Add precompiled header support to CMakeLists.txt and configure.py -
it improves compilation time by approximately 10%.
New header `stdafx.hh` is added, don't include it manually -
the compiler will include it for you. The header contains includes from
external libraries used by Scylla - seastar, standard library,
linux headers and zlib.
The feature is enabled by default, use CMake option `Scylla_USE_PRECOMPILED_HEADER`
or configure.py --disable-precompiled-header to disable.
The feature should be disabled, when trying to check headers - otherwise
you might get false negatives on missing includes from seastar / abseil and so on.
Note: following configuration needs to be added to ccache.conf:
sloppiness = pch_defines,time_macros,include_file_mtime,include_file_ctime
Closesscylladb/scylladb#26617
Add precompiled header support to CMakeLists.txt and configure.py -
it improves compilation time by approximately 10%.
New header `stdafx.hh` is added, don't include it manually -
the compiler will include it for you. The header contains includes from
external libraries used by Scylla - seastar, standard library,
linux headers and zlib.
The feature is enabled by default, use CMake option `Scylla_USE_PRECOMPILED_HEADER`
or configure.py --disable-precompiled-header to disable.
The feature should be disabled, when trying to check headers - otherwise
you might get false negatives on missing includes from seastar / abseil and so on.
Note: following configuration needs to be added to ccache.conf:
sloppiness = pch_defines,time_macros
Closes#25182
Our "sstring_view" is an historic alias for the standard std::string_view.
The patch changes the last remaining random uses of this old alias across
our source directory to the standard type name.
After this patch, there are no more uses of the "sstring_view" alias.
It will be removed in the following patch.
Refs #4062.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
in UUID_gen.cc, we are using `std::atomic<int64_t>` in
`make_thread_local_node()`, but this template is not defined by
any of the included headers. but we should include used headers
to be self-contained.
when compiling on ubuntu:jammy with libstdc++-13, we have following
error:
```
/usr/local/bin/cmake -E __run_co_compile --tidy="clang-tidy-18;--checks=-*,bugprone-use-after-move;--extra-arg-before=--driver-mode=g++" --source=/home/runner/work/scylladb/scylladb/utils/UUID_gen.cc -- /usr/bin/clang++-18 -DBOOST_ALL_NO_LIB -DBOOST_NO_CXX98_FUNCTION_BASE -DBOOST_REGEX_DYN_LINK -DSCYLLA_BUILD_MODE=release -DSEASTAR_API_LEVEL=7 -DSEASTAR_LOGGER_COMPILE_TIME_FMT -DSEASTAR_LOGGER_TYPE_STDOUT -DSEASTAR_SCHEDULING_GROUPS_COUNT=16 -DSEASTAR_SSTRING -DXXH_PRIVATE_API -I/home/runner/work/scylladb/scylladb -I/home/runner/work/scylladb/scylladb/seastar/include -I/home/runner/work/scylladb/scylladb/build/seastar/gen/include -I/home/runner/work/scylladb/scylladb/build/seastar/gen/src -isystem /home/runner/work/scylladb/scylladb/cooking/include -ffunction-sections -fdata-sections -O3 -g -gz -std=gnu++20 -fvisibility=hidden -Wall -Werror -Wextra -Wno-error=deprecated-declarations -Wimplicit-fallthrough -Wno-c++11-narrowing -Wno-deprecated-copy -Wno-mismatched-tags -Wno-missing-field-initializers -Wno-overl
Error: /home/runner/work/scylladb/scylladb/utils/UUID_gen.cc:29:33: error: implicit instantiation of undefined template 'std::atomic<long>' [clang-diagnostic-error]
29 | static std::atomic<int64_t> thread_id_counter;
| ^
/usr/lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/bits/shared_ptr_atomic.h:361:11: note: template is declared here
361 | class atomic;
| ^
```
so, in this change, we include `<atomic>` to address this
build failure.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#18387
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
A follow up for the patch for #7611. This change was requested
during review and moved out of #7611 to reduce its scope.
The patch switches UUID_gen API from using plain integers to
hold time units to units from std::chrono.
For one, we plan to switch the entire code base to std::chrono units,
to ensure type safety. Secondly, using std::chrono units allows to
increase code reuse with template metaprogramming and remove a few
of UUID_gen functions that beceme redundant as a result.
* switch get_time_UUID(), unix_timestamp(), get_time_UUID_raw(), switch
min_time_UUID(), max_time_UUID(), create_time_safe() to
std::chrono
* remove unused variant of from_unix_timestamp()
* remove unused get_time_UUID_bytes(), create_time_unsafe(),
redundant get_adjusted_timestamp()
* inline get_raw_UUID_bytes()
* collapse to similar implementations of get_time_UUID()
* switch internal constants to std::chrono
* remove unnecessary unique_ptr from UUID_gen::_instance
Message-Id: <20210406130152.3237914-2-kostja@scylladb.com>
Scylla list cells are represented internally as a map of
timeuuid => value. To append a new value to a list
the coordinator generates a timeuuid reflecting the current time as key
and adds a value to the map using this key.
