Commit Graph

579 Commits

Author SHA1 Message Date
Piotr Smaron
5afa3028a3 Introduce TABLET_KEYSPACE event to differentiate processing path of a vnode vs tablets ks 2024-05-30 08:33:15 +03:00
Dawid Medrek
54ae9797b9 service: Add locator::host_id to on_leave_cluster
We extend the function
endpoint_lifecycle_subscriber::on_leave_cluster
by another argument -- locator::host_id.
It's more convenient to have a consistent
pair of IP and host ID.
2024-04-26 22:44:03 +02:00
Kefu Chai
9e8805bb49 repair, transport: s/get0()/get()/
`future::get0()` was deprecated in favor of `future::get()`. so
let's use the latter instead. this change silences a `-Wdeprecated`
warning.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18357
2024-04-23 15:48:54 +03:00
Kefu Chai
372a4d1b79 treewide: do not define FMT_DEPRECATED_OSTREAM
since we do not rely on FMT_DEPRECATED_OSTREAM to define the
fmt::formatter for us anymore, let's stop defining `FMT_DEPRECATED_OSTREAM`.

in this change,

* utils: drop the range formatters in to_string.hh and to_string.c, as
  we don't use them anymore. and the tests for them in
  test/boost/string_format_test.cc are removed accordingly.
* utils: use fmt to print chunk_vector and small_vector. as
  we are not able to print the elements using operator<< anymore
  after switching to {fmt} formatters.
* test/boost: specialize fmt::details::is_std_string_like<bytes>
  due to a bug in {fmt} v9, {fmt} fails to format a range whose
  element type is `basic_sstring<uint8_t>`, as it considers it
  as a string-like type, but `basic_sstring<uint8_t>`'s char type
  is signed char, not char. this issue does not exist in {fmt} v10,
  so, in this change, we add a workaround to explicitly specialize
  the type trait to assure that {fmt} format this type using its
  `fmt::formatter` specialization instead of trying to format it
  as a string. also, {fmt}'s generic ranges formatter calls the
  pair formatter's `set_brackets()` and `set_separator()` methods
  when printing the range, but operator<< based formatter does not
  provide these method, we have to include this change in the change
  switching to {fmt}, otherwise the change specializing
  `fmt::details::is_std_string_like<bytes>` won't compile.
* test/boost: in tests, we use `BOOST_REQUIRE_EQUAL()` and its friends
  for comparing values. but without the operator<< based formatters,
  Boost.Test would not be able to print them. after removing
  the homebrew formatters, we need to use the generic
  `boost_test_print_type()` helper to do this job. so we are
  including `test_utils.hh` in tests so that we can print
  the formattable types.
* treewide: add "#include "utils/to_string.hh" where
  `fmt::formatter<optional<>>` is used.
* configure.py: do not define FMT_DEPRECATED_OSTREAM
* cmake: do not define FMT_DEPRECATED_OSTREAM

Refs #13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-04-19 22:57:36 +08:00
Mikołaj Grzebieluch
a0915115c3 maintenance_socket: change log message to differentiate from regular CQL ports
Scylla-ccm uses function `wait_for_binary_interface` that waits for
scylla logs to print "Starting listening for CQL clients". If this log
is printed far before the regular cql_controller is initialized,
scylla-ccm assumes too early that node is initialized.
It can result in timeouts that throw errors, for example in the function
`watch_rest_for_alive`.

Closes scylladb/scylladb#17496
2024-03-08 10:08:09 +01:00
Kefu Chai
19e02de1aa transport/controller: remove unused struct definition
the removed struct definition is not used, so drop it.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#17537
2024-03-06 10:17:08 +02:00
Avi Kivity
93af3dd69b Merge 'Maintenance socket: set filesystem permissions to 660' from Mikołaj Grzebieluch
Set filesystem permissions for the maintenance socket to 660 (previously it was 755) to allow a scyllaadm's group to connect.
Split the logic of creating sockets into two separate functions, one for each case: when it is a regular cql controller or used by maintenance_socket.

Fixes https://github.com/scylladb/scylladb/issues/16487.

