Commit Graph

3857 Commits

Author SHA1 Message Date
Benny Halevy
71d90b2fbc view: check_needs_view_update_path: get token_metadata_ptr
check_needs_view_update_path is async and might yield
so the token_metadata reference passed to it must be kept
alive throughout the call.

Fixes scylladb/scylladb#20979

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
(cherry picked from commit d34878e96c)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>

Closes scylladb/scylladb#21039
2024-10-22 09:16:40 +03:00
Calle Wilund
4a1e83d6be commitlog: Fix buffer_list_bytes not updated correctly
Fixes #20862

With the change in 60af2f3cb2 the bookkeep
for buffer memory was changed subtly, the problem here that we would
shrink buffer size before we after flush use said buffer's size to
decrement the buffer_list_bytes value, previously inc:ed by the full,
allocated size. I.e. we would slowly grow this value instead of adjusting
properly to actual used bytes.

Test included.

(cherry picked from commit ee5e71172f)

Closes scylladb/scylladb#20914
2024-10-03 09:11:40 +03:00
Avi Kivity
8ddfd0d70d cql3: add option to not unify bind variables with the same name
Bind variables in CQL have two formats: positional (`?`) where a
variable is referred to by its relative position in the statement,
and named (`:var`), where the user is expected to supply a
name->value mapping.

In 19a6e69001 we identified the case where a named bind variable
appears twice in a query, and collapsed it to a single entry in the
statement metadata. Without this, a driver using the named variable
syntax cannot disambiguate which variable is referred to.

However, it turns out that users can use the positional call form
even with the named variable syntax, by using the positional
API of the driver. To support this use case, we add a configuration
variable to disable the same-variable detection.

Because the detection has to happen when the entire statement is
visible, we have to supply the configuration to the parser. We
call it the `dialect` and pass it from all callers. The alternative
would be to add a pre-prepare call similar to fill_prepare_context that
rewrites all expressions in a statement to deduplicate variables.

A unit test is added.

Fixes #15559

(cherry picked from commit ea8441dfa3)
(cherry picked from commit edb3068ecf)
2024-09-13 18:17:15 +03:00
Avi Kivity
92dd47c6d6 cql3: introduce dialect infrastructure
A dialect is a different way to interpret the same CQL statement.

Examples:
 - how duplicate bind variable names are handled (later in this series)
 - whether `column = NULL` in LWT can return true (as is now) or
   whether it always returns NULL (as in SQL)

Currently, dialect is an empty structure and will be filled in later.
It is passed to query_processor methods that also accept a CQL string,
and from there to the parser. It is part of the prepared statement cache
key, so that if the dialect is changed online, previous parses of the
statement are ignored and the statement is prepared again.

The patch is careful to pick up the dialect at the entry point (e.g.
CQL protocol server) so that the dialect doesn't change while a statement
is parsed, prepared, and cached.

(cherry picked from commit d69bf4f010)
2024-09-13 18:11:11 +03:00
Nadav Har'El
d9ba5423bb Merge 'config: round-trip boolean configuration variables' from Avi Kivity
When you SELECT a boolean from system.config, it reads as true/false, but this isn't accepted
on UPDATE (instead, we accept 1/0). This is surprising and annoying, so accept true/false in
both directions.

Not a regression, so a backport isn't strictly necessary.

Closes scylladb/scylladb#19792

* github.com:scylladb/scylladb:
  config: specialize from-string conversion for bool
  config: wrap boost::lexical_cast<> when converting from strings

(cherry picked from commit 9eb47b3ef0)
2024-09-13 17:54:37 +03:00
Piotr Dulikowski
2556c7a0dc hints: send hints with CL=ALL if target is leaving
Currently, when attempting to send a hint, we might choose its
recipients in one of two ways:

- If the original destination is a natural endpoint of the hint, we only
  send the hint to that node and none other,
- Otherwise, we send the hint to all current replicas of the mutation.

There is a problem when we decommission a node: while data is streamed
away from that node, it is still considered to be a natural endpoint of
the data that it used to own. Because of that, it might happen that a
hint is sent directly to it but streaming will miss it, effectively
resulting in the hint being discarded.

As sending the hint _only_ to the leaving replica is a rather bad idea,
send the hint to all replicas also in the case when the original
destiantion of the hint is leaving.

Note that this is a conservative fix written only with the decommission
+ vnode-based keyspaces combo in mind. In general, such "data loss" can
occur in other situations where the replica set is changing and we go
through a streaming phase, i.e. other topology operations in case of
vnodes and tablet load balancing. However, the consistency guarantees of
hinted handoff in the face of topology changes are not defined and it is
not clear what they should be, if there should be any at all. The
picture is further complicated by the fact that hints are used by
materialized views, and sending view updates to more replicas than
necessary can introduce inconsistencies in the form of "ghost rows".
This fix was developed in response to a failing test which checked the
hint replay + decommission scenario, and it makes it work again.

Fixes scylladb/scylla-dtest#4582
Refs scylladb/scylladb#19835

(cherry picked from commit 61ac0a336d)
2024-09-12 10:55:29 +02:00
Piotr Dulikowski
132d77f447 hints: inline do_send_one_mutation
It's a small method and it is only used once in send_one_mutation.
Inlining it lets us get rid of its declaration in the header - now, if
one needs to change the variables passed from one function to another,
it is no longer necessary to change the header.

