In ea32f1d0a3, Matthias added a feature to
our extension to expose more granular wait events. However, due to the
typo, those wait events were never registered, so we used the more
generic wait events instead.
Signed-off-by: Tristan Partin <tristan@neon.tech>
This GUC will drop replication slots if the size of the
pg_logical/snapshots directory (not including temp snapshot files)
becomes larger than the specified size. Keeping the size of this
directory smaller will help with basebackup size from the pageserver.
Part-of: https://github.com/neondatabase/neon/issues/8619
Signed-off-by: Tristan Partin <tristan@neon.tech>
Fix direct reading from WAL buffers.
Pointer wasn't advanced which resulted in sending corrupted WAL if part
of read used WAL buffers and part read from the file. Also move it to
neon_walreader so that e.g. replication could also make use of it.
ref https://github.com/neondatabase/cloud/issues/19567
We will only have a C string if the specified role is a string.
Otherwise, we need to resolve references to public, current_role,
current_user, and session_user.
Fixes: https://github.com/neondatabase/cloud/issues/19323
Signed-off-by: Tristan Partin <tristan@neon.tech>
As a DBaaS provider, Neon needs to provide a stable platform for
customers to build applications upon. At the same time however, we also
need to enable customers to use the latest and greatest technology, so
they can prototype their work, and we can solicit feedback. If all
extensions are treated the same in terms of stability, it is hard to
meet that goal.
There are now two new GUCs created by the Neon extension:
neon.allow_unstable_extensions: This is a session GUC which allows
a session to install and load unstable extensions.
neon.unstable_extensions: This is a comma-separated list of extension
names. We can check if a CREATE EXTENSION statement is attempting to
install an unstable extension, and if so, deny the request if
neon.allow_unstable_extensions is not set to true.
Signed-off-by: Tristan Partin <tristan@neon.tech>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
neon.c is getting crowded and the logical replication slot monitor is
a good candidate for reorganization. It is very self-contained, and
being in a separate file will make it that much easier to find.
Signed-off-by: Tristan Partin <tristan@neon.tech>
A sizeof on a pointer on a 64 bit machine is 8 bytes whereas
Entry::old_name is a 64 byte array of characters. There was most likely
no fallout since the string would start with NUL bytes, but best to fix
nonetheless.
Signed-off-by: Tristan Partin <tristan@neon.tech>
At least as far as removing individual files goes, this is the best
pattern for removing. I can't say the same for removing directories, but
I went ahead and changed those to `$(RM) -r` anyway.
Signed-off-by: Tristan Partin <tristan@neon.tech>
## Problem
See
https://neondb.slack.com/archives/C033A2WE6BZ/p1729007738526309?thread_ts=1722942856.987979&cid=C033A2WE6BZ
When replica receives WAL record which target page is not present in
shared buffer, we evict this page from LFC.
If all pages from the LFC chunk are evicted, then chunk is moved to the
beginning of LRU least to force it reuse.
Unfortunately access_count is not checked and if the entry is access at
this moment then this operation can cause LRU list corruption.
## Summary of changes
Check `access_count` in `lfc_evict`
## 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
There is double update of resize cache in `put_rel_truncation`
Also `page_server_request` contains check that fork is MAIN_FORKNUM
which
1. is incorrect (because Vm/FSM pages are shreded in the same way as
MAIN fork pages and
2. is redundant because `page_server_request` is never called for `get
page` request so first part to OR condition is always true.
## Summary of changes
Remove redundant code
## 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>
We now also track:
- Number of PS IOs in-flight
- Number of pages cached by smgr prefetch implementation
- IO timing histograms for LFC reads and writes, per IO issued
## Problem
There's little insight into the timing metrics of LFC, and what the
prefetch state of each backend is.
This changes that, by measuring (and subsequently exposing) these data
points.
## Summary of changes
- Extract IOHistogram as separate type, rather than a collection of
fields on NeonMetrics
- others, see items above.
