Commit Graph

1147 Commits

Author SHA1 Message Date
Gleb Natapov
c437c8be36 test: add test to check that coordinator lwt semaphore continues functioning after locking failures
(cherry picked from commit 4178589826)
2024-07-18 15:34:17 +00:00
Michael Litvak
815a707b0a storage_proxy: remove response handler if no targets
When writing a mutation, it might happen that there are no live targets
to send the mutation to, yet the request can be satisfied. For example,
when writing with CL=ANY to a dead node, the request is completed by
storing a local hint.

Currently, in that case, a write response handler is created for the
request and it remains active until it timeouts because it is not
removed anywhere, even though the write is completed successfuly after
storing the hint. The response handler should be removed usually when
receiving responses from all targets, but in this case there are no
targets to trigger the removal.

In this commit we check if we don't have live targets to send the
mutation to. If so, we remove the response handler immediately.

Fixes scylladb/scylladb#19529

(cherry picked from commit a9fdd0a93a)

Closes scylladb/scylladb#19680
2024-07-15 08:24:18 +02:00
Wojciech Przytuła
a7fe9eeffd storage_proxy: fix uninitialized LWT contention counter
When debugging the issue of high LWT contention metric, we (the
drivers team) discovered that at least 3 drivers (Go, Java, Rust)
cause high numbers in that metrics in LWT workloads - we doubted that
all those drivers route LWT queries badly. We tried to understand that
metric and its semantics. It took 3 people over 10 hours to figure out
what it is supposed to count.

People from core team suspected that it was the drivers sending
requests to different shards, causing contention. Then we ran the
workload against a single node single shard cluster... and observed
contention. Finally, we looked into the Scylla code and saw it.

**Uninitialized stack value.**

The core member was shocked. But we, the drivers people, felt we always
knew it. It's yet another time that we are blamed for a server-side
issue. We rebuilt scylla with the variable initialized to 0 and the
metric kept being 0.

To prevent such errors in the future, let's consider some lints that
warn against uninitialized variables. This is such an obvious feature
of e.g. Rust, and yet this has shown to be cause a painful bug in 2024.

Fixes: scylladb/scylladb#19654
(cherry picked from commit 36a125bf97)

Closes scylladb/scylladb#19657
2024-07-09 11:41:10 +02:00
Michał Chojnowski
80ac0da11c storage_proxy: avoid infinite growth of _throttled_writes
storage_proxy has a throttling mechanism which attempts to limit the number
of background writes by forcefully raising CL to ALL
(it's not implemented exactly like that, but that's the effect) when
the amount of background and queued writes is above some fixed threshold.
If this is applied to a write, it becomes "throttled",
and its ID is appended to into _throttled_writes.

Whenever the amount of background and queued writes falls below the threshold,
writes are "unthrottled" — some IDs are popped from _throttled_writes
and the writes represented by these IDs — if their handlers still exist —
have their CL lowered back.

The problem here is that IDs are only ever removed from _throttled_writes
if the number of queued and background writes falls below the threshold.
But this doesn't have to happen in any finite time, if there's constant write
pressure. And in fact, in one load test, it hasn't happened in 3 hours,
eventually causing the buffer to grow into gigabytes and trigger OOM.

This patch is intended to be a good-enough-in-practice fix for the problem.

Fixes #17476
Fixes #1834

(cherry picked from commit fee48f67ef)

Closes scylladb/scylladb#19180
2024-06-11 18:33:38 +03:00
Dawid Medrek
82d635b6a7 db/hints: Ensure that draining happens
Before hinted handoff is migrated to using host IDs
to identify nodes in the cluster, we keep track
of mappings between hint endpoint managers
identified by host IDs and the hint directories
managed by them and represented by IP addresses.
As a consequence, it may happen that one hint
directory corresponds to multiple nodes
-- it's intended. See 64ba620 for more details.

Before these changes, we only started the draining
process of a hint directory if the node leaving
the cluster corresponded to that hint directory
AND was identified by the same host ID as
the hint endpoint manager managing that directory.
As a result, the draining did not always happen
when it was supposed to.

Draining should start no matter which of the nodes
corresponding to a hint directory is leaving
the cluster. This commit ensures that it happens.

(cherry picked from commit 745a9c6ab8)
2024-06-04 14:42:08 +00:00
Avi Kivity
52fe351c31 Merge 'Balance tablets within nodes (intra-node migration)' from Tomasz Grabiec
This is needed to avoid severe imbalance between shards which can
happen when some table grows and is split. The inter-node balance can
be equal, so inter-node migration cannot fix the imbalance. Also, if RF=N
then there is not even a possibility of moving tablets around to fix the imbalance.
The only way to bring the system to balance is to move tablets within the nodes.

The system is not prepared for intra-node migration currently. Request coordination
is host-based, while for intra-node migration it should be (also) shard-based.
The solution employed here is to keep the coordination between nodes as-is,
and for intra-node migration storage_proxy-level coordinator is not aware of
the migration (no pending host). The replica-side request handler will be a
second-level coordinator which routes requests to shards, similar to how
the first-level coordinator routes them to hosts.

Tablet sharder is adjusted to handle intra-migration where a tablet
can have two replicas on the same host. For reads, sharder uses the
read selector to resolve the conflict. For writes, the write selector
is used.

The old shard_of() API is kept to represent shard for reads, and new
method is introduced to query the shards for writing:
shard_for_writes(). All writers should be switched to that API, which
is not done in this patch yet.

