Commit Graph

387 Commits

Author SHA1 Message Date
Nikita Kurashkin
2a7932efa1 alternator: fix DeleteTable return values to match DynamoDB's
It seems that Scylla has more values returned by DeleteTable operation than DynamoDB.
In this patch I added a table status check when generating output.
If we delete the table, values KeySchema, AttributeDefinitions and CreationDateTime won't be returned.
The test has also been modified to check that these attributes are not returned.

Fixes scylladb#14132

Closes scylladb/scylladb#15707
2023-10-19 09:34:16 +03:00
Benny Halevy
3208af1880 gossiper: add num_endpoints
Return the number of endpoints tracked by gossiper.
This is useful when the caller doesn't need
access to the endpoint states map.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2023-08-31 08:30:40 +03:00
Kamil Braun
59c410fb97 Merge 'migration_manager: announce: provide descriptions for all calls' from Patryk Jędrzejczak
The `system.group0_history` table provides useful descriptions for each
command committed to Raft group 0. One way of applying a command to
group 0 is by calling `migration_manager::announce`. This function has
the `description` parameter set to empty string by default. Some calls
to `announce` use this default value which causes `null` values in
`system.group0_history`. We want `system.group0_history` to have an
actual description for every command, so we change all default
descriptions to reasonable ones.

Going further, We remove the default value for the `description`
parameter of `migration_manager::announce` to avoid using it in the
future. Thanks to this, all commands in `system.group0_history` will
have a non-null description.

Fixes #13370

Closes #14979

* github.com:scylladb/scylladb:
  migration_manager: announce: remove the default value of description
  test: always pass empty description to migration_manager::announce
  migration_manager: announce: provide descriptions for all calls
2023-08-09 16:58:41 +02:00
Pavel Emelyanov
f1515c610e code: Remove query-context.hh
The whole thing is unused now, so the header is no longer needed

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2023-08-08 11:11:07 +03:00
Patryk Jędrzejczak
27ddf78171 migration_manager: announce: provide descriptions for all calls
The system.group0_history table provides useful descriptions
for each command committed to Raft group 0. One way of applying
a command to group 0 is by calling migration_manager::announce.
This function has the description parameter set to empty string
by default. Some calls to announce use this default value which
causes null values in system.group0_history. We want
system.group0_history to have an actual description for every
command, so we change all default descriptions to reasonable ones.

We can't provide a reasonable description to announce in
query_processor::execute_thrift_schema_command because this
function is called in multiple situations. To solve this issue,
we add the description parameter to this function and to
handler::execute_schema_command that calls it.
2023-08-07 14:38:11 +02:00
Kamil Braun
84bb75ea0a Merge 'service: migration_manager: change the prepare_ methods to functions' from Patryk Jędrzejczak
The `migration_manager` service is responsible for schema convergence in
the cluster - pushing schema changes to other nodes and pulling schema
when a version mismatch is observed. However, there is also a part of
`migration_manager` that doesn't really belong there - creating
mutations for schema updates. These are the functions with `prepare_`
prefix. They don't modify any state and don't exchange any messages.
They only need to read the local database.

We take these functions out of `migration_manager` and make them
separate functions to reduce the dependency of other modules (especially
`query_processor` and CQL statements) on `migration_manager`. Since all
of these functions only need access to `storage_proxy` (or even only
`replica::database`), doing such a refactor is not complicated. We just
have to add one parameter, either `storage_proxy` or `database` and both
of them are easily accessible in the places where these functions are
called.

This refactor makes `migration_manager` unneeded in a few functions:
- `alternator::executor::create_keyspace`,
- `cql3::statements::alter_type_statement::prepare_announcement_mutations`,
- `cql3::statements::schema_altering_statement::prepare_schema_mutations`,
- `cql3::query_processor::execute_thrift_schema_command:`,
- `thrift::handler::execute_schema_command`.

We remove the `migration_manager&` parameter from all these functions.

