Replacing `restrict_replication_simplestrategy` config option with
2 config options: `replication_strategy_{warn,fail}_list`, which
allow us to impose soft limits (issue a warning) and hard limits (not
execute CQL) on replication strategy when creating/altering a keyspace.
The reason to rather replace than extend `restrict_replication_simplestrategy` config
option is that it was not used and we wanted to generalize it.
Only soft guardrail is enabled by default and it is set to SimpleStrategy,
which means that we'll generate a CQL warning whenever replication strategy
is set to SimpleStrategy. For new cloud deployments we'll move
SimpleStrategy from warn to the fail list.
Guardrails violations will be tracked by metrics.
Resolves#5224
Refs #8892 (the replication strategy part, not the RF part)
Closesscylladb/scylladb#15399
Replacing `minimum_keyspace_rf` config option with 4 config options:
`{minimum,maximum}_replication_factor_{warn,fail}_threshold`, which
allow us to impose soft limits (issue a warning) and hard limits (not
execute CQL) on RF when creating/altering a keyspace.
The reason to rather replace than extend `minimum_keyspace_rf` config
option is to be aligned with Cassandra, which did the same, and has the
same parameters' names.
Only min soft limit is enabled by default and it is set to 3, which means
that we'll generate a CQL warning whenever RF is set to either 1 or 2.
RF's value of 0 is always allowed and means that there will not be any
replicas on a given DC. This was agreed with PM.
Because we don't allow to change guardrails' values when scylla is
running (per PM), there're no tests provided with this PR, and dtests will be
provided separately.
Exceeding guardrails' thresholds will be tracked by metrics.
Resolves#8619
Refs #8892 (the RF part, not the replication-strategy part)
Closes#14262
use {} instead of {0ul} for zero initialization. as `_query_cnt`
is a multi-dimension array, each elements in `_query_cnt` is yet
another array. so we cannot initialize it with a `{0ul}`. but
to zero-initialize this array, we can just use `{}`, as per
https://en.cppreference.com/w/cpp/language/zero_initialization
> If T is array type, each element is zero-initialized.
so this should recursively zero-initialize all arrays in `_query_cnt`.
this change should silence following warning:
stats.hh:88:60: error: suggest braces around initialization of subobject [-Werror,-Wmissing-braces]
[statements::statement_type::MAX_VALUE + 1] = {0ul};
^~~
{ }
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Detect whether a statement is a count(*) query in prepare time. If so,
instantiate a new `select_statement` subclass -
`parallelized_select_statement`. This subclass has a different execution
logic, that enables it to distribute count(*) queries across a cluster.
Also, a new counter was added - `select_parallelized` that counts the
number of parallelized aggregation SELECT query executions.
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
Implements a counter of executions of SELECT queries with ALLOW FILTERING option.
In scope of #5209
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
This patch adds "type" label to the following CQL metrics:
inserts
updates
deletes
batches
statements_in_batches
The label is set to "cas" for conditional statements and "non-cas" for
unconditional statements.
Note, for a batch to be accounted as CAS, it is enough to have just one
conditional statement. In this case all statements within the batch are
accounted as CAS as well.
Rather than passing a pointer to a cql_stats member corresponding to
the statement type, pass a reference to a cql_stats object and use
statement_type, which is already stored in modification_statement, for
determining which counter to increment. This will allow us to account
conditional statements, which will have a separate set of counters,
right in modification_statement::execute() - all we'll need to do is
add the new counters and bump them in case execute_with_condition is
called.
While we are at it, remove extra inclusions from statement_type.hh so as
not to introduce any extra dependencies for cql_stats.hh users.
Message-Id: <20191022092258.GC21588@esperanza>
Add a metric to account writes which arrived to a non-replica and
had to be forwarded by a coordinator to a replica.
The name of the added metric is 'writes_coordinator_outside_replica_set'.
Do not account forwarded read repair writes, since they are already
accounted by a reads_coordinator_outside_replica_set metric, added in a
subsequent patch.
In scope of #4338.
The following metrics are defined for ALLOW FILTERING:
* number of read request that required filtering
* total number of rows read that required filtering
* number of rows read that required filtering and matched
- Add a inserts, updates, deletes members to cql_stats.
- Store cql_stats& in a modification_statement and increment the corresponding counter according to the value of a "type" field.
- Store cql_stats& in a batch_statement and increment the statistics for each BATCH member.
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
- Add a "reads" counter to a cql3::cql_stats struct.
- Store a reference for a query_processor::_cql_stats in the select_statement object.
- Increment a "reads" counter where needed.
Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