Closes scylladb/scylladb#17113

* github.com:scylladb/scylladb:
  maintenance_socket: add option to set owning group
  transport/controller: get rid of magic number for socket path's maximal length
  transport/controller: set unix_domain_socket_permissions for maintenance_socket
  transport/controller: pass unix_domain_socket_permissions to generic_server::listen
  transport/controller: split configuring sockets into separate functions
2024-02-20 15:09:54 +02:00
Mikołaj Grzebieluch
182cfebe40 maintenance_socket: add option to set owning group
Option `maintenance-socket-group` sets the owning group of the maintenance socket.
If not set, the group will be the same as the user running the scylla node.
2024-02-19 10:21:00 +01:00
Benny Halevy
ac83df4875 transport: controller: do_start_server: do not set_cql_read for maintenance port
RPC is not ready yet at this point, so we should not
set this application state yet.

This is indicated by the following warning from
`gossiper::add_local_application_state`:
```
WARN  2024-01-22 23:40:53,978 [shard 0:stmt] gossip - Fail to apply application_state: std::runtime_error (endpoint_state_map does not contain endpoint = 127.227.191.13, application_states = {{RPC_READY -> Value(1,1)}})
```

That should really be an internal error, but
it can't because of this bug.

Fixes #16932

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2024-02-11 11:49:52 +02:00
Mikołaj Grzebieluch
38191144ac transport/controller: get rid of magic number for socket path's maximal length
Calculate `max_socket_length` from the size of the structure
representing the Unix domain socket address.
2024-02-09 12:32:37 +01:00
Mikołaj Grzebieluch
fffb732704 transport/controller: set unix_domain_socket_permissions for maintenance_socket
Set filesystem permissions for the maintenance socket to 660.

Fixes #16487
2024-02-09 12:32:26 +01:00
Mikołaj Grzebieluch
4cecda7ead transport/controller: pass unix_domain_socket_permissions to generic_server::listen 2024-02-05 14:22:03 +01:00
Mikołaj Grzebieluch
6b178f9a4a transport/controller: split configuring sockets into separate functions
TCP sockets and unix domain sockets don't share common listen options
excluding `socket_address`. For unix domain sockets, available options will be
expanded to cover also filesystem permissions and owner for the socket.
Storing listen options for both types of sockets in one structure would become messy.
For now, both use `listen_cfg`.

In a singular cql controller, only sockets of one type are created, thus it
can be easily split into two cases.
Isolate maintenance socket from `listen_cfg`.
2024-02-05 14:20:17 +01:00
Avi Kivity
784c2f8ad2 Merge 'treewide: replace calls to future::get0() by calls to future::get()' from Kefu Chai
get0() dates back from the days where Seastar futures carried tuples, and get0() was a way to get the first (and usually only) element. Now it's a distraction, and Seastar is likely to deprecate and remove it.

Replace with seastar::future::get(), which does the same thing.

Closes scylladb/scylladb#17130

* github.com:scylladb/scylladb:
  treewide: replace seastar::future::get0() with seastar::future::get()
  sstable: capture return value of get0() using auto
  utils: result_loop: define result_type with decayed type

[avi: add another one that snuck in while this was cooking]
2024-02-04 15:23:33 +02:00
Avi Kivity
7cb1c10fed treewide: replace seastar::future::get0() with seastar::future::get()
get0() dates back from the days where Seastar futures carried tuples, and
get0() was a way to get the first (and usually only) element. Now
it's a distraction, and Seastar is likely to deprecate and remove it.

Replace with seastar::future::get(), which does the same thing.
2024-02-02 22:12:57 +08:00
Kefu Chai
c7a01b9eb4 transport: do not include unused headers
these unused includes were identified by clangd. see
https://clangd.llvm.org/guides/include-cleaner#unused-include-warning
for more details on the "Unused include" warning.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#17092
2024-02-02 11:20:24 +02:00
Pavel Emelyanov
7c5c89ba8d Revert "Merge 'Use utils::directories instead of db::config to get dirs' from Patryk Wróbel"
This reverts commit 370fbd346c, reversing
changes made to 0912d2a2c6.

This makes scylla-manager mis-interpret the data_file_directories
somehow, issue #17078
2024-01-31 15:08:14 +03:00
Patryk Wrobel
0f3b00f9ad cql_transport/controler: use utils::directories to get paths of dirs
This change replaces usage of db::config with
usage of utils::directories to get paths of
directories in cql_transport/controler.

