This is cherry-picked-then-improved version of release branch commit
4204960942 PR #4861)
The commit
commit 5f8fd640bf
Author: Alek Westover <alek.westover@gmail.com>
Date: Wed Jul 26 08:24:03 2023 -0400
Upload Test Remote Extensions (#4792)
switched to using the release tag instead of `latest`, but,
the `promote-images` job only uploads `latest` to the prod ECR.
The switch to using release tag was good in principle, but,
it broke the release pipeline. So, switch release pipeline
back to using `latest`.
Note that a proper fix should abandon use of `:latest` tag
at all: currently, if a `main` pipeline runs concurrently
with a `release` pipeline, the `release` pipeline may end
up using the `main` pipeline's images.
---------
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Accidentially giving is_incremental=true for ImageLayers costs a lot of
debugging time. Removes all API which would allow to do that. They can
easily be restored later *when needed*.
Split off from #4938.
When doing global queries in VictoriaMetrics, the per-timeline
histograms make us run into cardinality limits.
We don't want to give them up just yet because we don't
have an alternative for drilling down on timeline-specific
performance issues.
So, add a pre-aggregated histogram and add observations to it
whenever we add observations to the per-timeline histogram.
While we're at it, switch to using a strummed enum for the operation
type names.
#4938 will make on-demand download of layers in compaction possible, so
it's not suitable for our "policy" of no `spawn_blocking(|| ...
Handle::block_on(async { spawn_blocking(...).await })` because this
poses a clear deadlock risk. Nested spawn_blockings are because of the
download using `tokio::fs::File`.
- Remove `spawn_blocking` from caller of `compact_level0_phase1`
- Remove `Handle::block_on` from `compact_level0_phase1` (indentation
change)
- Revert to `AsLayerDesc::layer_desc` usage temporarily (until it
becomes field access in #4938)
## Problem
many duplicate windows crates pollute the cargo deny output
## Summary of changes
we don't build those crates, so remove those targets from being checked
## Problem
cargo deny lint broken
Links to the CVEs:
[rustsec.org/advisories/RUSTSEC-2023-0052](https://rustsec.org/advisories/RUSTSEC-2023-0052)
[rustsec.org/advisories/RUSTSEC-2023-0053](https://rustsec.org/advisories/RUSTSEC-2023-0053)
One is fixed, the other one isn't so we allow it (for now), to unbreak
CI. Then later we'll try to get rid of webpki in favour of the rustls
fork.
## Summary of changes
```
+ignore = ["RUSTSEC-2023-0052"]
```
## Problem
There are some common types that we pass into tenants and timelines as
we construct them, such as remote storage and the broker client.
Currently the list is small, but this is likely to grow -- the deletion
queue PR (#4960) pushed some methods to the point of clippy complaining
they had too many args, because of the extra deletion queue client being
passed around.
There are some shared objects that currently aren't passed around
explicitly because they use a static `once_cell` (e.g.
CONCURRENT_COMPACTIONS), but as we add more resource management and
concurreny control over time, it will be more readable & testable to
pass a type around in the respective Resources object, rather than to
coordinate via static objects. The `Resources` structures in this PR
will make it easier to add references to central coordination functions,
without having to rely on statics.
## Summary of changes
- For `Tenant`, the `broker_client` and `remote_storage` are bundled
into `TenantSharedResources`
- For `Timeline`, the `remote_client` is wrapped into
`TimelineResources`.
Both of these structures will get an additional deletion queue member in
#4960.
## Problem
IndexPart contains two redundant lists of layer names: a set of the
names, and then a map of name to metadata.
We already required that all the layers in `timeline_layers` are also in
`layers_metadata`, in `initialize_with_current_remote_index_part`, so if
there were any index_part.json files in the field that relied on these
sets being different, they would already be broken.
## Summary of changes
`timeline_layers` is made private and no longer read at runtime. It is
still serialized, but not deserialized.
`disk_consistent_lsn` is also made private, as this field only exists
for convenience of humans reading the serialized JSON.
This prepares us to entirely remove `timeline_layers` in a future
release, once this change is fully deployed, and therefore no
pageservers are trying to read the field.
I made a mistake when I adding `env.initial_timeline:
Optional[TimelineId]` in the #3839, should had just generated it and
used it to create a specific timeline. This PR fixes those mistakes, and
some extra calling into psql which must be slower than python field
access.
