutations have no rows for the current table -- the keyspace exists, but the table doesn't.
* Add negative tests for schema-loading.
Fixes: https://github.com/scylladb/scylladb/issues/16459Closesscylladb/scylladb#16494
* github.com:scylladb/scylladb:
test/cql-pytest: test_tools.py: add test for failed schema loadig
tools/scylla-sstable: use at() instead of operator [] when obtaining data dirs
tools/schema_loader: also check for empty table/column mutations
tools/schema_loader: log more details when loading schema from schema tables
CQL Local Secondary Index is a Scylla-only extension to Cassandra's
secondary index API where the index is separate per partition.
Scylla's documentation guarantees that:
"As of Scylla Open Source 4.0, updates for local secondary indexes are
performed synchronously. When updates are synchronous, the client
acknowledges the write operation only after both the base table
modification and the view up date are written."
This happened automatically with vnodes, because the base table and the
view have the same partition key, so base and view replicas are co-located,
and the view update is always local and therefore done synchronously.
But with tablets, this does NOT happen automatically - the base and view
tablets may be located on different nodes, and the view update may be
remote, and NOT synchronous.
So in this patch we explicitly mark the view as synchronous_update when
building the view for an LSI.
The bigger part of this patch is to add a test which reliably fails
before this patch, and passes after it. The test creates a two-node
cluster and a table with LSI, and pins the base's tablets to one node
and the view's to the second node, forcing the view updates to be
remote. It also uses an injection point to make the view update slower.
The test then writes to the base and immediately tries to use the index
to read. Before this patch, the read doesn't find the new data (contrary
to the guarantee in the documentation). After this patch, the read
does find the new data - because the write waited for the index to
be updated.
Fixes#16371
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
One of the unfortunate anti-features of cql_test_env (the framework used
in our CQL tests that are written in C++) is that it needs to repeat
various bizarre initializations steps done in main.cc, otherwise various
requests work incorrectly. One of these steps that main.cc is to initialize
various "schema extensions" which some of the Scylla features need to work
correctly.
We remembered to initialize some schema extensions in cql_test_env, but
forgot others. The one I will need in the following patch is the "tags"
extension, which we need to mark materialized views used by local
secondary indexes as "synchronous_updates" - without this patch the LSI
tests in secondary_index_test.cc will crash.
In addition to adding the missing extension, this patch also replaces
the segmentation-fault crash when it's missing (caused by a dynamic
cast failure) by a clearer on_internal_error() - so if we ever have
this bug again, it will be easier to debug.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
In commit 88a5ddabce, we fixed materialized
view creation to support tablets. We added to the function called to
create materialized views in CQL, prepare_new_view_announcement()
a missing call to the on_before_create_column_family() notifier that
creates tablets for this new view.
Unfortunately, We have the same problem when creating a secondary index,
because it does not use prepare_new_view_announcement(), and instead uses
a generic function to "update" the base table, which in some cases ends
up creating new views when a new index is requested. In this path, the
notifier did not get called to the notifier, so we must add it here too.
Unfortunately, the notifiers must run in a Seastar thread, which means
that yet another function now needs to run in a Seastar thread.
Before this patch, creating a secondary index in a table using tablets
fails with "Tablet map not found for table <uuid>". With this patch,
it works.
The patch also includes tests for creating a regular and local secondary
index. Both tests fail (with the aforementioned error) before this
patch, and pass with it.
Fixes#16396
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Observer, that references table_for_test, must of course, not
outlive table_for_test. Observer can be called later after the
last input sstable is removed from sstable manager.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#16428
The interface is fragile because the user may incorrectly use the
wrong "gc before". Given that sstable knows how to properly calculate
"gc before", let's do it in estimate__d__t__r(), leaving no room
for mistakes.
sstable_run's variant was also changed to conform to new interface,
allowing ICS to properly estimate droppable ratio, using GC before
that is calculated using each sstable's range. That's important for
upcoming tablets, as we want to query only the range that belongs
to a particular tablet in the repair history table.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#15931
Currently, `tool_app_template::run_async()` crashes when invoked with empty argv (with just `argv[0]` populated). This can happen if the tool app is invoked without any further args, e.g. just invoking `scylla nodetool`. The crash happens because unconditional dereferencing of `argv[1]` to get the current operation.
To fix, add an early-exit for this case, just printing a usage message and exiting with exit code 2.
Fixes: #16451Closesscylladb/scylladb#16456
* github.com:scylladb/scylladb:
test: add regression tests for invoking tools with no args
tools/utils: tool_app_template: handle the case of no args
tools/utils: tool_app_template: remove "scylla-" prefix from app name
It enables interaction with the node through CQL protocol without authentication. It gives full-permission access.
