4251 Commits

Author SHA1 Message Date
Lakshmi Narayanan Sreethar
705ec24977 db/config.cc: increment components_memory_reclaim_threshold config default
Incremented the components_memory_reclaim_threshold config's default
value to 0.2 as the previous value was too strict and caused unnecessary
eviction in otherwise healthy clusters.

Fixes #18607

Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 3d7d1fa72a)

Closes #19011
2024-06-04 07:13:28 +03:00
Botond Dénes
e89eb41e70 Merge '[Backport 5.2] : Reload reclaimed bloom filters when memory is available ' from Lakshmi Narayanan Sreethar
PR https://github.com/scylladb/scylladb/pull/17771 introduced a threshold for the total memory used by all bloom filters across SSTables. When the total usage surpasses the threshold, the largest bloom filter will be removed from memory, bringing the total usage back under the threshold. This PR adds support for reloading such reclaimed bloom filters back into memory when memory becomes available (i.e., within the 10% of available memory earmarked for the reclaimable components).

The SSTables manager now maintains a list of all SSTables whose bloom filter was removed from memory and attempts to reload them when an SSTable, whose bloom filter is still in memory, gets deleted. The manager reloads from the smallest to the largest bloom filter to maximize the number of filters being reloaded into memory.

Backported from https://github.com/scylladb/scylladb/pull/18186 to 5.2.

Closes #18666

* github.com:scylladb/scylladb:
  sstable_datafile_test: add testcase to test reclaim during reload
  sstable_datafile_test: add test to verify auto reload of reclaimed components
  sstables_manager: reload previously reclaimed components when memory is available
  sstables_manager: start a fiber to reload components
  sstable_directory_test: fix generation in sstable_directory_test_table_scan_incomplete_sstables
  sstable_datafile_test: add test to verify reclaimed components reload
  sstables: support reloading reclaimed components
  sstables_manager: add new intrusive set to track the reclaimed sstables
  sstable: add link and comparator class to support new instrusive set
  sstable: renamed intrusive list link type
  sstable: track memory reclaimed from components per sstable
  sstable: rename local variable in sstable::total_reclaimable_memory_size
2024-05-30 11:11:39 +03:00
Botond Dénes
331e0c4ca7 Merge '[Backport 5.2] mutation_fragment_stream_validating_filter: respect validating_level::none' from ScyllaDB
Even when configured to not do any validation at all, the validator still did some. This small series fixes this, and adds a test to check that validation levels in general are respected, and the validator doesn't validate more than it is asked to.

Fixes: #18662

(cherry picked from commit f6511ca1b0)

(cherry picked from commit e7b07692b6)

(cherry picked from commit 78afb3644c)

 Refs #18667

Closes #18723

* github.com:scylladb/scylladb:
  test/boost/mutation_fragment_test.cc: add test for validator validation levels
  mutation: mutation_fragment_stream_validating_filter: fix validation_level::none
  mutation: mutation_fragment_stream_validating_filter: add raises_error ctor parameter
2024-05-27 08:52:06 +03:00
Alexey Novikov
32be38dae5 make timestamp string format cassandra compatible
when we convert timestamp into string it must look like: '2017-12-27T11:57:42.500Z'
it concerns any conversion except JSON timestamp format
JSON string has space as time separator and must look like: '2017-12-27 11:57:42.500Z'
both formats always contain milliseconds and timezone specification

Fixes #14518
Fixes #7997

Closes #14726
Fixes #16575

(cherry picked from commit ff721ec3e3)

Closes #18852
2024-05-26 16:30:06 +03:00
Botond Dénes
3dacf6a4b1 test/boost/mutation_fragment_test.cc: add test for validator validation levels
To make sure that the validator doesn't validate what the validation
level doesn't include.

(cherry picked from commit 78afb3644c)
2024-05-24 03:36:28 -04:00
Benny Halevy
d947f1e275 chunked_vector_test: add more exception safety tests
For insertion, with and without reservation,
and for fill and copy constructors.

Reproduces https://github.com/scylladb/scylladb/issues/18635

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2024-05-21 11:33:42 +03:00
Benny Halevy
d727382cc1 chunked_vector_test: exception_safe_class: count also moved objects
We have to account for moved objects as well
as copied objects so they will be balanced with
the respective `del_live_object` calls called
by the destructor.

However, since chunked_vector requires the
value_type to be nothrow_move_constructible,
just count the additional live object, but
do not modify _countdown or, respectively, throw
an exception, as this should be considered only
for the default and copy constructors.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2024-05-21 11:33:42 +03:00
Lakshmi Narayanan Sreethar
d4c523e9ef sstable_datafile_test: add testcase to test reclaim during reload
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 4d22c4b68b)
2024-05-14 19:20:06 +05:30
Lakshmi Narayanan Sreethar
b505ce4897 sstable_datafile_test: add test to verify auto reload of reclaimed components
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit a080daaa94)
2024-05-14 19:20:06 +05:30
Lakshmi Narayanan Sreethar
72494af137 sstable_directory_test: fix generation in sstable_directory_test_table_scan_incomplete_sstables
The testcase uses an sstable whose mutation key and the generation are
owned by different shards. Due to this, when process_sstable_dir is
called, the sstable gets loaded into a different shard than the one that
was intended. This also means that the sstable and the sstable manager
end up in different shards.

