these unused includes are identified by clang-include-cleaner.
after auditing the source files, all of the reports have been
confirmed.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
The feature::when_enabled function takes a callback and returns a
listener_registration object. Unless the feature were enabled right from
the start, the listener_registration will be non-null and will keep the
callback registered until the registration is destroyed. If the
registration is destroyed before the feature is enabled, the callback
will not be called. It's easy to make a mistake and forget to keep the
returned registration alive - especially when, in tests, the feature is
enabled early in boot, because in that case when_enabled calls the
callback immediately and returns a null object instead.
In order to prevent issues with prematurely dropped
listener_registration in the future, mark feature::when_enabled with the
[[nodiscard]] attribute.
Features are usually used as booleans, so forcing allowing them
to implicitly decay to bool is not a mistake. In fact a bunch
of helper functions exist to cast feature variables to bool.
Prepare to reduce this boilerplate by allowing automatic conversion
to bool.
Active feature names are present four or five times in the code:
a delaration in feature.hh, a definition and initialization (two copies)
in feature_service.cc, a use in feature_service.cc, and a possible
reference in feature_service.cc if the feature is conditionally enabled.
Switch to just one copy or two, using the "foo"sv operator (and "foo"s)
to generate a string_view (string) as before.
Note that a few features had different external and C++ names; we
preserve the external name.
This patch does cause literal strings to be present in two places,
making them vulnerable to misspellings. But since feature names
are immutable, there is little risk that one will change without
the other.
Deprecated features are unused, but are present four times in the code:
a delaration in feature.hh, a definition and initialization (two copies)
in feature_service.cc, and a use in feature_service.cc. Switch to just
one copy, using the "foo"sv operator to generate a string_view as before.
Note that a few features had different external and C++ names; we
preserve the external name.
The feature represents the ability to store storage options
in keyspace metadata: represented as a map of options,
e.g. storage type, bucket, authentication details, etc.
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
The gc_grace_seconds is a very fragile and broken design inherited from
Cassandra. Deleted data can be resurrected if cluster wide repair is not
performed within gc_grace_seconds. This design pushes the job of making
the database consistency to the user. In practice, it is very hard to
guarantee repair is performed within gc_grace_seconds all the time. For
example, repair workload has the lowest priority in the system which can
be slowed down by the higher priority workload, so that there is no
guarantee when a repair can finish. A gc_grace_seconds value that is
used to work might not work after data volume grows in a cluster. Users
might want to avoid running repair during a specific period where
latency is the top priority for their business.
To solve this problem, an automatic mechanism to protect data
resurrection is proposed and implemented. The main idea is to remove the
tombstone only after the range that covers the tombstone is repaired.
In this patch, a new table option tombstone_gc is added. The option is
used to configure tombstone gc mode. For example:
1) GC a tombstone after gc_grace_seconds
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'timeout'} ;
This is the default mode. If no tombstone_gc option is specified by the
user. The old gc_grace_seconds based gc will be used.
2) Never GC a tombstone
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'disabled'};
3) GC a tombstone immediately
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'immediate'};
4) GC a tombstone after repair
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'repair'};
In addition to the 'mode' option, another option 'propagation_delay_in_seconds'
is added. It defines the max time a write could possibly delay before it
eventually arrives at a node.
A new gossip feature TOMBSTONE_GC_OPTIONS is added. The new tombstone_gc
option can only be used after the whole cluster supports the new
feature. A mixed cluster works with no problem.
Tests: compaction_test.py, ninja test
Fixes#3560
[avi: resolve conflicts vs data_dictionary]
The patch adds the `SUPPORTS_RAFT_CLUSTER_MANAGEMENT`
and `USES_RAFT_CLUSTER_MANAGEMENT` gossiper features.
These features provide a way to organize the automatic
switch to raft-based cluster management.
The scheme is as follows:
1. Every new node declares support for raft-based cluster ops.
2. At the moment, no nodes in the cluster can actually use
raft for cluster management, until the `SUPPORTS*` feature is enabled
(i.e. understood by every node in the cluster).
3. After the first `SUPPORTS*` feature is enabled, the nodes
can declare support for the second, `USES*` feature, which
means that the node can actually switch to use raft-based cluster
ops.
The scheme ensures that even if some nodes are down while
transitioning to new bootstrap mechanism, they can easily
switch to the new procedure, not risking to disrupt the
cluster.