I'm still a bit nervous about attach -> crash case. But it should work.
(unlike case with timeline). Ideally would be cool to cover this with
test.
This continues tradition of adding bool flags for Tenant::set_stopping.
Probably lifecycle project will help with fixing it.
## Problem
Before, DeltaLayer dumping (via `cargo run --release -p pagectl --
print-layer-file` ) would crash as one can't call `Handle::block_on` in
an async executor thread.
## Summary of changes
Avoid the problem by using `DeltaLayerInner::load_keys` to load the keys
into RAM (which we already do during compaction), and then load the
values one by one during dumping.
- move them to pageserver which is the only dependant on the crate fail
- "move" the exported macro to the new module
- support at init time the same failpoints as runtime
Found while debugging test failures and making tests more repeatable by
allowing "exit" from pageserver start via environment variables. Made
those changes to `test_gc_cutoff.py`.
---------
Co-authored-by: Christian Schwarz <christian@neon.tech>
A very slight change that allows us to configure the UID of the
neon-postgres cgroup owner. We start postgres in this cgroup so we can
scale it with the cgroups v2 api. Currently, the control plane
overwrites the entrypoint set by `vm-builder`, so `compute_ctl` (and
thus postgres), is not started in the neon-postgres cgroup. Having
`compute_ctl` start postgres in the cgroup should fix this. However, at
the moment appears like it does not have the correct permissions.
Configuring the neon-postgres UID to `postgres` (which is the UID
`compute_ctl` runs under) should hopefully fix this.
See #4920 - the PR to modify `compute_ctl` to start postgres in the
cgorup.
See: neondatabase/autoscaling#480, neondatabase/autoscaling#477. Both
these PR's are part of an effort to increase `vm-builder`'s
configurability and allow us to adjust it as we integrate in the
monitor.
(This PR is the successor of https://github.com/neondatabase/neon/pull/4984 )
## Summary
The current way in which `EphemeralFile` uses `PageCache` complicates
the Pageserver code base to a degree that isn't worth it.
This PR refactors how we cache `EphemeralFile` contents, by exploiting
the append-only nature of `EphemeralFile`.
The result is that `PageCache` only holds `ImmutableFilePage` and
`MaterializedPage`.
These types of pages are read-only and evictable without write-back.
This allows us to remove the writeback code from `PageCache`, also
eliminating an entire failure mode.
Futher, many great open-source libraries exist to solve the problem of a
read-only cache,
much better than our `page_cache.rs` (e.g., better replacement policy,
less global locking).
With this PR, we can now explore using them.
## Problem & Analysis
Before this PR, `PageCache` had three types of pages:
* `ImmutableFilePage`: caches Delta / Image layer file contents
* `MaterializedPage`: caches results of Timeline::get (page
materialization)
* `EphemeralPage`: caches `EphemeralFile` contents
`EphemeralPage` is quite different from `ImmutableFilePage` and
`MaterializedPage`:
* Immutable and materialized pages are for the acceleration of (future)
reads of the same data using `PAGE_CACHE_SIZE * PAGE_SIZE` bytes of
DRAM.
* Ephemeral pages are a write-back cache of `EphemeralFile` contents,
i.e., if there is pressure in the page cache, we spill `EphemeralFile`
contents to disk.
`EphemeralFile` is only used by `InMemoryLayer`, for the following
purposes:
* **write**: when filling up the `InMemoryLayer`, via `impl BlobWriter
for EphemeralFile`
* **read**: when doing **page reconstruction** for a page@lsn that isn't
written to disk
* **read**: when writing L0 layer files, we re-read the `InMemoryLayer`
and put the contents into the L0 delta writer
(**`create_delta_layer`**). This happens every 10min or when
InMemoryLayer reaches 256MB in size.
The access patterns of the `InMemoryLayer` use case are as follows:
* **write**: via `BlobWriter`, strictly append-only
* **read for page reconstruction**: via `BlobReader`, random
* **read for `create_delta_layer`**: via `BlobReader`, dependent on
data, but generally random. Why?
* in classical LSM terms, this function is what writes the
memory-resident `C0` tree into the disk-resident `C1` tree
* in our system, though, the values of InMemoryLayer are stored in an
EphemeralFile, and hence they are not guaranteed to be memory-resident
* the function reads `Value`s in `Key, LSN` order, which is `!=` insert
order
What do these `EphemeralFile`-level access patterns mean for the page
cache?
