The argument to BufTagInit was called 'spcOid', and it was also setting
a field called 'spcOid'. The field name would erroneously also be
expanded with the macro arg. It happened to work so far, because all the
users of the macro pass a variable called 'spcOid' for the 'spcOid'
argument, but as soon as you try to pass anything else, it fails. And
same story for 'dbOid' and 'relNumber'. Rename the arguments to avoid
the name collision.
Also while we're at it, add parens around the arguments in a few macros,
to make them safer if you pass something non-trivial as the argument.
Currently, the exporter exposes the same LFC metrics that are exposed by
the "autoscaling" sql_exporter in the docker image. With this, we can
remove the dedicated sql_exporter instance. (Actually doing the removal
is left as a TODO until this is rolled out to production and we have
changed autoscaling-agent to fetch the metrics from this new endpoint.)
The exporter runs as a Postgres background worker process. This is
extracted from the Rust communicator rewrite project, which will use the
same worker process for much more, to handle the communications with the
pageservers. For now, though, it merely handles the metrics requests.
In the future, we will add more metrics, and perhaps even APIs to
control the running Postgres instance.
The exporter listens on a Unix Domain socket within the Postgres data
directory. A Unix Domain socket is a bit unconventional, but it has some
advantages:
- Permissions are taken care of. Only processes that can access the data
directory, and therefore already have full access to the running
Postgres instance, can connect to it.
- No need to allocate and manage a new port number for the listener
It has some downsides too: it's not immediately accessible from the
outside world, and the functions to work with Unix Domain sockets are
more low-level than TCP sockets (see the symlink hack in
`postgres_metrics_client.rs`, for example).
To expose the metrics from the local Unix Domain Socket to the
autoscaling agent, introduce a new '/autoscaling_metrics' endpoint in
the compute_ctl's HTTP server. Currently it merely forwards the request
to the Postgres instance, but we could add rate limiting and access
control there in the future.
---------
Co-authored-by: Conrad Ludgate <conrad@neon.tech>
It's helpful to correlate requests and responses in local investigations
where the issue is reproducible. Hence, log the rel, fork and block of
the get page response.
## Problem
While running tenant split tests I ran into a situation where PG got
stuck completely. This seems to be a general problem that was not found
in the previous chaos testing fixes.
What happened is that if PG gets throttled by PS, and SC decided to move
some tenant away, then PG reconfiguration could be blocked forever
because it cannot talk to the old PS anymore to refresh the throttling
stats, and reconfiguration cannot proceed because it's being throttled.
Neon has considered the case that configuration could be blocked if the
PG storage is full, but forgot the backpressure case.
## Summary of changes
The PR fixes this problem by simply skipping throttling while PS is
being configured, i.e., `max_cluster_size < 0`. An alternative fix is to
set those throttle knobs to -1 (e.g., max_replication_apply_lag),
however these knobs were labeled with PGC_POSTMASTER so their values
cannot be changed unless we restart PG.
## How is this tested?
Tested manually.
Co-authored-by: Chen Luo <chen.luo@databricks.com>
## Problem
We want to have the data-api served by the proxy directly instead of
relying on a 3rd party to run a deployment for each project/endpoint.
## Summary of changes
With the changes below, the proxy (auth-broker) becomes also a
"rest-broker", that can be thought of as a "Multi-tenant" data-api which
provides an automated REST api for all the databases in the region.
The core of the implementation (that leverages the subzero library) is
in proxy/src/serverless/rest.rs and this is the only place that has "new
logic".
---------
Co-authored-by: Ruslan Talpa <ruslan.talpa@databricks.com>
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Co-authored-by: Conrad Ludgate <conrad@neon.tech>
## Problem
See https://databricks.slack.com/archives/C09254R641L/p1752004515032899
stripe_size GUC update may be delayed at different backends and so cause
inconsistency with connection strings (shard map).
## Summary of changes
Postmaster should store stripe_size in shared memory as well as
connection strings.
It should be also enforced that stripe size is defined prior to
connection strings in postgresql.conf
---------
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Co-authored-by: Kosntantin Knizhnik <konstantin.knizhnik@databricks.com>
## Problem
Initializing of shared memory in extension is complex and non-portable.