The request handler on replica side acts as a second-level
coordinator, using sharder to determine routing to shards. A given
sharder has a scope of a single topology version, a single
effective_replication_map_ptr, which should be kept alive during
writes.

perf-simple-query test results show no signs of regression:

Command: perf-simple-query -c1 -m1G --write --tablets --duration=10

Before:

> 83294.81 tps ( 59.5 allocs/op,  14.3 tasks/op,   53725 insns/op,        0 errors)
> 87756.72 tps ( 59.5 allocs/op,  14.3 tasks/op,   54049 insns/op,        0 errors)
> 86428.47 tps ( 59.6 allocs/op,  14.3 tasks/op,   54208 insns/op,        0 errors)
> 86211.38 tps ( 59.7 allocs/op,  14.3 tasks/op,   54219 insns/op,        0 errors)
> 86559.89 tps ( 59.6 allocs/op,  14.3 tasks/op,   54188 insns/op,        0 errors)
> 86609.39 tps ( 59.6 allocs/op,  14.3 tasks/op,   54117 insns/op,        0 errors)
> 87464.06 tps ( 59.5 allocs/op,  14.3 tasks/op,   54039 insns/op,        0 errors)
> 86185.43 tps ( 59.6 allocs/op,  14.3 tasks/op,   54169 insns/op,        0 errors)
> 86254.71 tps ( 59.6 allocs/op,  14.3 tasks/op,   54139 insns/op,        0 errors)
> 83395.35 tps ( 60.2 allocs/op,  14.4 tasks/op,   54693 insns/op,        0 errors)
>
> median 86428.47 tps ( 59.6 allocs/op,  14.3 tasks/op,   54208 insns/op,        0 errors)
> median absolute deviation: 243.04
> maximum: 87756.72
> minimum: 83294.81
>

After:

> 85523.06 tps ( 59.5 allocs/op,  14.3 tasks/op,   53872 insns/op,        0 errors)
> 89362.47 tps ( 59.6 allocs/op,  14.3 tasks/op,   54226 insns/op,        0 errors)
> 88167.55 tps ( 59.7 allocs/op,  14.3 tasks/op,   54400 insns/op,        0 errors)
> 87044.40 tps ( 59.7 allocs/op,  14.3 tasks/op,   54310 insns/op,        0 errors)
> 88344.50 tps ( 59.6 allocs/op,  14.3 tasks/op,   54289 insns/op,        0 errors)
> 88355.06 tps ( 59.6 allocs/op,  14.3 tasks/op,   54242 insns/op,        0 errors)
> 88725.46 tps ( 59.6 allocs/op,  14.3 tasks/op,   54230 insns/op,        0 errors)
> 88640.08 tps ( 59.6 allocs/op,  14.3 tasks/op,   54210 insns/op,        0 errors)
> 90306.31 tps ( 59.4 allocs/op,  14.3 tasks/op,   54043 insns/op,        0 errors)
> 87343.62 tps ( 59.8 allocs/op,  14.3 tasks/op,   54496 insns/op,        0 errors)
>
> median 88355.06 tps ( 59.6 allocs/op,  14.3 tasks/op,   54242 insns/op,        0 errors)
> median absolute deviation: 1007.41
> maximum: 90306.31
> minimum: 85523.06

Command (reads): perf-simple-query -c1 -m1G  --tablets --duration=10

Before:

> 95860.18 tps ( 63.1 allocs/op,  14.1 tasks/op,   42476 insns/op,        0 errors)
> 97537.69 tps ( 63.1 allocs/op,  14.1 tasks/op,   42454 insns/op,        0 errors)
> 97549.23 tps ( 63.1 allocs/op,  14.1 tasks/op,   42470 insns/op,        0 errors)
> 97511.29 tps ( 63.1 allocs/op,  14.1 tasks/op,   42470 insns/op,        0 errors)
> 97227.32 tps ( 63.1 allocs/op,  14.1 tasks/op,   42471 insns/op,        0 errors)
> 94031.94 tps ( 63.1 allocs/op,  14.1 tasks/op,   42441 insns/op,        0 errors)
> 96978.04 tps ( 63.1 allocs/op,  14.1 tasks/op,   42462 insns/op,        0 errors)
> 96401.70 tps ( 63.1 allocs/op,  14.1 tasks/op,   42473 insns/op,        0 errors)
> 96573.77 tps ( 63.1 allocs/op,  14.1 tasks/op,   42440 insns/op,        0 errors)
> 96340.54 tps ( 63.1 allocs/op,  14.1 tasks/op,   42468 insns/op,        0 errors)
>
> median 96978.04 tps ( 63.1 allocs/op,  14.1 tasks/op,   42462 insns/op,        0 errors)
> median absolute deviation: 571.20
> maximum: 97549.23
> minimum: 94031.94
>

After:

> 99794.67 tps ( 63.1 allocs/op,  14.1 tasks/op,   42471 insns/op,        0 errors)
> 101244.99 tps ( 63.1 allocs/op,  14.1 tasks/op,   42472 insns/op,        0 errors)
> 101128.37 tps ( 63.1 allocs/op,  14.1 tasks/op,   42485 insns/op,        0 errors)
> 101065.27 tps ( 63.1 allocs/op,  14.1 tasks/op,   42465 insns/op,        0 errors)
> 101212.98 tps ( 63.1 allocs/op,  14.1 tasks/op,   42456 insns/op,        0 errors)
> 101413.31 tps ( 63.1 allocs/op,  14.1 tasks/op,   42463 insns/op,        0 errors)
> 101464.92 tps ( 63.1 allocs/op,  14.1 tasks/op,   42466 insns/op,        0 errors)
> 101086.74 tps ( 63.1 allocs/op,  14.1 tasks/op,   42488 insns/op,        0 errors)
> 101559.09 tps ( 63.1 allocs/op,  14.1 tasks/op,   42468 insns/op,        0 errors)
> 100742.58 tps ( 63.1 allocs/op,  14.1 tasks/op,   42491 insns/op,        0 errors)
>
> median 101212.98 tps ( 63.1 allocs/op,  14.1 tasks/op,   42456 insns/op,        0 errors)
> median absolute deviation: 200.33
> maximum: 101559.09
> minimum: 99794.67
>

