If mutation is bigger than this limit
it won't be read and mutation_from_streamed_mutation
will return empty optional.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
(cherry picked from commit 0d39bb1ad0)
"Currently data query digest includes cells and tombstones which may have
expired or be covered by higher-level tombstones. This causes digest
mismatch between replicas if some elements are compacted on one of the
nodes and not on others. This mismatch triggers read-repair which doesn't
resolve because mutations received by mutation queries are not differing,
they are compacted already.
The fix adds compacting step before writing and digesting query results by
reusing the algorithm used by mutation query. This is not the most optimal
way to fix this. The compaction step could be folded with the query writing,
there is redundancy in both steps. However such change carries more risk,
and thus was postponed.
perf_simple_query test (cassandra-stress-like partitions) shows regression
from 83k to 77k (7%) ops/s.
Fixes #1165."
Currently data query digest includes cells and tombstones which may have
expired or be covered by higher-level tombstones. This causes digest
mismatch between replicas if some elements are compacted on one of the
nodes and not on others. This mismatch triggers read-repair which doesn't
resolve because mutations received by mutation queries are not differing,
they are compacted already.
The fix adds compacting step before writing and digesting query results by
reusing the algorithm used by mutation query. This is not the most optimal
way to fix this. The compaction step could be folded with the query writing,
there is redundancy in both steps. However such change carries more risk,
and thus was postponed.
perf_simple_query test (cassandra-stress-like partitions) shows regression
from 83k to 77k (7%) ops/s.
Fixes#1165.
Schema is tracked in memtable and cache per-entry. Entries are
upgraded lazily on access. Incoming mutations are upgraded to table's
current schema on given shard.
Mutating nodes need to keep schema_ptr alive in case schema version is
requested by target node.
frozen_schema will transfer schema definition across nodes with schema
mutations. Because different nodes may have different versions of
schema tables, we cannot use frozen_mutations to transfer these
because frozen_mutation can only be read using the same version of the
schema it was frozen with. To solve this problem, new from of mutation
is introduced called canonical_mutation, which can be read using any
version of the schema.
We use boost::any to convert to and from database values (stored in
serlialized form) and native C++ values. boost::any captures information
about the data type (how to copy/move/delete etc.) and stores it inside
the boost::any instance. We later retrieve the real value using
boost::any_cast.
However, data_value (which has a boost::any member) already has type
information as a data_type instance. By teaching data_type intances about
the corresponding native type, we can elimiante the use of boost::any.
While boost::any is evil and eliminating it improves efficiency somewhat,
the real goal is growing native type support in data_type. We will use that
later to store native types in the cache, enabling O(log n) access to
collections, O(1) access to tuples, and more efficient large blob support.
Since mutation stores all its data externally and the object itself is
basically just a std::unique_ptr<> there is no need for stdx::optional.
Smart pointer set to nullptr represents a disengaged mutation_opt.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
By passing mutation_partition oither by const ref or rref instead of
by value one move can be avoided if copying is necessary.
Signed-off-by: Paweł Dziepak <pdziepak@cloudius-systems.com>
The "mutation_reader" defined in database.cc is a convenient mechanism
for iterating over mutations. It can be useful for more than just
database.cc (I want to use it in the compaction code), so this patch moves
the type's definition to mutation.hh, and the make_memtable_reader()
function to memtable::make_reader() (in memtable.hh).
Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
As suggested by Avi, we can return an actual mutation by moving it out of our
consumer. We will encapsulate it within an optional, to handle the cases where
the mutation cannot be found.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
Reviewed-by: Nadav Har'El <nyh@cloudius-systems.com>
Reduces coupling. User's should not rely on the fact that it's an
std::map<>. It also allows us to extend row's interface with
domain-specific methods, which are a lot easier to discover than free
functions.
Ensure that read-side accessors are const. This is important in preparation
for multiple memtables (and later, sstables) since a read-side
mutation_partition may be a temporary object coming from multiple memtables
(and sstables) while a write-side mutation_partition is guaranteed to belong
to a single memtable (and thus, not be temporary).
Since writers will want non-const mutation_partitions to write to, they won't
be able to use the read-side accessors by accident.
Partitions should be ordered using Origin's ordering, which is first
by token, then by Origin's representation of the key. That is the
natural ordering of decorated_key.
This also changes mutation class to hold decorated_key, to avoid
decoration overhead at different layers.