Fixes #14339

Closes #14875

* github.com:scylladb/scylladb:
  cql3: query_processor::execute_thrift_schema_command: remove an unused parameter
  cql3: schema_altering_statement::prepare_schema_mutations: remove an unused parameter
  cql3: alter_type_statement::prepare_announcement_mutations: change parameters
  alternator: executor::create_keyspace: remove an unused parameter
  service: migration_manager: change the prepare_ methods to functions
2023-08-01 11:56:56 +02:00
Patryk Jędrzejczak
928ee9616c alternator: executor::create_keyspace: remove an unused parameter
After changing the prepare_ methods of migration_manager to
functions, the migration_manager& parameter of executor::create_key
has been unused.
2023-08-01 09:36:04 +02:00
Nadav Har'El
04e5082d52 alternator: limit expression length and recursion depth
DynamoDB limits of all expressions (ConditionExpression, UpdateExpression,
ProjectionExpression, FilterExpression, KeyConditionExpression) to just
4096 bytes. Until now, Alternator did not enforce this limit, and we had
an xfailing test showing this.

But it turns out that not enforcing this limit can be dangerous: The user
can pass arbitrarily-long and arbitrarily nested expressions, such as:

    a<b and (a<b and (a<b and (a<b and (a<b and (a<b and (...))))))

or
    (((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((

and those can cause recursive algorithms in Alternator's parser and
later when applying expressions to recurse very deeply, overflow the
stack, and crash.

This patch includes new tests that demonstrate how Scylla crashes during
parsing before enforcing the 4096-byte length limit on expressions.
The patch then enforces this length limit, and these tests stop crashing.
We also verify that deeply-nested expressions shorter than the 4096-byte
limit are apparently short enough for our recursion ability, and work
as expected.

Unforuntately, running these tests many times showed that the 4096-byte
limit is not low enough to avoid all crashes so this patch needs to do
more:

The parsers created by ANTLR are recursive, and there is no way to limit
the depth of their recursion (i.e., nothing like YACC's YYMAXDEPTH).
Very deep recursion can overflow the stack and crash Scylla. After we
limited the length of expression strings to 4096 bytes this was *almost*
enough to prevent stack overflows. But unfortunetely the tests revealed
that even limited to 4096 bytes, the expression can sometimes recurse
too deeply: Consider the expression "((((((....((((" with 4000 parentheses.
To realize this is a syntax error, the parser needs to do a recursive
call 4000 times. Or worse - because of other Antlr limitations (see rants
in comments in expressions.g) it's actually 12000 recursive calls, and
each of these calls have a pretty large frame. In some cases, this
overflows the stack.

The solution used in this patch is not pretty, but works. We add to rules
in alternator/expressions.g that recurse (there are two of those - "value"
and "boolean_expression") an integer "depth" parameter, which we increase
when the rule recurses. Moreover, we add a so-called predicate
"{depth<MAX_DEPTH}?" that stops the parsing when this limit is reached.
When the parsing is stopped, the user will see a special kind of parse
error, saying "expression nested too deeply".

With this last modification to expressions.g, the tests for deeply-nested but
still-below-4096-bytes expressions
(test_limits.py::test_deeply_nested_expression_*) would not fail sporadically
as they did without it.

While adding the "expression nested too deeply" case, I also made the
general syntax-error reporting in Alternator nicer: It no longer prints
the internal "expression_syntax_error" type name (an exception type will
only be printed if some sort of unexpected exception happens), and it
prints the character position where the syntax error (or too deep
nested expression) was recognized.

Fixes #14473

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

Closes #14477
2023-07-31 08:57:54 +03:00
Patryk Jędrzejczak
3468cbd66b service: migration_manager: change the prepare_ methods to functions
The migration_manager service is responsible for schema convergence
in the cluster - pushing schema changes to other nodes and pulling
schema when a version mismatch is observed. However, there is also
a part of migration_manager that doesn't really belong there -
creating mutations for schema updates. These are the functions with
prepare_ prefix. They don't modify any state and don't exchange any
messages. They only need to read the local database.

We take these functions out of migration_manager and make them
separate functions to reduce the dependency of other modules
(especially query_processor and CQL statements) on
migration_manager. Since all of these functions only need access
to storage_proxy (or even only replica::database), doing such a
refactor is not complicated. We just have to add one parameter,
either storage_proxy or database and both of them are easily
accessible in the places where these functions are called.
2023-07-28 13:55:27 +02:00
Nadav Har'El
e01a369708 alternator: detect errors in AttributeDefinitions parameter
Add missing validation of the AttributeDefinitions parameter of the
CreateTable operation in Alternator. This validation isn't needed
for correctness or safety - the invalid entries would have been
ignored anyway. But this patch is useful for user-experience - the
user should be notified when the request is malformed instead of
ignoring the error.

