All view live in the same keyspace as their base
table, so calculate the keyspace-dependent flags
once, outside the per-view update loop.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
In order to reduce the dependency on external libraries, and for better integration with ranges in C++ standard library. let's use the homebrew `utils::views::unique()` before unique is accepted by the C++ standard.
---
it's a cleanup, hence no need to backport.
Closesscylladb/scylladb#22393
* github.com:scylladb/scylladb:
cql3, test: switch from boost::adaptors::uniqued to utils::views:unique
utils: implement drop-in replacement for replacing boost::adaptors::uniqued
The log file names created in `scylla_cluster.py` by
`ScyllaClusterManager`
and files to be collected in conftest.py by `manager` should be in
sync. This patch fixes the issue, originally introduced in
scylladb/scylladb#22192Fixesscylladb/scylladb#22387
Backports: 6.1 and 6.2.
Closesscylladb/scylladb#22415
In order to reduce the dependency on external libraries, and for better
integration with ranges in C++ standard library. let's use the homebrew
`utils::views::unique()` before unique is accepted by the C++ standard.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Add a custom implementation of boost::adaptors::uniqued that is compatible
with C++20 ranges library. This bridges the gap between Boost.Range and
the C++ standard library ranges until std::views::unique becomes available
in C++26. Currently, the unique view is included in
[P2214](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2760r0.html)
"A Plan for C++ Ranges Evolution", which targets C++26.
The implementation provides:
- A lazy view adaptor that presents unique consecutive elements
- No modification of source range
- Compatibility with C++20 range views and concepts
- Lighter header dependencies compared to Boost
This resolves compilation errors when piping C++20 range views to
boost::adaptors::uniqued, which fails due to concept requirements
mismatch. For example:
```c++
auto range = std::views::take(n) | boost::adaptors::uniqued; // fails
```
This change also offers us a lightweight solution in terms of smaller
header dependency.
While std::ranges::unique exists in C++23, it's an eager algorithm that
modifies the source range in-place, unlike boost::adaptors::uniqued which
is a lazy view. The proposed std::views::unique (P2214) targeting C++26
would provide this functionality, but is not yet available.
This implementation serves as an interim solution for filtering consecutive
duplicate elements using range views until std::views::unique is
standardized.
For more details on the differences between `std::ranges::unique` and
`boost::adaptors::uniqued`:
- boost::adaptors::uniqued is a view adaptor that creates a lazy view over the original range. It:
* Doesn't modify the source range
* Returns a view that presents unique consecutive elements
* Is non-destructive and lazy-evaluated
* Can be composed with other views
- std::ranges::unique is an algorithm that:
* Modifies the source range in-place
* Removes consecutive duplicates by shifting elements
* Returns an iterator to the new logical end
* Cannot be used as a view or composed with other range adaptors
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Currently, when we load a frozen schema into the registry, we lose
the base info if the schema was of a view. Because of that, in various
places we need to set the base info again, and in some codepaths we
may miss it completely, which may make us unable to process some
requests (for example, when executing reverse queries on views).
Even after setting the base info, we may still lose it if the schema
entry gets deactivated due to all `schema_ptr`s temporarily dying.
To fix this, this patch adds the base schema to the registry, alongside
the view schema. We store just the frozen base schema, so that we can
transfer it across shards. With the base schema, we can now set the base
info when returning the schema from the registry. As a result, we can now
assume that all view schemas returned by the registry have base_info set.
In this series we also make sure that the view schemas in the registry are
kept up-to-date in regards to base schema changes.
Fixes https://github.com/scylladb/scylladb/issues/21354
This issue is a bug, so adding backport labels 6.1 and 6.2
Closesscylladb/scylladb#21862
* github.com:scylladb/scylladb:
test: add test for schema registry maintaining base info for views
schema_registry: avoid setting base info when getting the schema from registry
schema_registry: update cached base schemas when updating a view
schema_registry: cache base schemas for views
db: set base info before adding schema to registry
As discussed in
https://github.com/scylladb/scylladb/issues/12263#issuecomment-1853576813,
compact storage tables are deprecated.
Yet, there's is nothing in the code that prevents users
from creating such tables.
This patch adds a live-updateable config option:
`enable_create_table_with_compact_storage`, set to
`false` by default, that require users to opt-in
in order to create new tables WITH COMPACT STORAGE.
