Add essential safekeeper and pageserver::walreceiver metrics. Mostly
counters, such as the number of received queries, broker messages,
removed WAL segments, or connection switches events in walreceiver.
Also logs broker push loop duration.
Otherwise it can lag a lot, preventing WAL segments cleanup. Also max
wal_backup_lsn on update, pulling it down is pointless.
Should help with https://github.com/neondatabase/neon/issues/3957, but
will not fix it completely.
- Add support for splitting async postgres_backend into read and write halfes.
Safekeeper needs this for bidirectional streams. To this end, encapsulate
reading-writing postgres messages to framed.rs with split support without any
additional changes (relying on BufRead for reading and BytesMut out buffer for
writing).
- Use async postgres_backend throughout safekeeper (and in proxy auth link
part).
- In both safekeeper COPY streams, do read-write from the same thread/task with
select! for easier error handling.
- Tidy up finishing CopyBoth streams in safekeeper sending and receiving WAL
-- join split parts back catching errors from them before returning.
Initially I hoped to do that read-write without split at all, through polling
IO:
https://github.com/neondatabase/neon/pull/3522
However that turned out to be more complicated than I initially expected
due to 1) borrow checking and 2) anon Future types. 1) required Rc<Refcell<...>>
which is Send construct just to satisfy the checker; 2) can be workaround with
transmute. But this is so messy that I decided to leave split.
1.66 release speeds up compile times for over 10% according to tests.
Also its Clippy finds plenty of old nits in our code:
* useless conversion, `foo as u8` where `foo: u8` and similar, removed
`as u8` and similar
* useless references and dereferenced (that were automatically adjusted
by the compiler), removed various `&` and `*`
* bool -> u8 conversion via `if/else`, changed to `u8::from`
* Map `.iter()` calls where only values were used, changed to
`.values()` instead
Standing out lints:
* `Eq` is missing in our protoc generated structs. Silenced, does not
seem crucial for us.
* `fn default` looks like the one from `Default` trait, so I've
implemented that instead and replaced the `dummy_*` method in tests with
`::default()` invocation
* Clippy detected that
```
if retry_attempt < u32::MAX {
retry_attempt += 1;
}
```
is a saturating add and proposed to replace it.
Changes:
* Remove `RemoteObjectId` concept from remote_storage.
Operate directly on /-separated names instead.
These names are now represented by struct `RemotePath` which was renamed from struct `RelativePath`
* Require remote storage to operate on relative paths for its contents, thus simplifying the way to derive them in pageserver and safekeeper
* Make `IndexPart` to use `String` instead of `RelativePath` for its entries, since those are just the layer names
This API is rather pointless, as sane choice anyway requires knowledge of peers
status and leaders lifetime in any case can intersect, which is fine for us --
so manual elections are straightforward. Here, we deterministically choose among
the reasonably caught up safekeepers, shifting by timeline id to spread the
load.
A step towards custom broker https://github.com/neondatabase/neon/issues/2394
- Split postgres_ffi into two version specific files.
- Preserve pg_version in timeline metadata.
- Use pg_version in safekeeper code. Check for postgres major version mismatch.
- Clean up the code to use DEFAULT_PG_VERSION constant everywhere, instead of hardcoding.
- Parameterize python tests: use DEFAULT_PG_VERSION env and pg_version fixture.
To run tests using a specific PostgreSQL version, pass the DEFAULT_PG_VERSION environment variable:
'DEFAULT_PG_VERSION='15' ./scripts/pytest test_runner/regress'
Currently don't all tests pass, because rust code relies on the default version of PostgreSQL in a few places.
We had a pattern like this:
match remote_storage {
GenericRemoteStorage::Local(storage) => {
let source = storage.remote_object_id(&file_path)?;
...
storage
.function(&source, ...)
.await
},
GenericRemoteStorage::S3(storage) => {
... exact same code as for the Local case ...
},
This removes the code duplication, by allowing you to call the functions
directly on GenericRemoteStorage.
Also change RemoveObjectId to be just a type alias for String. Now that
the callers of GenericRemoteStorage functions don't know whether they're
dealing with the LocalFs or S3 implementation, RemoveObjectId must be the
same type for both.
Another preparatory commit for pg15 support:
* generate bindings for both pg14 and pg15;
* update Makefile and CI scripts: now neon build depends on both PostgreSQL versions;
* some code refactoring to decrease version-specific dependencies.
Re-export only things that are used by other modules.
In the future, I'm imagining that we run bindgen twice, for Postgres
v14 and v15. The two sets of bindings would go into separate
'bindings_v14' and 'bindings_v15' modules.
Rearrange postgres_ffi modules.
Move function, to avoid Postgres version dependency in timelines.rs
Move function to generate a logical-message WAL record to postgres_ffi.
I made the check at launcher level with the perspective of generally moving
election (decision who offloads) there.
Also log timeline 'active' changes.
I still don't like the surroundings and feel we'd better get away without using
election API at all, but this is a quick fix to keep CI green.
ref #1815
- Uncomment accidently `self.keep_alive.abort()` commented line, due to this
task never finished, which blocked launcher.
- Mess up with initialization one more time, to fix offloader trying to back up
segment 0. Now we initialize all required LSNs in handle_elected,
where we learn start LSN for the first time.
- Fix blind attempt to provide safekeeper service file with remote storage
params.
Separate task is launched for each timeline and stopped when timeline doesn't
need offloading. Decision who offloads is done through etcd leader election;
currently there is no pre condition for participating, that's a TODO.
neon_local and tests infrastructure for remote storage in safekeepers added,
along with the test itself.
ref #1009
Co-authored-by: Anton Shyrabokau <ahtoxa@Antons-MacBook-Pro.local>