(cherry picked from commit 8abb06ab82)
2024-09-12 10:55:21 +02:00
Gleb Natapov
bb9249f055 db/consistency_level: do not use result from hit weighted load balancer if it contains duplicates
Because of https://github.com/scylladb/scylladb/issues/9285 hit weighted
load balancer may sometimes return same node twice. It may cause wrong
data to be read or unexpected errors to be returned to a client. Since
the original bug is not easy to fix and it is rare lets introduce a
workaround. We will check for duplicates and will use non HWLB one if
one is found.

(cherry picked from commit e06a772b87)

Closes scylladb/scylladb#20468
2024-09-10 17:18:47 +03:00
Benny Halevy
31f3ff37f4 schema_tables: calculate_schema_digest: filter the key earlier
Currently, each frozen mutation we get from
system_keyspace::query_mutations is unfrozen in whole
to a mutation and only then we check its key with
the provided `accept_keyspace` function.

This is wasteful, since they key can be processed
directly form the frozen mutation, before taking
the toll of unfreezing it.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
(cherry picked from commit 52234214e5)
2024-08-22 09:06:26 +00:00
Benny Halevy
828595786a schema_tables: calculate_schema_digest: prevent stalls due to large mutations vector
With a large number of table the schema mutations
vector might get big enoug to cause reactor stalls
when freed.

For example, the following stall was hit on
2023.1.0~rc1-20230208.fe3cc281ec73 with 5000 tables:
```
 (inlined by) ~vector at /usr/bin/../lib/gcc/x86_64-redhat-linux/12/../../../../include/c++/12/bits/stl_vector.h:730
 (inlined by) db::schema_tables::calculate_schema_digest(seastar::sharded<service::storage_proxy>&, enum_set<super_enum<db::schema_feature, (db::schema_feature)0, (db::schema_feature)1, (db::schema_feature)2, (db::schema_feature)3, (db::schema_feature)4, (db::schema_feature)5, (db::schema_feature)6, (db::schema_feature)7> >, seastar::noncopyable_function<bool (std::basic_string_view<char, std::char_traits<char> >)>) at ./db/schema_tables.cc:799
```

This change returns a mutations generator from
the `map` lambda coroutine so we can process them
one at a time, destroy the mutations one at a time,
and by that, reducing memory footprint and preventing
reactor stalls.

Fixes #18173

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
(cherry picked from commit 95a5fba0ea)
2024-08-22 09:06:25 +00:00
Dawid Medrek
8d90b81766 db/hints: Make commitlog use commitlog IO scheduling group
Before these changes, we didn't specify which I/O scheduling
group commitlog instances in hinted handoff should use.
In this commit, we set it explicitly to the commitlog
scheduling group. The rationale for this choice is the fact
we don't want to cause a bottleneck on the write path
-- if hints are written too slowly, new incoming mutations
(NOT hints) might be rejected due to a too high number
of hints currently being written to disk; see
`storage_proxy::create_write_response_handler_helper()`
for more context.

(cherry picked from commit 6a7fb18b52)

Closes scylladb/scylladb#20093
2024-08-14 22:14:43 +03:00
Piotr Dulikowski
30b0cb4f5d db/view: drop view updates to replaced node marked as left
When a node that is permanently down is replaced, it is marked as "left"
but it still can be a replica of some tablets. We also don't keep IPs of
nodes that have left and the `node` structure for such node returns an
empty IP (all zeros) as the address.

This interacts badly with the view update logic. The base replica paired
with the left node might decide to generate a view update. Because
storage proxy still uses IPs and not host IDs, it needs to obtain the
view replica's IP and tell the storage proxy to write a view update to
that node - so, it chooses 0.0.0.0. Apparently, storage proxy decides to
write a hint towards this address - hinted handoff on the other hand
operates on host IDs and not IPs, so it attempts to translate the IP
back, which triggers an assertion as there is no replica with IP
0.0.0.0.

As a quick workaround for this issue just drop view updates towards
nodes which seem to have IPs that are all zeros. It would be more proper
to keep the view updates as hints and replay them later to the new
paired replica, but achieving this right now would require much more
significant changes. For now, fixing a crash is more important than
keeping views consistent with base replicas.

Fixes: scylladb/scylladb#19439
(cherry picked from commit 6af7882c59)
2024-07-26 14:02:50 +00:00
Botond Dénes
53a6ec05ed Merge 'replica: remove rwlock for protecting iteration over storage group map' from Raphael "Raph" Carvalho
rwlock was added to protect iterations against concurrent updates to the map.

the updates can happen when allocating a new tablet replica or removing an old one (tablet cleanup).

the rwlock is very problematic because it can result in topology changes blocked, as updating token metadata takes the exclusive lock, which is serialized with table wide ops like split / major / explicit flush (and those can take a long time).

to get rid of the lock, we can copy the storage group map and guard individual groups with a gate (not a problem since map is expected to have a maximum of ~100 elements). so cleanup can close that gate (carefully closed after stopping individual groups such that migrations aren't blocked by long-running ops like major), and ongoing iterations (e.g. triggered by nodetool flush) can skip a group that was closed, as such a group is being migrated out.