The following patch will introduce a condition variable in sstables
manager which will be signalled from the sstables. If the sstable and
the sstable manager are in different shards, the signalling will cause
the testcase to fail in debug mode with this error : "Promise task was
set on shard x but made ready on shard y". So, fix it by supplying
appropriate generation number owned by the same shard which owns the
mutation key as well.

Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 24064064e9)
2024-05-14 19:19:22 +05:30
Lakshmi Narayanan Sreethar
c15e72695d sstable_datafile_test: add test to verify reclaimed components reload
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 69b2a127b0)
2024-05-14 19:19:18 +05:30
Kamil Braun
b68c06cc3a direct_failure_detector: increase ping timeout and make it tunable
The direct failure detector design is simplistic. It sends pings
sequentially and times out listeners that reached the threshold (i.e.
didn't hear from a given endpoint for too long) in-between pings.

Given the sequential nature, the previous ping must finish so the next
ping can start. We timeout pings that take too long. The timeout was
hardcoded and set to 300ms. This is too low for wide-area setups --
latencies across the Earth can indeed go up to 300ms. 3 subsequent timed
out pings to a given node were sufficient for the Raft listener to "mark
server as down" (the listener used a threshold of 1s).

Increase the ping timeout to 600ms which should be enough even for
pinging the opposite side of Earth, and make it tunable.

Increase the Raft listener threshold from 1s to 2s. Without the
increased threshold, one timed out ping would be enough to mark the
server as down. Increasing it to 2s requires 3 timed out pings which
makes it more robust in presence of transient network hiccups.

In the future we'll most likely want to decrease the Raft listener
threshold again, if we use Raft for data path -- so leader elections
start quickly after leader failures. (Faster than 2s). To do that we'll
have to improve the design of the direct failure detector.

Ref: scylladb/scylladb#16410
Fixes: scylladb/scylladb#16607

---

I tested the change manually using `tc qdisc ... netem delay`, setting
network delay on local setup to ~300ms with jitter. Without the change,
the result is as observed in scylladb/scylladb#16410: interleaving
```
raft_group_registry - marking Raft server ... as dead for Raft groups
raft_group_registry - marking Raft server ... as alive for Raft groups
```
happening once every few seconds. The "marking as dead" happens whenever
we get 3 subsequent failed pings, which is happens with certain (high)
probability depending on the latency jitter. Then as soon as we get a
successful ping, we mark server back as alive.

With the change, the phenomenon no longer appears.

(cherry picked from commit 8df6d10e88)

Closes #18558
2024-05-08 15:46:59 +02:00
Lakshmi Narayanan Sreethar
0fc0474ccc sstables: reclaim_memory_from_components: do not update _recognised_components
When reclaiming memory from bloom filters, do not remove them from
_recognised_components, as that leads to the on-disk filter component
being left back on disk when the SSTable is deleted.

Fixes #18398

Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>

Closes scylladb/scylladb#18400

(cherry picked from commit 6af2659b57)

Closes #18437
2024-04-29 10:02:52 +03:00
Lakshmi Narayanan Sreethar
dd9ab15bb5 test_bloom_filter.py: disable reclaiming memory from components
Disabled reclaiming memory from sstable components in the testcase as it
interferes with the false positive calculation.

Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit d86505e399)
2024-04-16 15:50:22 +05:30
Lakshmi Narayanan Sreethar
96db5ae5e3 sstable_datafile_test: add tests to verify auto reclamation of components
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit d261f0fbea)
2024-04-16 15:49:58 +05:30
Lakshmi Narayanan Sreethar
beea229deb test/lib: allow overriding available memory via test_env_config
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 169629dd40)
2024-04-16 15:30:39 +05:30
Lakshmi Narayanan Sreethar
31251b37dd sstable_datafile_test: add testcase to verify reclamation from sstables
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit e0b6186d16)
2024-04-16 15:30:30 +05:30
Aleksandra Martyniuk
97671eb935 test: add test for repair_row::size()
Add test which checs whether repair_row::size() considers external
memory.

(cherry picked from commit 51c09a84cc)
2024-04-09 13:29:33 +02:00
Kefu Chai
6209f5d6d4 tests: utils: error injection: print time duration instead of count
instead of casting / comparing the count of duration unit, let's just
compare the durations, so that boost.test is able to print the duration
in a more informative and user friendly way (line wrapped)

test/boost/error_injection_test.cc(167): fatal error:
    in "test_inject_future_disabled":
      critical check wait_time > sleep_msec has failed [23839ns <= 10ms]

Refs #15902
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
(cherry picked from commit 1d33a68dd7)
2024-03-20 09:40:16 +00:00
Kamil Braun
0bb338c521 test: remove test_writes_to_recent_previous_cdc_generations
The test in its original form relies on the
`error_injections_at_startup` feature, which 5.2 doesn't have, so I
adapted the test to enable error injections after bootstrapping nodes in
the backport (9c44bbce67). That is however
incorrect, it's important for the injection to be enabled while the
nodes are booting, otherwise the test will be flaky, as we observed.
Details in scylladb/scylladb#17749.