The fix itself is simple (a new validate_attribute_definitions()
function, calling it in the right place), but much of the contents
of this patch is a fairly large set of tests covering all the
interesting cases of how AttributeDefinitions can be broken.
Particularly interesting is the case where the same AttributeName
appears more than once, e.g., attempting to give two different types
to the same key attribute - which is not allowed.

One of the new tests remains xfail even after this patch - it checks
the case that a user attempts to add a GSI to an existing table where
another GSI defined the key's type differently. This test can't
succeed until we allow adding GSIs to existing tables (Refs #11567).

Fixes #13870.

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

Closes #14556
2023-07-13 11:28:47 +03:00
Nadav Har'El
d6aba8232b alternator: configurable override for DescribeEndpoints
The AWS C++ SDK has a bug (https://github.com/aws/aws-sdk-cpp/issues/2554)
where even if a user specifies a specific enpoint URL, the SDK uses
DescribeEndpoints to try to "refresh" the endpoint. The problem is that
DescribeEndpoints can't return a scheme (http or https) and the SDK
arbitrarily picks https - making it unable to communicate with Alternator
over http. As an example, the new "dynamodb shell" (written in C++)
cannot communicate with Alternator running over http.

This patch adds a configuration option, "alternator_describe_endpoints",
which can be used to override what DescribeEndpoints does:

1. Empty string (the default) leaves the current behavior -
   DescribeEndpoints echos the request's "Host" header.

2. The string "disabled" disables the DescribeEndpoints (it will return
   an UnknownOperationException). This is how DynamoDB Local behaves,
   and the AWS C++ SDK and the Dynamodb Shell work well in this mode.

3. Any other string is a fixed string to be returned by DescribeEndpoints.
   It can be useful in setups that should return a known address.

Note that this patch does not, by default, change the current behaivor
of DescribeEndpoints. But it us the future to override its behavior
in a user experiences problems in the field - without code changes.

Fixes #14410.

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

Closes #14432
2023-07-07 11:08:10 +02:00
Marcin Maliszkiewicz
6424dd5ec4 alternator: close output_stream when exception is thrown during response streaming
When exception occurs and we omit closing output_stream then the whole process is brought down
by an assertion in ~output_stream.

Fixes https://github.com/scylladb/scylladb/issues/14453
Relates https://github.com/scylladb/scylladb/issues/14403

Closes #14454
2023-07-04 16:15:08 +03:00
Harsh Soni
d8c3b144cb alternator: optimize validate_table_name call
Prior to this `table_name` was validated for every request in `find_table_name` leading to unnecessary overhead (although small, but unnecessary). Now, the `table_name` is only validated while creation reqeust and in other requests iff the table does not exist (to keep compatibility with DynamoDB's exception).

Fixes: #12538

Closes #13966
2023-06-12 10:46:13 +03:00
Nadav Har'El
d2e089777b Merge 'Yield while building large results in Alternator - rjson::print, executor::batch_get_item' from Marcin Maliszkiewicz
Adds preemption points used in Alternator when:
 - sending bigger json response
 - building results for BatchGetItem

I've tested manually by inserting in preemptible sections (e.g. before `os.write`) code similar to:

    auto start  = std::chrono::steady_clock::now();
    do { } while ((std::chrono::steady_clock::now() - start) < 100ms);

and seeing reactor stall times. After the patch they
were not increasing while before they kept building up due to no preemption.

Refs #7926
Fixes #13689

Closes #12351

* github.com:scylladb/scylladb:
  alternator: remove redundant flush call in make_streamed
  utils: yield when streaming json in print()
  alternator: yield during BatchGetItem operation
2023-06-04 23:22:51 +03:00
Nadav Har'El
8a1334cf6f Merge 'alternator: eliminate duplicated rjson::find() of ExpressionAttributeNames and ExpressionAttributeValues' from Marcin Maliszkiewicz
Summary of the patch set:
- eliminates not needed calls to rjson::find (~1% tps improvement in `perf-simple-query --write`)
- adds some very specific test in this area (more general cases were covered already)
- fixes some minor validation bug

