Commit Graph

364 Commits

Author SHA1 Message Date
Konstantin Knizhnik
be23eae3b6 Mark pages as avaiable in LFC only after generation check (#12350)
## Problem

If LFC generation is changed then `lfc_readv_select` will return -1 but
pages are still marked as available in bitmap.

## Summary of changes

Update bitmap after generation check.

Co-authored-by: Kosntantin Knizhnik <konstantin.knizhnik@databricks.com>
2025-06-26 07:06:27 +00:00
Heikki Linnakangas
3d822dbbde Refactor Makefile rules for building the extensions under pgxn/ (#12305) 2025-06-22 19:43:14 +00:00
Mikhail
e95f2f9a67 compute_ctl: return LSN in /terminate (#12240)
- Add optional `?mode=fast|immediate` to `/terminate`, `fast` is
default. Immediate avoids waiting 30
  seconds before returning from `terminate`.
- Add `TerminateMode` to `ComputeStatus::TerminationPending`
- Use `/terminate?mode=immediate` in `neon_local` instead of `pg_ctl
stop` for `test_replica_promotes`.
- Change `test_replica_promotes` to check returned LSN
- Annotate `finish_sync_safekeepers` as `noreturn`.

https://github.com/neondatabase/cloud/issues/29807
2025-06-18 12:25:19 +00:00
Mikhail
7d4f662fbf upgrade default neon version to 1.6 (#12185)
Changes for 1.6 were merged and deployed two months ago
https://github.com/neondatabase/neon/blob/main/pgxn/neon/neon--1.6--1.5.sql.
In order to deploy https://github.com/neondatabase/neon/pull/12183, we
need 1.6 to be default, otherwise we can't use prewarm API on read-only
replica (`ALTER EXTENSION` won't work) and we need it for promotion
2025-06-17 17:46:35 +00:00
Konstantin Knizhnik
dfa055f4be Support event trigger for Neon users (#10624)
## Problem

https://github.com/neondatabase/neon/issues/7570

Even triggers are supported only for superusers.

## Summary of changes

Temporary switch to superuser when even trigger is created and disable
execution of user's even triggers under superuser.

---------

Co-authored-by: Dimitri Fontaine <dim@tapoueh.org>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-06-17 15:44:50 +00:00
Konstantin Knizhnik
24038033bf Remove default from DROP FUNCTION (#12202)
## Problem

DROP FUNCTION doesn't allow to specify default for parameters.

## Summary of changes

Remove DEFAULT clause from pgxn/neon/neon--1.6--1.5.sql

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-06-11 13:16:58 +00:00
Konstantin Knizhnik
21949137ed Return last ring index instead of min_ring_index in prefetch_register_bufferv (#12039)
## Problem

See https://github.com/neondatabase/neon/issues/12018

Now `prefetch_register_bufferv` calculates min_ring_index of all vector
requests.
But because of pump prefetch state or connection failure, previous slots
can be already proceeded and reused.

## Summary of changes

Instead of returning minimal index, this function should return last
slot index.
Actually result of this function is used only in two places. A first
place just fort checking (and this check is redundant because the same
check is done in `prefetch_register_bufferv` itself.
And in the second place where index of filled slot is actually used,
there is just one request.
Sp fortunately this bug can cause only assert failure in debug build.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-06-10 10:09:46 +00:00
Dmitrii Kovalkov
73be6bb736 fix(compute): use proper safekeeper in VotesCollectedMset (#12175)
## Problem
`VotesCollectedMset` uses the wrong safekeeper to update truncateLsn.
This led to some failed assert later in the code during running
safekeeper migration tests.
- Relates to https://github.com/neondatabase/neon/issues/11823

## Summary of changes
Use proper safekeeper to update truncateLsn in VotesCollectedMset
2025-06-10 07:16:42 +00:00
Konstantin Knizhnik
9c6c780201 Replica promote (#12090)
## Problem

This PR is part of larger computes support activity:

https://www.notion.so/neondatabase/Larger-computes-114f189e00478080ba01e8651ab7da90

Epic: https://github.com/neondatabase/cloud/issues/19010

In case of planned node restart, we are going to 
1. create new read-only replica
2. capture LFC state at primary
3. use this state to prewarm replica
4. stop old primary
5. promote replica to primary

Steps 1-3 are currently implemented and support from compute side.
This PR provides compute level implementation of replica promotion.