Refs: scylladb#5626

Signed-off-by: Patryk Wrobel <patryk.wrobel@scylladb.com>
2024-01-29 13:20:38 +01:00
Mikołaj Grzebieluch
8b2f0e38d9 service/maintenance_mode: move maintenance_socket_enabled definition to seperate file 2024-01-25 15:27:53 +01:00
Sylwia Szunejko
eabe97bcd0 transport: remove additional options from TABLETS_ROUTING_V1
Closes scylladb/scylladb#16701
2024-01-10 09:00:25 +02:00
Sylwia Szunejko
91a5a41313 add a way to negotiate generation of the tablet info for drivers
Tablets metadata is quite expensive to generate (each data_value is
an allocation), so an old driver (without support for tablets) will
generate huge amounts of such notifications. This commit adds a way
to negotiate generation of the notification: a new driver will ask
for them, and an old driver won't get them. It uses the
OPTIONS/SUPPORTED/STARTUP protocol described in native_protocol_v4.spec.

Closes scylladb/scylladb#16611
2024-01-02 20:00:50 +02:00
Sylwia Szunejko
467d466f7e put all tablet info into one field of custom_payload and update docs
Previously, the tablet information was sent to the drivers
in two pieces within the custom_payload. We had information
about the replicas under the `tablet_replicas` key and token range
information under `token_range`. These names were quite generic
and might have caused problems for other custom_payload users.
Additionally, dividing the information into two pieces raised
the question of what to do if one key is present while the other
is missing.

This commit changes the serialization mechanism to pack all information
under one specific name, `tablets-routing-v1`.

From: Sylwia Szunejko <sylwia.szunejko@scylladb.com>

Closes scylladb/scylladb#16148
2024-01-02 14:35:37 +02:00
Mikołaj Grzebieluch
2b9a88d17a cql_controller: maintenance socket: fix indentation 2023-12-18 17:58:13 +01:00
Mikołaj Grzebieluch
ac61d0f695 cql_controller: add option to start maintenance socket
Add an option to listen on the maintenance socket. It is set up on an unix domain socket
and the metrics are disabled.
This enables having an independent authentication mechanism for this socket.

To start the maintenance socket, a new cql_controller has to be created
with
`db::maintenance_socket_enabled::yes` argument.

Creating maintenance socket will raise an exception if
* the path is longer than 107 chars (due to linux limits),
* a file or a directory already exists in the path.

The indentation is fixed in the next commit.
2023-12-18 17:58:13 +01:00
Kefu Chai
0b69a1badc transport: cast unaligned<T> to T for formatting it
in fmt v10, it does not cast unaligned<T> to T when formatting it,
instead it insists on finding a matched fmt::formatter<> specialization for it.
that's why we have FTBFS with fmt v10 when printing
these packed<T> variables with fmtlib v10.

in this change, we just cast them to the underlying types before
formatting them. because seastar::unaligned<T> does not provide
a method for accessing the raw value, neither does it provide
a type alias of the type of the underlying raw value, we have
to cast to the type without deducing it from the printed value.

Refs #13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#16167
2023-11-27 15:26:13 +02:00
Kefu Chai
a9c1a435ec result_message: add formatter for result_message::rows
before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.

in this change, we define a formatter for
`cql_transport::messages::result_message::rows`

Refs #13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#16143
2023-11-23 11:12:55 +02:00
Tomasz Grabiec
b06a0078fb Merge 'Support for sending tablet info to the drivers' from Sylwia Szunejko
There is a need for sending tablet info to the drivers so they can be tablet aware. For the best performance we want to get this info lazily only when it is needed.

The info is send when driver asks about the information that the specific tablet contains and it is directed to the wrong node/shard so it could use that information for every subsequent query. If we send the query to the wrong node/shard, we want to send the RESULT message with additional information about the tablet (replicas and token range) in custom_payload.

Mechanism for sending custom_payload added.

Sending custom_payload tested using three node cluster and cqlsh queries. I used RF=1 so choosing wrong node was testable.

I also manually tested it with the python-driver and confirmed that the tablet info can be deserialized properly.

Automatic tests added.