Refs scylladb/scylladb#12263, scylladb/scylladb#16375
* Since this guardrail is an enhancement, no backport is needed
Closesscylladb/scylladb#16403
* github.com:scylladb/scylladb:
docs: ddl: document the deprecation of compact tables
test: enable_create_table_with_compact_storage for tests that need it
config: add enable_create_table_with_compact_storage
The repair_time in system.tablets will be updated when repair runs
successfully. We can now use it to update the repair time for tombstone
gc, i.e, when the system.tablets.repair_time is propagated, call
gc_state.update_repair_time() on the node that is the owner of the
tablet.
Since b3b3e880d3 ("repair: Reduce hints and batchlog flush"), the
repair time that could be used for tombstone gc might be smaller than
when the repair is started, so the actual repair time for tombstone gc
is returned by the repair rpc call from the repair master node.
Fixes#17507
New feature. No backport is needed.
Closesscylladb/scylladb#21896
* github.com:scylladb/scylladb:
repair: Stop using rpc to update repair time for repairs scheduled by scheduler
repair: Wire repair_time in system.tablets for tombstone gc
test: Disable flush_cache_time for two tablet repair tests
test: Introduce guarantee_repair_time_next_second helper
repair: Return repair time for repair_service::repair_tablet
service: Add tablet_operation.hh
Update configure.py to use wasm32-wasip1 as an alternative to wasm32-wasi,
matching the behavior previously implemented for CMake builds in 8d7786cb0e.
This ensures consistent WASI target handling across both build systems.
Refs #20878
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22386
File based stream is a new feature that optimizes tablet movement
significantly. It streams the entire SSTable files without deserializing
SSTable files into mutation fragments and re-serializing them back into
SSTables on receiving nodes. As a result, less data is streamed over the
network, and less CPU is consumed, especially for data models that
contain small cells.
The following patches are imported from the scylla enterprise:
*) Merge 'Introduce file stream for tablet' from Asias He
This patch uses Seastar RPC stream interface to stream sstable files on
network for tablet migration.
It streams sstables instead of mutation fragments. The file based
stream has multiple advantages over the mutation streaming.
- No serialization or deserialization for mutation fragments
- No need to read and process each mutation fragments
- On wire data is more compact and smaller
In the test below, a significant speed up is observed.
Two nodes, 1 shard per node, 1 initial_tablets:
- Start node 1
- Insert 10M rows of data with c-s
- Bootstrap node 2
Node 1 will migration data to node2 with the file stream.
Test results:
1) File stream: bytes on wire = 1132006250 bytes, bw = 836MB/s
[shard 0:stre] stream_blob - stream_sstables[eadaa8e0-a4f2-4cc6-bf10-39ad1ce106b0]
Finished sending sstable_nr=2 files_nr=18 files={} range=(-1,9223372036854775807] bytes_sent=1132006250 stream_bw=836MB/s
[shard 0:stre] storage_service - Streaming for tablet migration of a4f68900-568a-11ee-b7b9-c2b13945eed2:1 took 1.08004s seconds
2) Mutation stream: bytes on wire = 3030004736 bytes, bw = 125410.87 KiB/s = 128MB/s
[shard 0:stre] stream_session - [Stream #406dc8b0-56b5-11ee-bc2d-000bf4871058]
Streaming plan for Tablet migration-ks1-index-0 succeeded, peers={127.0.0.1}, tx=0 KiB, 0.00 KiB/s, rx=2958989 KiB, 125410.87 KiB/s
[shard 0:stre] storage_service - Streaming for tablet migration of a4f68900-568a-11ee-b7b9-c2b13945eed2:1 took 23.5992s seconds
Test Summary:
File stream v.s. Mutation stream improvements
- Stream bandwidth = 836 / 128 (MB/s) = 6.53X
- Stream time = 23.60 / 1.08 (Seconds) = 21.85X
- Stream bytes on wire = 3030004736 / 1132006250 (Bytes)= 2.67X
Closes scylladb/scylla-enterprise#3438
* github.com:scylladb/scylla-enterprise:
tests: Add file_stream_test
streaming: Implement file stream for tablet
*) streaming: Use new take_storage_snapshot interface
The new take_storage_snapshot returns a file object instead of a file
name. This allows the file stream sender to read from the file even if
the file is deleted by compaction.