* **write**:
* the common case is that `Value` is a WAL record, and if it isn't a
full-page-image WAL record, then it's smaller than `PAGE_SIZE`
* So, the `EphemeralPage` pages act as a buffer for these `< PAGE_CACHE`
sized writes.
* If there's no page cache eviction between subsequent
`InMemoryLayer::put_value` calls, the `EphemeralPage` is still resident,
so the page cache avoids doing a `write` system call.
* In practice, a busy page server will have page cache evictions because
we only configure 64MB of page cache size.
* **reads for page reconstruction**: read acceleration, just as for the
other page types.
* **reads for `create_delta_layer`**:
* The `Value` reads happen through a `BlockCursor`, which optimizes the
case of repeated reads from the same page.
* So, the best case is that subsequent values are located on the same
page; hence `BlockCursor`s buffer is maximally effective.
* The worst case is that each `Value` is on a different page; hence the
`BlockCursor`'s 1-page-sized buffer is ineffective.
* The best case translates into `256MB/PAGE_SIZE` page cache accesses,
one per page.
* the worst case translates into `#Values` page cache accesses
* again, the page cache accesses must be assumed to be random because
the `Value`s aren't accessed in insertion order but `Key, LSN` order.
## Summary of changes
Preliminaries for this PR were:
- #5003
- #5004
- #5005
- uncommitted microbenchmark in #5011
Based on the observations outlined above, this PR makes the following
changes:
* Rip out `EphemeralPage` from `page_cache.rs`
* Move the `block_io::FileId` to `page_cache::FileId`
* Add a `PAGE_SIZE`d buffer to the `EphemeralPage` struct.
It's called `mutable_tail`.
* Change `write_blob` to use `mutable_tail` for the write buffering
instead of a page cache page.
* if `mutable_tail` is full, it writes it out to disk, zeroes it out,
and re-uses it.
* There is explicitly no double-buffering, so that memory allocation per
`EphemeralFile` instance is fixed.
* Change `read_blob` to return different `BlockLease` variants depending
on `blknum`
* for the `blknum` that corresponds to the `mutable_tail`, return a ref
to it
* Rust borrowing rules prevent `write_blob` calls while refs are
outstanding.
* for all non-tail blocks, return a page-cached `ImmutablePage`
* It is safe to page-cache these as ImmutablePage because EphemeralFile
is append-only.
## Performance
How doe the changes above affect performance?
M claim is: not significantly.
* **write path**:
* before this PR, the `EphemeralFile::write_blob` didn't issue its own
`write` system calls.
* If there were enough free pages, it didn't issue *any* `write` system
calls.
* If it had to evict other `EphemeralPage`s to get pages a page for its
writes (`get_buf_for_write`), the page cache code would implicitly issue
the writeback of victim pages as needed.
* With this PR, `EphemeralFile::write_blob` *always* issues *all* of its
*own* `write` system calls.
* Also, the writes are explicit instead of implicit through page cache
write back, which will help #4743
* The perf impact of always doing the writes is the CPU overhead and
syscall latency.
* Before this PR, we might have never issued them if there were enough
free pages.
* We don't issue `fsync` and can expect the writes to only hit the
kernel page cache.
* There is also an advantage in issuing the writes directly: the perf
impact is paid by the tenant that caused the writes, instead of whatever
tenant evicts the `EphemeralPage`.
* **reads for page reconstruction**: no impact.
* The `write_blob` function pre-warms the page cache when it writes the
`mutable_tail` to disk.
* So, the behavior is the same as with the EphemeralPages before this
PR.
* **reads for `create_delta_layer`**: no impact.
* Same argument as for page reconstruction.
* Note for the future:
* going through the page cache likely causes read amplification here.
Why?
* Due to the `Key,Lsn`-ordered access pattern, we don't read all the
values in the page before moving to the next page. In the worst case, we
might read the same page multiple times to read different `Values` from
it.
* So, it might be better to bypass the page cache here.
* Idea drafts:
* bypass PS page cache + prefetch pipeline + iovec-based IO
* bypass PS page cache + use `copy_file_range` to copy from ephemeral
file into the L0 delta file, without going through user space
## Problem
The performance benchmark in `test_runner/performance/test_layer_map.py`
is currently failing due to the warning added in #4888.
