mutation_result_merger merges results from different shards and stops as
soon as a shard returned a short read or memory usage on the merging
shard is too high. However, it should never stop unless at least one
live rows is in the merged result.
* 'tgrabiec/calculate-hash-once-compaction' of github.com:cloudius-systems/seastar-dev:
sstables: Calculate key hash only once during compaction
tests: sstables: Add more test cases to tombstone_purge_test
db: Expose column_family::add_sstable
tests: sstables: Ensure timestamps are increasing
tests: sstables: Simplify tombstone_purge_test
- moved to seastar thread
- extracted sstable creation and validation logic
- reduced code duplication
- switched to mutation_reader assertions
- used result of compact_sstable() to locate the new sstable
- rather than setting gc timestamp in the past, bump the clock
before compacting
Some code paths were obtaining db_clock timestamp to only convert it
to gc_clock later. Avoid this. In the future we could make gc_clock
cheaper cause it has low precision.
Message-Id: <1482401190-2035-1-git-send-email-tgrabiec@scylladb.com>
Shared sstables will now be resharded in the same order to guarantee
that all shards owning a sstable will agree on its deletion nearly
the same time, therefore, reducing disk space requirement.
That's done by picking which column family to reshard in UUID order,
and each individual column family will reshard its shared sstables
in generation order.
Fixes#1952.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <87ff649ed24590c55c00cbb32bffd8fa2743e36e.1482342754.git.raphaelsc@scylladb.com>
Currently server-side timestamps use a clock with millisecond
precision. Timestamps have microsecond resolution, with lower bits
used to serialize mutations originating from given client.
Timestamps for column drops always use just the millisecond base. A
column drop which is executed after an insert may thus be given lower
timestamp than the insert, even when the two are serialized on the
client side over same connection.
Use microsecond precision to reduce chances of that event.
This is supposed to fix sporadic failures of
schema_test.py:TestSchema.drop_column_queries_test dtest.
Message-Id: <1482343119-27698-1-git-send-email-tgrabiec@scylladb.com>
Refs #1943.
* 'tgrabiec/optimize-bloom-filter' of github.com:cloudius-systems/seastar-dev:
db: Compute key hash once in partition_presence_checker
bloom_filter: Allow checking presence using pre-hashed key
db: Use incremental selector in partition_presence_checker
RPC messaging service is initialized before the Tracing service, so
we should prevent creation of tracing spans before the service is
fully initialized.
We will use an already existing "_down" state and extend it in a way
that !_down equals "started", where "started" is TRUE when the local
service is fully initialized.
We will also split the Tracing service initialization into two parts:
1) Initialize the sharded object.
2) Start the tracing service:
- Create the I/O backend service.
- Enable tracing.
Fixes issue #1939
Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
Message-Id: <1481836429-28478-1-git-send-email-vladz@scylladb.com>
If a node gets more MUTATION request that it can handle via RPC it will
stop reading from this RPC connection, but this will prevent it from
getting MUTATION_DONE responses for requests it coordinates because
currently MUTATION and MUTATION_DONE messages shares same connection.
To solve this problem this patches moves MUTATION_DONE messages to
separate connection.
Fixes: #1843
Message-Id: <20161201155942.GC11581@scylladb.com>
This reverts commit b81a57e8eb.
With exponential range scanning, we should now be able to survive
msb ignore bits of 12, which allows better sharding on large clusters.
When murmur3_partitioner_ignore_msb_bits = 12 (which we'd like to be the
default), a scan range can be split into a large number of subranges, each
going to a separate shard. With the current implementation, subranges were
queried sequentially, resulting in very long latency when the table was empty
or nearly empty.
Switch to an exponential retry mechanism, where the number of subranges
queried doubles each time, dropping the latency from O(number of subranges)
to O(log(number of subranges)).
If, during an iteration of a retry, we read at most one range
from each shard, then partial results are merged by concatentation. This
optimizes for the dense(r) case, where few partial results are required.
If, during an iteration of a retry, we need more than one range per
shard, then we collapse all of a shard's ranges into just one range,
and merge partial results by sorting decorated keys. This reduces
the number of sstable read creations we need to make, and optimizes for
the sparse table case, where we need many partial results, most of which
are empty.
We don't merge subranges that come from different partition ranges,
because those need to be sorted in request order, not decorated key order.
[tgrabiec: trivial conflicts]
Message-Id: <20161220170532.25173-1-avi@scylladb.com>
This patchset implements the multiple CQL3 statements relating to
materialized views, as well as ensuring other statements now take
materialized views into account. It also adds the necessary internal
data structures to hold materialized view metadata.
This patch adds a set of tests for materialized view schema
handling, complementing the dtests for the same feature.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch introduces the do_with_cql_env_thread() function, which
behaves like do_with_cql_env() except that it executes the
user-specified function in the context of a Seastar thread.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds an utility function that creates a raw select
statement from a set of columns and a where clause. It is intended to
be used to create the prepared select statement used by the view
class.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds the alter_view_statement, which enables users to
change the properties of a materialized view.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds the MATERIALIZED_VIEWS_FEATURE to the set of cluster
features and requires its presence to allow creating a view. This
ensures view schemas can be safely propagated across nodes.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch propagates the for_view argument, used by
statement_restrictions to ensure IS NOT NULL can be used when creating
a materialized view.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch checks for additional permissions when modifying a table
with views, since that update will require reading from the table and
writing into its views.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch forbids dropping a column family if there are still views
associated with it, and also forbids dropping a view through the drop
table statement.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch ensures that changes to a base table's schema
are reflected in that table's materialized views.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
To minimize code duplication, have query_processor use
do_with_parser() instead of manually creating the CqlParser.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds an utility function to rename a column occurring a
textual where clause. It is intended to change a view's where clause
when users alter the underlying base table.
To do this, we rely on functions that transform a textual where clause
into a set of relations, which allows to reliably rename the column.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds an utility function to rename an identifier
occurring in a cql3 relation. This function will be used when renaming
an identifier in a view's where clause.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch builds the mutations to announce a new view. Aside from
including the view schema, we include the base table mutations so
that a node is resilient against receiving create view mutations
before the base table create mutations.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