Before this patch, Scylla always generated a timeuuid for a new
value, even if the query had a user supplied or LWT timestamp.
This could break LWT linearizability. User supplied timestamps were
ignored.
This is reported as https://github.com/scylladb/scylla/issues/7611
A statement which appended multiple values to a list or a BATCH
generated an own microsecond-resolution timeuuid for each value:
BEGIN BATCH
UPDATE ... SET a = a + [3]
UPDATE ... SET a = a + [4]
APPLY BATCH
UPDATE ... SET a = a + [3, 4]
To fix the bug, it's necessary to preserve monotonicity of
timeuuids within a batch or multi-value append, but make sure
they all use the microsecond time, as is set by LWT or user.
To explain the fix, it's first necessary to recall the structure
of time-based UUIDs:
60 bits: time since start of GMT epoch, year 1582, represented
in 100-nanosecond units
4 bits: version
14 bits: clock sequence, a random number to avoid duplicates
in case system clock is adjusted
2 bits: type
48 bits: MAC address (or other hardware address)
The purpose of clockseq bits is as defined in
https://tools.ietf.org/html/rfc4122#section-4.1.5
is to reduce the probability of UUID collision in case clock
goes back in time or node id changes. The implementation should reset it
whenever one of these events may occur.
Since LWT microsecond time is guaranteed to be
unique by Paxos, the RFC provisioning for clockseq and MAC
slots becomes excessive.
The fix thus changes timeuuid slot content in the following way:
- time component now contains the same microsecond time for all
values of a statement or a batch. The time is unique and monotonic in
case of LWT. Otherwise it's most always monotonic, but may not be
unique if two timestamps are created on different coordinators.
- clockseq component is used to store a sequence number which is
unique and monotonic for all values within the statement/batch.
- to protect against time back-adjustments and duplicates
if time is auto-generated, MAC component contains a random (spoof)
MAC address, re-created on each restart. The address is different
at each shard.
The change is made for all sources of time: user, generated, LWT.
Conditioning the list key generation algorithm on the source of
time would unnecessarily complicate the code while not increase
quality (uniqueness) of created list keys.
Since 14 bits of clockseq provide us with only 16383 distinct slots
per statement or batch, 3 extra bits in nanosecond part of the time
are used to extend the range to 131071 values per statement/batch.
If the rang is exceeded beyond the limit, an exception is produced.
A twist on the use of clockseq to extend timeuuid uniqueness is
that Scylla, like Cassandra, uses int8 compare to compare lower
bits of timeuuid for ordering. The patch takes this into account
and sign-complements the clockseq value to make it monotonic
according to the legacy compare function.
Fixes#7611
test: unit (dev)
Before this patch, UUID generation code was not creating
sufficiently unique IDs: the 6 byte node identifier was mostly
empty, i.e. only containing shard id. This could lead to
collisions between queries executed concurrently at different
coordinators, and, since timeuuid is used as key in list append
and prepend operations, lead to lost updates.
To generate a unique node id, the patch uses a combination of
hardware MAC address (or a random number if no hardware address is
available) and the current shard id.
The shard id is mixed into higher bits of MAC, to reduce the
chances on NIC collision within the same network.
With sufficiently unique timeuuids as list cell keys, such updates
are no longer lost, but multi-value update can still be "merged"
with another multi-value update.
E.g. if node A executes SET l = l + [4, 5] and node B executes SET
l = l + [6, 7], the list value could be any of [4, 5, 6, 7], [4,
6, 5, 7], [6, 4, 5, 7] and so on.
At least we are now less likely to get any value lost.
Fixes#6208.
@todo: initialize UUID subsystem explicitly in main()
and switch to using seastar::engine().net().network_interfaces()
test: unit (dev)
cryptopp's config.h has the following pragma:
#pragma GCC diagnostic ignored "-Wunused-function"
It is not wrapped in a push/pop. Because of that, including cryptopp
headers disables that warning on scylla code too.
The issue has been reported as
https://github.com/weidai11/cryptopp/issues/793
To work around it, this patch uses a pimpl to have a single .cc file
that has to include cryptopp headers.
While at it, it also reduces the differences and code duplication
between the md5 and sha1 hashers.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
This code would have be to refactored by the next patch. Since it is
commented out, just delete it.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
UUID_gen::create_time_safe() does not synchronize across cores. The
comment says that it assumes it runs on a single core. This is no
longer true, we can run urchin on many cores. This easily leads to
UUID conflicts with more than one core. Fix by adding a per-core
unique number to the node part of the UUID.
Convert Cassandra's UUIDGen class, which generates time-dependent UUID,
and parts of the java.util.UUID which I thought we need, to C++.
It is possible I missed some needed features of java.util.UUID that we'll
need to add later.
Also, part of the version-1 UUID is supposed to be node-unique (so that
if two nodes happen to boot at the same time and get a UUID at exactly
the same time, they still get different UUIDs). Cassandra uses for this
a hash function of the IP address, we should use in the future the MAC
address (from Seastar's network stack). But currently we just use 0.
Left a FIXME to fix that.
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
[avi: add to ./configure.py]