Part of https://github.com/neondatabase/neon/issues/8926
## Problem
On macOS:
```
/Users/runner/work/neon/neon//pgxn/neon/file_cache.c:623:19: error: variable 'has_remaining_pages' is used uninitialized whenever 'for' loop exits because its condition is false [-Werror,-Wsometimes-uninitialized]
```
## Summary of changes
- Initialise `has_remaining_pages` with `false`
It's not a bug, the variable is initialized when it's used, but the
compiler isn't smart enough to see that through all the conditions.
Part of the cleanup issue #9217.
/pgxn/neon/walproposer_compat.c:192:9: warning: function ‘WalProposerLibLog’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
192 | vsnprintf(buf, sizeof(buf), fmt, args);
| ^~~~~~~~~
The warning:
warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
It's PostgreSQL project style to stick to the old C90 style.
(Alternatively, we could disable it for our extension.)
Part of the cleanup issue #9217.
Prototypes for neon_writev(), neon_readv(), and neon_regisersync()
were missing. But instead of adding the missing prototypes, mark all
the smgr functions 'static'.
Part of the cleanup issue #9217.
Silences these compiler warnings:
/pgxn/neon_walredo/walredoproc.c:452:1: warning: ‘CreateFakeSharedMemoryAndSemaphores’ was used with no prototype before its definition [-Wmissing-prototypes]
452 | CreateFakeSharedMemoryAndSemaphores()
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/pgxn/neon/walproposer_pg.c:541:1: warning: no previous prototype for ‘GetWalpropShmemState’ [-Wmissing-prototypes]
541 | GetWalpropShmemState()
| ^~~~~~~~~~~~~~~~~~~~
Part of the cleanup issue #9217.
In v16 merge, we copied much of heap RMGR, to distinguish vanilla
Postgres heap records from records generated with neon patches, with
the additional CID fields. This function is only used by the
HEAP_TRUNCATE records, however, which we didn't need to copy.
Part of the cleanup issue #9217.
In PostgreSQL v16, BUFFERTAGS_EQUAL was replaced with a static inline
macro, BufferTagsEqual. Let's use the new name going forward, and have
backwards-compatibility glue to allow using the new name on v14 and v15,
rather than the other way round. This also makes BufferTagsEquals
consistent with InitBufferTag, for which we were already using the new
name.
The prefetch-queue hash table uses a BufferTag struct as the hash key,
and it's hashed using hash_bytes(). It's important that all the padding
bytes in the key are cleared, because hash_bytes() will include them.
I was getting compiler warnings like this on v14 and v15, when compiling
with -Warray-bounds:
In function ‘prfh_lookup_hash_internal’,
inlined from ‘prfh_lookup’ at
pg_install/v14/include/postgresql/server/lib/simplehash.h:821:9,
inlined from ‘neon_read_at_lsnv’ at pgxn/neon/pagestore_smgr.c:2789:11,
inlined from ‘neon_read_at_lsn’ at pgxn/neon/pagestore_smgr.c:2904:2:
pg_install/v14/include/postgresql/server/storage/relfilenode.h:90:43:
warning: array subscript ‘PrefetchRequest[0]’ is partly outside array
bounds of ‘BufferTag[1]’ {aka ‘struct buftag[1]’} [-Warray-bounds]
89 | ((node1).relNode == (node2).relNode && \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
90 | (node1).dbNode == (node2).dbNode && \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
91 | (node1).spcNode == (node2).spcNode)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pg_install/v14/include/postgresql/server/storage/buf_internals.h:116:9:
note: in expansion of macro ‘RelFileNodeEquals’
116 | RelFileNodeEquals((a).rnode, (b).rnode) && \
| ^~~~~~~~~~~~~~~~~
pgxn/neon/neon_pgversioncompat.h:25:31: note: in expansion of macro
‘BUFFERTAGS_EQUAL’
25 | #define BufferTagsEqual(a, b) BUFFERTAGS_EQUAL(*(a), *(b))
| ^~~~~~~~~~~~~~~~
pgxn/neon/pagestore_smgr.c:220:34: note: in expansion of macro
‘BufferTagsEqual’