Fixes #16594

Closes scylladb/scylladb#18026

* github.com:scylladb/scylladb:
  Implement fast streaming for intra-node migration
  test: tablets_test: Test sharding during intra-node migration
  test: tablets_test: Check sharding also on the pending host
  test: py: tablets: Test writes concurrent with migration
  test: py: tablets: Test crash during intra-node migration
  api, storage_service: Introduce API to wait for topology to quiesce
  dht, replica: Remove deprecated sharder APIs
  test: Avoid using deprecated sharded API
  db: do_apply_many() avoid deprecated sharded API
  replica: mutation_dump: Avoid deprecated sharder API
  repair: Avoid deprecated sharder API
  table: Remove optimization which returns empty reader when key is not owned by the shard
  dht: is_single_shard: Avoid deprecated sharder API
  dht: split_range_to_single_shard: Work with static_sharder only
  dht: ring_position_range_sharder: Avoid deprecated sharder APIs
  dht: token: Avoid use of deprecated sharder API by switching to static_sharder
  selective_token_sharder: Avoid use of deprecated sharder API
  docs: Document tablet sharding vs tablet replica placement
  readers/multishard.cc: use shard_for_reads() instead of shard_of()
  multishard_mutation_query.cc: use shard_for_reads() instead of shard_of()
  storage_proxy: Extract common code to apply mutations on many shards according to sharder
  storage_proxy: Prepare per-partition rate-limiting for intra-node migration
  storage_proxy: Avoid shard_of() use in mutate_counter_on_leader_and_replicate()
  storage_proxy: Prepare mutate_hint() for intra-node tablet migration
  commitlog_replayer: Avoid deprecated sharder::shard_of()
  lwt: Avoid deprecated sharder::shard_of()
  compaction: Avoid deprecated sharder::shard_of()
  dht: Extract dht::static_sharder
  replica: Deprecate table::shard_of()
  locator: Deprecate effective_replication_map::shard_of()
  dht: Deprecate old sharder API: shard_of/next_shard/token_for_next_shard
  tests: tablets: py: Add intra-node migration test
  tests: tablets: Test that drained nodes are not balanced internally
  tests: tablets: Add checks of replica set validity to test_load_balancing_with_random_load
  tests: tablets: Verify that disabling balancing results in no intra-node migrations
  tests: tablets: Check that nodes are internally balanced
  tests: tablets: Improve debuggability by showing which rows are missing
  tablets, storage_service: Support intra-node migration in move_tablet() API
  tablet_allocator: Generate intra-node migration plan
  tablet_allocator: Extract make_internode_plan()
  tablet_allocator: Maintain candidate list and shard tablet count for target nodes
  tablet_allocator: Lift apply_load/can_accept_load lambdas to member functions
  tablets, streaming: Implement tablet streaming for intra-node migration
  dht, auto_refreshing_sharder: Allow overriding write selector
  multishard_writer: Handle intra-node migration
  storage_proxy: Handle intra-node tablet migration for writes
  tablets: Get rid of tablet_map::get_shard()
  tablets: Avoid tablet_map::get_shard in cleanup
  tablets: test: Use sharder instead of tablet_map::get_shard()
  tablets: tablet_sharder: Allow working with non-local host
  sharding: Prepare for intra-node-migration
  docs: Document sharder use for tablets
  tablets: Introduce tablet transition kind for intra-node migration
  tests: tablets: Fix use-after-move of skiplist in rebalance_tablets()
  sstables, gdb: Track readers in a linked list
  raft topology: Fix global token metadata barrier to not fence ahead of what is drained
2024-05-20 16:13:01 +03:00
Kefu Chai
a517fcf970 service/storage_proxy: capture tr_state by copy in handle_paxos_accept()
this change is inspired by following warning from clang-tidy

```
Warning: /home/runner/work/scylladb/scylladb/service/storage_proxy.cc:884:13: warning: 'tr_state' used after it was moved [bugprone-use-after-move]
  884 |         if (tr_state) {
      |             ^
/home/runner/work/scylladb/scylladb/service/storage_proxy.cc:872:139: note: move occurred here
  872 |         auto f = get_schema_for_read(proposal.update.schema_version(), src_addr, *timeout).then([&sp = _sp, &sys_ks = _sys_ks, tr_state = std::move(tr_state),
      |                                                                                                                                           ^
```

this is not a false positive. as `tr_state` is a captured by move for
constructing a variable in the captured list of a lambda which is in
turn passed to the expression evaluated to `f`.

even the expression itself is not evaluated yet when we reference
`tr_state` to check if it is empty after preparing the expression,
`tr_state` is already moved away into the captured variable. so
at that moment, the statement of `f = f.finally(...)` is never
evaluated, because `tr_state` is always empty by then.

so before this change, the trace message is never recorded.

in this change, we address this issue by capturing `tr_state` by
copying it. as `tr_state` is backed by a `lw_shared_ptr`, the overhead is
neglectable.

after this change, the tracing message is recorded.

the change introduced this issue was 548767f91e.

please note, we could coroutinize this function to improve its
readability, but since this is a fix and should be backported,
let's start with a minimal fix, and worry about the readability
in a follow-up change.