Fixes #18821.

```
WRITE
=====

./build/release/scylla perf-simple-query --smp 1 --memory 2G --initial-tablets 10 --tablets --write

- BEFORE

65559.52 tps ( 59.6 allocs/op,  16.4 logallocs/op,  14.3 tasks/op,   52841 insns/op,   30946 cycles/op,        0 errors)
67408.05 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53018 insns/op,   30874 cycles/op,        0 errors)
67714.72 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53026 insns/op,   30881 cycles/op,        0 errors)
67825.57 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53015 insns/op,   30821 cycles/op,        0 errors)
67810.74 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53009 insns/op,   30828 cycles/op,        0 errors)

         throughput: mean=67263.72 standard-deviation=967.40 median=67714.72 median-absolute-deviation=547.02 maximum=67825.57 minimum=65559.52
instructions_per_op: mean=52981.61 standard-deviation=79.09 median=53014.96 median-absolute-deviation=36.54 maximum=53025.79 minimum=52840.56
  cpu_cycles_per_op: mean=30869.90 standard-deviation=50.23 median=30874.06 median-absolute-deviation=42.11 maximum=30945.94 minimum=30820.89

- AFTER
65448.76 tps ( 59.5 allocs/op,  16.4 logallocs/op,  14.3 tasks/op,   52788 insns/op,   31013 cycles/op,        0 errors)
67290.83 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53025 insns/op,   30950 cycles/op,        0 errors)
67646.81 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53025 insns/op,   30909 cycles/op,        0 errors)
67565.90 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   53058 insns/op,   30951 cycles/op,        0 errors)
67537.32 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   52983 insns/op,   30963 cycles/op,        0 errors)

         throughput: mean=67097.93 standard-deviation=931.44 median=67537.32 median-absolute-deviation=467.97 maximum=67646.81 minimum=65448.76
instructions_per_op: mean=52975.85 standard-deviation=108.07 median=53024.55 median-absolute-deviation=49.45 maximum=53057.99 minimum=52788.49
  cpu_cycles_per_op: mean=30957.17 standard-deviation=37.43 median=30951.31 median-absolute-deviation=7.51 maximum=31013.01 minimum=30908.62

READ
=====

./build/release/scylla perf-simple-query --smp 1 --memory 2G --initial-tablets 10 --tablets

- BEFORE

79423.36 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41840 insns/op,   26820 cycles/op,        0 errors)
81076.70 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41837 insns/op,   26583 cycles/op,        0 errors)
80927.36 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41829 insns/op,   26629 cycles/op,        0 errors)
80539.44 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41841 insns/op,   26735 cycles/op,        0 errors)
80793.10 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41864 insns/op,   26662 cycles/op,        0 errors)

         throughput: mean=80551.99 standard-deviation=661.12 median=80793.10 median-absolute-deviation=375.37 maximum=81076.70 minimum=79423.36
instructions_per_op: mean=41842.20 standard-deviation=13.26 median=41840.14 median-absolute-deviation=5.68 maximum=41864.50 minimum=41829.29
  cpu_cycles_per_op: mean=26685.88 standard-deviation=93.31 median=26662.18 median-absolute-deviation=56.47 maximum=26820.08 minimum=26582.68

- AFTER
79464.70 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41799 insns/op,   26761 cycles/op,        0 errors)
80954.58 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41803 insns/op,   26605 cycles/op,        0 errors)
81160.90 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41811 insns/op,   26555 cycles/op,        0 errors)
81263.10 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41814 insns/op,   26527 cycles/op,        0 errors)
81162.97 tps ( 63.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   41806 insns/op,   26549 cycles/op,        0 errors)

         throughput: mean=80801.25 standard-deviation=755.54 median=81160.90 median-absolute-deviation=361.72 maximum=81263.10 minimum=79464.70
instructions_per_op: mean=41806.47 standard-deviation=5.85 median=41806.05 median-absolute-deviation=4.05 maximum=41813.86 minimum=41799.36
  cpu_cycles_per_op: mean=26599.22 standard-deviation=94.84 median=26554.54 median-absolute-deviation=50.51 maximum=26761.06 minimum=26527.05
```

Closes scylladb/scylladb#19469

* github.com:scylladb/scylladb:
  replica: remove rwlock for protecting iteration over storage group map
  replica: get rid of fragile compaction group intrusive list
2024-07-12 15:45:36 +03:00
Raphael S. Carvalho
ad5c5bca5f replica: get rid of fragile compaction group intrusive list
It was added to make integration of storage groups easier, but it's
complicated since it's another source of truth and we could have
problems if it becomes inconsistent with the group map.

Fixes #18506.

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
2024-07-09 16:53:35 -03:00
Avi Kivity
f31d5e3204 Merge 'repair/streaming: enable toggling tombstone gc with a config item' from Botond Dénes
We currently disable tombstone GC for compaction done on the read path of streaming and repair, because those expired tombstones can still prevent data resurrection. With time-based tombstone GC, missing a repair for long enough can cause data resurrection because a tombstone is potentially GC'd before it could be spread to every node by repair. So repair disseminating these expired tombstones helps clusters which missed repair for long enough. It is not a guarantee because compaction could have done the GC itself, but it is better than nothing.
This last resort is getting less important with repair-based tombstone GC. Furthermore, we have seen this cause huge repair amplification in a cluster, where expired tombstones triggered repair replicating otherwise identical rows.

This series makes tombstone GC on the streaming/repair compaction path configurable with a config item. This new config item defaults to `false` (current behaviour), setting it to `true`, will enable tombstone GC.