Support replica promotion

## Summary of changes

Right now replica promotion is done in three steps:
1. Set safekeepers list (now it is empty for replica)
2. Call `pg_promote()` top promote replica
3. Update endpoint setting to that it ids not more treated as replica.

May be all this three steps should be done by some function in
compute_ctl. But right now this logic is only implement5ed in test.

Postgres submodules PRs:
https://github.com/neondatabase/postgres/pull/648
https://github.com/neondatabase/postgres/pull/649
https://github.com/neondatabase/postgres/pull/650
https://github.com/neondatabase/postgres/pull/651

---------

Co-authored-by: Matthias van de Meent <matthias@neon.tech>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-06-05 11:27:14 +00:00
Konstantin Knizhnik
6123fe2d5e Add query execution time histogram (#10050)
## Problem


It will be useful to understand what kind of queries our clients are
executed.
And one of the most important characteristic of query is query execution
time - at least it allows to distinguish OLAP and OLTP queries. Also
monitoring query execution time can help to detect problem with
performance (assuming that workload is more or less stable).

## Summary of changes

Add query execution time histogram.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-06-05 11:23:39 +00:00
Arpad Müller
dae203ef69 pgxn: support generations in safekeepers_cmp (#12129)
`safekeepers_cmp` was added by #8840 to make changes of the safekeeper
set order independent: a `sk1,sk2,sk3` specifier changed to
`sk3,sk1,sk2` should not cause a walproposer restart. However, this
check didn't support generations, in the sense that it would see the
`g#123:` as part of the first safekeeper in the list, and if the first
safekeeper changes, it would also restart the walproposer.

Therefore, parse the generation properly and make it not be a part of
the generation.

This PR doesn't add a specific test, but I have confirmed locally that
`test_safekeepers_reconfigure_reorder` is fixed with the changes of PR
#11712 applied thanks to this PR.

Part of https://github.com/neondatabase/neon/issues/11670
2025-06-04 23:02:31 +00:00
Tristan Partin
fe1513ca57 Add neon.safekeeper_conninfo_options GUC (#11901)
In order to enable TLS connections between computes and safekeepers, we
need to provide the control plane with a way to configure the various
libpq keyword parameters, sslmode and sslrootcert. neon.safekeepers is a
comma separated list of safekeepers formatted as host:port, so isn't
available for extension in the same way that neon.pageserver_connstring
is. This could be remedied in a future PR.

Part-of: https://github.com/neondatabase/cloud/issues/25823
Link:
https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS

Signed-off-by: Tristan Partin <tristan@neon.tech>
2025-05-27 02:21:24 +00:00
Konstantin Knizhnik
d5023f2b89 Restrict pump prefetch state only to regular backends (#12000)
## Problem

See https://github.com/neondatabase/neon/issues/11997

This guard prevents race condition with pump prefetch state (initiated
by timeout).
Assert checks that prefetching is also done under guard.
But prewarm knows nothing about it.

## Summary of changes

Pump prefetch state only in regular backends.
Prewarming is done by background workers now.
Also it seems to have not sense to pump prefetch state in any other
background workers: parallel executors, vacuum,... because they are
short living and can not leave unconsumed responses in socket.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-05-23 08:48:06 +00:00
Konstantin Knizhnik
81c557d87e Unlogged build get smgr (#11954)
## Problem

See https://github.com/neondatabase/neon/issues/11910
and https://neondb.slack.com/archives/C04DGM6SMTM/p1747314649059129

## Summary of changes

Do not change persistence in `start_unlogged_build`

Postgres PRs:
https://github.com/neondatabase/postgres/pull/642
https://github.com/neondatabase/postgres/pull/641
https://github.com/neondatabase/postgres/pull/640
https://github.com/neondatabase/postgres/pull/639

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-05-18 05:02:47 +00:00
Konstantin Knizhnik
8e05639dbf Invalidate LFC after unlogged build (#11951)
## Problem


See https://neondb.slack.com/archives/C04DGM6SMTM/p1747391617951239

LFC is not always properly updated during unlogged build so it can
contain stale content.

## Summary of changes

Invalidate LFC content at the end of unlogged build

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-05-17 19:06:59 +00:00
Konstantin Knizhnik
290369061f Check prefetch result in DEBUG_COMPARE_LOCAL mode (#11502)
## Problem

Prefetched and LFC results are not checked in DEBUG_COMPARE_LOCAL mode

## Summary of changes

Add check for this results as well.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-05-13 14:13:42 +00:00
Matthias van de Meent
3b7cc4234c Fix PS connect attempt timeouts when facing interrupts (#11880)
With the 50ms timeouts of pumping state in connector.c, we need to
correctly handle these timeouts that also wake up pg_usleep.