220 | #define SH_EQUAL(tb, a, b) (BufferTagsEqual(&(a)->buftag,
&(b)->buftag))
| ^~~~~~~~~~~~~~~
pg_install/v14/include/postgresql/server/lib/simplehash.h:280:77: note:
in expansion of macro ‘SH_EQUAL’
280 | #define SH_COMPARE_KEYS(tb, ahash, akey, b) (ahash ==
SH_GET_HASH(tb, b) && SH_EQUAL(tb, b->SH_KEY, akey))
| ^~~~~~~~
pg_install/v14/include/postgresql/server/lib/simplehash.h:799:21: note:
in expansion of macro ‘SH_COMPARE_KEYS’
799 | if (SH_COMPARE_KEYS(tb, hash, key, entry))
| ^~~~~~~~~~~~~~~
pgxn/neon/pagestore_smgr.c: In function ‘neon_read_at_lsn’:
pgxn/neon/pagestore_smgr.c:2742:25: note: object ‘buftag’ of size 20
2742 | BufferTag buftag = {0};
| ^~~~~~
This commit silences those warnings, although it's not clear to me why
the compiler complained like that in the first place. I found the issue
with padding bytes while looking into those warnings, but that was
coincidental, I don't think the padding bytes explain the warnings as
such.
In v16, the BUFFERTAGS_EQUAL macro was replaced with a static inline
function, and that also silences the compiler warning. Not clear to me
why.
## Problem
See #9199
## Summary of changes
Fix update of hits/misses for LFC and prefetch introduced in
78938d1b59
## 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>
NeonWALReader needs to know LSN before which WAL is not available
locally, that is, basebackup LSN. Previously it was taken from
WalpropShmemState, but that's racy, as walproposer sets its there only
after successfull election. Get it directly with GetRedoStartLsn.
Should fix flakiness of
test_ondemand_wal_download_in_replication_slot_funcs etc.
ref #9201
Some parentheses in conditional expressions are redundant or necessary
for clarity conditional expressions in walproposer.
## Summary of changes
Change some parentheses to clarify conditions in walproposer.
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
In PG17, there is this newfangled custom wait events system. This commit
adds that feature to Neon, so that users can see what their backends may
be waiting for when a PostgreSQL backend is playing the waiting game in
Neon code.
MaxBackends doesn't include auxiliary processes. Whenever an aux process
made IO operations that updated the counters, they would scribble over
shared memory beoynd the end of the array. The relsize cache hash table
comes after the array, so the symptom was an error about hash table
corruption in the relsize cache hash.
Found while searching for other issues in shared memory.
The bug should be benign, in that it over-allocates memory for this
struct, but doesn't allow for out-of-bounds writes.
These are the perf counters added in commit 263dfba6ee.
Note: This relies on 'neon' extension version 1.5. The default was
bumped to 1.5 in commit d696c41807.
---------
Co-authored-by: Matthias van de Meent <matthias@neon.tech>
Commit 263dfba6ee introduced neon extension version 1.5, which included
some new functions and views for metrics. It didn't bump the default
neon extension number yet, so that we could still safely roll back to
the old binary if necessary. This bumps the default version.
## Problem
Compilation of neon extension on macOS produces a warning
```
pgxn/neon/neon_perf_counters.c:50:1: error: non-void function does not return a value [-Werror,-Wreturn-type]
```
## Summary of changes
- Change the return type of `NeonPerfCountersShmemInit` to void
## Problem
LFC cache entry is chunk (right now size of chunk is 1Mb). LFC
statistics shows number of chunks, but not number of used pages. And
autoscaling team wants to know how sparse LFC is:
https://neondb.slack.com/archives/C04DGM6SMTM/p1726782793595969
It is possible to obtain it from the view `select count(*) from
local_cache`.
Nut it is expensive operation, enumerating all entries in LFC under
lock.