Fixes: https://github.com/scylladb/scylladb/issues/19015

Not a regression, no backport needed

Closes scylladb/scylladb#19016

* github.com:scylladb/scylladb:
  test/topology_custom/test_repair: add test for enable_tombstone_gc_for_streaming_and_repair
  replica/table: maybe_compact_for_streaming(): toggle tombstone GC based on the control flag
  replica: propagate enable_tombstone_gc_for_streaming_and_repair to maybe_compact_for_streaming()
  db/config: introduce enable_tombstone_gc_for_streaming_and_repair
2024-07-09 19:04:11 +03:00
Patryk Wrobel
a89e3d10af code-cleanup: add missing header guards
The following command had been executed to get the
list of headers that did not contain '#pragma once':
'grep -rnw . -e "#pragma once" --include *.hh -L'

This change adds missing include guard to headers
that did not contain any guard.

Signed-off-by: Patryk Wrobel <patryk.wrobel@scylladb.com>

Closes scylladb/scylladb#19626
2024-07-09 18:31:35 +03:00
Piotr Dulikowski
3c535641fd Merge 'service/storage_proxy: Add metrics keeping track of incoming hints' from Dawid Mędrek
Although Scylla already exposes metrics keeping track of various information related to hinted handoff, all of them correspond to either storing or sending hints. However, when debugging, it's also crucial to be aware of how many hints are coming to a given node and what their size is. Unfortunately, the existing metrics are not enough to obtain that information.

This PR introduces the following new metrics:

* `sent_bytes_total` – the total size of the hints that have been sent from a given shard,
* `received_hints_total` – the total number of hints that a given shard has received,
* `received_hints_bytes_total` – the total size of the hints a given shard has received.

It also renames `hints_manager_sent` to `hints_manager_sent_total` to avoid conflicts of prefixes between that metric and `sent_bytes_total` in tests.

Fixes scylladb/scylladb#10987

Closes scylladb/scylladb#18976

* github.com:scylladb/scylladb:
  db/hints: Add a metric for the size of sent hints
  service/storage_proxy: Add metrics for received hints
2024-07-08 10:29:53 +02:00
Dawid Medrek
0e1cb0dc73 db/hints: Add logging when ignoring hint directories
In 2446cce, we stopped trying to attempt to create
endpoint managers for invalid hint directories
even when their names represented IP addresses or
host IDs. In this commit, we add logging informing
the user about it.

Refs scylladb/scylladb#19173

Closes scylladb/scylladb#19618
2024-07-04 20:14:52 +03:00
Avi Kivity
0626e0487d Merge 'Add copy on write to functions schema code' from Marcin Maliszkiewicz
This is the first patch from series which would allow us to unify raft command code. Property we want to achieve is that all modifications performed by a single raft command can be made visible atomically. This helps to exclude accidental dependencies across subsystem updates and make easier to reason about state.

Here we alter functions schema code so that changes are first applied to a copy of declared functions and then made visible atomically. Later work will apply similar strategy to the whole schema.

Relates scylladb/scylladb#19153

Closes scylladb/scylladb#19598

* github.com:scylladb/scylladb:
  cql3: functions: make modification functions accessible only via batch class
  db: replica: batch functions schema modifications
  cql3: functions: introduce class for batching functions modifications
  cql3: functions: make functions class non-static
  cql3: functions: remove reduntant class access specifiers
  cql3: functions: remove unused java snippet
2024-07-04 17:40:23 +03:00
Marcin Maliszkiewicz
32fe101f9d db: replica: batch functions schema modifications
Before each function change was immediately visible as
during event notification logic yielded.

Now we first gather the modifications and then commit them.

Further work will broaden the scope of atomicity to the whole
schema and even across other subsystems.
2024-07-04 13:10:26 +02:00
Nadav Har'El
96dff367f8 Merge 'storage_proxy: update view update backlog on correct shard when writing' from Wojciech Mitros
This series is another approach of https://github.com/scylladb/scylladb/pull/18646 and https://github.com/scylladb/scylladb/pull/19181. In this series we only change where the view backlog gets
updated - we do not assure that the view update backlog returned in a response is necessarily the backlog
that increased due to the corresponding write, the returned backlog may be outdated up to 10ms. Because
 this series does not include this change, it's considerably less complex and it doesn't modify the common
write patch, so no particular performance considerations were needed in that context. The issue being fixed
is still the same, the full description can be seen below.