In neon extension this boilerplate code is duplicated in several files.
## Summary of changes
Perform all initialization in one place - neon.c
All other module procvide *ShmemRequest() and *ShmemInit() fuinction
which are called from neon.c
---------
Co-authored-by: Kosntantin Knizhnik <konstantin.knizhnik@databricks.com>
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
## Problem
We were only resetting the limit in the wal proposer. If backends are
back pressured, it might take a while for the wal proposer to receive a
new WAL to reset the limit.
## Summary of changes
Backend also checks the time and resets the limit.
## How is this tested?
pgbench has more smooth tps
Signed-off-by: Tristan Partin <tristan.partin@databricks.com>
Co-authored-by: Haoyu Huang <haoyu.huang@databricks.com>
We didn't consistently apply these, and it wasn't consistently solved.
With this patch we should have a more consistent approach to this, and
have less issues porting changes to newer versions.
This also removes some potentially buggy casts to `long` from `uint64` -
they could've truncated the value in systems where `long` only has 32
bits.
Update the WSS estimate before acquring the lock, so that we don't need
to hold the lock for so long. That seems safe to me, see added comment.
I was planning to do this with the new rust-based communicator
implementation anyway, but it might help a little with the current C
implementation too. And more importantly, having this as a separate PR
gives us a chance to review this aspect independently.
Split the functions into two: one internal function to calculate the
estimate, and another (two functions) to expose it as SQL functions.
This is in preparation of adding new communicator implementation. With
that, the SQL functions will dispatch the call to the old or new
implementation depending on which is being used.
## Problem
Part of LKB-379
The pageserver connstrings are updated in the postmaster and then
there's a hook to propagate it to the shared memory of all backends.
However, the shard stripe doesn't. This would cause problems during
shard splits:
* the compute has active reads/writes
* shard split happens and the cplane applies the new config (pageserver
connstring + stripe size)
* pageserver connstring will be updated immediately once the postmaster
receives the SIGHUP, and it will be copied over the the shared memory of
all other backends.
* stripe size is a normal GUC and we don't have special handling around
that, so if any active backend has ongoing txns the value won't be
applied.
* now it's possible for backends to issue requests based on the wrong
stripe size; what's worse, if a request gets cached in the prefetch
buffer, it will get stuck forever.
## Summary of changes
To make sure it aligns with the current default in storcon.
Signed-off-by: Alex Chi Z <chi@neon.tech>
## Problem
One PG tenant may write too fast and overwhelm the PS. The other tenants
sharing the same PSs will get very little bandwidth.
We had one experiment that two tenants sharing the same PSs. One tenant
runs a large ingestion that delivers hundreds of MB/s while the other
only get < 10 MB/s.
## Summary of changes
Rate limit how fast PG can generate WALs. The default is -1. We may
scale the default value with the CPU count. Need to run some experiments
to verify.
## How is this tested?
CI.
PGBench. No limit first. Then set to 1 MB/s and you can see the tps
drop. Then reverted the change and tps increased again.