This new approach makes the connection attempts re-start the wait
whenever it gets woken up early; and CHECK_FOR_INTERRUPTS() is called to
make sure we don't miss query cancellations.

## Problem

https://neondb.slack.com/archives/C04DGM6SMTM/p1746794528680269

## Summary of changes

Make sure we start sleeping again if pg_usleep got woken up ahead of
time.
2025-05-09 17:02:24 +00:00
Konstantin Knizhnik
03d635b916 Add more guards for prefetch_pump_state (#11859)
## Problem

See https://neondb.slack.com/archives/C08PJ07BZ44/p1746566292750689

Looks like there are more cases when `prefetch_pump_state` can be called
in unexpected place and cause core dump.

## Summary of changes

Add more guards.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-05-09 09:07:08 +00:00
Konstantin Knizhnik
f0e7b3e0ef Use unlogged build for gist_indexsortbuild_flush_ready_pages (#11753)
## Problem

See https://github.com/neondatabase/neon/issues/11718

GIST index can be constructed in two ways: GIST_SORTED_BUILD and
GIST_BUFFERING.
We used unlogged build in the second case but not in the first.

## Summary of changes

Use unlogged build in `gist_indexsortbuild_flush_ready_pages`

Correspondent Postgres PRsL:
https://github.com/neondatabase/postgres/pull/624
https://github.com/neondatabase/postgres/pull/625
https://github.com/neondatabase/postgres/pull/626

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
2025-05-06 07:24:27 +00:00
Dmitrii Kovalkov
c6ff18affc cosmetics(pgxn/neon): WP code small clean up (#11824)
## Problem
Some small cosmetic changes I made while reading the code. Should not
affect anything.

## Summary of changes
- Remove `n_votes` field because it's not used anymore
- Explicitly initialize `safekeepers_generation` with
`INVALID_GENERATION` if the generation is not present (the struct is
zero-initialized anyway, but the explicit initialization is better IMHO)
- Access SafekeeperId via pointer `sk_id` created above
2025-05-06 06:51:51 +00:00
Konstantin Knizhnik
4b9087651c Checked that stored LwLSN >= FirstNormalUnloggedLSN (#11750)
## Problem

Undo unintended change 60b9fb1baf

## Summary of changes

Add assert that we are not storing fake LSN in LwLSN.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-05-02 19:27:59 +00:00
Konstantin Knizhnik
79699aebc8 Reserve in file descriptor pool sockets used for connections to page servers (#11798)
## Problem

See https://github.com/neondatabase/neon/issues/11790

The neon extension opens extensions to the pageservers, which consumes
file descriptors. Postgres has a mechanism to count how many FDs are in
use, but it doesn't know about those FDs. We should call
ReserveExternalFD() or AcquireExternalFD() to account for them.

## Summary of changes

Call `ReserveExternalFD()` for each shard

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Co-authored-by: Mikhail Kot <mikhail@neon.tech>
2025-05-02 14:36:10 +00:00
Dmitrii Kovalkov
1b789e8d7c fix(pgxn/neon): Use proper member size in TermsCollectedMset and VotesCollectedMset (#11785)
## Problem
`TermsCollectedMset` and `VotesCollectedMset` accept a MemberSet
argument to find a quorum in. It may be either `wp->mconf.members` or
`wp->mconf.new_members`. But the loops inside always use
`wp->mconf.members.len`.

If the sizes of member sets are different, it may lead to these
functions not scanning all the safekeepers from `mset`.

We are not planning to change the member set size dynamically now, but
it's worth fixing anyway.

- Part of https://github.com/neondatabase/neon/issues/11669

## Summary of changes
- Use proper size of member set in `TermsCollectedMset` and
`VotesCollectedMset`
2025-04-30 16:50:21 +00:00
Konstantin Knizhnik
1d68577fbd Check target slot state in prefetch_wait_for (#11779)
## Problem

See https://neondb.slack.com/archives/C04DGM6SMTM/p1745599814030679

Assume the following scenario: prefetch_wait_for is doing
`CHECK_FOR_INTERRUPTS` which tries to load prefetch responses.
In case of error is calls pageserver_disconnect which aborts all
in-flight requests. But such failure is not detected by
`prefetch_wait_for` which returns true. As a result
`communicator_read_at_lsnv` assumes that slot is received, but as far as
asserts are disables at prod, it is not actually checked.
Then it tries to interpret response and ... *SIGSEGV*

## Summary of changes

Check target slot state  in `prefetch_wait_for`.