Refs 548767f91e
Fixes #18725
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18702
2024-05-20 12:58:49 +03:00
Avi Kivity
2fbd78c769 feature: grandfather DIGEST_FOR_NULL_VALUES
The DIGEST_FOR_NULL_VALUES feature was added in 21a77612b3 (2020; 4.4)
and can now be assumed to be always present. The hasher which it invoked
is removed.
2024-05-18 00:24:00 +03:00
Avi Kivity
879583c489 storage_proxy: drop use of MD5 as a digest algorithm
The XXHASH feature was introduced in 0bab3e59c2 (2017; 2.2) and made
mandatory in defe6f49df (2020; 4.4), but some vestiges remain.
Remove them now. Note that md5_hasher itself is still in use by
other components, so it cannot be removed.
2024-05-18 00:23:47 +03:00
Avi Kivity
d52c424a5f feature: grandfather LWT
LWT was make non-experimental in 9948f548a5 (2020; 4.1) and can now be
assumed to be always present.
2024-05-18 00:20:53 +03:00
Avi Kivity
93088d0921 feature: grandfather HINTED_HANDOFF_SEPARATE_CONNECTION
The HINTED_HANDOFF_SEPARATE_CONNECTION feature was introduced in 3a46b1bb2b (2019; 3.3)
and can be assumed always present.
2024-05-18 00:18:27 +03:00
Piotr Dulikowski
68eca3778c Merge 'mv: throttle view update generation for large queries' from Wojciech Mitros
This series is a reupload of #13792 with a few modifications, namely a test is added and the conflicts with recent tablet related changes are fixed.

See https://github.com/scylladb/scylladb/issues/12379 and https://github.com/scylladb/scylladb/pull/13583 for a detailed description of the problem and discussions.

This PR aims to extend the existing throttling mechanism to work with requests that internally generate a large amount of view updates, as suggested by @nyh.

The existing mechanism works in the following way:

* Client sends a request, we generate the view updates corresponding to the request and spawn background tasks which will send these updates to remote nodes
* Each background task consumes some units from the `view_update_concurrency_semaphore`, but doesn't wait for these units, it's just for tracking
* We keep track of the percent of consumed units on each node, this is called `view update backlog`.
* Before sending a response to the client we sleep for a short amount of time. The amount of time to sleep for is based on the fullness of this `view update backlog`. For a well behaved client with limited concurrency this will limit the amount of incoming requests to a manageable level.

This mechanism doesn't handle large DELETE queries. Deleting a partition is fast for the base table, but it requires us to generate a view update for every single deleted row. The number of deleted rows per single client request can be in the millions. Delaying response to the request doesn't help when a single request can generate millions of updates.

To deal with this we could treat the view update generator just like any other client and force it to wait a bit of time before sending the next batch of updates. The amount of time to wait for is calculated just like in the existing throttling code, it's based on the fullness of `view update backlogs`.

The new algorithm of view update generation looks something like this:
```c++
for(;;) {
    auto updates = generate_updates_batch_with_max_100_rows();
    co_await seastar::sleep(calculate_sleep_time_from_backlogs());
    spawn_background_tasks_for_updates(updates);
}
```
Fixes: https://github.com/scylladb/scylladb/issues/12379

Closes scylladb/scylladb#16819

* github.com:scylladb/scylladb:
  test: add test for bad_allocs during large mv queries
  mv: throttle view update generation for large queries
  exceptions: add read_write_timeout_exception, a subclass of request_timeout_exception
  db/view: extract view throttling delay calculation to a global function
  view_update_generator: add get_storage_proxy()
  storage_proxy: make view backlog getters public
2024-05-16 08:22:54 +02:00
Tomasz Grabiec
3b7d7088d1 storage_proxy: Extract common code to apply mutations on many shards according to sharder 2024-05-16 00:28:47 +02:00
Tomasz Grabiec
660b3d1765 storage_proxy: Prepare per-partition rate-limiting for intra-node migration
Note: there is a potential problem with rate-limit count going out of sync
during intra-node migration between old and the new shard.

Before this patch, when coordinator accounted and admitted the
request, so the rate_limit_info passed to apply_locally() is
account_only, it was converted to std::monostate for requests to the
local replia. This makes sense because the request was already
accounted by the coordinator.

However, during intra-node migration when we do double writes to two
shards locally, that means that the new shard will not account the
write, it will have lower count than the limiter on the old
shard. This means that the new shard may accept writes which will end
up being rejected. This is not desirable, but not the end of the world
since it's temporary, and the new shard will still protect itself from
overload based on its own rate limiter.
2024-05-16 00:28:47 +02:00
Tomasz Grabiec
7c3291b5ea storage_proxy: Avoid shard_of() use in mutate_counter_on_leader_and_replicate()
Cunters are not supported with tablets, so we should not reach this path.
2024-05-16 00:28:47 +02:00
Tomasz Grabiec
db2809317d storage_proxy: Prepare mutate_hint() for intra-node tablet migration 2024-05-16 00:28:47 +02:00
Tomasz Grabiec
c9294b1642 lwt: Avoid deprecated sharder::shard_of()
Instead, use shard_for_reads(). The justification is that:

 1) In cas_shard(), we need to pick a single request coordinator.
    shard_for_reads() gives that, which is equivalent to shard_of()
    if there is no intra-node migration.

 2) In paxos handler for prepare(), the shard we execute it on is
    the shard from which we read, so shard_for_reads() is the one.

 3) Updates of paxos state are separate CQL requests, and use their
    own sharding.

