Base tables that use compact storage may have a special artificial
column that has an empty type.
c010cefc4d fixed the main CDC path to
handle such columns correctly and to not include them in the CDC Log
schema.
This patch makes sure that generation of preimage ignores such empty
column as well.
Fixes#9876Closes#9910
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
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
When a table with compact storage has no regular column (only primary
key columns), an artificial column of type empty is added. Such column
type can't be returned via CQL so CDC Log shouldn't contain a column
that reflects this artificial column.
This patch does two things:
1. Make sure that CDC Log schema does not contain columns that reflect
the artificial column from a base table.
2. When composing mutation to CDC Log, ommit the artificial column.
Fixes#8410
Test: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Closes#8988
Cassandra 3.0 deprecated the 'sstable_compression' attribute and added
'class' as a replacement. Follow by supporting both.
The SSTABLE_COMPRESSION variable is renamed to SSTABLE_COMPRESSION_DEPRECATED
to detect all uses and prevent future misuse.
To prevent old-version nodes from seeing the new name, the
compression_parameters class preserves the key name when it is
constructed from an options map, and emits the same key name when
asked to generate an options map.
Existing unit tests are modified to use the new name, and a test
is added to ensure the old name is still supported.
Fixes#8948.
Closes#8949
The tests, when added, where not named kosher (*_test), which the
runner apparently quaintly, require to pick it up (instead of the more
sensisble *.cql).
Thusly, the test was never run beyond initial creation, and also
bit-rotted slightly during behaviour changes.
Renamed and re-resulted.
Closes#8581
Refs #8093
Refs /scylladb/scylla-tools-java#218
Adds keyword that can preface value tuples in (a, b, c) > (1, 2, 3)
expressions, forcing the restriction to bypass column sort order
treatment, and instead just create the raw ck bounds accordningly.
This is a very limited, and simple version, but since we only need
to cover this above exact syntax, this should be sufficient.
v2:
* Add small cql test
v3:
* Added comment in multi_column_restriction::slice, on what "mode" means and is for
* Added small document of our internal CQL extension keywords, including this.
v4:
* Added a few more cases to tests to verify multi-column restrictions
* Reworded docs a bit
v5:
* Fixed copy-paste error in comment
v6:
* Added negative (error) test cases
v7:
* Added check + reject of trying to combine SCYLLA_CLUST... slice and
normal one
Closes#8094
CQL test relied on quietly acceptiong non-existing DCs, so it had
to be removed. Also, one boost-test referred to nonexisting
`datacenter2` and had to be removed.
Merged patch series by Konstantin Osipov:
"These series improve uniqueness of generated timeuuids and change
list append/prepend logic to use client/LWT timestamp in timeuuids
generated for list keys. Timeuuid compare functions are
optimized.
The test coverage is extended for all of the above."
uuid: add a comment warning against UUID::operator<
uuid: replace slow versions of timeuiid compare with optimized/tested versions.
test: add tests for legacy uuid compare & msb monotonicity
test: add a test case for append/prepend limit
test: add a test case for monotonicity of timeuuid least significant bits
uuid: implement optimized timeuuid compare
test: add a test case for list prepend/append with custom timestamp
lists: rewrite list prepend to use append machinery
lists: use query timestamp for list cell values during append
uuid: fill in UUID node identifier part of UUID
test: add a CQL test for list append/prepend operations
Test single- and multi- value list append, prepend,
append and prepend in a batch, conditional statements.
This covers the parts of Cassandra which are working as documented
and which we intend to preserve compatibility with.
This is a preparation for the upcoming introduction of managed_bytes_view,
intended as a fragmented replacement for bytes_view.
To ease the transition, we want both types to give equal hashes for equal
contents.
Changing a user type may allow adding apparently duplicate rows to
tables where this type is used in a partitioning key. Fix by checking
all types of existing partitioning columns before allowing to add new
fields to the type.
Fixes#6941
Previously batch statement result set included rows for only
those updates which have a prefetch data present (i.e. there
was an "old" (pre-existing) row for a key).
Also, these rows were sorted not in the order in which statements
appear in the batch, but in the order of updated clustering keys.
If we have a batch which updates a few non-existent keys, then
it's impossible to figure out which update inserted a new key
by looking at the query response. Not only because the responses
may not correspond to the order of statements in the batch, but
even some rows may not show up in the result set at all.
The patch proposes the following fix:
For conditional batch statements the result set now always
includes a row for each LWT statement, in the same order
in which individual statements appear in the batch.