The maintenance socket is available by Unix domain socket with file permissions `755`, thus it is not accessible from outside of the node and from other POSIX groups on the node.
It is created before the node joins the cluster.
To set up the maintenance socket, use the `maintenance-socket` option when starting the node.
* If set to `ignore` maintenance socket will not be created.
* If set to `workdir` maintenance socket will be created in `<node's workdir>/cql.m`.
* Otherwise maintenance socket will be created in the specified path.
The default value is `ignore`.
* With python driver
```python
from cassandra.cluster import Cluster
from cassandra.connection import UnixSocketEndPoint
from cassandra.policies import HostFilterPolicy, RoundRobinPolicy
socket = "<node's workdir>/cql.m"
cluster = Cluster([UnixSocketEndPoint(socket)],
# Driver tries to connect to other nodes in the cluster, so we need to filter them out.
load_balancing_policy=HostFilterPolicy(RoundRobinPolicy(), lambda h: h.address == socket))
session = cluster.connect()
```
Merge note: apparently cqlsh does not support unix domain sockets; it
will have to be fixed in a follow-up.
Closesscylladb/scylladb#16172
* github.com:scylladb/scylladb:
test.py: add maintenance socket test
test.py: enable maintenance socket in tests by default
docs: add maintenance socket documentation
main: add maintenance socket
main: refactor initialization of cql controller and auth service
auth/service: don't create system_auth keyspace when used by maintenance socket
cql_controller: maintenance socket: fix indentation
cql_controller: add option to start maintenance socket
db/config: add maintenance_socket_enabled bool class
auth: add maintenance_socket_role_manager
db/config: add maintenance_socket variable
The pull requests adds support for tablets in Alternator, and particularly focuses in getting Alternator's GSI and LSI (i.e., materialized views) to work.
After this series support for tablets in Alternator _mostly_ work, but not completely:
1. CDC doesn't yet work with tablets, and Alternator needs to provide CDC (known as "DynamoDB Streams").
2. Alternator's TTL feature was not tested with tablets, and probably doesn't work because it assumes the replication map belongs to a keyspace.
Because of these reasons, Alternator does not yet use tablets by default and it needs to be enabled explicitly be adding an experimental tag to the new table. This will allow us to test Alternator with tablets even before it is ready for the limelight.
Fixes#16203Fixes#16313Closesscylladb/scylladb#16353
* github.com:scylladb/scylladb:
mv, tablets, alternator: test for Alternator LSI with tablets
mv: coroutinize wait code for remote view updates
mv, test: add injection point to delay remove view update
alternator: explicitly request synchronous updates for LSI
alternator: fix view creation when using tablets
alternator: add experimental method to create a table with tablets
The observed crash was in the following piece on "cf" access:
if (*table_is_dropped) {
sslog.info("[Stream #{}] Skipped streaming the dropped table {}.{}", si->plan_id, si->cf.schema()->ks_name(), si->cf.schema()->cf_name());
Fixes#16181
Also, add a test case which reproduces the problem by doing table drop during tablet migration. But note that the problem is not tablet-specific.
Closesscylladb/scylladb#16341
* github.com:scylladb/scylladb:
test: tablets: Add test case which tests table drop concurrent with migration
tests: tablets: Do read barrier in get_tablet_replicas()
streaming: Keep table by shared ptr to avoid crash on table drop
This patch adds a test (in the topology test framework) for issue #16313 -
the bug where Alternator LSI must use synchronous view updates but didn't.
This test fails with high probability (around 50%) before the previous patch,
which fixed this bug - and passes consistently after the patch (I ran it
100 times and it didn't fail even once).
This is the first test in the topology framework that uses the DynamoDB
API and not CQL. This required a couple of tiny convenience functions,
which are introduced in the only test file that uses them - but if we
want we can later move them out to a library file.
Unfortunately, the standard AWS SDK for Python - boto3 - is *not*
asynchronous, so this test is also not really asynchronous, and will
block the event loop while making requests to Alternator. However,
for now it doesn't matter (we do NOT run multiple tests in the same
event loop), and if it ever matters, I mentioned a couple of options
what we can do in a comment.
Because this test uses a 10-node cluster, it is skipped in debug-mode
runs. In a later patch we will replace it by a more efficent - and
more reliable - 2-node test.
Refs #16313
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Fixes#16312
This test replays a segment before it might be closed or even fully flushed, thus it can (with the new semantics) generate a segment_truncation exception if hitting eof earlier than expected. (Note: test does not use pre-allocated segments).
