Keyspace storage options series adds a new schema table:
system_schema.scylla_keyspaces. The regenerated cases ensure
that this new table is taken into account when the schema feature
is available.
As flat mutation reader {up,down}grades get added to the write path,
comparing range-tombstone-containing (at least) sstables byte-by-byte
to a reference is starting to seem like a fool's errand.
* When a flat mutation reader is {up,down}graded, information may get
lost while splitting range tombstones. Making those splits revertable
should in theory be possible but would surely make {up,down}graders
slower and more complex, and may also possibly entail adding
information to in-memory representation of range tombstones and
range rombstone changes. Such investment for the sake of 7 unit tests
does not seem wise, given that the plan is to get rid of reader
{up,down}grade logic once the move to flat mutation reader v2 is
completed.
* All affected tests also validate their written sstables
semantically.
* At least some of the offending reference sstables are not
"canonical" wrt range tombstones to begin with -- they contain range
tombstones that overlap with clustering rows. The fact that Scylla
does not "canonicalize" those in some way seems purely incidental.
Signed-off-by: Michael Livshin <michael.livshin@scylladb.com>
Prerequisite for the "ME sstable format support" series (which has been
posted to the mailing list) -- to be merged or rejected together with
that.
Signed-off-by: Michael Livshin <michael.livshin@scylladb.com>
Closes#9939
With previous design of the schema change test, a regeneration
was necessary each time a new distributed system table was added.
It was not the original purpose of the test to keep track of new
distributed tables which simply propagate on their own,
so the test case is now modified: internal distributed tables
are not part of the schema digest anymore, which means that
changes inside them will not cause mismatches.
This change involves a one-shot regeneration of all digests,
which due to historical reasons included internal distributed
tables in the digest, but no further regenerations should ever
be necessary when a new internal distributed table is added.
Commit a6ad70d3da changed the format of
stream IDs: the lower 8 bytes were previously generated randomly, now
some of them have semantics. In particular, the least significant byte
contains a version (stream IDs might evolve with further releases).
This is a backward-incompatible change: the code won't properly handle
stream IDs with all lower 8 bytes generated randomly. To protect us from
subtle bugs, the code has an assertion that checks the stream ID's
version.
This means that if an experimental user used CDC before the change and
then upgraded, they might hit the assertion when a node attempts to
retrieve a CDC generation with old stream IDs from the CDC description
tables and then decode it.
In effect, the user won't even be able to start a node.
Similarly as with the case described in
d89b7a0548, the simplest fix is to rename
the tables. This fix must get merged in before CDC goes out of
experimental.
Now, if the user upgrades their cluster from a pre-rename version, the
node will simply complain that it can't obtain the CDC generation
instead of preventing the cluster from working. The user will be able to
use CDC after running checkAndRepairCDCStreams.
Since a new table is added to the system_distributed keyspace, the
cluster's schema has changed, so sstables and digests need to be
regenerated for schema_digest_test.
Test also the md format in all_sstable_versions.
Add pre-computed md-sstable files generated using Cassandra version 3.11.7
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Commit 968177da04 has changed the schema
of cdc_topology_description and cdc_description tables in the
system_distributed keyspace.
Unfortunately this was a backwards-incompatible change: these tables
would always be created, irrespective of whether or not "experimental"
was enabled. They just wouldn't be populated with experimental=off.
If the user now tries to upgrade Scylla from a version before this change
to a version after this change, it will work as long as CDC is protected
b the experimental flag and the flag is off.
However, if we drop the flag, or if the user turns experimental on,
weird things will happen, such as nodes refusing to start because they
try to populate cdc_topology_description while assuming a different schema
for this table.
The simplest fix for this problem is to rename the tables. This fix must
get merged in before CDC goes out of experimental.
If the user upgrades his cluster from a pre-rename version, he will simply
have two garbage tables that he is free to delete after upgrading.
sstables and digests need to be regenerated for schema_digest_test since
this commit effectively adds new tables to the system_distributed keyspace.
This doesn't result in schema disagreement because the table is
announced to all nodes through the migration manager.
Some legacy `mc` SSTables (created in Scylla 3.0) may contain incorrect
serialization headers, which don't wrap frozen UDTs nested inside collections
with the FrozenType<...> tag. When reading such SSTable,
Scylla would detect a mismatch between the schema saved in schema
tables (which correctly wraps UDTs in the FrozenType<...> tag) and the schema
from the serialization header (which doesn't have these tags).
SSTables created in Scylla versions 3.1 and above, in particular in
Scylla versions that contain this commit, create correct serialization
headers (which wrap UDTs in the FrozenType<...> tag).
This commit does two things:
1. for all SSTables created after this commit, include a new feature
flag, CorrectUDTsInCollections, presence of which implies that frozen
UDTs inside collections have the FrozenType<...> tag.
2. when reading a Scylla SSTable without the feature flag, we assume that UDTs
nested inside collections are always frozen, even if they don't have
the tag. This assumption is safe to be made, because at the time of
this commit, Scylla does not allow non-frozen (multi-cell) types inside
collections or UDTs, and because of point 1 above.
There is one edge case not covered: if we don't know whether the SSTable
comes from Scylla or from C*. In that case we won't make the assumption
described in 2. Therefore, if we get a mismatch between schema and
serialization headers of a table which we couldn't confirm to come from
Scylla, we will still reject the table. If any user encounters such an
issue (unlikely), we will have to use another solution, e.g. using a
separate tool to rewrite the SSTable.
Fixes#6130.
The cdc_topology_description table will be used internally
by nodes to send new CDC stream generations to other nodes.
The cdc_description table is a user-facing table,
used to inform users about new sets of CDC streams.
Regenerate sstables and digests for schema_change_test.
We don't need to protect this change by a schema feature:
when a node creates these tables, it announces them
to all other nodes. If schema agreement happens before
this migration, all nodes will use a digest calculated
without these tables. If it happens after, then all nodes
will eventually know about these tables and use a digest
calculated with these tables.
The original "test_schema_digest_does_not_change" test case ensures
that schema digests will match for older nodes that do not support
all the features yet (including computed columns).
The additional case uses sstables generated after CDC was enabled
and a table with CDC enabled is created,
in order to make sure that the digest computed
including CDC column does not change spuriously as well.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
The plan is to move the unstructured content of tests/ directory
into the following directories of test/:
test/lib - shared header and source files for unit tests
test/boost - boost unit tests
test/unit - non-boost unit tests
test/manual - tests intended to be run manually
test/resource - binary test resources and configuration files
In order to not break git bisect and preserve the file history,
first move most of the header files and resources.
Update paths to these files in .cc files, which are not moved.