Closes scylladb/scylladb#15410

* github.com:scylladb/scylladb:
  docs: add documentation about sending tablet info to protocol extensions
  Add tests for sending tablet info
  cql3: send tablet if wrong node/shard is used during modification statement
  cql3: send tablet if wrong node/shard is used during select statement
  locator: add function to check locality
  locator: add function to check if host is local
  transport: add function to add tablet info to the result_message
  transport: add support for setting custom payload
2023-11-22 17:44:07 +02:00
sylwiaszunejko
93420353f4 transport: add function to add tablet info to the result_message 2023-11-21 15:15:20 +01:00
sylwiaszunejko
75b3dbf7ea transport: add support for setting custom payload
A custom payload can now be added to response_message.
If it is set, it will be sent to client and the custom_payload
flag will be set.

write_string_bytes_map method is added to response class
and a missing custom_payload flag is added to
cql_frame_flags.
2023-11-21 15:09:36 +01:00
Kefu Chai
15bfa09454 treewide: do not mark return value const if this has no effect
this change is a cleanup.

to mark a return value without value semantics has no effect. these
`const` specifier useless. so let's drop them.

and, if we compile the tree with `-Wignore-qualifiers`, the compiler
would warn like:

```
/home/kefu/dev/scylladb/schema/schema.hh:245:5: error: 'const' type qualifier on return type has no effect [-Werror,-Wignored-qualifiers]
  245 |     const index_metadata_kind kind() const;
      |     ^~~~~
```
so this change also silences the above warnings.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2023-11-17 17:46:19 +08:00
Kefu Chai
efd65aebb2 build: cmake: add check-header target
to have feature parity with `configure.py`. we won't need this
once we migrate to C++20 modules. but before that day comes, we
need to stick with C++ headers.

we generate a rule for each .hh files to create a corresponding
.cc and then compile it, in order to verify the self-containness of
that header. so the number of rule is quite large, to avoid the
unnecessary overhead. the check-header target is enabled only if
`Scylla_CHECK_HEADERS` option is enabled.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#15913
2023-11-13 10:27:06 +02:00
Botond Dénes
844a0e426f Merge 'Mark counters with skip when empty' from Amnon Heiman
This series mark multiple high cardinality counters with skip_when_empty flag.
After this patch the following counters will not be reported if they were never used:
```
scylla_transport_cql_errors_total
scylla_storage_proxy_coordinator_reads_local_node
scylla_storage_proxy_coordinator_completed_reads_local_node
scylla_transport_cql_errors_total
```
Also marked, the CAS related CQL operations.
Fixes #12751

Closes scylladb/scylladb#13558

* github.com:scylladb/scylladb:
  service/storage_proxy.cc: mark counters with skip_when_empty
  cql3/query_processor.cc: mark cas related metrics with skip_when_empty
  transport/server.cc: mark metric counter with skip_when_empty
2023-09-19 15:02:39 +03:00
Avi Kivity
ab6988c52f Merge "auth: do not grant permissions to creator without actually creating" from Wojciech Mitros
Currently, when creating the table, permissions may be mistakenly
granted to the user even if the table is already existing. This
can happen in two cases:

The query has a IF NOT EXISTS clause - as a result no exception
is thrown after encountering the existing table, and the permission
granting is not prevented.
The query is handled by a non-zero shard - as a result we accept
the query with a bounce_to_shard result_message, again without
preventing the granting of permissions.
These two cases are now avoided by checking the result_message
generated when handling the query - now we only grant permissions
when the query resulted in a schema_change message.

Additionally, a test is added that reproduces both of the mentioned
cases.

CVE-2023-33972

Fixes #15467.

* 'no-grant-on-no-create' of github.com:scylladb/scylladb-ghsa-ww5v-p45p-3vhq:
  auth: do not grant permissions to creator without actually creating
  transport: add is_schema_change() method to result_message
2023-09-18 21:47:28 +03:00
Pavel Emelyanov
b42391bfbe transport: Shutdown server on disablebinary
... and do the real "sharded::stop" in the background. On node shutdown
it needs to pick up all dangling background stopping.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2023-09-11 17:37:48 +03:00
Pavel Emelyanov
bc2d44994a transport/controller: Coroutinize do_stop_server()
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2023-09-11 17:32:07 +03:00
Pavel Emelyanov
7701aa0789 transport/controller: Coroutinize stop_server()
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2023-09-11 17:32:07 +03:00
Nadav Har'El
548386a0bb treewide: reduce include of cql_statement.hh
ClangBuildAnalyzer reports cql3/cql_statement.hh as being one of the
most expensive header files in the project - being included (mostly
indirectly) in 129 source files, and costing a total of 844 CPU seconds
of compilation.