(First patch makes the test coroutinized to make for a nicer, easier fix change.
Closesscylladb/scylladb#16368
* github.com:scylladb/scylladb:
commitlog_test::test_commitlog_reader: handle segment_truncation
commitlog_test: coroutinize test_commitlog_reader
This was recently found to produce a crash. Add a simple regression
test, to make sure future changes don't re-introduce problems with this
rarely used code-path.
The maintenance socket is created before joining the cluster. When maintenance auth service
is started it creates system_auth keyspace if it's missing. It is not synchronized
with other nodes, because this node hasn't joined the group0 yet. Thus a node has
a mismatched schema and is unable to join the cluster.
The maintenance socket doesn't use role management, thus the problem is solved
by not creating system_auth keyspace when maintenance auth service is created.
The logic of regular CQL port's auth service won't be changed. For the maintenance
socket will be created a new separate auth service.
After restarting each node, we should wait for other nodes to notice
the node is UP before restarting the next server. Otherwise, the next
node we restart may not send the shutdown notification to the
previously restarted node, if it still sees it as down when we
initiate its shutdown. In this case, the node will learn about the
restart from gossip later, possible when we already started CQL
requests. When a node learns that some node restarted while it
considers it as UP, it will close connections to that node. This will
fail RPC sent to that node, which will cause CQL request to time-out.
Fixes#14746Closesscylladb/scylladb#16010
asyncio.get_event_loop() returns the current event loop. but if there
is not, the result of `get_event_loop_policy().get_event_loop()` is
returned. but this behavior is deprecated since Python 3.12, so let's
use asyncio.run() as recommended by
https://docs.python.org/3/library/asyncio-eventloop.html.
asyncio.run() was introduced by Python 3.7, so we should be able to
use it.
this change should silence the waring when running this script
as a stand-alone script with Python 3.12.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#16385
We make `consistent_cluster_management` mandatory in 5.5. This
option will be always unused and assumed to be true.
Additionally, we make `override_decommission` deprecated, as this option
has been supported only with `consistent_cluster_management=false`.
Making `consistent_cluster_management` mandatory also simplifies
the code. Branches that execute only with
`consistent_cluster_management` disabled are removed.
We also update documentation by removing information irrelevant in 5.5.
Fixesscylladb/scylladb#15854
Note about upgrades: this PR does not introduce any more limitations
to the upgrade procedure than there are already. As in
scylladb/scylladb#16254, we can upgrade from the first version of Scylla
that supports the schema commitlog feature, i.e. from 5.1 (or
corresponding Enterprise release) or later. Assuming this PR ends up in
5.5, the documented upgrade support is from 5.4. For corresponding
Enterprise release, it's from 2023.x (based on 5.2), so all requirements
are met.
Closesscylladb/scylladb#16334
* github.com:scylladb/scylladb:
docs: update after making consistent_cluster_management mandatory
system_keyspace, main, cql_test_env: fix indendations
db: config: make consistent_cluster_management mandatory
test: boost: schema_change_test: replace disable_raft_schema_config
db: config: make override_decommission deprecated
db: config: make force_schema_commit_log deprecated
The test case that validates upload-sink works does this by getting several random ranges from the uploaded object and checks that the content is what it should be. The range boundaries are generated like this:
```
uint64_t len = random(1, chunk_size);
uint64_t offset = random(file_size) - len;
```
The 2nd line is not correct, if random number happens less than the len the offset befomes "negative", i.e. -- very large 64-bit unsigned value.
Next, this offset:len gets into s3 client's get_object_contiguous() helper which in turn converts them into http range header's bytes-specifier format which is "first_bytet-last_byte" one. The math here is
```
first_byte = offset;
last_byte = offset + len - 1;
```
Here the overflow of the offset thing results in underflow of the last_byte -- it becomes less than the first_byte. According to RFC this range-specifier is invalid and (!) can be ignored by the server. This is what minio does -- it ignores invalid range and returns back full object.
But that's not all. When returning object portion the http request status code is PartialContent, but when the range is ignored and full object is returned, the status is OK. This makes s3 client's request fail with unexpected_status_error in the middle of the test. Then the object is removed with deferred action and actual error is printed into logs. In the end of the day logs look as if deletion of an object failed with OK status %)
fixes: #16133Closesscylladb/scylladb#16324
* github.com:scylladb/scylladb:
test/s3: Avoid object range overflow
s3/client: Handle GET-with-Range overflows correctly
Support for splitting tablet storage is added.