Remove the test from 5.2 branch.

Fixes scylladb/scylladb#17749

Closes #17750
2024-03-15 10:22:22 +02:00
Nadav Har'El
08077ff3e8 alternator, mv: fix case of two new key columns in GSI
A materialized view in CQL allows AT MOST ONE view key column that
wasn't a key column in the base table. This is because if there were
two or more of those, the "liveness" (timestamp, ttl) of these different
columns can change at every update, and it's not possible to pick what
liveness to use for the view row we create.

We made an exception for this rule for Alternator: DynamoDB's API allows
creating a GSI whose partition key and range key are both regular columns
in the base table, and we must support this. We claim that the fact that
Alternator allows neither TTL (Alternator's "TTL" is a different feature)
nor user-defined timestamps, does allow picking the liveness for the view
row we create. But we did it wrong!

We claimed in a comment - and implemented in the code before this patch -
that in Alternator we can assume that both GSI key columns will have the
*same* liveness, and in particular timestamp. But this is only true if
one modifies both columns together! In fact, in general it is not true:
We can have two non-key attributes 'a' and 'b' which are the GSI's key
columns, and we can modify *only* b, without modifying a, in which case
the timestamp of the view modification should be b's newer timestamp,
not a's older one. The existing code took a's timestamp, assuming it
will be the same as b's, which is incorrect. The result was that if
we repeatedly modify only b, all view updates will receive the same
timestamp (a's old timestamp), and a deletion will always win over
all the modifications. This patch includes a reproducing test written by
a user (@Zak-Kent) that demonstrates how after a view row is deleted
it doesn't get recreated - because all the modifications use the same
timestamp.

The fix is, as suggested above, to use the *higher* of the two
timestamps of both base-regular-column GSI key columns as the timestamp
for the new view rows or view row deletions. The reproducer that
failed before this patch passes with it. As usual, the reproducer
passes on AWS DynamoDB as well, proving that the test is correct and
should really work.

Fixes #17119

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#17172

(cherry picked from commit 21e7deafeb)
2024-03-13 15:08:32 +02:00
Kamil Braun
405387c663 test: unflake test_topology_remove_garbage_group0
The test is booting nodes, and then immediately starts shutting down
nodes and removing them from the cluster. The shutting down and
removing may happen before driver manages to connect to all nodes in the
cluster. In particular, the driver didn't yet connect to the last
bootstrapped node. Or it can even happen that the driver has connected,
but the control connection is established to the first node, and the
driver fetched topology from the first node when the first node didn't
yet consider the last node to be normal. So the driver decides to close
connection to the last node like this:
```
22:34:03.159 DEBUG> [control connection] Removing host not found in
   peers metadata: <Host: 127.42.90.14:9042 datacenter1>
```

Eventually, at the end of the test, only the last node remains, all
other nodes have been removed or stopped. But the driver does not have a
connection to that last node.

Fix this problem by ensuring that:
- all nodes see each other as NORMAL,
- the driver has connected to all nodes
at the beginning of the test, before we start shutting down and removing
nodes.

Fixes scylladb/scylladb#16373

(cherry picked from commit a68701ed4f)

Closes #17703
2024-03-12 13:43:21 +01:00
Michał Chojnowski
54048e5613 sstables: fix a use-after-free in key_view::explode()
key_view::explode() contains a blatant use-after-free:
unless the input is already linearized, it returns a view to a local temporary buffer.

This is rare, because partition keys are usually not large enough to be fragmented.
But for a sufficiently large key, this bug causes a corrupted partition_key down
the line.

Fixes #17625

(cherry picked from commit 7a7b8972e5)

Closes #17725
2024-03-11 16:17:32 +02:00
Lakshmi Narayanan Sreethar
e8736ae431 reader_permit: store schema_ptr instead of raw schema pointer
Store schema_ptr in reader permit instead of storing a const pointer to
schema to ensure that the schema doesn't get changed elsewhere when the
permit is holding on to it. Also update the constructors and all the
relevant callers to pass down schema_ptr instead of a raw pointer.

Fixes #16180

Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>

Closes scylladb/scylladb#16658

(cherry picked from commit 76f0d5e35b)

Closes #17694
2024-03-08 10:56:12 +02:00
Botond Dénes
ba373f83e4 Merge '[Backport 5.2] repair: streaming: handle no_such_column_family from remote node' from Aleksandra Martyniuk
RPC calls lose information about the type of returned exception.
Thus, if a table is dropped on receiver node, but it still exists
on a sender node and sender node streams the table's data, then
the whole operation fails.

To prevent that, add a method which synchronizes schema and then
checks, if the exception was caused by table drop. If so,
the exception is swallowed.