When a replica applies a write on a table which has a materialized view
it generates view updates. These updates take memory which is tracked
by `database::_view_update_concurrency_sem`, separate on each shard.
The fraction of units taken from the semaphore to the semaphore limit
is the shard's view update backlog. Based on these backlogs, we want
to estimate how busy a node is with its view updates work. We do that
by taking the max backlog across all shards.
To avoid excessive cross-shard operations, the node's (max) backlog isn't
calculated each time we need it, but up to 1 time per 10ms (the `_interval`) with an optimization where the backlog of the calculating shard is immediately up-to-date (we don't need cross-shard operations for it):
```
update_backlog node_update_backlog::fetch() {
    auto now = clock::now();
    if (now >= _last_update.load(std::memory_order_relaxed) + _interval) {
        _last_update.store(now, std::memory_order_relaxed);
        auto new_max = boost::accumulate(
                _backlogs,
                update_backlog::no_backlog(),
                [] (const update_backlog& lhs, const per_shard_backlog& rhs) {
                    return std::max(lhs, rhs.load());
                });
        _max.store(new_max, std::memory_order_relaxed);
        return new_max;
    }
    return std::max(fetch_shard(this_shard_id()), _max.load(std::memory_order_relaxed));
}
```
For the same reason, even when we do calculate the new node's backlog,
we don't read from the `_view_update_concurrency_sem`. Instead, for
each shard we also store a update_backlog atomic which we use for
calculation:
```
    struct per_shard_backlog {
        // Multiply by 2 to defeat the prefetcher
        alignas(seastar::cache_line_size * 2) std::atomic<update_backlog> backlog = update_backlog::no_backlog();
        need_publishing need_publishing = need_publishing::no;

        update_backlog load() const {
            return backlog.load(std::memory_order_relaxed);
        }
    };
 std::vector<per_shard_backlog> _backlogs;
```
Due to this distinction, the update_backlog atomic need to be updated
separately, when the `_view_update_concurrency_sem` changes.
This is done by calling `storage_proxy::update_view_update_backlog`, which reads the `_view_update_concurrency_sem` of the shard (in `database::get_view_update_backlog`)
and then calls node`_update_backlog::add` where the read backlog
is stored in the atomic:
```
void storage_proxy::update_view_update_backlog() {
    _max_view_update_backlog.add(get_db().local().get_view_update_backlog());
}
void node_update_backlog::add(update_backlog backlog) {
    _backlogs[this_shard_id()].backlog.store(backlog, std::memory_order_relaxed);
    _backlogs[this_shard_id()].need_publishing = need_publishing::yes;
}
```
For this implementation of calculating the node's view update backlog to work,
we need the atomics to be updated correctly when the semaphores of corresponding
shards change.

The main event where the view update backlog changes is an incoming write
request. That's why when handling the request and preparing a response
we update the backlog calling `storage_proxy::get_view_update_backlog` (also
because we want to read the backlog and send it in the response):
backlog update after local view updates (`storage_proxy::send_to_live_endpoints` in `mutate_begin`)
```
 auto lmutate = [handler_ptr, response_id, this, my_address, timeout] () mutable {
     return handler_ptr->apply_locally(timeout, handler_ptr->get_trace_state())
             .then([response_id, this, my_address, h = std::move(handler_ptr), p = shared_from_this()] {
         // make mutation alive until it is processed locally, otherwise it
         // may disappear if write timeouts before this future is ready
         got_response(response_id, my_address, get_view_update_backlog());
     });
 };
backlog update after remote view updates (storage_proxy::remote::handle_write)

 auto f = co_await coroutine::as_future(send_mutation_done(netw::messaging_service::msg_addr{reply_to, shard}, trace_state_ptr,
         shard, response_id, p->get_view_update_backlog()));
```
Now assume that on a certain node we have a write request received on shard A,
which updates a row on shard B (A!=B). As a result, shard B will generate view
updates and consume units from its `_view_update_concurrency_sem`, but will
not update its atomic in `_backlogs` yet. Because both shards in the example
are on the same node, shard A will perform a local write calling `lmutate` shown
above. In the `lmutate` call, the `apply_locally` will initiate the actual write on
shard B and the `storage_proxy::update_view_update_backlog` will be called back
on shard A. In no place will the backlog atomic on shard B get updated even
though it increased in size due to the view updates generated there.
Currently, what we calculate there doesn't really matter - it's only used for the
MV flow control delays, so currently, in this scenario, we may only overload
a replica causing failed replica writes which will be later retried as hints. However,
when we add MV admission control, the calculated backlog will be the difference
between an accepted and a rejected request.

Fixes: https://github.com/scylladb/scylladb/issues/18542

Without admission control (https://github.com/scylladb/scylladb/pull/18334), this patch doesn't affect much, so I'm marking it as backport/none

Closes scylladb/scylladb#19341

* github.com:scylladb/scylladb:
  test: add test for view backlog not being updated on correct shard
  test: move auxiliary methods for waiting until a view is built to util
  mv: update view update backlog when it increases on correct shard
2024-07-04 11:40:09 +03:00
Marcin Maliszkiewicz
16b770ff1a cql3: functions: make functions class non-static
This is done to ease code reuse in the following commit.
It'd also help should we ever want properly mount functions
class to schema object instead of static storage.
2024-07-04 10:24:57 +02:00
Kefu Chai
cccec07581 db: use format_as() in favor of fmt::streamed()
since fedora 38 is EOL. and fedora 39 comes with fmt v10.0.0, also,
we've switched to the build image based on fedora 40, which ships
fmt-devel v10.2.1, there is no need to use fmt::streamed() when
the corresponding format_as() as available.

simpler this way.