Fixes https://github.com/scylladb/scylladb/issues/13251

Closes #12675

* github.com:scylladb/scylladb:
  alternator: fix unused ExpressionAttributeNames validation when used as a part of BatchGetItem
  alternator: eliminate duplicated rjson::find() of ExpressionAttributeNames and ExpressionAttributeValues
2023-06-04 23:10:12 +03:00
Alexey Novikov
ffd4fcceec Alternator: return full table description on return of DeleteTable
The DeleteTable operation in Alternator shoudl return a TableDescription
object describing the table which has just been deleted, similar to what
DescribeTable returns

Fixes scylladb#11472

Closes #11628
2023-06-04 21:00:26 +03:00
Marcin Maliszkiewicz
9ce65270d5 alternator: fix unused ExpressionAttributeNames validation when used as a part of BatchGetItem
BatchGetItem request is a map of table names and 'sub-requests', ExpressionAttributeNames is defined on
'sub-request' level but the code was instead checking the top level, obtaining nullptr every time which
effectively disables unused names check.

Fixes #13251
2023-05-26 15:03:15 +02:00
Marcin Maliszkiewicz
fb5c325cfd alternator: eliminate duplicated rjson::find() of ExpressionAttributeNames and ExpressionAttributeValues
rjson::find is not a very cheap function, it involves bunch of function calls and loop iteration.
Overall it costs 120-170 intructions even for small requests. Some example profile of alternator::executor::query
execution shows ~18 rjson::find calls, taking in total around 7% of query internal proessing time (note that
JSON parse/print and http handling are not part of this function).

This patch eliminates 2 rjson::find calls for most request types. I saw 1-2% tps improvement
in `perf-simple-query --write` although it does improve tps I suspect real percentage is smaller and
don't have much confindentce in this particular number, observed benchmark variance is too high to measure it reliably.
2023-05-26 15:03:15 +02:00
Gleb Natapov
a429018a8a migration_manager: add wait_for_schema_agreement() function
Several subsystems re-implement the same logic for waiting for schema
agreement. Provide the function in the migration_manager and use it
instead.
2023-05-25 14:44:53 +03:00
Botond Dénes
0cff0ffa08 Merge 'alternator,config: make alternator_timeout_in_ms live-updateable' from Kefu Chai
before this change, alternator_timeout_in_ms is not live-updatable,
as after setting executor's default timeout right before creating
sharded executor instances, they never get updated with this option
anymore. but many users would like to set the driver timers based on
server timers. we need to enable them to configure timeout even
when the server is still running.

in this change,

* `alternator_timeout_in_ms` is marked as live-updateable
* `executor::_s_default_timeout` is changed to a thread_local variable,
   so it can be updated by a per-shard updateable_value. and
   it is now a updateable_value, so its variable name is updated
   accordingly. this value is set in the ctor of executor, and
   it is disconnected from the corresponding named_value<> option
   in the dtor of executor.
* alternator_timeout_in_ms is passed to the constructor of
   executor via sharded_parameter, so `executor::_timeout_in_ms` can
   be initialized on per-shard basis
* `executor::set_default_timeout()` is dropped, as we already pass
   the option to executor in its ctor.

Fixes #12232

Closes #13300

* github.com:scylladb/scylladb:
  alternator: split the param list of executor ctor into multi lines
  alternator,config: make alternator_timeout_in_ms live-updateable
2023-05-15 10:16:29 +03:00
Nadav Har'El
e57252092c Merge 'cql3: result_set, selector: change value type to managed_bytes_opt' from Avi Kivity
CQL evolved several expression evaluation mechanisms: WHERE clause,
selectors (the SELECT clause), and the LWT IF clause are just some
examples. Most now use expressions, which use managed_bytes_opt
as the underlying value representation, but selectors still use bytes_opt.

This poses two problems:
1. bytes_opt generates large contiguous allocations when used with large blobs, impacting latency
2. trying to use expressions with bytes_opt will incur a copy, reducing performance

To solve the problem, we harmonize the data types to managed_bytes_opt
(#13216 notwithstanding). This is somewhat difficult since the source of the values
are views into a bytes_ostream. However, luckily bytes_ostream and managed_bytes_view
are mostly compatible so with a little effort this can be done.