Until now, tablet storage was composed of a single compaction group, i.e. a group of sstables eligible to be compacted together.
For splitting, tablet storage can now be composed of multiple compaction groups, main, left and right.
Main group stores sstables that require splitting, whereas left and right groups store sstables that were already split according to the tablet's token range.
After table storage is put in splitting mode, new writes will only go to either left or right group, depending on the token.
When all main groups completed splitting their sstables, then coordinator can proceed with tablet metadata changes.
The coordination part is not implemented yet. Only the storage part. The former will come next and will be wired into the latter.
Missing:
- splitting monitor (verify whether coordinator asked for splitting and acts accordingly) (will come next)
Closesscylladb/scylladb#16158
* github.com:scylladb/scylladb:
replica: Introduce storage group splitting
replica: Add storage_group::memtable_count()
replica: Add compaction_group::empty()
replica: Rename compaction_group_manager to storage_group_manager
replica: Introduce concept of storage group
compaction: Add splitting compaction task to manager
compaction: Prepare rewrite_sstables_compaction_task_executor to be reused for splitting
compaction: remove scrub-specific code from rewrite_sstables_compaction_task_executor
replica: Allow uncompacted SSTables to be moved into a new set
compaction: Add splitting compaction
flat_mutation_reader: Allow interposer consumers to be stacked
mutation_writer: Introduce token-group-based mutation segregator
locator: Introduce tablet_map::get_tablet_id_and_range_side(token)
Scylla can be configured to use different IPs for the internode communication
and client connections. This test allocates and configure unique IP addresses
for the client connections (`rpc_address`) for 2-nodes cluster.
Two scenarios tested:
1) Change RPC IPs sequentially
2) Change RPC IPs simultaneously
Closesscylladb/scylladb#15965
This introduces the ability to split a storage group.
The main compaction group is split into left and right groups.
set_split() is used to set the storage group to splitting mode, which
will create left and right compaction groups. Incoming writes will
now be placed into memtable of either left or right groups.
split() is used to complete the splitting of a group. It only
returns when all preexisting data is split. That means main
compaction group will be empty and all the data will be stored
in either left or right group.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The task for splitting compaction will run until all sstables
in the main set are split. The only exceptions are shutdown
or user has explicitly asked for abort.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Token group is an abstraction that allows us to easily segregate a
mutation stream into buckets. Groups share the same properties as
compaction groups. Groups follow the ring order and they don't
overlap each other. Groups are defined according to a classifier,
which return an id given a token. It's expected that classifier
return ids in monotonic increasing order.
The reasons for this abstraction are:
1) we don't want to make segregator aware of compaction groups
2) splitting happens before tablet metadata is changed, so the
the segregator will have to classify based on whether the token
belongs to left (group id 0) or right (group id 1) side of
the range to be split.
The reason for not extending sstable writer instead, is that
today, writer consumer can only tell producer to switch to a
new writer, when consuming the end of a partition, but that
would be too late for us, as we have to decide to move to
a new writer at partition start instead.
It will be wired into compaction when it happens in split mode.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The currently used versions of "time" and "rustix" depencies
had minor security vulnerabilities.
In this patch:
- the "rustix" crate is updated
- the "chrono" crate that we depend on was not compatible
with the version of the "time" crate that had fixes, so
we updated the "chrono" crate, which actually removed the
dependency on "time" completely.
Both updated were performed using "cargo update" on the
relevant package and the corresponding version.
Fixes#15772Closesscylladb/scylladb#16378
when migrating to the uuid-based identifiers, the mapping from the
integer-based generation to the shard-id is preserved. we used to have
"gen % smp_count" for calculating the shard which is responsible to host
a given sstable. despite that this is not a documented behavior, this is
handy when we try to correlate an sstable to a shard, typically when
looking at a performance issue.
in this change, a new subcommand is added to expose the connection
between the sstable and its "owner" shards.
Fixes#16343
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#16345
Reduce code duplication by defining each metric just once, instead of three times, by having the semaphore register metrics by itself. This also makes the lifecycle of metrics contained in that of the semaphore. This is important on enterprise where semaphores are added and removed, together with service levels.
We don't want all semaphores to export metrics, so a new parameter is introduced and all call-sites make a call whether they opt-in or not.
Fixes: https://github.com/scylladb/scylladb/issues/16402Closesscylladb/scylladb#16383
* github.com:scylladb/scylladb:
database, reader_concurrency_sempaphore: deduplicate reader_concurrency_sempaphore metrics
reader_concurrency_semaphore: add register_metrics constructor parameter
sstables: name sstables_manager