Closes scylladb/scylla-enterprise#3728
*) streaming: Protect unsupported file types for file stream
Currently, we assume the file streamed over the stream_blob rpc verb is
a sstable file. This patch rejects the unsupported file types on the
receiver side. This allows us to stream more file types later using the
current file stream infrastructure without worrying about old nodes
processing the new file types in the wrong way.
- The file_ops::noop is renamed to file_ops::stream_sstables to be
explicit about the file types
- A missing test_file_stream_error_injection is added to the idl
Fixes: #3846
Tests: test_unsupported_file_ops
Closesscylladb/scylla-enterprise#3847
*) idl: Add service::session_id id to idl
It will be used in the next patch.
Refs #3907
*) streaming: Protect file stream with topology_guard
Similar to "storage_service, tablets: Use session to guard tablet
streaming", this patch protects file stream with topology_guard.
Fixes#3907
*) streaming: Take service topology_guard under the try block
Taking the service::topology_guard could throw. Currently, it throws
outside the try block, so the rpc sink will not be closed, causing the
following assertion:
```
scylla: seastar/include/seastar/rpc/rpc_impl.hh:815: virtual
seastar::rpc::sink_impl<netw::serializer,
streaming::stream_blob_cmd_data>::~sink_impl() [Serializer =
netw::serializer, Out = <streaming::stream_blob_cmd_data>]: Assertion
`this->_con->get()->sink_closed()' failed.
```
To fix, move more code including the topology_guard taking code to the
try block.
Fixes https://github.com/scylladb/scylla-enterprise/issues/4106Closesscylladb/scylla-enterprise#4110
*) Merge 'Preserve original SSTable state with file based tablet migration' from Raphael "Raph" Carvalho
We're not preserving the SSTable state across file based migration, so
staging SSTables for example are being placed into main directory, and
consequently, we're mixing staging and non-staging data, losing the
ability to continue from where the old replica left off.
It's expected that the view update backlog is transferred from old
into new replica, as migration doesn't wait for leaving replica to
complete view update work (which can take long). Elasticity is preferred.
So this fix guarantees that the state of the SSTable will be preserved
by propagating it in form of subdirectory (each subdirectory is
statically mapped with a particular state).
The staging sstables aren't being registered into view update generator
yet, as that's supposed to be fixed in OSS (more details can be found
at https://github.com/scylladb/scylladb/issues/19149).
Fixes#4265.
Closesscylladb/scylla-enterprise#4267
* github.com:scylladb/scylla-enterprise:
tablet: Preserve original SSTable state with file based tablet migration
sstables: Add get method for sstable state
*) sstable: (Re-)add shareabled_components getter
*) Merge 'File streaming sstables: Use sstable source/sink to transfer snapshots' from Calle Wilund
Fixes#4246
Alternative approach/better separation of concern, transport vs. sstable layer. Builds on #4472, but fancier.
Ensures we transfer and pre-process scylla metadata for streamed
file blobs first, then properly apply receiving nodes local config
by using a source and sink layer exported from sstables, which
handles things like ordering, metadata filtering (on source) as well
as handling metadata and proper IO paths when writing data on
receiver node (sink).
This implementation maintains the statelessness of the current
design, and the delegated sink side will re-read and re-write the
metadata for each component processed. This is a little wasteful,
but the meta is small, and it is less error prone than trying to do
caching cross-shards etc. The transport is isolated from the
knowledge.
This is an alternative/complement to #4436 and #4472, fixing the
underlying issue. Note that while the layers/API:s here allows easy
fixing of other fundamental problems in the feature (such as
destination location etc), these are not included in the PR, to keep
it as close to the current behaviour as possible.
Closesscylladb/scylla-enterprise#4646
* github.com:scylladb/scylla-enterprise:
raft_tests: Copy/add a topology test with encryption
file streaming: Use sstable source/sink to transfer snapshots
sstables: Add source and sink objects + producers for transfering a snapshot
sstable::types: Add remove accessor for extension info in metadata
*) The change for error injection in merge commit 966ea5955dd8760:
File streaming now has "stream_mutation_fragments" error injection points
so test_table_dropped_during_streaming works with file streaming.
*) doc: document file-based streaming
This commit adds a description of the file-based streaming feature to the documentation.
It will be displayed in the docs using the scylladb_include_flag directive after
https://github.com/scylladb/scylladb/pull/20182 is merged, backported to branch-6.0,
and, in turn, branch-2024.2.
