I have experimented with the runner threads number, and looks like 8
threads win us a few seconds.
Bumping the thread count more did not improve the situation much:
* 20 threads were not allowed by pytest
* 16 threads were flacking quite notably
My guess would be that all pageservers, safekeepers, and other nodes we
start occupy quite much of the CPU and other resources to make this
approach more scalable.
I looked at "cargo tree" output and noticed that through various
dependencies, we are depending on both native-tls and rustls. We have
tried to standardize on rustls for everything, but dependencies on
native-tls have crept in recently. One such dependency came from
'reqwest' with default features in pageserver, used for
consumption_metrics. Another dependency was from 'sentry'. Both
'reqwest' and 'sentry' use native-tls by default, but can use 'rustls'
if compiled with the right feature flags.
Send this metric only when it is fully calculated.
Make consumption metrics more stable:
- Send per-timeline metrics only for active timelines.
- Adjust test assertions to make test_metric_collection test more stable.
Refactor update_gc_info function so that it calls the potentially
expensive find_lsn_for_timestamp() function before acquiring the
lock. This will also be needed if we make find_lsn_for_timestamp()
async in the future; it cannot be awaited while holding the lock.
Fixes:
- serialize TenantId and TimelineId as strings,
- skip TimelineId if none
- serialize `metric_type` field as `type`
- add `idempotency_key` field to uniquely identify metrics
Changes are:
* Pageserver: start reading from NEON_AUTH_TOKEN by default.
Warn if ZENITH_AUTH_TOKEN is used instead.
* Compute, Docs: fix the default token name.
* Control plane: change name of the token in configs and start
sequences.
Compatibility:
* Control plane in tests: works, no compatibility expected.
* Control plane for local installations: never officially supported
auth anyways. If someone did enable it, `pageserver.toml` should be updated
with the new `neon.pageserver_connstring` and `neon.safekeeper_token_env`.
* Pageserver is backward compatible: you can run new Pageserver with old
commands and environment configurations, but not vice-versa.
The culprit is the hard-coded `NEON_AUTH_TOKEN`.
* Compute has no code changes. As long as you update its configuration
file with `pageserver_connstring` in sync with the start up scripts,
you are good to go.
* Safekeeper has no code changes and has never used `ZENITH_AUTH_TOKEN` in
the first place.
While @bojanserafimov is still working on best replacement of R-Tree in
layer_map.rs there is obvious pitfall in the current `search` method
implementation: is returns delta layer even if there is image layer if
greater LSN. I think that it should be fixed.
The PR aims to fix two missing redownloads in a flacky
test_remote_storage_upload_queue_retries[local_fs]
([example](https://neon-github-public-dev.s3.amazonaws.com/reports/pr-3190/release/3759194738/index.html#categories/80f1dcdd7c08252126be7e9f44fe84e6/8a70800f7ab13620/))
1. missing redownload during walreceiver work
```
2022-12-22T16:09:51.509891Z ERROR wal_connection_manager{tenant=fb62b97553e40f949de8bdeab7f93563 timeline=4f153bf6a58fd63832f6ee175638d049}: wal receiver task finished with an error: walreceiver connection handling failure
Caused by:
Layer needs downloading
Stack backtrace:
0: pageserver::tenant::timeline::PageReconstructResult<T>::no_ondemand_download
at /__w/neon/neon/pageserver/src/tenant/timeline.rs:467:59
1: pageserver::walingest::WalIngest::new
at /__w/neon/neon/pageserver/src/walingest.rs:61:32
2: pageserver::walreceiver::walreceiver_connection::handle_walreceiver_connection::{{closure}}
at /__w/neon/neon/pageserver/src/walreceiver/walreceiver_connection.rs:178:25
....
```
That looks sad, but inevitable during the current approach: seems that
we need to wait for old layers to arrive in order to accept new data.
For that, `WalIngest::new` now started to return the
`PageReconstructResult`.
Sync methods from `import_datadir.rs` use `WalIngest::new` too, but both
of them import WAL during timeline creation, so no layers to download
are needed there, ergo the `PageReconstructResult` is converted to
`anyhow::Result` with `no_ondemand_download`.