Resolves https://github.com/neondatabase/cloud/issues/28258

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-30 12:44:59 +00:00
Arseny Sher
60f63c076f Make safekeeper proto version 3 default (#11518)
## Problem

We have been running compute <-> sk protocol version 3 for a while on
staging with no issues observed, and want to fully migrate to it
eventually.

## Summary of changes

Let's make v3 the default.

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

---------

Co-authored-by: Arpad Müller <arpad@neon.tech>
2025-04-30 12:23:20 +00:00
Mikhail Kot
8da4ec9740 Postgres metrics for stuck getpage requests (#11710)
https://github.com/neondatabase/neon/issues/10327
Resolves: #11720 

New metrics:
- `compute_getpage_stuck_requests_total`
- `compute_getpage_max_inflight_stuck_time_ms`
2025-04-30 12:01:41 +00:00
Konstantin Knizhnik
3593356c10 Prewarm sql api (#11742)
## Problem

Continue work on prewarm, see 
https://github.com/neondatabase/neon/pull/11740
https://github.com/neondatabase/neon/pull/11741

## Summary of changes

Add SQL API to prewarm

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-29 06:44:28 +00:00
Konstantin Knizhnik
6d6b83e737 Prewarm implementation (#11741)
## Problem

Continue work on prewarm started in PR
https://github.com/neondatabase/neon/pull/11740

## Summary of changes

Implement prewarm using prefetch

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-28 18:17:03 +00:00
Tristan Partin
a750026c2e Fix compiler warning in libpagestore.c when WITH_SANITIZERS=yes (#11755)
Postgres has a nice self-documenting macro called pg_unreachable() when
you want to assert that a location in code won't be hit.

Warning in question:

```
/home/tristan957/Projects/work/neon//pgxn/neon/libpagestore.c: In function ‘pageserver_connect’:
/home/tristan957/Projects/work/neon//pgxn/neon/libpagestore.c:739:1: warning: control reaches end of non-void function [-Wreturn-type]
  739 | }
      | ^
```

Signed-off-by: Tristan Partin <tristan@neon.tech>
2025-04-28 17:09:48 +00:00
Konstantin Knizhnik
692c0f3fb8 Prepare to prewarm support (#11740)
## Problem

See
(original prewarm implementation)
https://github.com/neondatabase/neon/pull/9197
(functions for storing/restoring LFC state)
https://github.com/neondatabase/neon/pull/9587
(store prefetch results in LFC)
https://github.com/neondatabase/neon/pull/10442

## Summary of changes

Preparation for prewarm implementation.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-28 13:24:18 +00:00
Konstantin Knizhnik
60b9fb1baf Ignore unlogged LSNs in set last written LSN (#11743)
## Problem

See https://github.com/neondatabase/neon/issues/11718
and https://neondb.slack.com/archives/C033RQ5SPDH/p1745122797538509

GIST other indexes performing "unlogged build" are using so called fake
LSNs - not a real LSN, but something like 0/1. Been stored in lwlsn
cache they cause incorrect lookup at PS.

## Summary of changes

Do not store fake LSNs in LwLSN hash.

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-28 12:16:29 +00:00
Konstantin Knizhnik
132b6154bb Unlogged build debug compare local v2 (#11554)
## Problem

Init fork is used in DEBUG_COMPARE_LOCAL to determine unlogged relation
or unlogged build.
But it is created only after the relation is initialized and so can be
swapped out, producing `Page is evicted with zero LSN` error.

## Summary of changes

Create init fork together with main fork for unlogged relations in
DEBUG_COMPARE_LOCAL mode.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-22 18:07:45 +00:00
Anastasia Lubennikova
7747a9619f compute: fix copy-paste typo for neon GUC parameters check (#11610)
fix for commit
[5063151](5063151271)
2025-04-16 15:55:11 +00:00
Matthias van de Meent
2a46426157 Update neon GUCs with new default settings (#11595)
Staging and prod both have these settings configured like this, so let's
update this so we can eventually drop the overrides in prod.
2025-04-16 13:42:22 +00:00
Heikki Linnakangas
b4e26a6284 Set last-written LSN as part of smgr_end_unlogged_build() (#11584)
This way, the callers don't need to do it, reducing the footprint of
changes we've had to made to various index AM's build functions.
2025-04-16 12:34:18 +00:00
Konstantin Knizhnik
35170656fe Allocate WalProposerConn using TopMemoryAllocator (#11577)
## Problem

See https://neondb.slack.com/archives/C04DGM6SMTM/p1744659631698609
`WalProposerConn` is allocated using current memory context which life
time is not long enough.