 4) Handler for learn is executing updates using calls to
    storage_proxy::mutate_locally() which will use the right sharder for writes

However, the code is still not prepared for intra-node migration, and
possibly regular migration too in case of abandoned requests, because
the locking of paxos state assumes that the shard is static. That
would have to be fixed separately, e.g. by locking both shards
(shard_for_writes()) during migration, so that the set of locked
shards always intersects during migration and local serialization of
paxos state updates is achieved. I left FIXMEs for that.
2024-05-16 00:28:47 +02:00
Tomasz Grabiec
4df818db98 storage_proxy: Handle intra-node tablet migration for writes
When sharder says that the write should go to multiple shards,
we need to consider the write as applied only if it was applied
to all those shards.

This can happen during intra-node tablet migration. During such migration,
the request coordinator on storage_proxy side is coordinating to hosts
as if no migration was in progress. The replica-side coordinator coordinates
to shards based on sharder response.

One way to think about it is that
effective_replication_map::get_natural_endpoints()/get_pending_endpoints()
tells how to coordinate between nodes, and sharder tells how to
coordinate between shards. Both work with some snapshot of tablet
metadata, which should be kept alive around the operation. Sharder is
associated with its own effective_replication_map, which marks the
topology version as used and allows barriers to synchronize with
replica-side operations.
2024-05-16 00:28:46 +02:00
Pavel Emelyanov
75d5eb96f2 storage_proxy: Get token metadata via local member, not database
The my_address() method eventually needs to access topology and goes
long way via sharded<database>. No need in that, shared token metadata
is available on proxy itself.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2024-05-14 15:40:10 +03:00
Jan Ciolek
ae28b8bdb7 db/view: extract view throttling delay calculation to a global function
In order to prevent overload caused by too many view updates,
their number is limited by delaying client responses.
The amount of time to delay for is calculated based on the
fullness of the view update backlog.

Currently this is done in the function calculate_delay,
used by abstract_write_response_handler.

In the following commits I will introduce another throttling
mechanism that uses the same equation to calculate wait time,
so it would be good to reuse the exsiting function.

Let's make the function globally accessible.

Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
2024-05-13 18:14:56 +02:00
Botond Dénes
d82a31f15f service/storage_proxy: add useful version of base write throttle metrics
There are two metrics to help observe base-write throttling:
* current_throttled_base_writes
* last_mv_flow_control_delay

Both show a snapshot of what is happening right at the time of querying
these metrincs. This doesn't work well when one wants to investigate the
role throttling is playing in occasional write timeouts.s Prometheus
scrapes metrics in multi-second intervals, and the probability of that
instant catching the throttling at play is very small (almost zero).
Add two new metrics:
* throttled_base_writes_total
* mv_flow_control_delay_total

These accumulate all values, allowing graphana to derive the values and
extract information about throttle events that happened in the past
(but not necessarily at the instant of the scrape).
Note that dividing the two values, will yield the average delay for a
throttle, which is also useful.

Closes scylladb/scylladb#18435
2024-05-13 18:02:06 +03:00
Kefu Chai
2a9a874e19 db,service: fix typos in comments
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18567
2024-05-09 08:26:44 +03:00
Botond Dénes
155332ebf8 Merge 'Drain view_builder in generic drain (again)' from Pavel Emelyanov
Some time ago #16558 was merged that moved view builder drain into generic drain. After this merge dtests started to fail from time to time, so the PR was reverted (see #18278). In #18295 the hang was found. View builder drain was moved from "before stopping messaging service to "after" it, and view update write handlers in proxy hanged for hard-coded timeout of 5 minutes without being aborted. Tests don't wait for 5 minutes and kill scylla, then complain about it and fail.

This PR brings back the original PR as well as the necessary fix that cancels view update write handlers on stop.

Closes scylladb/scylladb#18408

* github.com:scylladb/scylladb:
  Reapply "Merge 'Drain view_builder in generic drain' from ScyllaDB"
  view: Abort pending view updates when draining
2024-05-09 08:26:44 +03:00
Benny Halevy
0156e97560 storage_proxy: cas: reject for tablets-enabled tables
Currently, LWT is not supported with tablets.
In particular the interaction between paxos and tablet
migration is not handled yet.

Therefore, it is better to outright reject LWT queries
for tablets-enabled tables rather than support them
in a flaky way.

This commit also marks tests that depend on LWT
as expeced to fail.

Fixes scylladb/scylladb#18066

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>

Closes scylladb/scylladb#18103
2024-05-09 08:26:43 +03:00
Piotr Dulikowski
64ba620dc2 Merge 'hinted handoff: Use host IDs instead of IPs in the module' from Dawid Mędrek
This pull request introduces host ID in the Hinted Handoff module. Nodes are now identified by their host IDs instead of their IPs. The conversion occurs on the boundary between the module and `storage_proxy.hh`, but aside from that, IPs have been erased.

The changes take into considerations that there might still be old hints, still identified by IPs, on disk – at start-up, we map them to host IDs if it's possible so that they're not lost.

Refs scylladb/scylladb#6403
Fixes scylladb/scylladb#12278

Closes scylladb/scylladb#15567

* github.com:scylladb/scylladb:
  docs: Update Hinted Handoff documentation
  db/hints: Add endpoint_downtime_not_bigger_than()
  db/hints: Migrate hinted handoff when cluster feature is enabled
  db/hints: Handle arbitrary directories in resource manager
  db/hints: Start using hint_directory_manager
  db/hints: Enforce providing IP in get_ep_manager()
  db/hints: Introduce hint_directory_manager
  db/hints/resource_manager: Update function description
  db/hints: Coroutinize space_watchdog::scan_one_ep_dir()
  db/hints: Expose update lock of space watchdog
  db/hints: Add function for migrating hint directories to host ID
  db/hints: Take both IP and host ID when storing hints
  db/hints: Prepare initializing endpoint managers for migrating from IP to host ID
  db/hints: Migrate to locator::host_id
  db/hints: Remove noexcept in do_send_one_mutation()
  service: Add locator::host_id to on_leave_cluster
  service: Fix indentation
  db/hints: Fix indentation
2024-05-06 09:58:18 +02:00
Kefu Chai
ea791919cf service/storage_proxy: drop unused operator<<
operator<<(ostream, paxos_response_handler) is not used anymore,
so let's drop it.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18520
2024-05-05 16:33:29 +03:00
Benny Halevy
890b890e36 storage_proxy: add mutate_locally(vector<frozen_mutation_and_schema>) method
Generalizing the ad-hoc implementation out of
group0_state_machine.write_mutations_to_database.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2024-05-02 19:42:58 +03:00
Benny Halevy
a126160d7e frozen_mutation: move unfreeze_gently to async_utils
Unfreeze_gently doesn't have to be a method of
frozen_mutation.  It might as well be implemented as
a free function reading from a frozen_mutation
and preparing a mutation gently.