Use the method in streaming and repair to continue them when
the table is dropped in the meantime.

Fixes: https://github.com/scylladb/scylladb/issues/17028.
Fixes: https://github.com/scylladb/scylladb/issues/15370.
Fixes: https://github.com/scylladb/scylladb/issues/15598.

Closes #17528

* github.com:scylladb/scylladb:
  repair: handle no_such_column_family from remote node gracefully
  test: test drop table on receiver side during streaming
  streaming: fix indentation
  streaming: handle no_such_column_family from remote node gracefully
  repair: add methods to skip dropped table
2024-02-28 16:33:01 +02:00
Aleksandra Martyniuk
23493bb342 test: test drop table on receiver side during streaming
(cherry picked from commit 2ea5d9b623)
2024-02-28 11:46:02 +01:00
Aleksandra Martyniuk
296be93714 test: add test to check if reader is closed
Add test to check if reader is closed in sstable::has_partition_key.

(cherry picked from commit 4530be9e5b)
2024-02-26 16:17:12 +01:00
Avi Kivity
9c44bbce67 Merge 'cdc: metadata: allow sending writes to the previous generations' from Patryk Jędrzejczak
Before this PR, writes to the previous CDC generations would
always be rejected. After this PR, they will be accepted if the
write's timestamp is greater than `now - generation_leeway`.

This change was proposed around 3 years ago. The motivation was
to improve user experience. If a client generates timestamps by
itself and its clock is desynchronized with the clock of the node
the client is connected to, there could be a period during
generation switching when writes fail. We didn't consider this
problem critical because the client could simply retry a failed
write with a higher timestamp. Eventually, it would succeed. This
approach is safe because these failed writes cannot have any side
effects. However, it can be inconvenient. Writing to previous
generations was proposed to improve it.

The idea was rejected 3 years ago. Recently, it turned out that
there is a case when the client cannot retry a write with the
increased timestamp. It happens when a table uses CDC and LWT,
which makes timestamps permanent. Once Paxos commits an entry
with a given timestamp, Scylla will keep trying to apply that entry
until it succeeds, with the same timestamp. Applying the entry
involves writing to the CDC log table. If it fails, we get stuck.
It's a major bug with an unknown perfect solution.

Allowing writes to previous generations for `generation_leeway` is
a probabilistic fix that should solve the problem in practice.

Apart from this change, this PR adds tests for it and updates
the documentation.

This PR is sufficient to enable writes to the previous generations
only in the gossiper-based topology. The Raft-based topology
needs some adjustments in loading and cleaning CDC generations.
These changes won't interfere with the changes introduced in this
PR, so they are left for a follow-up.

Fixes scylladb/scylladb#7251
Fixes scylladb/scylladb#15260

Closes scylladb/scylladb#17134

* github.com:scylladb/scylladb:
  docs: using-scylla: cdc: remove info about failing writes to old generations
  docs: dev: cdc: document writing to previous CDC generations
  test: add test_writes_to_previous_cdc_generations
  cdc: generation: allow increasing generation_leeway through error injection
  cdc: metadata: allow sending writes to the previous generations

(cherry picked from commit 9bb4482ad0)

Backport note: replaced `servers_add` with `server_add` loop in tests
replaced `error_injections_at_startup` (not implemented in 5.2) with
`enable_injection` post-boot
2024-02-22 15:05:19 +01:00
Nadav Har'El
6a6115cd86 mv: fix missing view deletions in some cases of range tombstones
For efficiency, if a base-table update generates many view updates that
go the same partition, they are collected as one mutation. If this
mutation grows too big it can lead to memory exhaustion, so since
commit 7d214800d0 we split the output
mutation to mutations no longer than 100 rows (max_rows_for_view_updates)
each.

This patch fixes a bug where this split was done incorrectly when
the update involved range tombstones, a bug which was discovered by
a user in a real use case (#17117).

Range tombstones are read in two parts, a beginning and an end, and the
code could split the processing between these two parts and the result
that some of the range tombstones in update could be missed - and the
view could miss some deletions that happened in the base table.

This patch fixes the code in two places to avoid breaking up the
processing between range tombstones:

1. The counter "_op_count" that decides where to break the output mutation
   should only be incremented when adding rows to this output mutation.
   The existing code strangely incrmented it on every read (!?) which
   resulted in the counter being incremented on every *input* fragment,
   and in particular could reach the limit 100 between two range
   tombstone pieces.

2. Moreover, the length of output was checked in the wrong place...
   The existing code could get to 100 rows, not check at that point,
   read the next input - half a range tombstone - and only *then*
   check that we reached 100 rows and stop. The fix is to calculate
   the number of rows in the right place - exactly when it's needed,
   not before the step.