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

Closes scylladb/scylladb#19594
2024-07-04 11:10:43 +03:00
Wojciech Mitros
1fdc65279d test: add test for view backlog not being updated on correct shard
This patch adds a test for reproducing issue https://github.com/scylladb/scylladb/issues/18542
The test performs writes on a table with a materialized view and
checks that the view backlog increases. To get the current view
update backlog, a new metric "view_update_backlog" is added to
the `storage_proxy` metrics. The metric differs from the metric
from `database` metric with the same name by taking the backlog
from the max_view_update_backlog which keeps view update backlogs
from all shards which may be a bit outdated, instead of taking
the backlog by checking the view_update_semaphore which the backlog
is based on directly.
2024-07-03 23:18:52 +02:00
Wojciech Mitros
fd9c7d4d59 mv: update view update backlog when it increases on correct shard
When performing a write, we should update the view update backlog
on the shard where the mutation is actually applied. Instead,
currently we only update it on the shard that initially received
the write request (which didn't change at all) and as a result,
the backlog on the correct shard and the aggregated max view update
backlog are not updated at all.
This patch enables updating the backlog on the correct shard. The
update is now performed just after the view generation and propagation
finishes, so that all backlog increases are noted and the backlog is
ready to be used in the write response.
Additionally, after this patch, we no longer (falsely) assume that
the backlog is modified on the same shard as where we later read it
to attach to a response. However, we still compare the aggregated
backlog from all shards and the backlog from the shard retrieving
the max, as with a shard-aware driver, it's likely the exact shard
whose backlog changed.
2024-07-03 23:18:52 +02:00
Michael Litvak
08b29460fc mv: skip building view updates on a pending replica
Currently, a pending replica that applies a write on a table that has
materialized views, will build all the view updates as a normal replica,
only to realize at a late point, in db::view::get_view_natural_endpoint(),
that it doesn't have a paired view replica to send the updates to. It will
then either drop the view updates, or send them to a pending view
replica, if such exists.

This work is unnecessary since it may be dropped, and even if there is a
pending view replica to send the updates to, the updates that are built
by the pending replica may be wrong since it may have incomplete
information.

This commit fixes the inefficiency by skipping the view update building
step when applying an update on a pending replica.

The metric total_view_updates_on_wrong_node is added to count the cases
that a view update is determined to be unnecessary.

The test reproduces the scenario of writing to a table and applying
the update on a pending replica, and verifies that the pending replica
doesn't try to build view updates.

Fixes scylladb/scylladb#19152

Closes scylladb/scylladb#19488
2024-07-02 13:10:18 +02:00
Nadav Har'El
d61513c41c Merge 'reader_concurrency_semaphore: make CPU concurrency configurable' from Botond Dénes
The reader concurrency semaphore restricts the concurrency of reads that require CPU (intention: they read from the cache) to 1, meaning that if there is even a single active read which declares that it needs just CPU to proceed, no new read is admitted. This is meant to keep the concurrency of reads in the cache at 1. The idea is that concurrency in the cache is not useful: it just leads to the reactor rotating between these reads, all of the finishing later then they could if they were the only active read in the cache.
This was observed to backfire in the case where there reads from a single table are mostly very fast, but on some keys are very slow (hint: collection full of tombstones). In this case the slow read keeps up the fast reads in the queue, increasing the 99th percentile latencies significantly.

This series proposes to fix this, by making the CPU concurrency configurable. We don't like tunables like this and this is not a proper fix, but a workaround. The proper fix would be to allow to cut any page early, but we cannot cut a page in the middle of a row. We could maybe have a way of detecting slow reads and excluding them from the CPU concurrency. This would be a heuristic and it would be hard to get right. So in this series a robust and simple configurable is offered, which can be used on those few clusters which do suffer from the too strict concurrency limit. We have seen it in very few cases so far, so this doesn't seem to be wide-spread.

Fixes: https://github.com/scylladb/scylladb/issues/19017

This fixes a regression introduced in 5.0, so we have to backport to all currently supported releases

Closes scylladb/scylladb#19018

* github.com:scylladb/scylladb:
  test/boost/reader_concurrency_semaphore_test: add test for live-configurable cpu concurrenc  Please enter the commit message for your changes. Lines starting
  test/boost/reader_concurrency_semaphore_test: hoist require_can_admit
  reader_concurrency_semaphore: wire in the configurable cpu concurrency
  reader_concurrency_semaphore: add cpu_concurrency constructor parameter
  db/config: introduce reader_concurrency_semahore_cpu_concurrency
2024-07-02 13:39:00 +03:00
Kefu Chai
b71b638b2e config: add descriptions for default_log_level and friends
so that their description can be displayed in
`reference/configuration-parameters/` web page.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-07-01 09:47:28 +08:00
Kefu Chai
b486f4ef01 config: define log_to_syslog in a different line
before this change, docs/_ext/scylladb_cc_properties.py parses
the options line by line, because `log_to_stdout` and `log_to_syslog`
are defined in a single line, this script is not able to parse them,
hence fails to display them on the `reference/configuration-parameters/`
web page.

after this change, these two member variables are defined on different
lines. both of them can be displayed.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-07-01 09:47:28 +08:00
Benny Halevy
b7f00ba4bf schema_tables: remove dead code
Well, even after 10 years, the c++ compilers still
do not compile Java...