Refs https://github.com/scylladb/scylla-enterprise/issues/4585
Refs https://github.com/scylladb/scylla-enterprise/issues/4254Closesscylladb/scylla-enterprise#4587
*) doc: move File-based streaming to the Tablets source file-based-streaming
This commit moves the description of file-based streaming from a common include file
to the regular doc source file where tablets are described.
Closesscylladb/scylla-enterprise#4652
*) streaming: sstable_stream_sink_impl: abort: prevent null pointer dereference
Closesscylladb/scylladb#22034
The content of the header file noexcept_traits.hh is unused throughout ScyllaDB's code base.
As part of a greater effort to cleanup Scylla's code and reduce content in the root directory, this header file is simply removed.
This is code cleanup - no need to backport.
Fixes: https://github.com/scylladb/scylladb/issues/22117
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Closesscylladb/scylladb#22139
The way that the "test/cqlpy/run --release" feature runs older Scylla
releases is that it takes *today*'s command line parameters and "fixes"
it to conform to what old releases took. This approach was easy to
implement (and the resulting "--release" feature is super useful), but
the downside is that we need to update this fixup code whenever we add
new options to the Scylla command line used by test/cqlpy/run.py.
Commit d04f376 made test/cqlpy/run.py use a new option
"--experimental-features=views-with-tablets", so now we need to remove
it when running older versions of Scylla. So this is what we do in this
patch.
Fixes#22349
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#22350
The small cqlpy test in this patch is a regression test for issue #14390,
which claimed that the Scylla-only "tombstone_gc" option is missing from
the output of "describe table".
This test shows that this report is *not* true, at least not when the
"server-side describe" is used. "test/cqlpy/run --release ..." shows
that this test passes on master and also for Scylla versions all the
way back to Scylla 5.2 (Scylla 5.1 did not support server-side
describe, so the test fails for that reason).
This suggests that the report in issue #14390 was for old-style
client-side (cqlsh) describe, which we no longer support, so this
issue can be closed.
Fixes#14390.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#22354
in this changeset, some misspellings identified by codespell were corrected.
---
it's a cleanup, hence no need to backport.
Closesscylladb/scylladb#22301
* github.com:scylladb/scylladb:
ent/encryption: rename "sie" to "get_opt"
ent,main: fix misspellings
Add a paragraph documenting the decision to deprecate
the COMPACT STORAGE feature, and instruct the user
how to enable the feature despite that.
Note that we don't have an official migration strategy
for users like `DROP COMPACT STORAGE`, which is not
implemented at this time (See #3882).
Fixes#16375
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
As discussed in
https://github.com/scylladb/scylladb/issues/12263#issuecomment-1853576813,
compact storage tables are deprecated.
Yet, there's is nothing in the code that prevents users
from creating such tables.
This patch adds a live-updateable config option:
`enable_create_table_with_compact_storage` that require users
to opt-in in order to create new tables WITH COMPACT STORAGE.
The option is currently set to `true` by default in db/config
to reduce the churn to tests and to `false` in scylla.yaml,
for new clusters.
TODO: once regressions tests that use compact storage
are converted to enable the option, change the default in
db/config to false.
A unit test was added to test/cql-pytest that
checks that the respective cql query fails as expected
with the default option or when it is explicitly set to `false`,
and that the query succeeds when the option is set to `true`.
Note that `check_restricted_table_properties` already
returns an optional warning, but it is only logged
but not returned in the `prepared_statement`.
Fixing that is out of the scope of this patch.
See https://github.com/scylladb/scylladb/issues/20945
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Replace remaining uses of boost::adaptors::transformed with std::views::transform
to reduce Boost dependencies, following the migration pattern established in
bab12e3a. This change addresses recently merged code that reintroduced Boost
header dependencies through boost::adaptors::transformed usage.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22365
In this change, tablet_virtual_task starts supporting tablet
resize (i.e. split and merge).
Users can see running resize tasks - finished tasks are not
presented with the task manager API.
A new task state "suspended" is added. If a resize was revoked,
it will appear to users as suspended. We assume that the resize was revoked
when the tablet number didn't change.
Fixes: #21366.
Fixes: #21367.
