To avoid pageserver gc'ing data needed by standby, propagate standby apply LSN
through standby -> safekeeper -> broker -> pageserver flow and hold off GC for
it. Iteration of GC resets the value to remove the horizon when standby goes
away -- pushes are assumed to happen at least once between gc iterations. As a
safety guard max allowed lag compared to normal GC horizon is hardcoded as 10GB.
Add test for the feature.
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Old methods are unchanged for backwards compatibility. Added
`SafekeeperDiscoveryRequest` and `SafekeeperDiscoveryResponse` types to
serve as example, and also as a prerequisite for
https://github.com/neondatabase/neon/issues/5471
Add a condition to switch walreceiver connection to safekeeper that is
located in the same availability zone. Switch happens when commit_lsn of
a candidate is not less than commit_lsn from the active connection. This
condition is expected not to trigger instantly, because commit_lsn of a
current connection is usually greater than commit_lsn of updates from
the broker. That means that if WAL is written continuously, switch can
take a lot of time, but it should happen eventually.
Now protoc 3.15+ is required for building neon.
Fixes https://github.com/neondatabase/neon/issues/3200
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.
Which ought to replace etcd. This patch only adds the binary and adjusts
Dockerfile to include it; subsequent ones will add deploy of helm chart and the
actual replacement.
It is a simple and fast pub-sub message bus. In this patch only safekeeper
message is supported, but others can be easily added.
Compilation now requires protoc to be installed. Installing protobuf-compiler
package is fine for Debian/Ubuntu.
ref
https://github.com/neondatabase/neon/pull/2733https://github.com/neondatabase/neon/issues/2394
