before this change, we rely on `using namespace seastar` to use
`seastar::format()` without qualifying the `format()` with its
namespace. this works fine until we changed the parameter type
of format string `seastar::format()` from `const char*` to
`fmt::format_string<...>`. this change practically invited
`seastar::format()` to the club of `std::format()` and `fmt::format()`,
where all members accept a templated parameter as its `fmt`
parameter. and `seastar::format()` is not the best candidate anymore.
despite that argument-dependent lookup (ADT for short) favors the
function which is in the same namespace as its parameter, but
`using namespace` makes `seastar::format()` more competitive,
so both `std::format()` and `seastar::format()` are considered
as the condidates.
that is what is happening scylladb in quite a few caller sites of
`format()`, hence ADT is not able to tell which function the winner
in the name lookup:
```
/__w/scylladb/scylladb/mutation/mutation_fragment_stream_validator.cc:265:12: error: call to 'format' is ambiguous
265 | return format("{} ({}.{} {})", _name_view, s.ks_name(), s.cf_name(), s.id());
| ^~~~~~
/usr/bin/../lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/format:4290:5: note: candidate function [with _Args = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
4290 | format(format_string<_Args...> __fmt, _Args&&... __args)
| ^
/__w/scylladb/scylladb/seastar/include/seastar/core/print.hh:143:1: note: candidate function [with A = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
143 | format(fmt::format_string<A...> fmt, A&&... a) {
| ^
```
in this change, we
change all `format()` to either `fmt::format()` or `seastar::format()`
with following rules:
- if the caller expects an `sstring` or `std::string_view`, change to
`seastar::format()`
- if the caller expects an `std::string`, change to `fmt::format()`.
because, `sstring::operator std::basic_string` would incur a deep
copy.
we will need another change to enable scylladb to compile with the
latest seastar. namely, to pass the format string as a templated
parameter down to helper functions which format their parameters.
to miminize the scope of this change, let's include that change when
bumping up the seastar submodule. as that change will depend on
the seastar change.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
assert() is traditionally disabled in release builds, but not in
scylladb. This hasn't caused problems so far, but the latest abseil
release includes a commit [1] that causes a 1000 insn/op regression when
NDEBUG is not defined.
Clearly, we must move towards a build system where NDEBUG is defined in
release builds. But we can't just define it blindly without vetting
all the assert() calls, as some were written with the expectation that
they are enabled in release mode.
To solve the conundrum, change all assert() calls to a new SCYLLA_ASSERT()
macro in utils/assert.hh. This macro is always defined and is not conditional
on NDEBUG, so we can later (after vetting Seastar) enable NDEBUG in release
mode.
[1] 66ef711d68Closesscylladb/scylladb#20006
we don't provide it anymore, and if any of existing type provides
constructor accepting an `optional<>`, and hence can be formatted
using operator<< after converting it, neither shall we rely on this
behavior, as it is fragile.
so, in this change, we switch to `fmt::print()` to use {fmt} to
print `optional<>`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
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>
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 include `fmt/ranges.h` and/or `fmt/std.h`
for formatting the container types, like vector, map
optional and variant using {fmt} instead of the homebrew
formatter based on operator<<.
with this change, the changes adding fmt::formatter and
the changes using ostream formatter explicitly, we are
allowed to drop `FMT_DEPRECATED_OSTREAM` macro.
Refs scylladb#13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
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.
The test uses qualified ks.cf name to find the schema, but it's the only
test case that does it. There's no point in maintaining a dedicated
helper on the cql_test_env just for that
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Surprisingly there's a dedicated helper for the check opposite to the
one fixed in the previous patch. Fix one too
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Same as in previous patch, the cql_test_env::require_table_exists()
helper is exactly the same, but returns future and asserts on failures
for no gain
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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.
they are part of the CQL type system, and are "closer" to types.
let's move them into "types" directory.
the building systems are updated accordingly.
the source files referencing `types.hh` were updated using following
command:
```
find . -name "*.{cc,hh}" -exec sed -i 's/\"types.hh\"/\"types\/types.hh\"/' {} +
```
the source files under sstables include "types.hh", which is
indeed the one located under "sstables", so include "sstables/types.hh"
instea, so it's more explicit.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#12926
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
We have enabled the command line options without changing a
single line of code, we only had to replace old include
with scylla_test_case.hh.