This patch is an attempt, only *partially* successful, to reduce the
number of times that cql_statement.hh is included. It succeeds in
lowering the number 129 to 99, but not less :-( One of the biggest
difficulties in reducing it further is that query_processor.hh includes
a lot of templated code, which needs stuff from cql_statement.hh.
The solution should be to un-template the functions in
query_processor.hh and move them from the header to a source file, but
this is beyond the scope of this patch and query_processor.hh appears
problematic in other respects as well.

Unfortunately the compilation speedup by this patch is negligible
(the `du -bc build/dev/**/*.o` metric shows less than 0.01% reduction).
Beyond the fact that this patch only removes 30% of the inclusions of
this header, it appears that most of the source files that no longer
include cql_statement.hh after this patch, included anyway many of the
other headers that cql_statement.hh included, so the saving is minimal.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes #15212
2023-09-08 13:23:50 +03:00
Amnon Heiman
1abcd4bb11 transport/server.cc: mark metric counter with skip_when_empty
This patch mark scylla_transport_cql_errors_total with skip_when_empty
flag.

It reduces the overhead for metrics for types that are never reported.

Signed-off-by: Amnon Heiman <amnon@scylladb.com>
2023-08-23 09:30:35 -04:00
Gleb Natapov
4ffc39d885 cql3: Extend the scope of group0_guard during DDL statement execution
Currently we hold group0_guard only during DDL statement's execute()
function, but unfortunately some statements access underlying schema
state also during check_access() and validate() calls which are called
by the query_processor before it calls execute. We need to cover those
calls with group0_guard as well and also move retry loop up. This patch
does it by introducing new function to cql_statement class take_guard().
Schema altering statements return group0 guard while others do not
return any guard. Query processor takes this guard at the beginning of a
statement execution and retries if service::group0_concurrent_modification
is thrown. The guard is passed to the execute in query_state structure.

Fixes: #13942

Message-ID: <ZNsynXayKim2XAFr@scylladb.com>
2023-08-17 15:52:48 +03:00
Avi Kivity
d57a951d48 Revert "cql3: Extend the scope of group0_guard during DDL statement execution"
This reverts commit 70b5360a73. It generates
a failure in group0_test .test_concurrent_group0_modifications in debug
mode with about 4% probability.

Fixes #15050
2023-08-15 00:26:45 +03:00
Gleb Natapov
70b5360a73 cql3: Extend the scope of group0_guard during DDL statement execution
Currently we hold group0_guard only during DDL statement's execute()
function, but unfortunately some statements access underlying schema
state also during check_access() and validate() calls which are called
by the query_processor before it calls execute. We need to cover those
calls with group0_guard as well and also move retry loop up. This patch
does it by introducing new function to cql_statement class take_guard().
Schema altering statements return group0 guard while others do not
return any guard. Query processor takes this guard at the beginning of a
statement execution and retries if service::group0_concurrent_modification
is thrown. The guard is passed to the execute in query_state structure.

Fixes: #13942

Message-ID: <ZNSWF/cHuvcd+g1t@scylladb.com>
2023-08-13 14:19:39 +03:00
Kefu Chai
565f5c7380 transport: correct format string when printing logging message
we print the stream id in the logging messages, but in this case,
we forgot to pass `stream` to `log::debug()`. but the placeholder
for `stream` was added. if the underlying fmtlib actually formats
the argument with the format string, it would throw.