## Summary of changes
The test mentioned has a `compaction_target_size` of 8192, which is just
one page size. This is an unattainable goal, as we generate at least
three pages: one for the header, one for the b-tree (minimally sized
ones have just the root node in a single page), one for the data.
Therefore, we add two pages to the warning limit. The warning text
becomes a bit less accurate but I think this is okay.
## Problem
Errors and notices that happen during a pooled connection lifecycle have
no session identifiers
## Summary of changes
Using a watch channel, we set the session ID whenever it changes. This
way we can see the status of a connection for that session
Also, adding a connection id to be able to search the entire connection
lifecycle
I will have to change these as I change remote_timeline_client api in
#4938. So a bit of cleanup, handle my comments which were just resolved
during initial review.
Cleanup:
- use unwrap in tests instead of mixed `?` and `unwrap`
- use `Handle` instead of `&'static Reactor` to make the
RemoteTimelineClient more natural
- use arrays in tests
- use plain `#[tokio::test]`
## Problem
A customer is having trouble connecting to neon from their production
environment. The logs show a mix of "Internal error" and "authentication
protocol violation" but not the full error
## Summary of changes
Make sure we don't miss any logs during SASL/SCRAM
Rather temporary solution before proper:
https://github.com/neondatabase/neon/issues/5006
It requires more plumbing so lets not attach deleted tenants first and
then implement resume.
Additionally fix `assert_prefix_empty`. It had a buggy prefix calculation,
and since we always asserted for absence of stuff it worked. Here I
started to assert for presence of stuff too and it failed. Added more
"presence" asserts to other places to be confident that it works.
Resolves [#5016](https://github.com/neondatabase/neon/issues/5016)
## Problem
The previous version of neon (that we use in the forward compatibility test)
has installed `amcheck` extension now. We can run `pg_amcheck`
unconditionally.
## Summary of changes
- Run `pg_amcheck` in compatibility tests unconditionally
Before this patch, we had the `off` and `blknum` as function-wide
mutable state. Now it's contained in the `Writer` struct.
The use of `push_bytes` instead of index-based filling of the buffer
also makes it easier to reason about what's going on.
This is prep for https://github.com/neondatabase/neon/pull/4994
Don't download ext_index.json from s3, but instead receive it as a part of spec from control plane.
This eliminates s3 access for most compute starts,
and also allows us to update extensions spec on the fly
Restores #4937 work relating to the ability to use `ResidentDeltaLayer`
(which is an Arc wrapper) in #4938 for the ValueRef's by removing the
borrow from `ValueRef` and providing it from an upper layer.
This should not have any functional changes, most importantly, the
`main` will continue to use the borrowed `DeltaLayerInner`. It might be
that I can change #4938 to be like this. If that is so, I'll gladly rip
out the `Ref` and move the borrow back. But I'll first want to look at
the current test failures.
This makes it more explicit that these are different u64-sized
namespaces.
Re-using one in place of the other would be catastrophic.
Prep for https://github.com/neondatabase/neon/pull/4994
which will eliminate the ephemeral_file::FileId and move the
blob_io::FileId into page_cache.
It makes sense to have this preliminary commit though,
to minimize amount of new concept in #4994 and other
preliminaries that depend on that work.
## Problem
As documented, the global connection pool will be high contention.
## Summary of changes
Use DashMap rather than Mutex<HashMap>.
Of note, DashMap currently uses a RwLock internally, but it's partially
sharded to reduce contention by a factor of N. We could potentially use
flurry which is a port of Java's concurrent hashmap, but I have no good
understanding of it's performance characteristics. Dashmap is at least
equivalent to hashmap but less contention.
See the read heavy benchmark to analyse our expected performance
<https://github.com/xacrimon/conc-map-bench#ready-heavy>
I also spoke with the developer of dashmap recently, and they are
working on porting the implementation to use concurrent HAMT FWIW
## Problem
PR #4839 has already reduced the number of b-tree traversals and vec
creations from 3 to 2, but as pointed out in
https://github.com/neondatabase/neon/pull/4839#discussion_r1279167815 ,
we would ideally just traverse the b-tree once during compaction.
