Commit Graph

7 Commits

Author SHA1 Message Date
Evan Fleming
aa22572d8c safekeeper: refactor static remote storage usage to use Arc (#10179)
Greetings! Please add `w=1` to github url when viewing diff
(sepcifically `wal_backup.rs`)

## Problem

This PR is aimed at addressing the remaining work of #8200. Namely,
removing static usage of remote storage in favour of arc. I did not opt
to pass `Arc<RemoteStorage>` directly since it is actually
`Optional<RemoteStorage>` as it is not necessarily always configured. I
wanted to avoid having to pass `Arc<Optional<RemoteStorage>>` everywhere
with individual consuming functions likely needing to handle unwrapping.

Instead I've added a `WalBackup` struct that holds
`Optional<RemoteStorage>` and handles initialization/unwrapping
RemoteStorage internally. wal_backup functions now take self and
`Arc<WalBackup>` is passed as a dependency through the various consumers
that need it.

## Summary of changes
- Add `WalBackup` that holds `Optional<RemoteStorage>` and handles
initialization and unwrapping
- Modify wal_backup functions to take `WalBackup` as self (Add `w=1` to
github url when viewing diff here)
- Initialize `WalBackup` in safekeeper root
- Store `Arc<WalBackup>` in `GlobalTimelineMap` and pass and store in
each Timeline as loaded
- use `WalBackup` through Timeline as needed

## Refs

- task to remove global variables
https://github.com/neondatabase/neon/issues/8200
- drive-by fixes https://github.com/neondatabase/neon/issues/11501 
by turning the panic reported there into an error `remote storage not
configured`

---------

Co-authored-by: Christian Schwarz <christian@neon.tech>
2025-05-16 12:41:10 +00:00
Vlad Lazar
937876cbe2 safekeeper: don't skip empty records for shard zero (#11137)
## Problem

Shard zero needs to track the start LSN of the latest record
in adition to the LSN of the next record to ingest. The former
is included in basebackup persisted by the compute in WAL.

Previously, empty records were skipped for all shards. This caused
the prev LSN tracking on the PS to fall behind and led to logical
replication
issues.

## Summary of changes

Shard zero now receives emtpy interpreted records for LSN tracking
purposes.
A test is included too.
2025-03-07 15:52:01 +00:00
Arpad Müller
920040e402 Update storage components to edition 2024 (#10919)
Updates storage components to edition 2024. We like to stay on the
latest edition if possible. There is no functional changes, however some
code changes had to be done to accommodate the edition's breaking
changes.

The PR has two commits:

* the first commit updates storage crates to edition 2024 and appeases
`cargo clippy` by changing code. i have accidentially ran the formatter
on some files that had other edits.
* the second commit performs a `cargo fmt`

I would recommend a closer review of the first commit and a less close
review of the second one (as it just runs `cargo fmt`).

part of https://github.com/neondatabase/neon/issues/10918
2025-02-25 23:51:37 +00:00
Arseny Sher
758f597280 compute <-> sk protocol v3 (#10647)
## Problem

As part of https://github.com/neondatabase/neon/issues/8614 we need to
pass membership configurations between compute and safekeepers.

## Summary of changes

Add version 3 of the protocol carrying membership configurations.
Greeting message in both sides gets full conf, and other messages
generation number only. Use protocol bump to include other accumulated
changes:
- stop packing whole structs on the wire as is;
- make the tag u8 instead of u64;
- send all ints in network order;
- drop proposer_uuid, we can pass it in START_WAL_PUSH and it wasn't
much useful anyway.
Per message changes, apart from mconf:
- ProposerGreeting: tenant / timeline id is sent now as hex cstring.
Remove proto version, it is passed outside in START_WAL_PUSH. Remove
postgres timeline, it is unused. Reorder fields a bit.
- AcceptorGreeting: reorder fields
- VoteResponse: timeline_start_lsn is removed. It can be taken from
first member of term history, and later we won't need it at all when all
timelines will be explicitly created. Vote itself is u8 instead of u64.
- ProposerElected: timeline_start_lsn is removed for the same reasons.
- AppendRequest: epoch_start_lsn removed, it is known from term history
in ProposerElected.

