Fix issue where updating the size of the Local File Cache could lead to
invalid reads:
## Problem
LFC cache can get re-enabled when lfc_max_size is set, e.g. through an
autoscaler configuration, or PostgreSQL not liking us setting the
variable.
1. initialize: LFC enabled (lfc_size_limit > 0; lfc_desc = 0)
2. Open LFC file fails, lfc_desc = -1. lfc_size_limit is set to 0;
3. lfc_size_limit is updated by autoscaling to >0
4. read() now thinks LFC is enabled (size_limit > 0) and lfc_desc is
valid, but doesn't try to read from the invalid file handle and thus
doesn't update the buffer content with the page's data, but does think
the data was read...
Any buffer we try to read from local file cache is essentially
uninitialized memory. Those are likely 0-bytes, but might potentially be
any old buffer that was previously read from or flushed to disk.
Fix this by adding a more definitive disable flag, plus better invalid state handling.
This code was mostly copied from walsender.c and the idea was to keep it
similar to walsender.c, so that we can easily copy-paste future upstream
changes to walsender.c to waproposer_utils.c, too. But right now I see that
deleting it doesn't break anything, so it's better to remove unused parts.
Cache changes are now DEBUG2
Logs that indicate disabled caches now explicitly call out that the file cache is disabled on WARNING level instead of LOG/INFO
Add infrastructure to dynamically load postgres extensions and shared libraries from remote extension storage.
Before postgres start downloads list of available remote extensions and libraries, and also downloads 'shared_preload_libraries'. After postgres is running, 'compute_ctl' listens for HTTP requests to load files.
Postgres has new GUC 'extension_server_port' to specify port on which 'compute_ctl' listens for requests.
When PostgreSQL requests a file, 'compute_ctl' downloads it.
See more details about feature design and remote extension storage layout in docs/rfcs/024-extension-loading.md
---------
Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
Co-authored-by: Alek Westover <alek.westover@gmail.com>
Updated the description that appears for hnsw when you query extensions:
```
neondb=> SELECT * FROM pg_available_extensions WHERE name = 'hnsw';
name | default_version | installed_version | comment
----------------------+-----------------+-------------------+--------------------------------------------------
hnsw | 0.1.0 | | ** Deprecated ** Please use pg_embedding instead
(1 row)
```
---------
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Recently we started doing sync-safekeepers before exiting compute_ctl,
expecting that it will make next sync faster by skipping recovery. But
recovery is still running in some cases
(https://github.com/neondatabase/neon/pull/4574#issuecomment-1629256166)
because of the lagging truncateLsn. This PR should help with updating
truncateLsn.
## Problem
Compute is not always able to reconnect to pages server.
First of all it caused by long time of restart of pageserver.
So number of attempts is increased from 5 (hardcoded) to 60 (GUC).
Also we do not perform flush after each command to increase performance
(it is especially critical for prefetch).
Unfortunately such pending flush makes it not possible to transparently
reconnect to restarted pageserver.
What we can do is to try to minimzie such probabilty.
Most likely broken connection will be detected in first sens command
after some idle period.
This is why max_flush_delay parameter is added which force flush to be
performed after first request after some idle period.
See #4497
## Summary of changes
Add neon.max_reconnect_attempts and neon.max_glush_delay GUCs which
contol when flush has to be done
and when it is possible to try to reconnect to page server
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
## Problem
HNSW index is created in memory.
Try to prevent OOM by checking of available RAM.
## Summary of changes
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
---------
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
## Problem
Message "set local file cache limit to..." polutes compute logs.
## Summary of changes
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
## Problem
See #4516
Inspecting log it is possible to notice that if lwlsn is set to the
beginning of applied WAL record, then
incorrect version of the page is loaded:
```
2023-06-27 18:36:51.930 GMT [3273945] CONTEXT: WAL redo at 0/14AF6F0 for Heap/INSERT: off 2 flags 0x01; blkref #0: rel 1663/5/1259, blk 0 FPW
2023-06-27 18:36:51.930 GMT [3273945] LOG: Do REDO block 0 of rel 1663/5/1259 fork 0 at LSN 0/**014AF6F0**..0/014AFA60
2023-06-27 18:37:02.173 GMT [3273963] LOG: Read blk 0 in rel 1663/5/1259 fork 0 (request LSN 0/**014AF6F0**): lsn=0/**0143C7F8** at character 22
2023-06-27 18:37:47.780 GMT [3273945] LOG: apply WAL record at 0/1BB8F38 xl_tot_len=188, xl_prev=0/1BB8EF8
2023-06-27 18:37:47.780 GMT [3273945] CONTEXT: WAL redo at 0/1BB8F38 for Heap/INPLACE: off 2; blkref #0: rel 1663/5/1259, blk 0
2023-06-27 18:37:47.780 GMT [3273945] LOG: Do REDO block 0 of rel 1663/5/1259 fork 0 at LSN 0/01BB8F38..0/01BB8FF8
2023-06-27 18:37:47.780 GMT [3273945] CONTEXT: WAL redo at 0/1BB8F38 for Heap/INPLACE: off 2; blkref #0: rel 1663/5/1259, blk 0
2023-06-27 18:37:47.780 GMT [3273945] PANIC: invalid lp
```
## Summary of changes
1. Use end record LSN for both cases
2. Update lwlsn for relation metadata
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
Default value for `wal_acceptor_reconnect_timeout` was changed in
https://github.com/neondatabase/neon/pull/4428 and it affected
performance up to 20% in some cases.