This way we can always tell which update did actually insert
a new key or update the existing one.
`update_parameters::prefetch_data::row::is_in_cas_result_set`
member variable was removed as well as supporting code in
`cas_request::applies_to` which iterated through cas updates
and marked individual `prefetch_data` rows as "need to be in
cas result set".
Instead now `cas_request::applies_to` is significantly
simplified since it doesn't do anything more than checking
`stmt.applies_to()` in short-circuiting manner.
A few tests for the issue are written, other lwt-batch-related
tests were adjusted accordingly to include rows in result set
for each statement inside conditional batches.
Tests: unit(dev, debug)
Co-authored-by: Konstantin Osipov <kostja@scylladb.com>
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Fixes#7128
CDC logs are not useful without at least delta_mode==keys, since
pre/post image data has no info on _what_ was actually done to
base table in source mutation.
Fixes#7119Fixes#7120
If preimage select came up empty - i.e. the row did not exist, either
due to never been created, or once delete, we should not bother creating
a log preimage row for it. Esp. since it makes it harder to interpret the
cdc log.
If an operation in a cdc batch did a row delete (ranged, ck, etc), do
not generate postimage data, since the row does no longer exist.
Note that we differentiate deleting all (non-pk/ck) columns from actual
row delete.
Fixes#6900
Clustered range deletes did not clear out the "row_states" data associated
with affected rows (might be many).
Adds a sweep through and erases relevant data. Since we do pre- and
postimage in "order", this should only affect postimage.
A check, to validate that counter column cannot be added into non-counter table,
is missing for alter table statement. Validation is performed when building new
schema, but it's limited to checking that a schema will not contain both counter
and non-counter columns.
Due to lack of validation, the added counter column could be incorrectly
persisted to the schema, but this results in a crash when setting the new
schema to its table. On restart, it can be confirmed that the schema change
was indeed persisted when describing the table.
This problem is fixed by doing proper validation for the alter table statement,
which consists of making sure a new counter column cannot be added to a
non-counter table.
The test cdc_disallow_cdc_for_counters_test is adjusted because one of its tests
was built on the assumption that counter column can be added into a non-counter
table.
Fixes#7065.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20200824155709.34743-1-raphaelsc@scylladb.com>
Merged pull request https://github.com/scylladb/scylla/pull/6741
by Piotr Dulikowski:
This PR changes the algorithm used to generate preimages and postimages
in CDC log. While its behavior is the same for non-batch operations
(with one exception described later), it generates pre/postimages that
are organized more nicely, and account for multiple updates to the same
row in one CQL batch.
Fixes#6597, #6598
Tests:
- unit(dev), for each consecutive commit
- unit(debug), for the last commit
Previous method
The previous method worked on a per delta row basis. First, the base
table is queried for the current state of the rows being modified in
the processed mutation (this is called the "preimage query"). Then,
for each delta row (representing a modification of a row):
If preimage is enabled and the row was already present in the table,
a corresponding preimage row is inserted before the delta row.
The preimage row contains data taken directly from the preimage
query result. Only columns that are modified by the delta are
included in the preimage.
If postimage is enabled, then a postimage row is inserted after the
delta row. The postimage row contains data which was a result of
taking row data directly from the preimage query result and applying
the change the corresponding delta row represented. All columns
of the row are included in the postimage.
The above works well for simple cases such like singular CQL INSERT,
UPDATE, DELETE, or simple CQL BATCH-es. An example:
cqlsh:ks> BEGIN UNLOGGED BATCH
INSERT INTO tbl (pk, ck, v) VALUES (0, 1, 111);
INSERT INTO tbl (pk, ck, v) VALUES (0, 2, 222);
APPLY BATCH;
cqlsh:ks> SELECT "cdc$batch_seq_no", "cdc$operation", "cdc$ttl",
pk, ck, v from ks.tbl_scylla_cdc_log ;
cdc$batch_seq_no | cdc$operation | cdc$ttl | pk | ck | v
------------------+---------------+---------+----+----+-----
...snip...
0 | 0 | null | 0 | 1 | 100
1 | 2 | null | 0 | 1 | 111
2 | 9 | null | 0 | 1 | 111
3 | 0 | null | 0 | 2 | 200
4 | 2 | null | 0 | 2 | 222
5 | 9 | null | 0 | 2 | 222
Preimage rows are represented by cdc operation 0, and postimage by 9.