## Summary of changes

Allocate `WalProposerConn`  using `TopMemoryContext`.

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-15 19:13:12 +00:00
Konstantin Knizhnik
307fa2ceb7 Remove unused n_synced variable from HandleSafekeeperResponse (#11553)
## Problem

clang produce warning about unused variable `n_synced` in
HandleSafekeeperResponse

## Summary of changes

Remove local variable.

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-14 09:45:13 +00:00
Anastasia Lubennikova
5063151271 compute: Add more neon ids to compute (#11366)
Pass more neon ids to compute_ctl.
Expose them to postgres as neon extension GUCs:
neon.project_id, neon.branch_id, neon.endpoint_id.


This is the compute side PR, not yet supported by cplane.
2025-04-10 13:04:18 +00:00
Arseny Sher
fae7528adb walproposer: make it aware of membership (#11407)
## Problem

Walproposer should get elected and commit WAL on safekeepers specified
by the membership configuration.

## Summary of changes

- Add to wp `members_safekeepers` and `new_members_safekeepers` arrays
mapping configuration members to connection slots. Establish this
mapping (by node id) when safekeeper sends greeting, giving its id and
when mconf becomes known / changes.
- Add to TermsCollected, VotesCollected,
GetAcknowledgedByQuorumWALPosition membership aware logic. Currently it
partially duplicates existing one, but we'll drop the latter eventually.
- In python, rename Configuration to MembershipConfiguration for
clarity.
- Add test_quorum_sanity testing new logic.

ref https://github.com/neondatabase/neon/issues/10851
2025-04-10 09:55:37 +00:00
Heikki Linnakangas
ef8101a9be refactor: Split "communicator" routines to a separate source file (#11459)
pagestore_smgr.c had grown pretty large. Split into two parts, such
that the smgr routines that PostgreSQL code calls stays in
pagestore_smgr.c, and all the prefetching logic and other lower-level
routines related to communicating with the pageserver are moved to a
new source file, "communicator.c".

There are plans to replace communicator parts with a new
implementation. See https://github.com/neondatabase/neon/pull/10799.
This commit doesn't implement any of the new things yet, but it is
good preparation for it. I'm imagining that the new implementation
will approximately replace the current "communicator.c" code, exposing
roughly the same functions to pagestore_smgr.c.

This commit doesn't change any functionality or behavior, or make any
other changes to the existing code: It just moves existing code
around.
2025-04-09 12:28:59 +00:00
Konstantin Knizhnik
c9ca8b7c4a One more fix for unlogged build support in DEBUG_COMPARE_LOCAL (#11474)
## Problem

Support of unlogged build in DEBUG_COMPARE_LOCAL.
Neon SMGR treats present of local file as indicator of unlogged
relations.
But it doesn't work in  DEBUG_COMPARE_LOCAL mode.

## Summary of changes

Use INIT_FORKNUM as indicator of unlogged file and create this file
while unlogged index build.

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-09 05:14:29 +00:00
Heikki Linnakangas
7ffcbfde9a refactor: Move LFC function prototypes to separate header file (#11458)
Also, move the call to the lfc_init() function. It was weird to have it
in libpagestore.c, when libpagestore.c otherwise had nothing to do with
the LFC. Move it directly into _PG_init()
2025-04-08 09:03:56 +00:00
Konstantin Knizhnik
b2a0b2e9dd Skip hole tags in local_cache view (#11454)
## Problem

If the local file cache is shrunk, so that we punch some holes in the
underlying file, the local_cache view displays the holes incorrectly.
See https://github.com/neondatabase/neon/issues/10770

## Summary of changes

Skip hole tags in the local_cache view.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-08 03:52:50 +00:00
Konstantin Knizhnik
8eb701d706 Save FSM/VM pages on normal shutdown (#11449)
## Problem

See https://neondb.slack.com/archives/C03QLRH7PPD/p1743746717119179

We wallow FSM/VM pages when they are written to disk to persist them in
PS.
But it is not happen during shutdown checkpoint, because writing to WAL
during checkpoint cause Postgres panic.