The logic will be used in a later patch
to make a canonical mutation directly from
a frozen_mutation instead of unfreezing it
and then converting it to a canonical_mutation.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2024-05-02 19:27:56 +03:00
Pavel Emelyanov
d47053266b view: Abort pending view updates when draining
When view builder is drained (it now happens very early, but next patch
moves this into regular drain) it waits for all on-going view build
steps to complete. This includes waiting for any outstanding proxy view
writes to complete as well.

View writes in proxy have very high timeout of 5 minutes but they are
cancellable. However, canecelling of such writes happens in proxy's
drain_on_shutdown() call which, in turn, happens pretty late on
shutdown. Effectively, by the time it happens all view writes mush have
completed already, so stop-time cancelling doesn't really work nowadays.

Next patch makes view builder drain happen a bit later during shutdown,
namely -- _after_ shutting down messaging service. When it happen that
late, non-working view writes cancellation becomes critical, as view
builder drain hangs for aforementioned 5 minutes. This patch explicitly
cancels all view writes when view builder stops.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2024-05-02 08:16:12 +03:00
Dawid Medrek
e36f853f9b db/hints: Take both IP and host ID when storing hints
The store_hint() method starts taking both an IP
and a host ID as its arguments. The rationale
for the change is depending on the stage of
the cluster (before an upgrade to the
host-ID-based hinted handdof and after it),
we might need to create a directory representing
either an IP address, or a host ID.

Because locator::topology can change in the
before obtaining the host ID we pass
and when the function is being executed,
we need to pass both parameters explicitly
to ensure the consistency between them.
2024-04-27 20:35:58 +02:00
Dawid Medrek
cfd03fe273 db/hints: Migrate to locator::host_id
We change the type of node identifiers
used within the module and fix compilation.
Directories storing hints to specific nodes
are now represented by host IDs instead of
IPs.
2024-04-26 22:44:04 +02:00
Dawid Medrek
54ae9797b9 service: Add locator::host_id to on_leave_cluster
We extend the function
endpoint_lifecycle_subscriber::on_leave_cluster
by another argument -- locator::host_id.
It's more convenient to have a consistent
pair of IP and host ID.
2024-04-26 22:44:03 +02:00
Dawid Medrek
a36387d942 service: Fix indentation 2024-04-26 22:44:03 +02:00
Kefu Chai
c323c93fa4 treewide: remove {dclocal_,}read_repair_chance options
dclocal_read_repair_chance and read_repair_chance have been removed
in Cassandra 3.11 and 4.x, see
https://issues.apache.org/jira/browse/CASSANDRA-13910.
if we expose the properties via DDL, Cassandra would fails to consume
the CQL statement to creating the table when performing migration
from Scylla to Cassandra 4.x, as the latter does not understand
these properties anymore.

currently the default values of `dc_local_read_repair_chance` and
`read_repair_chance` are both "0". so this is practically disabled,
unless user deliberately set them to a value greater than 0.

also, as a side effect, Cassandra 4.x has better support of
Python3. the cqlsh shipped along with Cassandra 3.11.16 only
supports python2.7, see
https://github.com/apache/cassandra/blob/cassandra-3.11.16/bin/cqlsh.py
it errors out if the system only provides python3 with the error
of

```
No appropriate python interpreter found.
```
but modern linux systems do not provide python2 anymore.

so, in this change, we deprecate these two options.

Fixes #3502
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-04-25 17:15:27 +08:00
Kefu Chai
372a4d1b79 treewide: do not define FMT_DEPRECATED_OSTREAM
since we do not rely on FMT_DEPRECATED_OSTREAM to define the
fmt::formatter for us anymore, let's stop defining `FMT_DEPRECATED_OSTREAM`.

in this change,

* utils: drop the range formatters in to_string.hh and to_string.c, as
  we don't use them anymore. and the tests for them in
  test/boost/string_format_test.cc are removed accordingly.
* utils: use fmt to print chunk_vector and small_vector. as
  we are not able to print the elements using operator<< anymore
  after switching to {fmt} formatters.
* test/boost: specialize fmt::details::is_std_string_like<bytes>
  due to a bug in {fmt} v9, {fmt} fails to format a range whose
  element type is `basic_sstring<uint8_t>`, as it considers it
  as a string-like type, but `basic_sstring<uint8_t>`'s char type
  is signed char, not char. this issue does not exist in {fmt} v10,
  so, in this change, we add a workaround to explicitly specialize
  the type trait to assure that {fmt} format this type using its
  `fmt::formatter` specialization instead of trying to format it
  as a string. also, {fmt}'s generic ranges formatter calls the
  pair formatter's `set_brackets()` and `set_separator()` methods
  when printing the range, but operator<< based formatter does not
  provide these method, we have to include this change in the change
  switching to {fmt}, otherwise the change specializing
  `fmt::details::is_std_string_like<bytes>` won't compile.
* test/boost: in tests, we use `BOOST_REQUIRE_EQUAL()` and its friends
  for comparing values. but without the operator<< based formatters,
  Boost.Test would not be able to print them. after removing
  the homebrew formatters, we need to use the generic
  `boost_test_print_type()` helper to do this job. so we are
  including `test_utils.hh` in tests so that we can print
  the formattable types.
* treewide: add "#include "utils/to_string.hh" where
  `fmt::formatter<optional<>>` is used.
* configure.py: do not define FMT_DEPRECATED_OSTREAM
* cmake: do not define FMT_DEPRECATED_OSTREAM