No backport, new feature
Closesscylladb/scylladb#21891
* github.com:scylladb/scylladb:
test: boost: check resize_task_info in tablet_test.cc
test: add tests to check revoked resize virtual tasks
test: add tests to check the list of resize virtual tasks
test: add tests to check spilt and merge virtual tasks status
test: test_tablet_tasks: generalize functions
replica: service: add split virtual task's children
replica: service: pass parent info down to storage_group::split
tasks: children of virtual tasks aren't internal by default
tasks: initialize shard in task_info ctor
service: extend tablet_virtual_task::abort
service: retrun status_helper struct from tablet_virtual_task::get_status_helper
service: extend tablet_virtual_task::wait
tasks: add suspended task state
service: extend tablet_virtual_task::get_status
service: extend tablet_virtual_task::contains
service: extend tablet_virtual_task::get_stats
service: add service::task_manager_module::get_nodes
tasks: add task_manager::get_nodes
tasks: drop noexcept from module::get_nodes
replica: service: add resize_task_info static column to system.tablets
locator: extend tablet_task_info to cover resize tasks
Introduces a comprehensive audit system to track database operations for security
and compliance purposes. This change includes:
Core Components:
- New audit subsystem for logging database operations
- Service level integration for proper resource management
- CQL statement tracking with operation categories
- Login process integration for tenant management
Key Features:
- Configurable audit logging (syslog/table)
- Operation categorization (QUERY/DML/DDL/DCL/AUTH/ADMIN)
- Selective auditing by keyspace/table
- Password sanitization in audit logs
- Service level shares support (1-1000) for workload prioritization
- Proper lifecycle management and cleanup
I ran the dtests for audit (manually enabled) and they pass.
The in-repo tests pass.
Notably, there should be no non-whitespace changes between this and scylla-enterprise
Fixesscylladb/scylla-enterprise#4999Closesscylladb/scylladb#22147
* github.com:scylladb/scylladb:
audit: Add shares support to service level management
audit: Add service level support to CQL login process
audit: Add support to CQL statements
audit: Integrate audit subsystem into Scylla main process
audit: Add documentation for the audit subsystem
audit: Add the audit subsystem
Now that all topology related code uses host ids there is not point to
maintain ip to id (and back) mappings in the token metadata. After the
patch the mapping will be maintained in the gossiper only. The rest of
the system will use host ids and in rare cases where translation is
needed (mostly for UX compatibility reasons) the translation will be
done using gossiper.
Fixes: scylladb/scylla#21777
* 'gleb/drop-ip-from-tm-v3' of github.com:scylladb/scylla-dev: (57 commits)
hint manager: do not translate ip to id in case hint manager is stopped already
locator: token_metadata: drop update_host_id() function that does nothing now
locator: topology: drop indexing by ips
repair: drop unneeded code
storage_service: use host_id to look for a node in on_alive handler
storage_proxy: translate ips to ids in forward array using gossiper
locator: topology: remove unused functions
storage_service: check for outdated ip in on_change notification in the peers table
storage_proxy: translate id to ip using address map in tablets's describe_ring code instead of taking one from the topology
topology coordinator: change connection dropping code to work on host ids
cql3: report host id instead of ip in error during SELECT FROM MUTATION_FRAGMENTS query
locator: drop unused function from tablet_effective_replication_map
api: view_build_statuses: do not use IP from the topology, but translate id to ip using address map instead
locator: token_metadata: remove unused ip based functions
locator: network_topology_strategy: use host_id based function to check number of endpoints in dcs
gossiper: drop get_unreachable_token_owners functions
storage_service: use gossiper to map ip to id in node_ops operations
storage_service: fix indentation after the last patch
storage_service: drop loops from node ops replace_prepare handling since there can be only one replacing node
token_metadata: drop no longer used functions
...
these unused includes were identifier by clang-include-cleaner. after
auditing these source files, all of the reports have been confirmed.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22201
The methods to resolve a key/token/range to a table are all noexcept.
Yet the method below all of these, `storage_group_for_id()` can throw.
This means that if due to any mistake a tablet without local replica is
attempted to be looked up, it will result in a crash, as the exception
bubbles up into the noexcept methods.
There is no value in pretending that looking up the tablet replica is
noexcept, remove the noexcept specifiers so that any bad lookup only
fails the operation at hand and doesn't crash the node. This is
especially relevant to replace, which still has a window where writes
can arrive for tablets that don't (yet) have a local replica. Currently,
this results in a crash. After this patch, this will only fail the
writes and the replace can move on.
Fixes: #21480Closesscylladb/scylladb#22251
The API /storage_service/truncate/{ks} returns an unimplemented
error when invoked. As we already have a CQL command,
`TRUNCATE TABLE ks.cf` that causes the table to be truncated on all
nodes, the API can be dropped. Due to the error, it is unused.