Afer #4836, the two vecs created are one for the list of keys, lsns and
sizes, and one for the list of `(key, lsn, value reference)`. However,
they are not equal, as pointed out in
https://github.com/neondatabase/neon/pull/4839#issuecomment-1660418012
and the following comment: the key vec creation combines multiple
entries for which the lsn is changing but the key stays the same into
one, with the size being the sum of the sub-sizes. In SQL, this would
correspond to something like `SELECT key, lsn, SUM(size) FROM b_tree
GROUP BY key;` and `SELECT key, lsn, val_ref FROM b_tree;`. Therefore,
the join operation is non-trivial.
## Summary of changes
This PR merges the two lists of keys and value references into one. It's
not a trivial change and affects the size pattern of the resulting
files, which is why this is in a separate PR from #4839 .
The key vec is used in compaction for determining when to start a new
layer file. The loop uses various thresholds to come to this conclusion,
but the grouping via the key has led to the behaviour that regardless of
the threshold, it only starts a new file when either a new key is
encountered, or a new delta file.
The new code now does the combination after the merging and sorting of
the various keys from the delta files. This *mostly* does the same as
the old code, except for a detail: with the grouping done on a
per-delta-layer basis, the sorted and merged vec would still have
multiple entries for multiple delta files, but now, we don't have an
easy way to tell when a new input delta layer file is encountered, so we
cannot create multiple entries on that basis easily.
To prevent possibly infinite growth, our new grouping code compares the
combined size with the threshold, and if it is exceeded, it cuts a new
entry so that the downstream code can cut a new output file. Here, we
perform a tradeoff however, as if the threshold is too small, we risk
putting entries for the same key into multiple layer files, but if the
threshold is too big, we can in some instances exceed the target size.
Currently, we set the threshold to the target size, so in theory we
would stay below or roughly at double the `target_file_size`.
We also fix the way the size was calculated for the last key. The calculation
was wrong and accounted for the old layer's btree, even though we
already account for the overhead of the in-construction btree.
Builds on top of #4839 .
Previously list_prefixes was incorrectly used for that purpose. Change
to use list_files. Add a test.
Some drive by refactorings on python side to move helpers out of
specific test file to be widely accessible
resolves https://github.com/neondatabase/neon/issues/4499
For `delete_objects` it was injecting failures for whole delete_objects operation
and then for every delete it contains. Make it fail once for the whole operation.
## Problem
This was set to 5 seconds, which was very close to how long a compaction
took on my workstation, and when deletion is blocked on compaction the
test would fail.
We will fix this to make compactions drop out on deletion, but for the
moment let's stabilize the test.
## Summary of changes
Change timeout on timeline deletion in
`test_timeline_deletion_with_files_stuck_in_upload_queue` from 5 seconds
to 30 seconds.
To this end add
1) -e option to 'neon_local safekeeper start' command appending extra options
to safekeeper invocation;
2) Allow multiple occurrences of the same option in safekeepers, the last
value is taken.
3) Allow to specify empty string for *-auth-public-key-path opts, it
disables auth for the service.
The same option enables auth and specifies public key, so this allows to use
different public keys as well. The motivation is to
1) Allow to e.g. change pageserver key/token without replacing all compute
tokens.
2) Enable auth gradually.
## Problem
Deletions can be possibly reordered. Use fsync to avoid the case when
mark file doesnt exist but other tenant/timeline files do.
See added comments.
resolves#4987
## Problem
While adding new test results format, I've also changed the way we
upload Allure reports to S3
(722c7956bb)
to avoid duplicated results from previous runs. But it broke links at
earlier results (results are still available but on different URLs).
This PR fixes this (by reverting logic in
722c7956bb
changes), and moves the logic for storing test results into db to allure
generate step. It allows us to avoid test results duplicates in the db
and saves some time on extra s3 downloads that happened in a different
job before the PR.
Ref https://neondb.slack.com/archives/C059ZC138NR/p1691669522160229
## Summary of changes
- Move test results storing logic from a workflow to
`actions/allure-report-generate`
## Problem
HTTP batch queries currently allow us to set the isolation level and
read only, but not deferrable.
## Summary of changes
Add support for deferrable.
Echo deferrable status in response headers only if true.
Likewise, now echo read-only status in response headers only if true.
#4942 left old metrics in place for migration purposes. It was noticed
that from new metrics the total number of deleted objects was forgotten,
add it.
While reviewing, it was noticed that the delete_object could just be
delete_objects of one.
---------
Co-authored-by: Arpad Müller <arpad-m@users.noreply.github.com>