Refs #13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-04-19 22:57:36 +08:00
Kefu Chai
a439ebcfce treewide: include fmt/ranges.h and/or fmt/std.h
before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.

in this change, we include `fmt/ranges.h` and/or `fmt/std.h`
for formatting the container types, like vector, map
optional and variant using {fmt} instead of the homebrew
formatter based on operator<<.
with this change, the changes adding fmt::formatter and
the changes using ostream formatter explicitly, we are
allowed to drop `FMT_DEPRECATED_OSTREAM` macro.

Refs scylladb#13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-04-19 22:56:16 +08:00
Kefu Chai
168ade72f8 treewide: replace formatter<std::string_view> with formatter<string_view>
in in {fmt} before v10, it provides the specialization of `fmt::formatter<..>`
for `std::string_view` as well as the specialization of `fmt::formatter<..>`
for `fmt::string_view` which is an implementation builtin in {fmt} for
compatibility of pre-C++17. and this type is used even if the code is
compiled with C++ stadandard greater or equal to C++17. also, before v10,
the `fmt::formatter<std::string_view>::format()` is defined so it accepts
`std::string_view`. after v10, `fmt::formatter<std::string_view>` still
exists, but it is now defined using `format_as()` machinery, so it's
`format()` method does not actually accept `std::string_view`, it
accepts `fmt::string_view`, as the former can be converted to
`fmt::string_view`.

this is why we can inherit from `fmt::formatter<std::string_view>` and
use `formatter<std::string_view>::format(foo, ctx);` to implement the
`format()` method with {fmt} v9, but we cannot do this with {fmt} v10,
and we would have following compilation failure:

```
FAILED: service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o
/home/kefu/.local/bin/clang++ -DFMT_DEPRECATED_OSTREAM -DFMT_SHARED -DSCYLLA_BUILD_MODE=release -DSEASTAR_API_LEVEL=7 -DSEASTAR_LOGGER_COMPILE_TIME_FMT -DSEASTAR_LOGGER_TYPE_STDOUT -DSEASTAR_SCHEDULING_GROUPS_COUNT=16 -DSEASTAR_SSTRING -DXXH_PRIVATE_API -DCMAKE_INTDIR=\"RelWithDebInfo\" -I/home/kefu/dev/scylladb -I/home/kefu/dev/scylladb/build/gen -I/home/kefu/dev/scylladb/seastar/include -I/home/kefu/dev/scylladb/build/seastar/gen/include -I/home/kefu/dev/scylladb/build/seastar/gen/src -ffunction-sections -fdata-sections -O3 -g -gz -std=gnu++20 -fvisibility=hidden -Wall -Werror -Wextra -Wno-error=deprecated-declarations -Wimplicit-fallthrough -Wno-c++11-narrowing -Wno-deprecated-copy -Wno-mismatched-tags -Wno-missing-field-initializers -Wno-overloaded-virtual -Wno-unsupported-friend -Wno-enum-constexpr-conversion -Wno-unused-parameter -ffile-prefix-map=/home/kefu/dev/scylladb=. -march=westmere -mllvm -inline-threshold=2500 -fno-slp-vectorize -U_FORTIFY_SOURCE -Werror=unused-result -MD -MT service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o -MF service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o.d -o service/CMakeFiles/service.dir/RelWithDebInfo/topology_state_machine.cc.o -c /home/kefu/dev/scylladb/service/topology_state_machine.cc
/home/kefu/dev/scylladb/service/topology_state_machine.cc:254:41: error: no matching member function for call to 'format'
  254 |     return formatter<std::string_view>::format(it->second, ctx);
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~
/usr/include/fmt/core.h:2759:22: note: candidate function template not viable: no known conversion from 'seastar::basic_sstring<char, unsigned int, 15>' to 'const fmt::basic_string_view<char>' for 1st argument
 2759 |   FMT_CONSTEXPR auto format(const T& val, FormatContext& ctx) const
      |                      ^      ~~~~~~~~~~~~
```

because the inherited `format()` method actually comes from
`fmt::formatter<fmt::string_view>`. to reduce the confusion, in this
change, we just inherit from `fmt::format<string_view>`, where
`string_view` is actually `fmt::string_view`. this follows
the document at
https://fmt.dev/latest/api.html#formatting-user-defined-types,
and since there is less indirection under the hood -- we do not
use the specialization created by `FMT_FORMAT_AS` which inherit
from `formatter<fmt::string_view>`, hopefully this can improve
the compilation speed a little bit. also, this change addresses
the build failure with {fmt} v10.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#18299
2024-04-19 07:44:07 +03:00
Pavel Emelyanov
2c3d6fe72f storage_proxy: Simplify create_hint_sync_point() code
It tries to call container().invoke_on_all() the hard way.
Calling it directly is not possible, because there's no
sharded::invoke_on_all() const overload

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>

Closes scylladb/scylladb#18202
2024-04-16 07:26:06 +03:00
Avi Kivity
dd76e1c834 Merge 'Simplify error_injection::inject_with_handler()' from Pavel Emelyanov
The method in question can have a shorter name that matches all other injections in this class, and can be non-template