The first change needs more justification: The old code, that incremented
_op_count on every input fragment and not just output fragments did not
fit the stated goal of its introduction - to avoid large allocations.
In one test it resulted in breaking up the output mutation to chunks of
25 rows instead of the intended 100 rows. But, maybe there was another
goal, to stop the iteration after 100 *input* rows and avoid the possibility
of stalls if there are no output rows? It turns out the answer is no -
we don't need this _op_count increment to avoid stalls: The function
build_some() uses `co_await on_results()` to run one step of processing
one input fragment - and `co_await` always checks for preemption.
I verfied that indeed no stalls happen by using the existing test
test_long_skipped_view_update_delete_with_timestamp. It generates a
very long base update where all the view updates go to the same partition,
but all but the last few updates don't generate any view updates.
I confirmed that the fixed code loops over all these input rows without
increasing _op_count and without generating any view update yet, but it
does NOT stall.

This patch also includes two tests reproducing this bug and confirming
its fixed, and also two additional tests for breaking up long deletions
that I wanted to make sure doesn't fail after this patch (it doesn't).

By the way, this fix would have also fixed issue #12297 - which we
fixed a year ago in a different way. That issue happend when the code
went through 100 input rows without generating *any* output rows,
and incorrectly concluding that there's no view update to send.
With this fix, the code no longer stops generating the view
update just because it saw 100 input rows - it would have waited
until it generated 100 output rows in the view update (or the
input is really done).

Fixes #17117

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#17164

(cherry picked from commit 14315fcbc3)
2024-02-22 15:36:58 +02:00
Michał Jadwiszczak
0d22471222 schema::describe: print 'synchronous_updates' only if it was specified
While describing materialized view, print `synchronous_updates` option
only if the tag is present in schema's extensions map. Previously if the
key wasn't present, the default (false) value was printed.

Fixes: #14924

Closes #14928

(cherry picked from commit b92d47362f)
2024-02-19 09:10:34 +02:00
Botond Dénes
422a731e85 query: do not kill unpaged queries when they reach the tombstone-limit
The reason we introduced the tombstone-limit
(query_tombstone_page_limit), was to allow paged queries to return
incomplete/empty pages in the face of large tombstone spans. This works
by cutting the page after the tombstone-limit amount of tombstones were
processed. If the read is unpaged, it is killed instead. This was a
mistake. First, it doesn't really make sense, the reason we introduced
the tombstone limit, was to allow paged queries to process large
tombstone-spans without timing out. It does not help unpaged queries.
Furthermore, the tombstone-limit can kill internal queries done on
behalf of user queries, because all our internal queries are unpaged.
This can cause denial of service.

So in this patch we disable the tombstone-limit for unpaged queries
altogether, they are allowed to continue even after having processed the
configured limit of tombstones.

Fixes: #17241

Closes scylladb/scylladb#17242

(cherry picked from commit f068d1a6fa)
2024-02-15 12:50:30 +02:00
Botond Dénes
94af1df2cf Merge 'Fix mintimeuuid() call that could crash Scylla' from Nadav Har'El
This PR fixes the bug of certain calls to the `mintimeuuid()` CQL function which large negative timestamps could crash Scylla. It turns out we already had protections in place against very positive timestamps, but very negative timestamps could still cause bugs.

The actual fix in this series is just a few lines, but the bigger effort was improving the test coverage in this area. I added tests for the "date" type (the original reproducer for this bug used totimestamp() which takes a date parameter), and also reproducers for this bug directly, without totimestamp() function, and one with that function.

Finally this PR also replaces the assert() which made this molehill-of-a-bug into a mountain, by a throw.

Fixes #17035

Closes scylladb/scylladb#17073

* github.com:scylladb/scylladb:
  utils: replace assert() by on_internal_error()
  utils: add on_internal_error with common logger
  utils: add a timeuuid minimum, like we had maximum
  test/cql-pytest: tests for "date" type

(cherry picked from commit 2a4b991772)
2024-02-07 14:19:32 +02:00
Kamil Braun
4e257c5c74 test_raft_snapshot_request: fix flakiness (again)
At the end of the test, we wait until a restarted node receives a
snapshot from the leader, and then verify that the log has been
truncated.

To check the snapshot, the test used the `system.raft_snapshots` table,
while the log is stored in `system.raft`.

Unfortunately, the two tables are not updated atomically when Raft
persists a snapshot (scylladb/scylladb#9603). We first update
`system.raft_snapshots`, then `system.raft` (see
`raft_sys_table_storage::store_snapshot_descriptor`). So after the wait
finishes, there's no guarantee the log has been truncated yet -- there's
a race between the test's last check and Scylla doing that last delete.

But we can check the snapshot using `system.raft` instead of
`system.raft_snapshots`, as `system.raft` has the latest ID. And since
1640f83fdc, storing that ID and truncating
the log in `system.raft` happens atomically.

Closes scylladb/scylladb#17106

(cherry picked from commit c911bf1a33)
2024-02-02 11:31:19 +01:00
Kamil Braun
08021dc906 test_raft_snapshot_request: fix flakiness
Add workaround for scylladb/python-driver#295.

Also an assert made at the end of the test was false, it is fixed with
appropriate comment added.