Both compute and sk are able to talk v2 and v3 to make rollbacks (in
case we need them) easier; neon.safekeeper_proto_version GUC sets the
client version. v2 code can be dropped later.

So far empty conf is passed everywhere, future PRs will handle them.

To test, add param to some tests choosing proto version; we want to test
both 2 and 3 until we fully migrate.

ref https://github.com/neondatabase/neon/issues/10326

---------

Co-authored-by: Arthur Petukhovsky <petuhovskiy@yandex.ru>
2025-02-25 11:56:05 +00:00
Vlad Lazar
95588dab98 safekeeper: fix wal fan-out shard subscription data race (#10677)
## Problem

[This select
arm](https://github.com/neondatabase/neon/blob/main/safekeeper/src/send_interpreted_wal.rs#L414)
runs when we want to attach a new reader to the current cursor.
It checks the current position of the cursor and resets it if required.

The current position of the cursor is updated in the [other select
arm](https://github.com/neondatabase/neon/blob/main/safekeeper/src/send_interpreted_wal.rs#L336-L345).
That runs when we get some WAL to send.

Now, what happens if we want to attach two shards consecutively to the
cursor?
Let's say [this select
arm](https://github.com/neondatabase/neon/blob/main/safekeeper/src/send_interpreted_wal.rs#L397)
runs twice in a row.

Let's assume cursor is currently at LSN X. First shard wants to attach
at position V
and the other one at W. Assume X > W > V.

First shard resets the stream to position V. Second shard comes in, 
sees stale cursor position X and resets it to W. This means that the 
first shard doesn't get wal in the [V, W) range.

## Summary of changes

Ultimately, this boils down to the current position not being kept in
sync with the reset of the WAL stream. This patch fixes the race by
updating it when resetting the WAL stream and adds a unit test repro.

Closes https://github.com/neondatabase/cloud/issues/23750
2025-02-06 09:24:28 +00:00
Vlad Lazar
dbebede7bf safekeeper: fan out from single wal reader to multiple shards (#10190)
## Problem

Safekeepers currently decode and interpret WAL for each shard
separately.
This is wasteful in terms of CPU memory usage - we've seen this in
profiles.

## Summary of changes

Fan-out interpreted WAL to multiple shards. 
The basic is that wal decoding and interpretation happens in a separate
tokio task and senders
attach to it. Senders only receive batches concerning their shard and
only past the Lsn they've last seen.

Fan-out is gated behind the `wal_reader_fanout` safekeeper flag
(disabled by default for now).

When fan-out is enabled, it might be desirable to control the absolute
delta between the
current position and a new shard's desired position (i.e. how far behind
or ahead a shard may be).
`max_delta_for_fanout` is a new optional safekeeper flag which dictates
whether to create a new
WAL reader or attach to the existing one. By default, this behaviour is
disabled. Let's consider enabling
it if we spot the need for it in the field.

## Testing

Tests passed [here](https://github.com/neondatabase/neon/pull/10301)
with wal reader fanout enabled
as of
34f6a71718.

Related: https://github.com/neondatabase/neon/issues/9337
Epic: https://github.com/neondatabase/neon/issues/9329
2025-01-15 15:33:54 +00:00
Vlad Lazar
502d512fe2 safekeeper: lift benchmarking utils into safekeeper crate (#10200)
## Problem

The benchmarking utilities are also useful for testing. We want to write
tests in the safekeeper crate.

## Summary of changes

This commit lifts the utils to the safekeeper crate. They are compiled
if the benchmarking features is enabled or if in test mode.
2024-12-19 14:04:42 +00:00