## Problem
part of https://github.com/neondatabase/neon/issues/4392
## Summary of changes
This PR adds a new HashMap that maps persistent layer desc to the layer
object *inside* LayerMap. Originally I directly went towards adding such
layer cache in Timeline, but the changes are too many and cannot be
reviewed as a reasonably-sized PR. Therefore, we take this intermediate
step to change part of the codebase to use persistent layer desc, and
come up with other PRs to move this hash map of layer desc to the
timeline struct.
Also, file_size is now part of the layer desc.
---------
Signed-off-by: Alex Chi <iskyzh@gmail.com>
Co-authored-by: bojanserafimov <bojan.serafimov7@gmail.com>
This reverts commit 732acc5.
Reverted PR: #3869
As noted in PR #4094, we do in fact try to insert duplicates to the
layer map, if L0->L1 compaction is interrupted. We do not have a proper
fix for that right now, and we are in a hurry to make a release to
production, so revert the changes related to this to the state that we
have in production currently. We know that we have a bug here, but
better to live with the bug that we've had in production for a long
time, than rush a fix to production without testing it in staging first.
Cc: #4094, #4088
## Describe your changes
## Issue ticket number and link
#3673
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
---------
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
Cc: #3486
Adds a method to replace a particular layer from the LayerMap for the
purposes of remote layer download and layer eviction. In those use cases
read lock on layer map needs to be released after initial search, but
other operations could modify layermap before replacing thread gets to
run.
Co-authored-by: bojanserafimov <bojan.serafimov7@gmail.com>
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.
refactor: use new type LayerFileName when referring to layer file names in PathBuf/RemotePath
Before this patch, we would sometimes carry around plain file names in
`Path` types and/or awkwardly "rebase" paths to have a unified
representation of the layer file name between local and remote.
This patch introduces a new type `LayerFileName` which replaces the use
of `Path` / `PathBuf` / `RemotePath` in the `storage_sync2` APIs.
Instead of holding a string, it contains the parsed representation of
the image and delta file name.
When we need the file name, e.g., to construct a local path or
remote object key, we construct the name ad-hoc.
`LayerFileName` is also serde {Dese,Se}rializable, and in an initial
version of this patch, it was supposed to be used directly inside
`IndexPart`, replacing `RemotePath`.
However,
commit 3122f3282f
Ignore backup files (ones with .n.old suffix) in download_missing
fixed handling of `*.old` backup file names in IndexPart, and we need
to carry that behavior forward.
The solution is to remove `*.old` backup files names during
deserialization. When we re-serialize the IndexPart, the `*.old` file
will be gone.
This leaks the `.old` file in the remote storage, but makes it safe
to clean it up later.
There is additional churn by a preliminary refactoring that got squashed
into this change:
split off LayerMap's needs from trait Layer into super trait
That refactoring renames `Layer` to `PersistentLayer` and splits off a subset
of the functions into a super-trait called `Layer`.
The upser trait implements just the functions needed by `LayerMap`, whereas
`PersisentLayer` adds the context of the pageserver.
The naming is imperfect as some functions that reside in `PersistentLayer`
have nothing persistence-specific to it. But it's a step in the right direction.