(cherry picked from commit 74bf60a8ca)
2024-02-02 11:31:19 +01:00
Botond Dénes
ce0ed29ad6 Merge 'Add an API to trigger snapshot in Raft servers' from Kamil Braun
This allows the user of `raft::server` to cause it to create a snapshot
and truncate the Raft log (leaving no trailing entries; in the future we
may extend the API to specify number of trailing entries left if
needed). In a later commit we'll add a REST endpoint to Scylla to
trigger group 0 snapshots.

One use case for this API is to create group 0 snapshots in Scylla
deployments which upgraded to Raft in version 5.2 and started with an
empty Raft log with no snapshot at the beginning. This causes problems,
e.g. when a new node bootstraps to the cluster, it will not receive a
snapshot that would contain both schema and group 0 history, which would
then lead to inconsistent schema state and trigger assertion failures as
observed in scylladb/scylladb#16683.

In 5.4 the logic of initial group 0 setup was changed to start the Raft
log with a snapshot at index 1 (ff386e7a44)
but a problem remains with these existing deployments coming from 5.2,
we need a way to trigger a snapshot in them (other than performing 1000
arbitrary schema changes).

Another potential use case in the future would be to trigger snapshots
based on external memory pressure in tablet Raft groups (for strongly
consistent tables).

The PR adds the API to `raft::server` and a HTTP endpoint that uses it.

In a follow-up PR, we plan to modify group 0 server startup logic to automatically
call this API if it sees that no snapshot is present yet (to automatically
fix the aforementioned 5.2 deployments once they upgrade.)

Closes scylladb/scylladb#16816

* github.com:scylladb/scylladb:
  raft: remove `empty()` from `fsm_output`
  test: add test for manual triggering of Raft snapshots
  api: add HTTP endpoint to trigger Raft snapshots
  raft: server: add `trigger_snapshot` API
  raft: server: track last persisted snapshot descriptor index
  raft: server: framework for handling server requests
  raft: server: inline `poll_fsm_output`
  raft: server: fix indentation
  raft: server: move `io_fiber`'s processing of `batch` to a separate function
  raft: move `poll_output()` from `fsm` to `server`
  raft: move `_sm_events` from `fsm` to `server`
  raft: fsm: remove constructor used only in tests
  raft: fsm: move trace message from `poll_output` to `has_output`
  raft: fsm: extract `has_output()`
  raft: pass `max_trailing_entries` through `fsm_output` to `store_snapshot_descriptor`
  raft: server: pass `*_aborted` to `set_exception` call

(cherry picked from commit d202d32f81)

Backport notes:
- `has_output()` has a smaller condition in the backported version
  (because the condition was smaller in `poll_output()`)
- `process_fsm_output` has a smaller body (because `io_fiber` had a
  smaller body) in the backported version
- the HTTP API is only started if `raft_group_registry` is started
2024-02-01 15:38:51 +01:00
Michael Huang
84004ab83c raft: Store snapshot update and truncate log atomically
In case the snapshot update fails, we don't truncate commit log.

Fixes scylladb/scylladb#9603

Closes scylladb/scylladb#15540

(cherry picked from commit 1640f83fdc)
2024-02-01 13:10:05 +01:00
Kamil Braun
753e2d3c57 service: raft: force initial snapshot transfer in new cluster
When we upgrade a cluster to use Raft, or perform manual Raft recovery
procedure (which also creates a fresh group 0 cluster, using the same
algorithm as during upgrade), we start with a non-empty group 0 state
machine; in particular, the schema tables are non-empty.

In this case we need to ensure that nodes which join group 0 receive the
group 0 state. Right now this is not the case. In previous releases,
where group 0 consisted only of schema, and schema pulls were also done
outside Raft, those nodes received schema through this outside
mechanism. In 91f609d065 we disabled
schema pulls outside Raft; we're also extending group 0 with other
things, like topology-specific state.

To solve this, we force snapshot transfers by setting the initial
snapshot index on the first group 0 server to `1` instead of `0`. During
replication, Raft will see that the joining servers are behind,
triggering snapshot transfer and forcing them to pull group 0 state.

It's unnecessary to do this for cluster which bootstraps with Raft
enabled right away but it also doesn't hurt, so we keep the logic simple
and don't introduce branches based on that.

Extend Raft upgrade tests with a node bootstrap step at the end to
prevent regressions (without this patch, the step would hang - node
would never join, waiting for schema).

Fixes: #14066

Closes #14336

(cherry picked from commit ff386e7a44)

Backport note: contrary to the claims above, it turns out that it is
actually necessary to create snapshots in clusters which bootstrap with
Raft, because of tombstones in current schema state expire hence
applying schema mutations from old Raft log entries is not really
idempotent. Snapshot transfer, which transfers group 0 history and
state_ids, prevents old entries from applying schema mutations over
latest schema state.