Fixes https://github.com/scylladb/scylladb/issues/10520
No backport is required. A small cleanup of not working API.
Closesscylladb/scylladb#22258
The sstable loader relied on the generation id to provide an efficient
hint about the shard that owns an sstable. But, this hint was rendered
ineffective with the introduction of UUID generation, as the shard id
was no longer embedded in the generation id. This also became suboptimal
with the introduction of tablets. Commit 0c77f77 addressed this issue by
reading the minimum from disk to determine sstable ownership but this
improvement was lost with commit 63f1969, which optimistically assumed
that hints would work most of the time, which isn't true.
This commit restores that change - shard id of a table is deduced by
reading minially from disk and then the sstable is fully loaded only if
it belongs to the local shard. This patch also adds a testcase to verify
that the sstable are loaded only in their respective shards.
Fixes#21015
This fixes a regression and should be backported.
Closesscylladb/scylladb#22263
* github.com:scylladb/scylladb:
sstable_directory: do not load remote sstables in process_descriptor
sstable_directory: update `load_sstable()` definition
sstable_directory: reintroduce `get_shards_for_this_sstable()`
If a tablet repair is scheduled by tablet repair scheduler, the repair
time for tombstone gc will be updated when the system.tablet.repair_time
is updated. Skip updating using rpc calls in this case.
The repair_time in system.tablets will be updated when repair runs
successfully. We can now use it to update the repair time for tombstone
gc, i.e, when the system.tablets.repair_time is propagated, call
gc_state.update_repair_time() on the node that is the owner of the
tablet.
Since b3b3e880d3 ("repair: Reduce hints and batchlog flush"), the
repair time that could be used for tombstone gc might be smaller than
when the repair is started, so the actual repair time for tombstone gc
is returned by the repair rpc call from the repair master node.
Fixes#17507
The cache of the hints and batchlog flush makes the exact repair time
check difficult in the test. Disabling it for two repair tests
that check the exact repair time.
The repair time returned by repair_service::repair_tablet considers the
hints and batchlog flush time, so it could be used for the tombstone gc
purpose.
Declaring-but-not-defining a fully specialized template is a great way to
cut dependencies between users and providers, but unfortunately not
supported for variable templates. Clang 18 does support it, but
apparently it is a misinterpretation of the standard, and was removed
in clang 19.
We started using this non-feature in 7ed89266b3.
The fix is to use function templates. This is more verbose as
each specialization needs to define a static variable to return,
but is fully supported.
Closesscylladb/scylladb#22299
The commit b39ca29b3c introduced detection of admission-waiter
anomaly and dumps permit diagnostics as soon as the semaphore did
not admit readers even though it could.
Later on, the commit bf3d0b3543 introduces the optimization where
the admission check is moved to the fiber processing the _read_list.
Since the semaphore no longer admits readers as soon as it can,
dumping diagnostic errors is not necessary as the situation is not
abnormal.
Closesscylladb/scylladb#22344
For several years now, we have seen a strange, and very rare, flakiness
in Alternator tests described in issue #17564: We see all the test pass,
pytest declares them to have passed, and while Python is existing, it
crashes with a signal 11 (SIGSEGV). Because this happens exclusively in
test/alternator and never in the test/cqlpy, we suspect that something
that the test/alternator leaves behind but test/cqlpy does not, causes
some race and crashes during shutdown.
The immediate suspect is the boto3 library, or rather, the urllib3 library
which it uses. This is more-or-less the only thing that test/alternator
does which test/cqlpy doesn't. The urllib3 library keeps around pools of
reusable connections, and it's possible (although I don't actually have any
proof for it) that these open connections may cause a crash during shutdown.
So in this patch I add to the "dynamodb" and "dynamodbstreams" fixtures
(which all Alternator tests use to connect to the server), a teardown which
calls close() for the boto3 client object. This close() call percolates
down to calling clear() on urllib3's PoolManager. Hopefully, this will
make some difference in the chance to crash during shutdown - and if it
doesn't, it won't hurt.
Refs #17564Closesscylladb/scylladb#22341
The code checks that it does not run for an ip address that is no longer
in use (after ip address change). To check that we can use peers table
and see if the host id is mapped to the address. If yes, this is the
latest address for this host id otherwise this is an outdated entry.