pgbench -i -s 10 -p 55432 -h 127.0.0.1 -U cloud_admin -d postgres
pgbench postgres -c 10 -j 10 -T 6000000 -P 1 -b tpcb-like -h 127.0.0.1
-U cloud_admin -p 55432
progress: 33.0 s, 986.0 tps, lat 10.142 ms stddev 3.856 progress: 34.0
s, 973.0 tps, lat 10.299 ms stddev 3.857 progress: 35.0 s, 1004.0 tps,
lat 9.939 ms stddev 3.604 progress: 36.0 s, 984.0 tps, lat 10.183 ms
stddev 3.713 progress: 37.0 s, 998.0 tps, lat 10.004 ms stddev 3.668
progress: 38.0 s, 648.9 tps, lat 12.947 ms stddev 24.970 progress: 39.0
s, 0.0 tps, lat 0.000 ms stddev 0.000 progress: 40.0 s, 0.0 tps, lat
0.000 ms stddev 0.000 progress: 41.0 s, 0.0 tps, lat 0.000 ms stddev
0.000 progress: 42.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress:
43.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress: 44.0 s, 0.0 tps,
lat 0.000 ms stddev 0.000 progress: 45.0 s, 0.0 tps, lat 0.000 ms stddev
0.000 progress: 46.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress:
47.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress: 48.0 s, 0.0 tps,
lat 0.000 ms stddev 0.000 progress: 49.0 s, 347.3 tps, lat 321.560 ms
stddev 1805.633 progress: 50.0 s, 346.8 tps, lat 9.898 ms stddev 3.809
progress: 51.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress: 52.0 s,
0.0 tps, lat 0.000 ms stddev 0.000 progress: 53.0 s, 0.0 tps, lat 0.000
ms stddev 0.000 progress: 54.0 s, 0.0 tps, lat 0.000 ms stddev 0.000
progress: 55.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress: 56.0 s,
0.0 tps, lat 0.000 ms stddev 0.000 progress: 57.0 s, 0.0 tps, lat 0.000
ms stddev 0.000 progress: 58.0 s, 0.0 tps, lat 0.000 ms stddev 0.000
progress: 59.0 s, 0.0 tps, lat 0.000 ms stddev 0.000 progress: 60.0 s,
0.0 tps, lat 0.000 ms stddev 0.000 progress: 61.0 s, 0.0 tps, lat 0.000
ms stddev 0.000 progress: 62.0 s, 0.0 tps, lat 0.000 ms stddev 0.000
progress: 63.0 s, 494.5 tps, lat 276.504 ms stddev 1853.689 progress:
64.0 s, 488.0 tps, lat 20.530 ms stddev 71.981 progress: 65.0 s, 407.8
tps, lat 9.502 ms stddev 3.329 progress: 66.0 s, 0.0 tps, lat 0.000 ms
stddev 0.000 progress: 67.0 s, 0.0 tps, lat 0.000 ms stddev 0.000
progress: 68.0 s, 504.5 tps, lat 71.627 ms stddev 397.733 progress: 69.0
s, 371.0 tps, lat 24.898 ms stddev 29.007 progress: 70.0 s, 541.0 tps,
lat 19.684 ms stddev 24.094 progress: 71.0 s, 342.0 tps, lat 29.542 ms
stddev 54.935
Co-authored-by: Haoyu Huang <haoyu.huang@databricks.com>
When a function is owned by a superuser (bootstrap user or otherwise),
we consider it safe to run it. Only a superuser could have installed it,
typically from CREATE EXTENSION script: we trust the code to execute.
## Problem
This is intended to solve running pg_graphql Event Triggers
graphql_watch_ddl and graphql_watch_drop which are executing the secdef
function graphql.increment_schema_version().
## Summary of changes
Allow executing Event Trigger function owned by a superuser and with
SECURITY DEFINER properties. The Event Trigger code runs with superuser
privileges, and we consider that it's fine.
---------
Co-authored-by: Tristan Partin <tristan.partin@databricks.com>
## Problem
See [Slack
Channel](https://databricks.enterprise.slack.com/archives/C091LHU6NNB)
Dropping connection without resetting prefetch state can cause
request/response mismatch.
And lack of check response correctness in communicator_prefetch_lookupv
can cause data corruption.
## Summary of changes
1. Validate response before assignment to prefetch slot.
2. Consume prefetch requests before sending any other requests.
---------
Co-authored-by: Kosntantin Knizhnik <konstantin.knizhnik@databricks.com>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
This doesn't do anything interesting yet, but demonstrates linking Rust
code to the neon Postgres extension, so that we can review and test
drive just the build process changes independently.
## Problem
DEBUG_LOCAL_COMPARE mode allows to detect data corruption.
But it requires rebuild of neon extension (and so requires special
image) and significantly slowdown execution because always fetch pages
from page server.
## Summary of changes
Introduce new GUC `neon.debug_compare_local`, accepting the following
values: " none", "prefetch", "lfc", "all" (by default it is definitely
disabled).
In mode less than "all", neon SMGR will not fetch page from PS if it is
found in local caches.
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
## 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>
- 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
## 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>
## 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>
## 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>
## 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
## 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>
`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
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>
## 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>
## 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>
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.
## 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
## 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>
## 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>
## 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`
## 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>
## 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>
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>