And having that legacy code laying around
not only it doesn't help anyone understand what's
going on, but on the contrary, it's confusing and distracting.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2024-06-27 20:34:02 +03:00
Botond Dénes
d5a149fc01 db/config: introduce enable_tombstone_gc_for_streaming_and_repair
To control whether the compacting reader (if enabled) for streaming and
repair can garbage-collect tombstones.
Default is false (previous behaviour).
Not wired yet.
2024-06-26 04:05:17 -04:00
Botond Dénes
31c0fa07d8 db/batchlog_manager: bypass cache when scanning batchlog table
Scans should not pollute the cache with cold data, in general. In the
case of the batchlog table, there is another reason to bypass the cache:
this table can have a lot of partition tombstones, which currently are
not purged from the cache. So in certain cases, using the cache can make
batch replay very slow, because it has to scan past tombstones of
already replayed batches.
2024-06-25 06:15:47 -04:00
Botond Dénes
29f610d861 db/batchlog_manager: replace open-coded paging with internal one
query_processor has built-in paging support, no need to open-code paging
in batchlog manager code.
2024-06-25 06:15:47 -04:00
Botond Dénes
2dd057c96d db/batchlog_manager: implement cleanup after all batchlog replay
We have a commented code snippet from Origin with cleanup and a FIXME to
implement it. Origin flushes the memtables and kicks a compaction. We
only implement the flush here -- the flush will trigger a compaction
check and we leave it up to the compaction manager to decide when a
compaction is worthwhile.
This method used to be called only from unbootstrap, so a cleanup was
not really needed. Now it is also called at the end of repair, if the
table is using repair-based tombstone-gc. If the memtable is filled with
tombstones, this can add a lot of time to the runtime of each repair. So
flush the memtable at the end, so the tombstones can be purged (they
aren't purged from memtables yet).
2024-06-25 06:15:47 -04:00
Botond Dénes
c7317be09a db/config: introduce reader_concurrency_semahore_cpu_concurrency
To allow increasing the semaphore's CPU concurrency, which is currently
hard-limited to 1. Not wired yet.
2024-06-25 04:00:11 -04:00
Kefu Chai
7b10cc8079 treewide: include seastar headers with brackets
this change was created in the same spirit of ebff5f5d.

despite that we include Seastar as a submodule, Seastar is not a
part of scylla project. so we'd better include its headers using
brackets.

ebff5f5d addressed this cosmetic issue a while back. but probably
clangd's header-insertion helped some of contributor to insert
the missing headers with `"`. so this style of `include` returned
to the tree with these new changes.

unfortunately, clangd does not allow us to configure the style
of `include` at the time of writing.

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

Closes scylladb/scylladb#19406
2024-06-21 19:20:27 +03:00
Dawid Medrek
2446cce272 db/hints: Initialize endpoint managers only for valid hint directories
Before these changes, it could happen that Scylla initialized
endpoint managers for hint directories representing

* host IDs before migrating hinted handoff to using host IDs,
* IP addresses after the migration.

One scenario looked like this:

1. Start Scylla and upgrade the cluster to using host IDs.
2. Create, by hand, a hint directory representing an IP address.
3. Trigger changing the host filter in hinted handoff; it could
   be achieved by, for example, restricting the set of data
   centers Scylla is allowed to save hints for.

When changing the host filter, we browse the hint directories
and create endpoint managers if we can send hints towards
the node corresponding to a given hint directory. We only
accepted hint directories representing IP addresses
and host IDs. However, we didn't check whether the local node
has already been upgraded to host-ID-based hinted handoff
or not. As a result, endpoint managers were created for
both IP addresses and host IDs, no matter whether we were
before or after the migration.

These changes make sure that any time we browse the hint
directories, we take that into account.

Fixes scylladb/scylladb#19172

Closes scylladb/scylladb#19173
2024-06-21 15:59:49 +02:00
Avi Kivity
fdc1449392 treewide: rename flat_mutation_reader_v2 to mutation_reader
flat_mutation_reader_v2 was introduced in a pair of commits in 2021:

  e3309322c3 "Clone flat_mutation_reader related classes into v2 variants"
  08b5773c12 "Adapt flat_mutation_reader_v2 to the new version of the API"

as a replacement for flat_mutation_reader, using range_tombstone_change
instead of range_tombstone to represent represent range tombstones. See
those commits for more information.

The transition was incremental; the last use of the original
flat_mutation_reader was removed in 2022 in commit

  026f8cc1e7 "db: Use mutation_partition_v2 in mvcc"

In turn, flat_mutation_reader was introduced in 2017 in commit

  748205ca75 "Introduce flat_mutation_reader"

To transition from a mutation_reader that nested rows within
a partition in a separate stream, to a flat reader that streamed
partitions and rows in the same stream.

Here, we reclaim the original name and rename the awkward
flat_mutation_reader_v2 to mutation_reader.

Note that mutation_fragment_v2 remains since we still use the original
for compatibilty, sometimes.

Some notes about the transition:

 - files were also renamed. In one case (flat_mutation_reader_test.cc), the
   rename target already existed, so we rename to
    mutation_reader_another_test.cc.

 - a namespace 'mutation_reader' with two definitions existed (in
   mutation_reader_fwd.hh). Its contents was folded into the mutation_reader
   class. As a result, a few #includes had to be adjusted.

Closes scylladb/scylladb#19356
2024-06-21 07:12:06 +03:00
Piotr Dulikowski
75441ee120 Merge 'mv: fix value of the gossiped view update backlog' from Wojciech Mitros
Currently, when calculating the view update backlog for gossip,
we start with `db::view::update_backlog()` and compare it to backlogs
from all shards. However, this backlog can't be compared to other
backlogs - it has size 0 and we compare the fraction current/size
when comparing backlogs, causing us to compare with `NaN`.
This patch fixes it by starting the comparisons with an empty backlog.