Next step is to add x-log-compaction-groups options, which will
determine the number of compaction groups to be used by all
instantiations of replica::table.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The test checked if creating a table with CDC enabled on shard other
than 0 would create the CDC log table as well; it was a regression test
for #5582. However we will soon bounce all schema change requests to
shard 0, so the test's purpose is gone.
I need to remove this test because `cquery_nofail` does not handle the
bouncing correctly: it silently accepts the bounce message, assumes that
the query was successful and returns. So after we change the code to
start bouncing all requests to shard 0, if a query was ran inside test
code using `cquery_nofail` on a shard different than 0 it would do
nothing and following queries executed on shard 0 would fail because they
depended on the effect of the aforementioned query.
Fixes#10489
Killing the CDC log table on CDC disable is unhelpful in many ways,
partly because it can cause random exceptions on nodes trying to
do a CDC-enabled write at the same time as log table is dropped,
but also because it makes it impossible to collect data generated
before CDC was turned off, but which is not yet consumed.
Since data should be TTL:ed anyway, retaining the table should not
really add any overhead beyond the compaction to eventually clear
it. And user did set TTL=0 (disabled), then he is already responsible
for clearing out the data.
This also has the nice feature of meshing with the alternator streams
semantics.
Closes#10601
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
This allows us to forward-declare raw_selector, which in turn reduces
indirect inclusions of expression.hh from 147 to 58, reducing rebuilds
when anything in that area changes.
Includes that were lost due to the change are restored in individual
translation units.
Closes#9434
Get rid of unused includes of seastar/util/{defer,closeable}.hh
and add a few that are missing from source files.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
The old table won't be created in clusters that are bootstrapped after
this commit. It will stay in clusters that were upgraded from a version
before this commit.
Note that a fully upgraded cluster doesn't automatically create a new
generation in the new format. Even if the last generation was created
before the upgrade, the cluster will keep using it.
A new generation will be created in the new format when either:
1. a new node bootstraps (in the new version),
2. or the user runs checkAndRepairCdcStreams, which has a new check: if
the current generation uses the old format, the command will decide
that repair is needed, even if the generation is completely fine
otherwise (also in the new version).
During upgrade, while the CDC_GENERATIONS_V2 feature is still not
enabled, the user may still bootstrap a node in the old version of
Scylla or run checkAndRepairCdcStreams on a not-yet-upgraded node. In
that case a new generation will be created in the old format,
using the old table definitions.
Add a test that checks whether the cdc$deleted_ columns are properly
filled in the pre/post-image rows.
This test checks tables with only atomic columns, tables with frozen
collections and non-frozen collections. The test is performed with
both 'true' pre-image mode and 'full' pre-image mode.
Until now, the lists of streams in the `cdc_streams_descriptions` table
for a given generation were stored in a single collection. This solution
has multiple problems when dealing with large clusters (which produce
large lists of streams):
1. large allocations
2. reactor stalls
3. mutations too large to even fit in commitlog segments
This commit changes the schema of the table as described in issue #7993.
The streams are grouped according to token ranges, each token range
being represented by a separate clustering row. Rows are inserted in
reasonably large batches for efficiency.
The table is renamed to enable easy upgrade. On upgrade, the latest CDC
generation's list of streams will be (re-)inserted into the new table.
Yet another table is added: one that contains only the generation
timestamps clustered in a single partition. This makes it easy for CDC
clients to learn about new generations. It also enables an elegant
two-phase insertion procedure of the generation description: first we
insert the streams; only after ensuring that a quorum of replicas
contains them, we insert the timestamp. Thus, if any client observes a
timestamp in the timestamps table (even using a ONE query),
it means that a quorum of replicas must contain the list of streams.