The series is neutral wrt performance:

before:
```
222118.61 tps ( 61.1 allocs/op,  12.1 tasks/op,   43092 insns/op,        0 errors)
224250.14 tps ( 61.1 allocs/op,  12.1 tasks/op,   43094 insns/op,        0 errors)
224115.66 tps ( 61.1 allocs/op,  12.1 tasks/op,   43092 insns/op,        0 errors)
223508.70 tps ( 61.1 allocs/op,  12.1 tasks/op,   43107 insns/op,        0 errors)
223498.04 tps ( 61.1 allocs/op,  12.1 tasks/op,   43087 insns/op,        0 errors)
```

after:
```
220708.37 tps ( 61.1 allocs/op,  12.1 tasks/op,   43118 insns/op,        0 errors)
225168.99 tps ( 61.1 allocs/op,  12.1 tasks/op,   43081 insns/op,        0 errors)
222406.00 tps ( 61.1 allocs/op,  12.1 tasks/op,   43088 insns/op,        0 errors)
224608.27 tps ( 61.1 allocs/op,  12.1 tasks/op,   43102 insns/op,        0 errors)
225458.32 tps ( 61.1 allocs/op,  12.1 tasks/op,   43098 insns/op,        0 errors)
```

Though I expect with some more effort we can eliminate some copies.

Closes #13637

* github.com:scylladb/scylladb:
  cql3: untyped_result_set: switch to managed_bytes_view as the cell type
  cql3: result_set: switch cell data type from bytes_opt to managed_bytes_opt
  cql3: untyped_result_set: always own data
  types: abstract_type: add mixed-type versions of compare() and equal()
  utils/managed_bytes, serializer: add conversion between buffer_view<bytes_ostream> and managed_bytes_view
  utils: managed_bytes: add bidirectional conversion between bytes_opt and managed_bytes_opt
  utils: managed_bytes: add managed_bytes_view::with_linearized()
  utils: managed_bytes: mark managed_bytes_view::is_linearized() const
2023-05-10 15:01:45 +03:00
Kefu Chai
5fa459bd1a treewide: do not include unused header
since #13452, we switched most of the caller sites from std::regex
to boost::regex. in this change, all occurences of `#include <regex>`
are dropped unless std::regex is used in the same source file.

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

Closes #13765
2023-05-07 19:01:29 +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
Tomasz Grabiec
5b046043ea migration_manager: Make prepare_keyspace_drop_announcement() return a future<>
It will be extended with listener notification firing, which is an
async operation.
2023-04-24 10:49:37 +02:00
Botond Dénes
dba1d36aa6 Merge 'alternator: fix isolation of concurrent modifications to tags' from Nadav Har'El
Alternator's implementation of TagResource, UntagResource and UpdateTimeToLive (the latter uses tags to store the TTL configuration) was unsafe for concurrent modifications - some of these modifications may be lost. This short series fixes the bug, and also adds (in the last patch) a test that reproduces the bug and verifies that it's fixed.

The cause of the incorrect isolation was that we separately read the old tags and wrote the modified tags. In this series we introduce a new function, `modify_tags()` which can do both under one lock, so concurrent tag operations are serialized and therefore isolated as expected.

Fixes #6389.

Closes #13150

* github.com:scylladb/scylladb:
  test/alternator: test concurrent TagResource / UntagResource
  db/tags: drop unsafe update_tags() utility function
  alternator: isolate concurrent modification to tags
  db/tags: add safe modify_tags() utility functions
  migration_manager: expose access to storage_proxy
2023-04-11 11:17:23 +03:00
Kefu Chai
500eeeb12c mutation: specialize fmt::formatter<partition_region>
this is a part of a series to migrating from `operator<<(ostream&, ..)`
based formatting to fmtlib based formatting. the goal here is to enable
fmtlib to print `partition_region` with the help of fmt::ostream.

to help with the review process, the corresponding `to_string()` is
dropped, and its callers now switch over to `fmt::to_string()` in
this change as well. to use `fmt::to_string()` helps with consolidating
all places to use fmtlib for printing/formatting.

Refs #13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2023-03-31 19:03:14 +08:00
Kefu Chai
69c21f490a alternator,config: make alternator_timeout_in_ms live-updateable
before this change, alternator_timeout_in_ms is not live-updatable,
as after setting executor's default timeout right before creating
sharded executor instances, they never get updated with this option
anymore.

in this change,

* alternator_timeout_in_ms is marked as live-updateable
* executor::_s_default_timeout is changed to a thread_local variable,
  so it can be updated by a per-shard updateable_value. and
  it is now a updateable_value, so its variable name is updated
  accordingly. this value is set in the ctor of executor, and
  it is disconnected from the corresponding named_value<> option
  in the dtor of executor.
* alternator_timeout_in_ms is passed to the constructor of
  executor via sharded_parameter, so executor::_timeout_in_ms can
  be initialized on per-shard basis
* executor::set_default_timeout() is dropped, as we already pass
  the option to executor in its ctor.

please note, in the ctor of executor, we always update the cached
value of `s_default_timeout` with the value of `_timeout_in_ms`,
and we set the default timeout to 10s in `alternator_test_env`.
this is a design decision to avoid bending the production code for
testing, as in production, we always set the timeout with the value
specified either by the default value of yaml conf file.

