Wrapping ranges are a pain, so we are moving wrap handling to the edges.
Since cql can't generate wrapping ranges, this means thrift and the ring
maintenance code; also range->ring transformations need to merge the first
and last ranges.
Message-Id: <1478105905-31613-1-git-send-email-avi@scylladb.com>
That overload was used only by unit test and violated guarantee that
partition range lives until mutation reader is done.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
That will be needed for optimization that will store decorated keys
in the sstable object, and also for a subsequent work that will
detect wrong metadata (min/max column names) by looking at columns
in the schema. As schema is stored in sstable, there's no longer
a need to store ks and cf names in it.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
sstable has member functions that create objects which need to extend
lifetime of the sstable (for example mutation_readers), the easiest way
to achieve that is to enable_lw_shared_from_this for sstable.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
This patch uses the composite_marker to add inclusiveness information
to the prefixes of a range tombstone.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Since Scylla now supports proper range tombstones, the code for
reading ranges from sstables and converting them to overlapping
tombstones is no longer necessary, and is, in fact, wasteful as
the internal representation converts overlapping tombstones back to
ranges.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch changes the type of the mutation partition's row_tombstones
to be a range_tombstone_list, so that they are now represented as a
set of disjoint ranges. All of its usages are updated accordingly.
Fixes#1155
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This is even a more elaborate tombstone merging unit test, with
3 levels of nesting, which did not pass with older range-tombstone
merging algorithms, and works with the current one.
I started with deletion of three nested levels of row -
aaa, aaa:bbb, and aaa:bbb::ccc. I then complicated the sstable
even further by adding additional middle-points with the same
timestamps (which we saw happening in some real-life sstables),
resulting in:
[
{"key": "pk",
"cells": [["aaa:_","aaa:bba:_",1459438519943668,"t",1459438519],
["aaa:bba:_","aaa:bbb:_",1459438519943668,"t",1459438519],
["aaa:bbb:_","aaa:bbb:ccb:_",1459438519950348,"t",1459438519],
["aaa:bbb:ccb:_","aaa:bbb:ccc:_",1459438519950348,"t",1459438519],
["aaa:bbb:ccc:_","aaa:bbb:ccc:!",1459438519958850,"t",1459438519],
["aaa:bbb:ccc:!","aaa:bbb:ddd:!",1459438519950348,"t",1459438519],
["aaa:bbb:ddd:!","aaa:bbb:!",1459438519950348,"t",1459438519],
["aaa:bbb:!","aaa:!",1459438519943668,"t",1459438519]]}
]
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <1459778074-10759-3-git-send-email-nyh@scylladb.com>
In the tombstone_merging test, we expected one row tombstone. But we did
not verify that in addition to that row tombstone, there is no other rows
(deleted or otherwise). It turns out that in the onld merging algorithm,
we did produce additional deleted rows which shouldn't have been there.
So this patch adds a test that there are no such additional deleted rows
beyond the one row tombstone we expect. The test passes with the new
range tombstone merging algorithm.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <1459778074-10759-2-git-send-email-nyh@scylladb.com>
This is another unit test for range tombstone merging, introduced in commit
0fc9a5ee4d and rewritten in commit
99ecda3c96.
In this test, a single large deletion was broken up into several smaller
ranges, all with the same time stamps, so we should recombine them into
one row tombstone, instead of failing the read.
The sstable in this test case was artificially created using json2sstable.
We don't know how yet to produce such a case using Cassandra 2, but we
have seen a similar occurance in the wild, in a real SSTable.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <1459429243-15821-1-git-send-email-nyh@scylladb.com>
Until recently, we believed that range tombstones we read from sstables will
always be for entire rows (or more generalized clustering-key prefixes),
not for arbitrary ranges. But as we found out, because Cassandra insists
that range tombstones do not overlap, it may take two overlapping row
tombstones and convert them into three range tombstones which look like
general ranges (see the patch for a more detailed example).
Not only do we need to accept such "split" range tombstones, we also need
to convert them back to our internal representation which, in the above
example, involves two overlapping tombstones. This is what this patch does.
This patch also contains a test for this case: We created in Cassandra
an sstable with two overlapping deletions, and verify that when we read
it to Scylla, we get these two overlapping deletions - despite the
sstable file actually having contained three non-overlapping tombstones.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <b7c07466074bf0db6457323af8622bb5210bb86a.1459399004.git.glauber@scylladb.com>
For simplicity, we want to have keys serializable and deserializable
without schema for now. We will serialize keys in a generic form of a
vector of components where the format of components is specified by
CQL binary protocol. So conversion between keys and vector of
components needs to be possible to do without schema.
We may want to make keys schema-dependent back in the future to apply
space optimizations specific to column types. Existing code should
still pass schema& to construct and access the key when possible.
One optimization had to be reverted in this change - avoidance of
storing key length (2 bytes) for single-component partition keys. One
consequence of this, in addition to a bit larger keys, is that we can
no longer avoid copy when constructing single-component partition keys
from a ready "bytes" object.
I haven't noticed any significant performance difference in:
tests/perf/perf_simple_query -c1 --write
It does ~130K tps on my machine.
Its definition as a lambda function is inconvenient, because it does not allow
us to use default values for parameters.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
The intent is to make data returned by queries always conform to a
single schema version, which is requested by the client. For CQL
queries, for example, we want to use the same schema which was used to
compile the query. The other node expects to receive data conforming
to the requested schema.
Interface on shard level accepts schema_ptr, across nodes we use
table_schema_version UUID. To transfer schema_ptr across shards, we
use global_schema_ptr.
Because schema is identified with UUID across nodes, requestors must
be prepared for being queried for the definition of the schema. They
must hold a live schema_ptr around the request. This guarantees that
schema_registry will always know about the requested version. This is
not an issue because for queries the requestor needs to hold on to the
schema anyway to be able to interpret the results. But care must be
taken to always use the same schema version for making the request and
parsing the results.
Schema requesting across nodes is currently stubbed (throws runtime
exception).
Since bytes is a very generic value that is returned from many calls,
it is easy to pass it by mistake to a function expecting a data_value,
and to get a wrong result. It is impossible for the data_value constructor
to know if the argument is a genuine bytes variable, a data_value of another
type, but serialized, or some other serialized data type.
To prevent misuse, make the data_value(bytes) constructor
(and complementary data_value(optional<bytes>) explicit.
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.
This patch tests that collection within a mutation behave properly.
That is what lead to #188.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
Using a lambda for implementing a mutation_reader is nifty, but does not
allow us to add methods.
Switch to a class-based implementation in anticipation of adding a close()
method.
When a schema is available, we use it. However, we have, by now, way too many
tests. Some of them use tables for which we don't even know the schema. It would
have been a massive amount of work to require a schema for all of them - so I am
keeping both constructors around.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