Closes scylladb/scylladb#17734

* github.com:scylladb/scylladb:
  error_injection: De-template inject() with handler
  error_injection: Overload inject() instead of inject_with_handler()
2024-03-14 13:37:54 +02:00
Pavel Emelyanov
d90db016bf treewide: Use partition_slice::is_reversed()
Continuation of cc56a971e8, more noisy places detected

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>

Closes scylladb/scylladb#17763
2024-03-13 08:52:46 +02:00
Pavel Emelyanov
1f44a374b8 error_injection: Overload inject() instead of inject_with_handler()
The inject_with_handler() method accepts a coroutine that can be called
wiht injection_handler. With such function as an argument, there's no
need in distinctive inject_with_handler() name for a method, it can be
overload of all the existing inject()-s

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2024-03-11 19:30:19 +03:00
Kefu Chai
e1dbfedcdb service: add fmt::formatter for service/storage_proxy.cc types
before this change, we rely on the default-generated fmt::formatter created
from operator<<, but fmt v10 dropped the default-generated formatter.

in this change, we define formatters for internal types in service/storage_proxy.cc.
please note, `service::storage_proxy::remote::read_verb` is extracted out of
the outter class, because, the class's implementation formats `read_verb` in this
class. so we have to put the formatter at the place where its callers can see.
that's why it is moved up and out of `service::storage_proxy::remote`.

some of the operator<<:s are preserved, as they are still being used by
the existing formatters, for instance, the one for
`seastar::shared_ptr<>`, which is used to print
`seastar::shared_ptr<service::paxos_response_handler>`.

Refs #13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#17708
2024-03-11 11:52:58 +02:00
Botond Dénes
8213e66815 replica/database: use include page-size in max-result-size
This patch changes get_unlimited_query_max_result_size():
* Also set the page-size field, not just the soft/hard limits
* Renames it to get_query_max_result_size()
* Update callers, specifically storage_proxy::get_max_result_size(),
  which now has a much simpler common return path and has to drop the
  page size on one rare return path.

This is a purely mechanical change, no behaviour is changed.
2024-02-27 02:27:55 -05:00
Avi Kivity
605bf6e221 range.hh: retire
range.hh was deprecated in bd794629f9 (2020) since its names
conflict with the C++ library concept of an iterator range. The name
::range also mapped to the dangerous wrapping_interval rather than
nonwrapping_interval.

Complete the deprecation by removing range.hh and replacing all the
aliases by the names they point to from the interval library. Note
this now exposes uses of wrapping intervals as they are now explicit.

The unit tests are renamed and range.hh is deleted.

Closes scylladb/scylladb#17428
2024-02-21 00:24:25 +02:00
Yaniv Kaul
d2ef100b60 Typos: more/less then -> more/less than
Fix repated typos in comments: more then -> more than, less then -> less than

Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>

Closes scylladb/scylladb#17303
2024-02-13 17:16:15 +02:00
Petr Gusev
4554653ad9 storage_proxy: add a test for stop_remote
This patch adds a reproducer test for an issue #16382.
See scylladb/seastar#2044 for details of the problem.

The test is enabled only in dev mode since it requires
error injection mechanism. The patch adds a new injection
into storage_proxy::handle_read to simulate the problem
scenario - the node is shutting down and there are some
unfinished pending replica requests.

Closes scylladb/scylladb#16776
2024-02-09 17:23:13 +01:00
Avi Kivity
7cb1c10fed treewide: replace seastar::future::get0() with seastar::future::get()
get0() dates back from the days where Seastar futures carried tuples, and
get0() was a way to get the first (and usually only) element. Now
it's a distraction, and Seastar is likely to deprecate and remove it.

Replace with seastar::future::get(), which does the same thing.
2024-02-02 22:12:57 +08:00
Pavel Emelyanov
7c5c89ba8d Revert "Merge 'Use utils::directories instead of db::config to get dirs' from Patryk Wróbel"
This reverts commit 370fbd346c, reversing
changes made to 0912d2a2c6.

This makes scylla-manager mis-interpret the data_file_directories
somehow, issue #17078
2024-01-31 15:08:14 +03:00
Patryk Wrobel
f08768e767 service/storage_proxy: use utils::directories to get paths of dirs
This change replaces usage of db::config with
usage of utils::directories to get paths of
directories in service/storage_proxy.

Refs: scylladb#5626
Signed-off-by: Patryk Wrobel <patryk.wrobel@scylladb.com>
2024-01-29 13:11:33 +01:00
Dawid Medrek
b92fb3537a main: Postpone start-up of hint manager
In this commit, we postpone the start-up
of the hint manager until we obtain information
about other nodes in the cluster.

When we start the hint managers, one of the
things that happen is creating endpoint
managers -- structures managed by
db::hints::manager. Whether we create
an instance of endpoint manager depends on
the value returned by host_filter::can_hint_for,
which, in turn, may depend on the current state
of locator::topology.

If locator::topology is incomplete, some endpoint
managers may not be started even though they
should (because the target node IS part of the
cluster and we SHOULD send hints to it if there
are some).

The situation like that can happen because we
start the hint managers too early. This commit
aims to solve that problem. We only start
the hint managers when we've gathered information
about the other nodes in the cluster and created
the locator::topology using it.

Hinted Handoff is not negatively affected by these
changes since in between the previous point of
starting the hint managers and the current one,
all of the mutations performed by
service::storage_proxy target the local node, so
no hints would need to be generated anyway.

Fixes scylladb/scylladb#11870
Closes scylladb/scylladb#16511
2024-01-26 12:49:40 +01:00