Fixes #12232
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2023-03-23 20:57:08 +08:00
Nadav Har'El
c196bd78de alternator: isolate concurrent modification to tags
Alternator modifies tags in three operations - TagResource, UntagResource
and UpdateTimeToLive (the latter uses a tag to store the TTL configuration).

All three operations were implemented by three separate steps:

 1. Read the current tags.
 2. Modify the tags according to the desired operation.
 3. Write the modified tags back with update_tags().

This implementation was not safe for concurrent operations - some
modifications may be be lost. We fix this in this patch by using the new
modify_tags() function introduced in the previous patch, which performs
all three steps under one lock so the tag operations are serialized and
correctly isolated.

Fixes #6389

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2023-03-13 12:25:03 +02:00
Kefu Chai
a37610f66a alternator: using chrono_literals before using it
we should assume that some included header does this for us.

we'd have following compiling failure if seastar's
src/http/request_parser.rl does not `using namespace httpd;` anymore.

```
/home/kefu/dev/scylladb/alternator/streams.cc:433:55: error: no matching literal operator for call to 'operator""h' with argument of type 'unsigned long long' or 'const char *', and no matching literal operator template
static constexpr auto dynamodb_streams_max_window = 24h;
                                                      ^
```

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2023-03-07 18:20:36 +08:00
Kefu Chai
0cb842797a treewide: do not define/capture unused variables
these warnings are found by Clang-17 after removing
`-Wno-unused-lambda-capture` and '-Wno-unused-variable' from
the list of disabled warnings in `configure.py`.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2023-02-15 22:57:18 +02:00
Avi Kivity
69a385fd9d Introduce schema/ module
Schema related files are moved there. This excludes schema files that
also interact with mutations, because the mutation module depends on
the schema. Those files will have to go into a separate module.

Closes #12858
2023-02-15 11:01:50 +02:00
Marcin Maliszkiewicz
0b5655021a alternator: remove redundant flush call in make_streamed
As output_stream close() is doing flush anyway.
2023-01-23 13:46:06 +01:00
Marcin Maliszkiewicz
f2788f5391 alternator: yield during BatchGetItem operation 2023-01-20 14:44:24 +01:00
Marcin Maliszkiewicz
7230841431 alternator: unify json streaming heuristic
Main assumption here is that if is_big is good enough for
GetBatchItems operation it should work well also for Scan,
Query and GetRecords. And it's easier to maintain more unified
code.

Additionally 'future<> print' documentation used for streaming
suggests that there is quite big overhead so since it seems the
only motivation for streaming was to reduce contiguous allocation
size below some threshold we should not stream when this threshold
is not exceeded.

Closes #12164
2023-01-19 16:40:43 +02:00
Marcin Maliszkiewicz
4c33791f96 alternator: eliminate regexes from the hot path
This decreases the whole alternator::get_table cpu time by 78%
(from 2.8 us to 0.6 us on my cpu).

In perf_simple_query it decreases allocs/op by 1.6% (by removing 4 allocations)
and increases median tps by 3.4%.

Raw results from running:

./build/release/test/perf/perf_simple_query_g --smp 1 \
         --alternator forbid --default-log-level error \
         --random-seed=1235000092 --duration=180 --write

Before the patch:

median 46903.65 tps (197.2 allocs/op,  12.1 tasks/op,  170886 insns/op, 0 errors)
median absolute deviation: 210.15
maximum: 47354.59
minimum: 42535.63

After the patch:

median 48484.76 tps (194.1 allocs/op,  12.1 tasks/op,  168512 insns/op, 0 errors)
median absolute deviation: 317.32
maximum: 49247.69
minimum: 44656.38

Closes #12445
2023-01-19 13:23:24 +02:00
Marcin Maliszkiewicz
bcbaccc143 rjson: avoid copy constructors in from_string calls when possible
This function anyway copies the value so no need to do extra copy.
2023-01-16 15:15:26 +01:00
Marcin Maliszkiewicz
668fffb6c5 alternator: remove unused parameters from describe_items func 2023-01-16 14:36:23 +01:00
Avi Kivity
2739ac66ed treewide: drop cql_serialization_format
Now that we don't accept cql protocol version 1 or 2, we can
drop cql_serialization format everywhere, except when in the IDL
(since it's part of the inter-node protocol).