When a row was inserted into a table with no regular columns, and no
such row existed in the first place, postimage would not be produced.
Fix this.
Fixes#7716.
Closes#7723
Now that CDC is GA and enabled by default, there's no longer a need
for a specific config in CDC tests.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Fixes#7435
Adds an "eor" (end-of-record) column to cdc log. This is non-null only on
last-in-timestamp group rows, i.e. end of a singular source "event".
A client can use this as a shortcut to knowing whether or not he has a
full cdc "record" for a given source mutation (single row change).
Closes#7436
Commit a6ad70d3da changed the format of
stream IDs: the lower 8 bytes were previously generated randomly, now
some of them have semantics. In particular, the least significant byte
contains a version (stream IDs might evolve with further releases).
This is a backward-incompatible change: the code won't properly handle
stream IDs with all lower 8 bytes generated randomly. To protect us from
subtle bugs, the code has an assertion that checks the stream ID's
version.
This means that if an experimental user used CDC before the change and
then upgraded, they might hit the assertion when a node attempts to
retrieve a CDC generation with old stream IDs from the CDC description
tables and then decode it.
In effect, the user won't even be able to start a node.
Similarly as with the case described in
d89b7a0548, the simplest fix is to rename
the tables. This fix must get merged in before CDC goes out of
experimental.
Now, if the user upgrades their cluster from a pre-rename version, the
node will simply complain that it can't obtain the CDC generation
instead of preventing the cluster from working. The user will be able to
use CDC after running checkAndRepairCDCStreams.
Since a new table is added to the system_distributed keyspace, the
cluster's schema has changed, so sstables and digests need to be
regenerated for schema_digest_test.
Fixes#7119Fixes#7120
If preimage select came up empty - i.e. the row did not exist, either
due to never been created, or once delete, we should not bother creating
a log preimage row for it. Esp. since it makes it harder to interpret the
cdc log.
If an operation in a cdc batch did a row delete (ranged, ck, etc), do
not generate postimage data, since the row does no longer exist.
Note that we differentiate deleting all (non-pk/ck) columns from actual
row delete.
C++20 introduced `contains` member functions for maps and sets for
checking whether an element is present in the collection. Previously
`count` function was often used in various ways.
`contains` does not only express the intend of the code better but also
does it in more unified way.
This commit replaces all the occurences of the `count` with the
`contains`.
Tests: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <b4ef3b4bc24f49abe04a2aba0ddd946009c9fcb2.1597314640.git.piotr@scylladb.com>
C++20 introduced std::erase_if which simplifies removal of elements
from the collection. Previously the code pattern looked like:
<collection>.erase(
std::remove_if(<collection>.begin(), <collection>.end(), <predicate>),
<collection>.end());
In C++20 the same can be expressed with:
std::erase_if(<collection>, <predicate>);
This commit replaces all the occurences of the old pattern with the new
approach.
Tests: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <6ffcace5cce79793ca6bd65c61dc86e6297233fd.1597064990.git.piotr@scylladb.com>
Moves responsibility for generating pre/postimage rows from the
"process_change" method to "produce_preimage" and "produce_postimage".
This commit actually affects the contents of generated CDC log
mutations.
Added a unit test that verifies more complicated cases with CQL BATCH.
Overwriting a collection cell using timestamp T is a process with
following steps:
1. inserting a row marker (if applicable) with timestamp T;
2. writing a collection tombstone with timestamp T-1;
3. writing the new collection value with timestamp T.
Since CDC does clustering of the operations by timestamp, this
would result in 3 separate calls to `transform` (in case of
INSERT, or 2 - in the case of UPDATE), which seems excessive,
especially when pre-/postimage is enabled. This patch makes
collection tombstones being treated as if they had the same TS as
the base write and thus they are processed in one call to `transform`
(as long as TTLs are not used).