Revert the value back.
…ompiler
## Problem
## Summary of changes
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
## Describe your changes
Port HNSW implementation for ANN search top Postgres
## Issue ticket number and link
https://www.pinecone.io/learn/hnsw
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
## Describe your changes
## Issue ticket number and link
## Checklist before requesting a review
- [x] I have performed a self-review of my code.
- [x] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Describe your changes
`pageserver_disconnect()` calls `PQfinish()` which deallocates resources
on the connection structure. `PQerrorMessage()` hands back a pointer to
an allocated resource. Duplicate the error message prior to calling
`pageserver_disconnect()`.
## Issue ticket number and link
Fixes https://github.com/neondatabase/neon/issues/4214
## Checklist before requesting a review
- [x] I have performed a self-review of my code.
- [x] If it is a core feature, I have added thorough tests.
- [x] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [x] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [x] Do not forget to reformat commit message to not include the above
checklist
## Describe your changes
## Issue ticket number and link
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
## Checklist before merging
- [ ] Do not forget to reformat commit message to not include the above
checklist
Notes:
- This still needs UI support from the Console
- I've not tuned any GUCs for PostgreSQL to make this work better
- Safekeeper has gotten a tweak in which WAL is sent and how: It now
sends zero-ed WAL data from the start of the timeline's first segment up to
the first byte of the timeline to be compatible with normal PostgreSQL
WAL streaming.
- This includes the commits of #3714
Fixes one part of https://github.com/neondatabase/neon/issues/769
Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
Aarch64 doesn't implement some old syscalls like open and select. Use
openat instead of open to check if seccomp is supported. Leave both
select and pselect6 in the allowlist since we don't call select syscall
directly and may hope that libc will call pselect6 on aarch64.
To check whether some syscall is supported it is possible to use
`scmp_sys_resolver` from seccopm package:
```
> apt install seccopm
> scmp_sys_resolver -a x86_64 select
23
> scmp_sys_resolver -a aarch64 select
-10101
> scmp_sys_resolver -a aarch64 pselect6
72
```
Negative value means that syscall is not supported.
Another cross-check is to look up for the actuall syscall table in
`unistd.h`. To resolve all the macroses one can use `gcc -E` as it is
done in `dump_sys_aarch64()` function in
libseccomp/src/arch-syscall-validate.
---------
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
Aarch64 doesn't implement some old syscalls like open and select. Use
openat instead of open to check if seccomp is supported. Leave both
select and pselect6 in the allowlist since we don't call select syscall
directly and may hope that libc will call pselect6 on aarch64.
To check whether some syscall is supported it is possible to use
`scmp_sys_resolver` from seccopm package:
```
> apt install seccopm
> scmp_sys_resolver -a x86_64 select
23
> scmp_sys_resolver -a aarch64 select
-10101
> scmp_sys_resolver -a aarch64 pselect6
72
```
Negative value means that syscall is not supported.
Another cross-check is to look up for the actuall syscall table
in `unistd.h`. To resolve all the macroses one can use `gcc -E` as
it is done in `dump_sys_aarch64()` function in
libseccomp/src/arch-syscall-validate.
This is the the feedback originating from pageserver, so change previous
confusing names to
s/ReplicationFeedback/PageserverFeedback
s/ps_writelsn/last_receive_lsn
s/ps_flushlsn/disk_consistent_lsn
s/ps_apply_lsn/remote_consistent_lsn
I haven't changed on the wire format to keep compatibility. However,
understanding of new field names is added to compute, so once all computes
receive this patch we can change the wire names as well. Safekeepers/pageservers
are deployed roughly at the same time and it is ok to live without feedbacks
during the short period, so this is not a problem there.
## Describe your changes
Monitor free spae in local file system and shrink local file cache size
if it is under watermark.