A few functions had duplicate versions, one with and one without
a cql_serialization_format parameter. They are deduplicated.

Care is taken that `partition_slice`, which communicates
the cql_serialization_format across nodes, still presents
a valid cql_serialization_format to other nodes when
transmitting itself and rejects protocol 1 and 2 serialization\
format when receiving. The IDL is unchanged.

One test checking the 16-bit serialization format is removed.
2023-01-03 19:54:13 +02:00
Marcin Maliszkiewicz
2bf2ffd3ed alternator: add maybe_quote to secondary indexes 'where' condition
This bug doesn't affect anything, the reason is descibed in the commit:
'alternator: fix wrong 'where' condition for GSI range key'.

But it's theoretically correct to escape those key names and
the difference can be observed via CQL's describe table. Before
the patch 'where' condition is missing one double quote in variable
name making it mismatched with corresponding column name.
2022-11-22 11:08:23 +01:00
Marcin Maliszkiewicz
d6d20134de alternator: fix wrong 'where' condition for GSI range key
This bug doesn't manifest in a visible way to the user.

Adding the index to an existing table via GlobalSecondaryIndexUpdates is not supported
so we don't need to consider what could happen for empty values of index range key.
After the index is added the only interesting value user can set is omitting
the value (null or empty are not allowed, see test_gsi_empty_value and
test_gsi_null_value).

In practice no matter of 'where' condition the underlaying materialized
view code is skipping row updates with missing keys as per this comment:
'If one of the key columns is missing, set has_new_row = false
meaning that after the update there will be no view row'.

Thats why the added test passes both before and after the patch.
But it's still usefull to include it to exercise those code paths.

Fixes #11800
2022-11-22 11:08:23 +01:00
Botond Dénes
f1a039fc2b treewide: use ::for_partition_start() instead of ::partition_start_tag_t{}
We just added a convenience static factory method for partition start,
change the present users of the clunky constructor+tag to use it
instead.
2022-11-11 09:58:18 +02:00
Alexander Turetskiy
636e14cc77 Alternator: Projection field added to return from DescribeTable which describes GSIs and LSIs.
The return from DescribeTable which describes GSIs and LSIs is missing
the Projection field. We do not yet support all the settings Projection
(see #5036), but the default which we support is ALL, and DescribeTable
should return that in its description.

Fixes #11470

Closes #11693
2022-10-19 19:01:08 +03:00
Nadav Har'El
4a7794fb64 alternator: better error message when adding a GSI to an existing table
Due to issue #11567, Alternator do not yet support adding a GSI to an
existing table via UpdateTable with the GlobalSecondaryIndexUpdates
parameter.

However, currently, we print a misleading error message in this case,
complaining about the AttributeDefinitions parameter. This parameter
is also required with GlobalSecondaryIndexUpdates, but it's not the
main problem, and the user is likely to be confused why the error message
points to that specific paramter and what it means that this parameter
is claimed to be "not supported" (while it is supported, in CreateTable).
With this patch, we report that GlobalSecondaryIndexUpdates is not
supported.

This patch does not fix the unsupported feature - it just improves
the error message saying that it's not supported.

Refs #11567

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

Closes #11650
2022-09-29 09:00:31 +03:00
Nadav Har'El
999ca2d588 alternator: fix crashes an errors when using ":attrs" attribute
Alternator uses a single column, a map, with the deliberately strange
name ":attrs", to hold all the schema-less attributes of an item.
The existing code is buggy when the user tries to write to an attribute
with this strange name ":attrs". Although it is extremely unlikely that
any user would happen to choose such a name, it is nevertheless a legal
attribute name in DynamoDB, and should definitely not cause Scylla to crash
as it does in some cases today.

The bug was caused by the code assuming that to check whether an attribute
is stored in its own column in the schema, we just need to check whether
a column with that name exists. This is almost true, except for the name
":attrs" - a column with this name exists, but it is a map - the attribute
with that name should be stored *in* the map, not as the map. The fix
is to modify that check to special-case ":attrs".