The features are not actually wired to anything yet,
providing a framework for the integration with `raft_group0`
code, which is subject for a follow-up series.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20211220081318.274315-1-pa.solodovnikov@scylladb.com>
This new feature will be used to determined whether the whole cluster
is ready to use additional page_size field in max_result_size.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
This patch adds stubs for the UpdateTimeToLive and DescribeTimeToLive
operations to Alternator. These operations can enable, disable, or inquire
about, the chosen expiration-time attribute.
Currently, the information about the chosen attribute is only saved, with
no actual expiration of any items taking place.
Some of the tests for the TTL feature start to pass, so their xfail tag
is removed.
Because this this new feature is incomplete, it is not enabled unless
the "alternator-ttl" experimental feature is enabled. Moreover, for
these operations to be allowed, the entire cluster needs to support
this experimental feature, because all nodes need to participate in the
data expiration - if some old nodes don't support Alternator TTL, some
of the data they hold won't get expired... So we don't allow enabling
TTL until all the nodes in the cluster support this feature.
The implementation is in a new source file, alternator/ttl.cc. This
source file will continue to grow as we implement the expiration feature.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
When a node joins this feature (which it does immediately when upgrading
to a version that has this commit), it says: "I understand the new
generation storage format and the new identifier format". Thus, when the
feature becomes enabled - after all nodes have joined it - it means that
it's safe to create new generations using these new storage/ID formats.
To control the transition to the data variant of range scans. As there
is a difference in how the data and mutation variants calculate pages
sizes, the transition to the former has to happen in a controlled
manner, when all nodes in the cluster support it, to avoid artificial
differences in page content and subsequently triggering false-positive
read repair.
Add new alternator-streams experimental flag for
alternator streams control.
CDC becomes GA and won't be guarded by an experimental flag any more.
Alternator Streams stay experimental so now they need to be controlled
by their own experimental flag.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Add new correct_idx_token_in_secondary_index feature, which will be used
to determine if all nodes in the cluster support new
token_column_computation. This column computation will replace
legacy_token_column_computation in secondary indexes, which was
incorrect as this column computation produced values that when compared
with unsigned comparison (CQL type bytes comparison) resulted in
different ordering than token signed comparison. See issue:
https://github.com/scylladb/scylla/issues/7443
This feature will ensure that caching can be switched
off per table only after the whole cluster supports it.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
This new feature is required because we now allow
setting partitioner per table. This will influence
the digest of table schema so we must not include
partitioner name into the digest unless we know that
the whole cluster already supports per table partitioners.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
In test_services.cc there is
gms::feature_service test_feature_service;
And the feature_service constructor has
, _lwt_feature(*this, features::LWT)
But features::LWT is a global sstring constructed in another file.
Solve the problem by making the feature strings constexpr
std::string_view.
I found the issue while trying to benchmark the std::string switch.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Acked-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20200309225749.36661-1-espindola@scylladb.com>
And leave some temporary storage_service->feature links. The plan
is to make every subsystem that needs storage_service for features
stop doing so and switch on the feature_service.
The feature_service is the service w/o any dependencies, it will be
freed last, thus making the service dependency tree be a tree,
not a graph with loops.
While at it -- make all const-s not have _FEATURE suffix (now there
are both options) and const-qualify cluster_supports_lwt().
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
It can be invoked with a lambda without the ceremony of creating a
class deriving from gms::feature::listener.
The reutrned registration object controls listener's scope.
Feature lifetime is tied to storage_service lifetime, but features are now managed
by gossip. To avoid circular dependency, add a new feature_service service to manage
feature lifetime.
To work around the problem, the current code re-initializes features after
gossip is initialized. This patch does not fix this problem; it only makes it
possible to solve it by untyping features from gossip.
Add the helper function to enable the a feature and log the feature is
enabled.
When a feature is enabled, we see
INFO 2016-12-15 11:29:32,443 [shard 0] gossip - Feature LARGE_PARTITIONS is enabled
INFO 2016-12-15 11:29:32,443 [shard 0] gossip - Feature RANGE_TOMBSTONES is enabled
in the log.
This class encapsulates the waiting for a cluster feature. A feature
object is registered with the gossiper, which is responsible for later
marking it as enabled.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