Please note that all rows presented above share the same value of
cdc$time column, which was not shown here for brevity.
Problems with previous approach
This simple algorithm has some conceptual and implementational problems
which arise when processing more complicated CQL BATCH-es. Consider
the following example:
cqlsh:ks> BEGIN UNLOGGED BATCH
INSERT INTO tbl (pk, ck, v1) VALUES (0, 0, 1) USING TTL 1000;
INSERT INTO tbl (pk, ck, v2) VALUES (0, 0, 2) USING TTL 2000;
APPLY BATCH;
cqlsh:ks> SELECT "cdc$batch_seq_no", "cdc$operation", "cdc$ttl",
pk, ck, v1, v2 FROM tbl_scylla_cdc_log;
cdc$batch_seq_no | cdc$operation | cdc$ttl | pk | ck | v1 | v2
------------------+---------------+---------+----+----+------+------
...snip...
0 | 0 | null | 0 | 0 | null | 0
1 | 2 | 2000 | 0 | 0 | null | 2
2 | 9 | null | 0 | 0 | 0 | 2
3 | 0 | null | 0 | 0 | 0 | null
4 | 1 | 1000 | 0 | 0 | 1 | null
5 | 9 | null | 0 | 0 | 1 | 0
A single cdc group (corresponding to rows sharing the same cdc$time)
might have more than one delta that modify the same row. For example,
this happens when modifying two columns of the same row with
different TTLs - due to our choice of CDC log schema, we must
represent such change with two delta rows.
It does not make sense to present a postimage after the first delta
and preimage before the second - both deltas are applied
simultaneously by the same CQL BATCH, so the middle "image" is purely
imaginary and does not appear at any point in the table.
Moreover, in this example, the last postimage is wrong - v1 is updated,
but v2 is not. None of the postimages presented above represent the
final state of the row.
New algorithm
The new algorithm works now on per cdc group basis, not delta row.
When starting processing a CQL BATCH:
Load preimage query results into a data structure representing
current state of the affected rows.
For each cdc group:
For each row modified within the group, a preimage is produced,
regardless if the row was present in the table. The preimage
is calculated based on the current state. Only include columns
that are modified for this row within the group.
For each delta, produce a delta row and update the current state
accordingly.
Produce postimages in the same way as preimages - but include all
columns for each row in the postimage.
The new algorithm produces postimage correctly when multiple deltas
affect one, because the state of the row is updated on the fly.
This algorithm moves preimage and postimage rows to the beginning and
the end of the cdc group, accordingly. This solves the problem of
imaginary preimages and postimages appearing inside a cdc group.
Unfortunately, it is possible for one CQL BATCH to contain changes that
use multiple timestamps. This will result in one CQL BATCH creating
multiple cdc groups, with different cdc$time. As it is impossible, with
our choice of schema, to tell that those cdc groups were created from
one CQL BATCH, instead we pretend as if those groups were separate CQL
operations. By tracking the state of the affected rows, we make sure
that preimage in later groups will reflect changes introduces in
previous groups.
One more thing - this algorithm should have the same results for
singular CQL operations and simple CQL BATCH-es, with one exception.
Previously, preimage not produced if a row was not present in the
table. Now, the preimage row will appear unconditionally - it will have
nulls in place of column values.
* 'cdc-pre-postimage-persistence' of github.com:piodul/scylla:
cdc: fix indentation
cdc: don't update partition state when not needed
cdc: implement pre/postimage persistence
cdc: add interface for producing pre/postimages
cdc: load preimage query result into partition state fields
cdc: introduce fields for keeping partition state
cdc: rename set_pk_columns -> allocate_new_log_row
cdc: track batch_no inside transformer
cdc: move cdc$time generation to transformer
cdc: move find_timestamp to split.cc
cdc: introduce change_processor interface
cdc: remove redundant schema arguments from cdc functions
cdc: move management of generated mutations inside transformer
cdc: move preimage result set into a field of transformer
cdc: keep ts and tuuid inside transformer
cdc: track touched parts of mutations inside transformer
cdc: always include preimage for affected rows
Moves responsibility for generating pre/postimage rows from the
"process_change" method to "produce_preimage" and "produce_postimage".
This commit actually affects the contents of generated CDC log
mutations.
Added a unit test that verifies more complicated cases with CQL BATCH.
Instead of `restriction` class methods, use the new free functions.
Specific replacement actions are listed below.
Note that class `restrictions` (plural) remains intact -- both its
methods and its type hierarchy remain intact for now.