This fix makes the relevant tests, which used to crash or fail, now pass.

This fix solves most of #5009, but one point is not yet solved (and
perhaps we don't need to solve): It is still not allowed to use the
name ":attrs" for a **key** attribute. But trying to do that fails cleanly
(during the table creation) with an appropriate error message, so is only
a very minor compatibility issue.

Refs #5009

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2022-09-19 10:30:11 +03:00
Nadav Har'El
941c719a23 alternator: return ProvisionedThroughput in DescribeTable
DescribeTable is currently hard-coded to return PAY_PER_REQUEST billing
mode. Nevertheless, even in PAY_PER_REQUEST mode, the DescribeTable
operation must return a ProvisionedThroughput structure, listing both
ReadCapacityUnits and WriteCapacityUnits as 0. This requirement is not
stated in some DynamoDB documentation but is explictly mentioned in
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_ProvisionedThroughput.html
Also in empirically, DynamoDB returns ProvisionedThroughput with zeros
even in PAY_PER_REQUEST mode. We even had an xfailing test to confirm this.

The ProvisionedThroughput structure being missing was a problem for
applications like DynamoDB connectors for Spark, if they implicitly
assume that ProvisionedThroughput is returned by DescribeTable, and
fail (as described in issue #11222) if it's outright missing.

So this patch adds the missing ProvisionedThroughput structure, and
the xfailing test starts to pass.

Note that this patch doesn't change the fact that attempting to set
a table to PROVISIONED billing mode is ignored: DescribeTable continues
to always return PAY_PER_REQUEST as the billing mode and zero as the
provisioned capacities.

Fixes #11222

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

Closes #11298
2022-08-22 09:58:09 +02:00
Botond Dénes
d1d53f1b84 query: add tombstone-limit to read-command
Propagate the tombstone-limit from coordinator to replicas, to make sure
all is using the same limit.
2022-08-10 06:01:47 +03:00
Benny Halevy
c71ef330b2 query-request, everywhere: define and use query_id as a strong type
Define query_id as a tagged_uuid
So it can be differentiated from other uuid-class types.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-08-08 08:13:28 +03:00
Michał Sala
041cb77ad0 alternator, db: move the tag code to db/tags
Tags are a useful mechanism that could be used outside of alternator
namespace. My motivation to move tags_extension and other utilities to
db/tags/ was that I wanted to use them to mark "synchronous mode" views.

I have extracted `get_tags_of_table`, `find_tag` and `update_tags`
method to db/tags/utils.cc and moved alternator/tags_extension.hh to
db/tags/.

The signature of `get_tags_of_table` was changed from `const
std::map<sstring, sstring>&` to `const std::map<sstring, sstring>*`
Original behavior of this function was to throw an
`alternator::api_error` exception. This was undesirable, as it
introduced a dependency on the alternator module. I chose to change it
to return a potentially null value, and added a wrapper function to the
alternator module - `get_tags_of_table_or_throw` to keep the previous
throwing behavior.
2022-07-25 09:53:33 +02:00
Benny Halevy
acae3cc223 treewide: stop use of deprecated coroutine::make_exception
Convert most use sites from `co_return coroutine::make_exception`
to `co_await coroutine::return_exception{,_ptr}` where possible.

In cases this is done in a catch clause, convert to
`co_return coroutine::exception`, generating an exception_ptr
if needed.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>

Closes #10972
2022-07-07 15:02:16 +03:00
Botond Dénes
2b6eeadc07 alternator: use position-in-partition in paging cookie only when reading CQL tables
Recently, we added full position-in-partition support to alternator's
paging cookie, so it can support stopping at arbitrary positions. This
support however is only really needed when tables have range tombstones
and alternator tables never have them. So to avoid having to make the
new fields in 'ExclusiveStartKey' reserved, we avoid filling these in
when reading an alternator table, as in this case it is safe to assume
the position is `after_key($clustring_key)`. We do include these new
members however when reading CQL tables through alternator. As this is
only supported for system tables, we can also be sure that the elaborate
names we used for these fields are enough to avoid naming clashes.
The condition in the code implementing this is actually even more
general: it only includes the region/weight members when the position
differs from that of a normal alternator one.
2022-06-30 15:10:30 +03:00