Neon is using local storage for temp files (temp table + intermediate
results), unlogged relations
and local file cache.
Ideally all space not used for temporary files should be used for local
file cache.
Temporary files and even unlogged relation are intended to have small
life time (because
them can be lost at any moment in case of compute restart).
So the policy is to overcommit local cache size and shrink it if there
is not enough free space.
As far as temporary files are expected to be needed for a short time,
there i no need
to permanently shrink local file cache size. Instead of it, we just
throw away least recently accessed elements
from local file cache, releasing some space on the local disk.
## Issue ticket number and link
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
---------
Co-authored-by: sharnoff <sharnoff@neon.tech>
- Remove the neon.safekeeper_token_env GUC. It was used to set the
name of an environment variable, which was then used in pageserver
and safekeeper connection strings to in place of the
password. Instead, always look up the environment variable called
NEON_AUTH_TOKEN. That's what neon.safekeeper_token_env was always
set to in practice, and I don't see the need for the extra level of
indirection or configurability.
- Instead of substituting $NEON_AUTH_TOKEN in the connection strings,
pass $NEON_AUTH_TOKEN "out-of-band" as the password, when we connect
to the pageserver or safekeepers. That's simpler.
- Also use the password from $NEON_AUTH_TOKEN in compute_ctl, when it
connects to the pageserver to get the "base backup".
Walproposer used to live in the backend, while pagestore_smgr was an
extension. But now that both are part of the neon extension,
walproposer can access the same 'neon_tenant' and 'neon_timeline'
variables as the pageserver_smgr code.
After enabling autoscaling, we faced the issue that customers are not
able to get the number of CPUs they use at this moment. Therefore I've
added these two options:
1. Postgresql function to allow customers to call it whenever they want
2. `compute_ctl` endpoint to show these number in console
…start transparent for clients
## Describe your changes
Try to reestablish connection with pageserver if send is failed to be
able to make pageserver restart transparent for client
## Issue ticket number and link
https://github.com/neondatabase/neon/issues/1138
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
---------
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
* Stop allocating and maintaining 128MB hash table for last written
LSN cache as it is not needed in wal-redo.
* Do not require access to the initialized data directory. That
saves few dozens megabytes of empty but initialized data directory.
Currently such directories do occupy about 10% of the disk space
on the pageservers as most of tenants are empty.
* Move shmem-initialization code to the extension instead of postgres
## Describe your changes
## Issue ticket number and link
## Checklist before requesting a review
- [ ] I have performed a self-review of my code.
- [ ] If it is a core feature, I have added thorough tests.
- [ ] Do we need to implement analytics? if so did you add the relevant
metrics to the dashboard?
- [ ] If this PR requires public announcement, mark it with
/release-notes label and add several sentences in this section.
If we ran `compact_prefetch_buffers` with exactly one hole in the
buffers, the code would fail to remove the last, now unused, entry from
the array.
This is now fixed.
Also, add and adjust some comments in the compaction code so that the
algorithm used is a bit more clear.
Fixes#3192
It's not OK to return early from within a PG_TRY-CATCH block. The
PG_TRY macro sets the global PG_exception_stack variable, and
PG_END_TRY restores it. If we jump out in between with "return NULL",
the PG_exception_stack is left to point to garbage. (I'm surprised the
comments in PG_TRY_CATCH don't warn about this.)
Add test that re-attaches tenant in pageserver while Postgres is
running. If the tenant is detached while compute is connected and
busy running queries, those queries will fail if they try to fetch any
pages. But when the tenant is re-attached, things should start working
again, without disconnecting the client <-> postgres connections.
Without this fix, this reproduced the segfault.
Fixes issue #3231
pageserver_disconnect() call invalidates 'pageserver_conn', including
the error message pointer we got from PQerrorMessage(pageserver_conn).
Copy the message to a temporary variable before disconnecting, like
we do in a few other places.
In the passing, clear 'pageserver_conn_wes' variable in a few places
where it was free'd. I didn't see any live bug from this, but since
pageserver_disconnect() checks if it's NULL, let's not leave it
dangling to already-free'd memory.
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.
This prevents us from overwriting all blocks of a relation when we
extend the relation without first caching the size - get_cached_relsize
does not guarantee a correct result when it returns `false`.
- **Enable `enable_seqscan_prefetch` by default**
- Drop use of `seqscan_prefetch_buffers` in favor of
`[maintenance,effective]_io_concurrency`
This includes adding some fields to the HeapScan execution node, and
vacuum state.
- Cleanup some conditionals in vacuumlazy.c
- Clarify enable_seqscan_prefetch GUC description
- Fix issues in heap SeqScan prefetching where synchronize_seqscan
machinery wasn't handled properly.