Ref: scylladb/scylladb#16683
2024-01-31 17:00:10 +01:00
Avi Kivity
351d6d6531 Merge 'Invalidate prepared statements for views when their schema changes.' from Eliran Sinvani
When a base table changes and altered, so does the views that might
refer to the added column (which includes "SELECT *" views and also
views that might need to use this column for rows lifetime (virtual
columns).
However the query processor implementation for views change notification
was an empty function.
Since views are tables, the query processor needs to at least treat them
as such (and maybe in the future, do also some MV specific stuff).
This commit adds a call to `on_update_column_family` from within
`on_update_view`.
The side effect true to this date is that prepared statements for views
which changed due to a base table change will be invalidated.

Fixes https://github.com/scylladb/scylladb/issues/16392

This series also adds a test which fails without this fix and passes when the fix is applied.

Closes scylladb/scylladb#16897

* github.com:scylladb/scylladb:
  Add test for mv prepared statements invalidation on base alter
  query processor: treat view changes at least as table changes

(cherry picked from commit 5810396ba1)
2024-01-23 21:31:47 +02:00
Michał Jadwiszczak
29da20b9e0 schema: add scylla specific options to schema description
Add `paxos_grace_seconds`, `tombstone_gc`, `cdc` and `synchronous_updates`
options to schema description.

Fixes: #12389
Fixes: scylladb/scylla-enterprise#2979

Closes #16786
2024-01-16 09:56:08 +02:00
Aleksandra Martyniuk
8b77fbc904 cql3: statements: call check_restricted_table_properties in prepare
Table properties validation is performed on statement execution.
Thus, when one attempts to create a table with invalid options,
an incorrect command gets committed in Raft. But then its
application fails, leading to a raft machine being stopped.

Check table properties when create and alter statements are prepared.

The error is no longer returned as an exceptional future, but it
is thrown. Adjust the tests accordingly.

(cherry picked from commit 60fdc44bce)
2024-01-11 16:10:26 +01:00
Nadav Har'El
ac0056f4bc Merge 'Fix partition estimation with TWCS tables during streaming' from Raphael "Raph" Carvalho
TWCS tables require partition estimation adjustment as incoming streaming data can be segregated into the time windows.

Turns out we had two problems in this area that leads to suboptimal bloom filters.

1) With off-strategy enabled, data segregation is postponed, but partition estimation was adjusted as if segregation wasn't postponed. Solved by not adjusting estimation if segregation is postponed.
2) With off-strategy disabled, data segregation is not postponed, but streaming didn't feed any metadata into partition estimation procedure, meaning it had to assume the max windows input data can be segregated into (100). Solved by using schema's default TTL for a precise estimation of window count.

For the future, we want to dynamically size filters (see https://github.com/scylladb/scylladb/issues/2024), especially for TWCS that might have SSTables that are left uncompacted until they're fully expired, meaning that the system won't heal itself in a timely manner through compaction on a SSTable that had partition estimation really wrong.

Fixes https://github.com/scylladb/scylladb/issues/15704.

Closes scylladb/scylladb#15938

* github.com:scylladb/scylladb:
  streaming: Improve partition estimation with TWCS
  streaming: Don't adjust partition estimate if segregation is postponed

(cherry picked from commit 64d1d5cf62)
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>

Closes #16672
2024-01-08 09:06:43 +02:00
Kamil Braun
287546923e Merge 'db: hints: add checksum to sync_point encoding' from Patryk Jędrzejczak
Fixes #9405

`sync_point` API provided with incorrect sync point id might allocate
crazy amount of memory and fail with `std::bad_alloc`.

To fix this, we can check if the encoded sync point has been modified
before decoding. We can achieve this by calculating a checksum before
encoding, appending it to the encoded sync point, and compering it with
a checksum calculated in `db::hints::decode` before decoding.

Closes #14534

* github.com:scylladb/scylladb:
  db: hints: add checksum to sync point encoding
  db: hints: add the version_size constant

(cherry picked from commit eb6202ef9c)

The only difference from the original merge commit is the include
path of `xx_hasher.hh`. On branch 5.2, this file is in the root
directory, not `utils`.

Closes #16458
2023-12-19 17:39:50 +02:00
Michael Huang
5499f7b5a8 cdc: use chunked_vector for topology_description entries
Lists can grow very big. Let's use a chunked vector to prevent large contiguous
allocations.
Fixes: #15302.

Closes scylladb/scylladb#15428

(cherry picked from commit 62a8a31be7)
2023-12-19 13:43:23 +01:00
Piotr Grabowski
7055ac45d1 test: use more frequent reconnection policy
The default reconnection policy in Python Driver is an exponential
backoff (with jitter) policy, which starts at 1 second reconnection
interval and ramps up to 600 seconds.

This is a problem in tests (refs #15104), especially in tests that restart
or replace nodes. In such a scenario, a node can be unavailable for an
extended period of time and the driver will try to reconnect to it
multiple times, eventually reaching very long reconnection interval
values, exceeding the timeout of a test.

Fix the issue by using a exponential reconnection policy with a maximum
interval of 4 seconds. A smaller value was not chosen, as each retry
clutters the logs with reconnection exception stack trace.