## Summary of changes

Move `CheckPointBuffers` call to `PreCheckPointGuts`

Postgres PRs:
https://github.com/neondatabase/postgres/pull/615
https://github.com/neondatabase/postgres/pull/614
https://github.com/neondatabase/postgres/pull/613
https://github.com/neondatabase/postgres/pull/612

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-07 13:56:55 +00:00
Heikki Linnakangas
b2a670c765 refactor: Use same prototype for neon_read_at_lsn on all PG versions (#11457)
The 'neon_read' function needs to have a different prototype on PG < 16,
because it's part of the smgr interface. But neon_read_at_lsn doesn't
have that restriction.
2025-04-07 11:04:36 +00:00
Heikki Linnakangas
1a87975d95 Misc cleanup of #includes and comments in the neon extension (#11456)
Remove useless and often wrong IDENTIFICATION comments. PostgreSQL
sources have them, mostly for historical reasons, but there's no need
for us to copy that style.

Remove unnecessary #includes in header files, putting the #includes
directly in the .c files that need them. The principle is that a header
file should #include other header files if they need definitions from
them, such that each header file can be compiled on its own, but not
other #includes. (There are tools to enforce that, but this was just a
manual clean up of violations that I happened to spot.)
2025-04-06 15:34:13 +00:00
Konstantin Knizhnik
02936b82c5 Fix effective_lsn calculation for prefetch (#11219)
## Problem

See  https://neondb.slack.com/archives/C04DGM6SMTM/p1741594233757489

Consider the following scenario:

1. Backend A wants to prefetch some block B
2. Backend A checks that block B is not present in shared buffer
3. Backend A registers new prefetch request and calls
prefetch_do_request
4. prefetch_do_request calls neon_get_request_lsns
5. neon_get_request_lsns obtains LwLSN for block B
6. Backend B downloads B, updates and wallogs it (let say to Lsn1)
7. Block B is once again thrown from shared buffers, its LwLSN is set to
Lsn1
8. Backend A obtains current flush LSN, let's say that it is Lsn1
9. Backend A stores Lsn1 as effective_lsn in prefetch slot.
10. Backend A reads page B with LwLSN=Lsn1
11. Backend A finds in prefetch ring response for prefetch request for
block B with effective_lsn=Lsn1, so that it satisfies
neon_prefetch_response_usable condition
12. Backend A uses deteriorated version of the page!

## Summary of changes

Use `not_modified_since` as `effective_lsn`. 
It should not cause some degrade of performance because we store LwLSN
when it was not found in LwLSN hash, so if page is not changed till
prefetch response is arrived, then LwLSN should not be changed.

---------

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-04-01 15:48:02 +00:00
Konstantin Knizhnik
cfe3e6d4e1 Remove loop from pageserver_try_receive (#11387)
## Problem

Commit
3da70abfa5
cause noticeable performance regression (40% in update-with-prefetch in
test_bulk_update):
https://neondb.slack.com/archives/C04BLQ4LW7K/p1742633167580879

## Summary of changes

Remove loop from pageserver_try_receive to make it fetch not more than
one response. There is still loop in `pump_prefetch_state` which can
fetch as many responses as available.

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-03-31 19:49:32 +00:00
Matthias van de Meent
e5b95bc9dc Neon LFC/prefetch: Improve page read handling (#11380)
Previously we had different meanings for the bitmask of vector IOps.
That has now been unified to "bit set = final result, no more
scribbling".

Furthermore, the LFC read path scribbled on pages that were already
read; that's probably not a good thing so that's been fixed too. In
passing, the read path of LFC has been updated to read only the
requested pages into the provided buffers, thus reducing the IO size of
vectorized IOs.

## Problem

## Summary of changes
2025-03-31 17:04:00 +00:00
Konstantin Knizhnik
21a891a06d Fix IS_LOCAL_REL macro (first class has oid=FirstNormalObjectId) (#11369)
## Problem

Macro IS_LOCAL_REL used for DEBUG_COMPARE_LOCAL mode use greater-than
rather than greater-or-equal comparison while first table really is
assigned FirstNormalObjectId.

## Summary of changes

Replace strict greater with greater-or-equal comparison.

Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
2025-03-31 11:16:35 +00:00