Ensure full test coverage of the replacement code with new file
test/boost/restrictions_test.cc and some extra testcases in
test/cql/*.
Drop some existing tests because they codify buggy behaviour
(reference #6369, #6382). Drop others because they forbid relation
combinations that are now allowed (eg, mixing equality and
inequality, comparing to NULL, etc.).
Here are some specific categories of what was replaced:
- restriction::is_foo predicates are replaced by using the free
function find_if; sometimes it is used transitively (see, eg,
has_slice)
- restriction::is_multi_column is replaced by dynamic casts (recall
that the `restrictions` class hierarchy still exists)
- utility methods is_satisfied_by, is_supported_by, to_string, and
uses_function are replaced by eponymous free functions; note that
restrictions::uses_function still exists
- restriction::apply_to is replaced by free function
replace_column_def
- when checking infinite_bound_range_deletions, the has_bound is
replaced by local free function bounded_ck
- restriction::bounds and restriction::value are replaced by the more
general free function possible_lhs_values
- using free functions allows us to simplify the
multi_column_restriction and token_restriction hierarchies; their
methods merge_with and uses_function became identical in all
subclasses, so they were moved to the base class
- single_column_primary_key_restrictions<clustering_key>::needs_filtering
was changed to reuse num_prefix_columns_that_need_not_be_filtered,
which uses free functions
Fixes#5799.
Fixes#6369.
Fixes#6371.
Fixes#6372.
Fixes#6382.
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
When a token is calculated for stream_id, we check that the key is
exactly 16 bytes long. If it's not - `minimum_token` is returned
and client receives empty result.
This used to be the expected behavior for empty keys; now it's
extended to keys of any incorrect length.
Fixes#6570
LWT batches conditions can't span multiple tables.
This was detected in batch_statement::validate() called in ::prepare().
But ::cas_result_set_metadata() was built in the constructor,
causing a bitset assert/crash in a reported scenario.
This patch moves validate() to the constructor before building metadata.
Closes#6332
Tested with https://github.com/scylladb/scylla-dtest/pull/1465
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Add a couple of cql tests regarding conditional batches:
1. Verify that "delete" takes priority over "insert"
when applied to the same row within the same batch.
2. Test that a workaround for the issue works as expected (i.e.
delete only individual cells instead of the full record).
Tests: unit(dev)
Fixes: #6273
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200506201200.176590-1-pa.solodovnikov@scylladb.com>
With synchronous local view updates enabled, local materialized views
can be queried right after base table insertions, without the risk
of reading stale values.
The is_log_for_some_table function incorrectly assumed that
database::find_schema would return a null pointer in case the queried
schema does not exist. This patch fixes that, and now this function
checks for existence of the schema using database::has_schema.
Tests: unit(dev)
SimpleStrategy creates a list of endpoints by iterating over the set of
all configured endpoints for the given token, until we reach keyspace
replication factor.
There is a trivial coding bug when we first add at least one endpoint
to the list, and then compare list size and replication factor.
If RF=0 this never yields true.
Fix by moving the RF check before at least one endpoint is added to the
list.
Cassandra never had this bug since it uses a less fancy while()
loop.
Fixes#5962
Message-Id: <20200306193729.130266-1-kostja@scylladb.com>
Introduce a test which checks how different CQL features (DML, LWT,
MV) work when no replicas are available (e.g. because
they are all in an unavailable data center).
Specifically the test checks that when we SELECT with IN clause
and there are no available replicas, there is no crash (#5935).
Message-Id: <20200306192521.73486-3-kostja@scylladb.com>
In case a static and a clustering row is written at the same time, but
a clustering row with given key was not present, the preimage query was
incorrectly configured and no rows were returned. This resulted in an
empty preimage, while a preimage for static row should be present.
This patch fixes this and now the static row is correctly written to cdc
log in the case above.
Tests: unit(dev)
This change disallows creating CDC log tables for already existing CDC
log tables. CDC logs nested in that way are not really useful and do not
work at the moment, therefore disallowing their creation prevents
confusion.
We were accessing the wrong stack location if a decimal was not at top
of the stack.
Fixes: #5711
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
We were accessing the wrong stack location if a varint was not at the
top of the stack.
Refs: #5711
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
These unit tests cover all CQL aspects of lightweight transactions,
such as grammar, null semantics, batch semantics, result set
format, and so on.
For now, comment out unicode tests: test output depends
on libjsoncpp version in use.