2. missing redownload during compaction work
```
2022-12-22T16:09:51.090296Z ERROR compaction_loop{tenant_id=fb62b97553e40f949de8bdeab7f93563}:compact_timeline{timeline=4f153bf6a58fd63832f6ee175638d049}: could not compact, repartitioning keyspace failed: Layer needs downloading
Stack backtrace:
0: pageserver::tenant::timeline::PageReconstructResult<T>::no_ondemand_download
at /__w/neon/neon/pageserver/src/tenant/timeline.rs:467:59
1: pageserver::pgdatadir_mapping::<impl pageserver::tenant::timeline::Timeline>::collect_keyspace::{{closure}}
at /__w/neon/neon/pageserver/src/pgdatadir_mapping.rs:506:41
<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/future/mod.rs:91:19
pageserver::tenant::timeline::Timeline::repartition::{{closure}}
at /__w/neon/neon/pageserver/src/tenant/timeline.rs:2161:50
<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/future/mod.rs:91:19
2: pageserver::tenant::timeline::Timeline::compact::{{closure}}
at /__w/neon/neon/pageserver/src/tenant/timeline.rs:700:14
<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/future/mod.rs:91:19
3: <tracing::instrument::Instrumented<T> as core::future::future::Future>::poll
at /github/home/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-0.1.37/src/instrument.rs:272:9
4: pageserver::tenant::Tenant::compaction_iteration::{{closure}}
at /__w/neon/neon/pageserver/src/tenant.rs:1232:85
<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/future/mod.rs:91:19
pageserver::tenant_tasks::compaction_loop::{{closure}}::{{closure}}
at /__w/neon/neon/pageserver/src/tenant_tasks.rs:76:62
<core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/future/mod.rs:91:19
pageserver::tenant_tasks::compaction_loop::{{closure}}
at /__w/neon/neon/pageserver/src/tenant_tasks.rs:91:6
```
Scan core dumps directory on exit. In case of existing core dumps
call gdb/lldb to get a backtrace and log it. By default look for
core dumps in postgres data directory as core.<pid>. That is how
core collection is configured in our k8s nodes (and a reasonable
convention in general).
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.
The code in this change was extracted from #2595 (Heikki’s on-demand
download draft PR).
High-Level Changes
- New RemoteLayer Type
- On-Demand Download As An Effect Of Page Reconstruction
- Breaking Semantics For Physical Size Metrics
There are several follow-up work items planned.
Refer to the Epic issue on GitHub: https://github.com/neondatabase/neon/issues/2029
closes https://github.com/neondatabase/neon/pull/3013
Co-authored-by: Kirill Bulatov <kirill@neon.tech>
Co-authored-by: Christian Schwarz <christian@neon.tech>
New RemoteLayer Type
====================
Instead of downloading all layers during tenant attach, we create
RemoteLayer instances for each of them and add them to the layer map.
On-Demand Download As An Effect Of Page Reconstruction
======================================================
At the heart of pageserver is Timeline::get_reconstruct_data(). It
traverses the layer map until it has collected all the data it needs to
produce the page image. Most code in the code base uses it, though many
layers of indirection.
Before this patch, the function would use synchronous filesystem IO to
load data from disk-resident layer files if the data was not cached.
That is not possible with RemoteLayer, because the layer file has not
been downloaded yet. So, we do the download when get_reconstruct_data
gets there, i.e., “on demand”.
The mechanics of how the download is done are rather involved, because
of the infamous async-sync-async sandwich problem that plagues the async
Rust world. We use the new PageReconstructResult type to work around
this. Its introduction is the cause for a good amount of code churn in
this patch. Refer to the block comment on `with_ondemand_download()`
for details.
Breaking Semantics For Physical Size Metrics
============================================
We rename prometheus metric pageserver_{current,resident}_physical_size to
reflect what this metric actually represents with on-demand download.
This intentionally BREAKS existing grafana dashboard and the cost model data
pipeline. Breaking is desirable because the meaning of this metrics has changed
with on-demand download. See
https://docs.google.com/document/d/12AFpvKY-7FZdR5a4CaD6Ir_rI3QokdCLSPJ6upHxJBo/edit#
for how we will handle this breakage.
Likewise, we rename the new billing_metrics’s PhysicalSize => ResidentSize.
This is not yet used anywhere, so, this is not a breaking change.
There is still a field called TimelineInfo::current_physical_size. It
is now the sum of the layer sizes in layer map, regardless of whether
local or remote. To compute that sum, we added a new trait method
PersistentLayer::file_size().
When updating the Python tests, we got rid of
current_physical_size_non_incremental. An earlier commit removed it from
the OpenAPI spec already, so this is not a breaking change.
test_timeline_size.py has grown additional assertions on the
resident_physical_size metric.