fortunately, we don't enable debug level logging often, guess that's
why we haven't spotted this issue yet.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes #14620
2023-07-13 11:21:43 +03:00
Calle Wilund
20e9619bb1 transport: Try to do early, transport based auth if possible
Bypassing the need for an AUTH message+response. I.e. do auth _without_ client having
login specified.
2023-06-26 15:00:21 +00:00
Wojciech Mitros
7883a88abd transport: add is_schema_change() method to result_message
In the next patch, we will want to observe when the result
message is a schema change and handle it differently than
when it is not. This patch adds a helper method for that,
which should be more readable than a dynamic_pointer_cast
and a comparison with nullptr.
2023-06-26 12:22:14 +02:00
Kefu Chai
c3d91f5190 tracing: drop trace(.., std::string&&) overload
this change is a follow-up of 4f5fcb02fd,
the goal is to avoid the programming oversights like

```c++
trace(trace_ptr, "foo {} with {} but {} is {}");
```

as `trace(const trace_state_ptr& p, const std::string& msg)` is
a better match than the templated one, i.e.,
`trace(const trace_state_ptr& p, fmt::format_string<T...> fmt, T&&...
args)`. so we cannot detect this with the compile-time format checking.

so let's just drop this overload, and update its callers to use
the other overload.

The change was suggested by Avi. the example also came from him.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes #14188
2023-06-10 20:09:35 +03:00
Avi Kivity
26c8470f65 treewide: use #include <seastar/...> for seastar headers
We treat Seastar as an external library, so fix the few places
that didn't do so to use angle brackets.

Closes #14037
2023-06-06 08:36:09 +03:00
Avi Kivity
42a1ced73b cql3: result_set: switch cell data type from bytes_opt to managed_bytes_opt
The expression system uses managed_bytes_opt for values, but result_set
uses bytes_opt. This means that processing values from the result set
in expressions requires a copy.

Out of the two, managed_bytes_opt is the better choice, since it prevents
large contiguous allocations for large blobs. So we switch result_set
to use managed_bytes_opt. Users of the result_set API are adjusted.

The db::function interface is not modified to limit churn; instead we
convert the types on entry and exit. This will be adjusted in a following
patch.
2023-05-07 17:17:36 +03:00
Kefu Chai
b76877fd99 transport: capture reference to temp value by value
`current_scheduling_group()` returns a temporary value, and `name()`
returns a reference, so we cannot capture the return value by reference,
and use the reference after this expression is evaluated. this would
cause undefined behavior. so let's just capture it by value.

this change also silence following warning from GCC-13:

```
/home/kefu/dev/scylladb/transport/server.cc:204:11: error: possibly dangling reference to a temporary [-Werror=dangling-reference]
  204 |     auto& cur_sg_name = current_scheduling_group().name();
      |           ^~~~~~~~~~~
/home/kefu/dev/scylladb/transport/server.cc:204:56: note: the temporary was destroyed at the end of the full expression ‘seastar::current_scheduling_group().seastar::scheduling_group::name()’
  204 |     auto& cur_sg_name = current_scheduling_group().name();
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
```

Fixes #13719
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes #13724
2023-05-01 22:40:36 +03:00
Kamil Braun
30cc07b40d Merge 'Introduce tablets' from Tomasz Grabiec
This PR introduces an experimental feature called "tablets". Tablets are
a way to distribute data in the cluster, which is an alternative to the
current vnode-based replication. Vnode-based replication strategy tries
to evenly distribute the global token space shared by all tables among
nodes and shards. With tablets, the aim is to start from a different
side. Divide resources of replica-shard into tablets, with a goal of
having a fixed target tablet size, and then assign those tablets to
serve fragments of tables (also called tablets). This will allow us to
balance the load in a more flexible manner, by moving individual tablets
around. Also, unlike with vnode ranges, tablet replicas live on a
particular shard on a given node, which will allow us to bind raft
groups to tablets. Those goals are not yet achieved with this PR, but it
lays the ground for this.

Things achieved in this PR:

  - You can start a cluster and create a keyspace whose tables will use
    tablet-based replication. This is done by setting `initial_tablets`
    option:

    ```
        CREATE KEYSPACE test WITH replication = {'class': 'NetworkTopologyStrategy',
                        'replication_factor': 3,
                        'initial_tablets': 8};
    ```

    All tables created in such a keyspace will be tablet-based.

    Tablet-based replication is a trait, not a separate replication
    strategy. Tablets don't change the spirit of replication strategy, it
    just alters the way in which data ownership is managed. In theory, we
    could use it for other strategies as well like
    EverywhereReplicationStrategy. Currently, only NetworkTopologyStrategy
    is augmented to support tablets.