The patch introducing this issue (f70f774e40) wasn't backported, so this one doesn't need to be either

Closes scylladb/scylladb#19247

* github.com:scylladb/scylladb:
  mv: make the view update backlog unmofidiable
  mv: fix value of the gossiped view update backlog
2024-06-20 06:27:11 +02:00
Wojciech Mitros
cde14a5788 mv: make the view update backlog unmofidiable
Currently, a view update backlog may reach an invalid state, when
its max is 0 and its relative_size() is NaN as a result. This can
be achieved either by constructing the backlog with a 0 max or by
modifying the max of an existing backlog. In particular, this
happens when creating the backlog using the default constructor.

In this patch the the default constructor is deleted and a check
is added to make sure that the max is different than 0 is added
to its constructor - if the check fails, we construct an empty
backlog instead, to handle the possibility of getting an invalid
backlog sent from a node with a version that's missing this check.
Additionally, we make the backlogs members private, exposing them
only through const getters.
2024-06-19 19:44:57 +02:00
Wojciech Mitros
1de5566cfa mv: fix value of the gossiped view update backlog
Currently, when calculating the view update backlog for gossip,
we start with `db::view::update_backlog()` and compare it to backlogs
from all shards. However, this backlog can't be compared to other
backlogs - it has size 0 and we compare the fraction current/size
when comparing backlogs, causing us to compare with `NaN`.
This patch fixes it by starting the comparisons with an empty backlog.
2024-06-18 13:15:18 +02:00
Kefu Chai
68ef7dda79 config: correct the comment on printable_to_json()
seastar::format() does not use operator<< under the hood, it uses
{fmt}, so update the comment accordingly.

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

Closes scylladb/scylladb#19315
2024-06-18 12:08:59 +03:00
Pavel Emelyanov
147552c34a Merge 'configurable maintenance (streaming) semaphore count resource limit' from Botond Dénes
Making the count resources on the maintenance (streaming) semaphore live update via config. This will allow us to improve repair speed on mixed-shard clusters, where we suspect that reader trashing -- due to the combination of high number of readers on each shard and very conservative reader count limit (10) -- is the main cause of the slowness.
Making this count limit confgurable allows us to start experimenting with this fix, without committing to a count limit increase (or removal), addressing the pain in the field.

Refs: #18269

No OSS backport needed.

Closes scylladb/scylladb#19248

* github.com:scylladb/scylladb:
  replica/database: wire in maintenance_reader_concurrency_semaphore_count_limit
  db/config: introduce maintenance_reader_concurrency_semaphore_count_limit
  reader_concurrency_semaphore: make count parameter live-update
2024-06-18 12:02:24 +03:00
Botond Dénes
1acc57e19d Merge 'schema: Make "describe" use extensions to string' from Calle Wilund
Fixes #19334

Current impl uses hardcoded printing of a few extensions.
Instead, use extension options to string and print all.

Note: required to make enterprise CI happy again.

Closes scylladb/scylladb#19337

* github.com:scylladb/scylladb:
  schema: Make "describe" use extensions to string
  schema_extensions: Add an option to string method
2024-06-18 11:28:11 +03:00
Nadav Har'El
4faceeaa33 Merge 'treewide: drop thrift support' from Kefu Chai
thrift support was deprecated since ScyllaDB 5.2

> Thrift API - legacy ScyllaDB (and Apache Cassandra) API is
> deprecated and will be removed in followup release. Thrift has
> been disabled by default.

so let's drop it. in this change,

* thrift protocol support is dropped
* all references to thrift support in document are dropped
* the "thrift_version" column in system.local table is preserved for backward compatibility, as we could load from an existing system.local table which still contains this clolumn, so we need to write this column as well.
* "/storage_service/rpc_server" is only preserved for backward compatibility with java-based nodetool.

Fixes #3811
Fixes #18416
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

- [x] not a fix, no need to backport

Closes scylladb/scylladb#18453

* github.com:scylladb/scylladb:
  config: expand on rpc_keepalive's description
  api: s/rpc/thrift/
  db/system_keyspace: drop thrift_version from system.local table
  transport: do not return client_type from cql_server::connection::make_client_key()
  treewide: drop thrift support
2024-06-17 22:36:49 +03:00
Kefu Chai
b64126fe1c db: remove unused operator<<
since we've switched almost all callers of the operator<< to {fmt},
let's drop the unused operator<<:s.

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

Closes scylladb/scylladb#19313
2024-06-17 17:33:31 +03:00
Calle Wilund
d27620e146 schema_extensions: Add an option to string method
Allow an extension to describe itself as the CQL property
string that created it (and is serialized to schema tables)

Only paxos extension requires override.
2024-06-17 13:30:10 +00:00
Dawid Medrek
670830091c db/hints: Use dedicated functions to lock a shared mutex
Seastar has functions implementing locking a `seastar::shared_mutex`.
We should use those now instead of reimplementing them in Scylla.

Closes scylladb/scylladb#19253
2024-06-14 20:31:37 +02:00
Wojciech Mitros
9bae1814ab test: add test for failed view building write
For various reasons, a view building write may fail. When that
happens, the view building should not finish until these writes
are successfully retried and they should not interfere with any
writes that are performed to the base table while the view is
building.

The test introduced in this patch confirms that this is the case.

Refs scylladb/scylladb#19261

Closes scylladb/scylladb#19263
2024-06-14 10:38:21 +02:00
Botond Dénes
665fdd6ce4 db/config: introduce maintenance_reader_concurrency_semaphore_count_limit
To control the amount of count resources of the maintenance (streaming)
semaphore. Not wired yet.
2024-06-13 01:59:21 -04:00