Also, `cdc_test` had to be updated in places that relied on former
splitting strategy.
Fixes#6084
Commit 968177da04 has changed the schema
of cdc_topology_description and cdc_description tables in the
system_distributed keyspace.
Unfortunately this was a backwards-incompatible change: these tables
would always be created, irrespective of whether or not "experimental"
was enabled. They just wouldn't be populated with experimental=off.
If the user now tries to upgrade Scylla from a version before this change
to a version after this change, it will work as long as CDC is protected
b the experimental flag and the flag is off.
However, if we drop the flag, or if the user turns experimental on,
weird things will happen, such as nodes refusing to start because they
try to populate cdc_topology_description while assuming a different schema
for this table.
The simplest fix for this problem is to rename the tables. This fix must
get merged in before CDC goes out of experimental.
If the user upgrades his cluster from a pre-rename version, he will simply
have two garbage tables that he is free to delete after upgrading.
sstables and digests need to be regenerated for schema_digest_test since
this commit effectively adds new tables to the system_distributed keyspace.
This doesn't result in schema disagreement because the table is
announced to all nodes through the migration manager.
For a column of type `frozen<list<T>>` in base table, a corresponding
column of type `frozen<map<timeuuid, T>>` is created in cdc log.
Although a similar change of type takes place in case of non-frozen
lists, this is unneeded in case of frozen lists - frozen collections are
atomic, therefore there is no need for complicated type that will be
able to represent a column update that depends on its previous value
(e.g. appending elements to the end of the list).
Moreover, only cdc log table creation logic performs this type change
for frozen lists. The logic of `transformer::transform`, which is
responsible for creation of mutations to cdc log, assumes that atomic
columns will have their types unchanged in cdc log table. It simply
copies new value of the column from original mutation to the cdc log
mutation. A serialized frozen list might be copied to a field that is of
frozen map type, which may cause the field to become impossible to
deserialize.
This patch causes frozen list base table columns to have a corresponding
column in cdc log with the same type.
A test is added which asserts that the type of cdc log columns is not
changed in the case of frozen base columns.
Tests: unit(dev)
Fixes#6172
Fixes#6143
When doing post-image generation, we also write values for columns not
in delta (actual update), based on data selected in pre-image row.
However, if we are doing initial update/insert with only a subset of
columns, when the pre-image result set is nil, this cannot be done.
Adds check to non-touched column post-image code. Also uses the
pre-image value extractor to handle non-atomic sets properly.
Tests updated.
Fixes#6073
The logic with pre/post image was tangled into looking at "rs"
and would cause pre-image info to be stored even if only post-image
data was enabled.
Now only generate keys (and rows for them) iff explicitly enabled.
And only generate pre-image key iff we have pre-image data.
Fixes#6070
When mutation splitting was added, non-atomic column assignments were broken
into two invocation of transform. This means the second (actual data assignment)
does not know about the tombstone in first one -> postimage is created as if
we were _adding_ to the collection, not replacing it.
While not pretty, we can handle this knowing that we always get
invoked in timestamp order -> tombstone first, then assign.
So we simply keep track of non-atomic columns deleted across calls
and filter out preimage data post this.
Added test cases for all non-atomics
This patch fixes a bug in mutation splitting logic of CDC. In the part
that handles updates of non-atomic clustering columns, the column
definition was fetched from a static column of the same id instead of
the actual definition of the clustering column. It could cause the value
to be written to a wrong column.
Tests: unit(dev)
Fixes#4992
Implements post-image support by synthesizing it from
pre-image + delta.
Post-image data differs from the delta data in two ways:
1.) It merges non-atomics into an actual result value
2.) It contains _all_ columns of the row, not just
those affected by the update.
For a non-atomic field, the post-image value of a column
is either the pre-image or the delta (maybe null)
Tested by adding post-image checks to pre-image test
and collection/udt tests