  - You can create and drop tablet-based tables (no DDL language changes)

  - DML / DQL work with tablet-based tables

    Replicas for tablet-based tables are chosen from tablet metadata
    instead of token metadata

Things which are not yet implemented:

  - handling of views, indexes, CDC created on tablet-based tables
  - sharding is done using the old method, it ignores the shard allocated in tablet metadata
  - node operations (topology changes, repair, rebuild) are not handling tablet-based tables
  - not integrated with compaction groups
  - tablet allocator piggy-backs on tokens to choose replicas.
    Eventually we want to allocate based on current load, not statically

Closes #13387

* github.com:scylladb/scylladb:
  test: topology: Introduce test_tablets.py
  raft: Introduce 'raft_server_force_snapshot' error injection
  locator: network_topology_strategy: Support tablet replication
  service: Introduce tablet_allocator
  locator: Introduce tablet_aware_replication_strategy
  locator: Extract maybe_remove_node_being_replaced()
  dht: token_metadata: Introduce get_my_id()
  migration_manager: Send tablet metadata as part of schema pull
  storage_service: Load tablet metadata when reloading topology state
  storage_service: Load tablet metadata on boot and from group0 changes
  db, migration_manager: Notify about tablet metadata changes via migration_listener::on_update_tablet_metadata()
  migration_notifier: Introduce before_drop_keyspace()
  migration_manager: Make prepare_keyspace_drop_announcement() return a future<>
  test: perf: Introduce perf-tablets
  test: Introduce tablets_test
  test: lib: Do not override table id in create_table()
  utils, tablets: Introduce external_memory_usage()
  db: tablets: Add printers
  db: tablets: Add persistence layer
  dht: Use last_token_of_compaction_group() in split_token_range_msb()
  locator: Introduce tablet_metadata
  dht: Introduce first_token()
  dht: Introduce next_token()
  storage_proxy: Improve trace-level logging
  locator: token_metadata: Fix confusing comment on ring_range()
  dht, storage_proxy: Abstract token space splitting
  Revert "query_ranges_to_vnodes_generator: fix for exclusive boundaries"
  db: Exclude keyspace with per-table replication in get_non_local_strategy_keyspaces_erms()
  db: Introduce get_non_local_vnode_based_strategy_keyspaces()
  service: storage_proxy: Avoid copying keyspace name in write handler
  locator: Introduce per-table replication strategy
  treewide: Use replication_strategy_ptr as a shorter name for abstract_replication_strategy::ptr_type
  locator: Introduce effective_replication_map
  locator: Rename effective_replication_map to vnode_effective_replication_map
  locator: effective_replication_map: Abstract get_pending_endpoints()
  db: Propagate feature_service to abstract_replication_strategy::validate_options()
  db: config: Introduce experimental "TABLETS" feature
  db: Log replication strategy for debugging purposes
  db: Log full exception on error in do_parse_schema_tables()
  db: keyspace: Remove non-const replication strategy getter
  config: Reformat
2023-04-27 09:40:18 +02:00
Botond Dénes
3e92bcaa20 Merge 'utils: redesign reusable_buffer' from Michał Chojnowski
Common compression libraries work on contiguous buffers.
Contiguous buffers are a problem for the allocator. However, as long as they are short-lived,
we can avoid the expensive allocations by reusing buffers across tasks.

This idea is already applied to the compression of CQL frames, but with some deficiencies.
`utils: redesign reusable_buffer` attempts to improve upon it in a few ways. See its commit message for an extended discussion.

Compression buffer reuse also happens in the zstd SSTable compressor, but the implementation is misguided. Every `zstd_processor` instance reuses a buffer, but each instance has its own buffer. This is very bad, because a healthy database might have thousands of concurrent instances (because there is one for each sstable reader). Together, the buffers might require gigabytes of memory, and the reuse actually *increases* memory pressure significantly, instead of reducing it.
`zstd: share buffers between compressor instances` aims to improve that by letting a single buffer be shared across all instances on a shard.

Closes #13324

* github.com:scylladb/scylladb:
  zstd: share buffers between compressor instances
  utils: redesign reusable_buffer
2023-04-27 09:09:09 +03:00