Fixes #15104

Closes #15112

(cherry picked from commit 17e3e367ca)
2023-12-19 13:43:23 +01:00
Alexey Novikov
6bcf9e6631 When add duration field to UDT check whether this UDT is used in some clustering key
Having values of the duration type is not allowed for clustering
columns, because duration can't be ordered. This is correctly validated
when creating a table but do not validated when we alter the type.

Fixes #12913

Closes scylladb/scylladb#16022

(cherry picked from commit bd73536b33)
2023-12-19 06:58:41 -05:00
Botond Dénes
46a29e9a02 Merge 'alternator: fix isolation of concurrent modifications to tags' from Nadav Har'El
Alternator's implementation of TagResource, UntagResource and UpdateTimeToLive (the latter uses tags to store the TTL configuration) was unsafe for concurrent modifications - some of these modifications may be lost. This short series fixes the bug, and also adds (in the last patch) a test that reproduces the bug and verifies that it's fixed.

The cause of the incorrect isolation was that we separately read the old tags and wrote the modified tags. In this series we introduce a new function, `modify_tags()` which can do both under one lock, so concurrent tag operations are serialized and therefore isolated as expected.

Fixes #6389.

Closes #13150

* github.com:scylladb/scylladb:
  test/alternator: test concurrent TagResource / UntagResource
  db/tags: drop unsafe update_tags() utility function
  alternator: isolate concurrent modification to tags
  db/tags: add safe modify_tags() utility functions
  migration_manager: expose access to storage_proxy

(cherry picked from commit dba1d36aa6)

Closes #16453
2023-12-19 10:19:31 +02:00
Nadav Har'El
91e05dc646 cql: fix SELECT toJson() or SELECT JSON of time column
The implementation of "SELECT TOJSON(t)" or "SELECT JSON t" for a column
of type "time" forgot to put the time string in quotes. The result was
invalid JSON. This is patch is a one-liner fixing this bug.

This patch also removes the "xfail" marker from one xfailing test
for this issue which now starts to pass. We also add a second test for
this issue - the existing test was for "SELECT TOJSON(t)", and the second
test shows that "SELECT JSON t" had exactly the same bug - and both are
fixed by the same patch.

We also had a test translated from Cassandra which exposed this bug,
but that test continues to fail because of other bugs, so we just
need to update the xfail string.

The patch also fixes one C++ test, test/boost/json_cql_query_test.cc,
which enshrined the *wrong* behavior - JSON output that isn't even
valid JSON - and had to be fixed. Unlike the Python tests, the C++ test
can't be run against Cassandra, and doesn't even run a JSON parser
on the output, which explains how it came to enshrine wrong output
instead of helping to discover the bug.

Fixes #7988

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#16121

(cherry picked from commit 8d040325ab)
2023-12-18 18:19:20 +02:00
Michael Huang
af38b255c8 cql3: Fix invalid JSON parsing for JSON objects with ASCII keys
For JSON objects represented as map<ascii, int>, don't treat ASCII keys
as a nested JSON string. We were doing that prior to the patch, which
led to parsing errors.

Included the error offset where JSON parsing failed for
rjson::parse related functions to help identify parsing errors
better.

Fixes: #7949

Signed-off-by: Michael Huang <michaelhly@gmail.com>

Closes scylladb/scylladb#15499

(cherry picked from commit 75109e9519)
2023-12-18 13:45:57 +02:00
Kamil Braun
9aaaa66981 Merge 'cql3: fix a few misformatted printouts of column names in error messages' from Nadav Har'El
Fix a few cases where instead of printing column names in error messages, we printed weird stuff like ASCII codes or the address of the name.

Fixes #13657

Closes #13658

* github.com:scylladb/scylladb:
  cql3: fix printing of column_specification::name in some error messages
  cql3: fix printing of column_definition::name in some error messages

(cherry picked from commit a29b8cd02b)
2023-12-18 09:55:37 +02:00
Botond Dénes
64503a7137 Merge 'mutation_query: properly send range tombstones in reverse queries' from Michał Chojnowski
reconcilable_result_builder passes range tombstone changes to _rt_assembler
using table schema, not query schema.
This means that a tombstone with bounds (a; b), where a < b in query schema
but a > b in table schema, will not be emitted from mutation_query.

This is a very serious bug, because it means that such tombstones in reverse
queries are not reconciled with data from other replicas.
If *any* queried replica has a row, but not the range tombstone which deleted
the row, the reconciled result will contain the deleted row.

In particular, range deletes performed while a replica is down will not
later be visible to reverse queries which select this replica, regardless of the
consistency level.

As far as I can see, this doesn't result in any persistent data loss.
Only in that some data might appear resurrected to reverse queries,
until the relevant range tombstone is fully repaired.

This series fixes the bug and adds a minimal reproducer test.

Fixes #10598

Closes scylladb/scylladb#16003

* github.com:scylladb/scylladb:
  mutation_query_test: test that range tombstones are sent in reverse queries
  mutation_query: properly send range tombstones in reverse queries

(cherry picked from commit 65e42e4166)
2023-12-14 12:53:07 +02:00