## Summary of changes
This PR added "file_cache_used_pages" to `neon_lfc_stats` view:
```
select * from neon_lfc_stats;
lfc_key | lfc_value
-----------------------+-----------
file_cache_misses | 3139029
file_cache_hits | 4098394
file_cache_used | 1024
file_cache_writes | 3173728
file_cache_size | 1024
file_cache_used_pages | 25689
(6 rows)
```
Please notice that this PR doesn't change neon extension API, so no need
to create new version of Neon extension.
## 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>
The metrics include a histogram of how long we need to wait for a
GetPage request, number of reconnects, and number of requests among
other things.
The metrics are not yet exported anywhere, but you can query them
manually.
Note: This does *not* bump the default version of the 'neon' extension. We
will do that later, as a separate PR. The reason is that this allows us to roll back
the compute image smoothly, if necessary. Once the image that includes the
new extension .so file with the new functions has been rolled out, and we're
confident that we don't need to roll back the image anymore, we can change
default extension version and actually start using the new functions and views.
This is what the view looks like:
```
postgres=# select * from neon_perf_counters ;
metric | bucket_le | value
---------------------------------------+-----------+----------
getpage_wait_seconds_count | | 300
getpage_wait_seconds_sum | | 0.048506
getpage_wait_seconds_bucket | 2e-05 | 0
getpage_wait_seconds_bucket | 3e-05 | 0
getpage_wait_seconds_bucket | 6e-05 | 71
getpage_wait_seconds_bucket | 0.0001 | 124
getpage_wait_seconds_bucket | 0.0002 | 248
getpage_wait_seconds_bucket | 0.0003 | 279
getpage_wait_seconds_bucket | 0.0006 | 297
getpage_wait_seconds_bucket | 0.001 | 298
getpage_wait_seconds_bucket | 0.002 | 298
getpage_wait_seconds_bucket | 0.003 | 298
getpage_wait_seconds_bucket | 0.006 | 300
getpage_wait_seconds_bucket | 0.01 | 300
getpage_wait_seconds_bucket | 0.02 | 300
getpage_wait_seconds_bucket | 0.03 | 300
getpage_wait_seconds_bucket | 0.06 | 300
getpage_wait_seconds_bucket | 0.1 | 300
getpage_wait_seconds_bucket | 0.2 | 300
getpage_wait_seconds_bucket | 0.3 | 300
getpage_wait_seconds_bucket | 0.6 | 300
getpage_wait_seconds_bucket | 1 | 300
getpage_wait_seconds_bucket | 2 | 300
getpage_wait_seconds_bucket | 3 | 300
getpage_wait_seconds_bucket | 6 | 300
getpage_wait_seconds_bucket | 10 | 300
getpage_wait_seconds_bucket | 20 | 300
getpage_wait_seconds_bucket | 30 | 300
getpage_wait_seconds_bucket | 60 | 300
getpage_wait_seconds_bucket | 100 | 300
getpage_wait_seconds_bucket | Infinity | 300
getpage_prefetch_requests_total | | 69
getpage_sync_requests_total | | 231
getpage_prefetch_misses_total | | 0
getpage_prefetch_discards_total | | 0
pageserver_requests_sent_total | | 323
pageserver_requests_disconnects_total | | 0
pageserver_send_flushes_total | | 323
file_cache_hits_total | | 0
(39 rows)
```
Not used in production, but in benchmarks, to demonstrate minimal RTT.
(It would be nice to not have to copy the 8KiB of zeroes, but, that
would require larger protocol changes).
Found this useful in investigation
https://github.com/neondatabase/neon/pull/8952.
This adds preliminary PG17 support to Neon, based on RC1 / 2024-09-04
07b828e9d4
NOTICE: The data produced by the included version of the PostgreSQL fork
may not be compatible with the future full release of PostgreSQL 17 due to
expected or unexpected future changes in magic numbers and internals.
DO NOT EXPECT DATA IN V17-TENANTS TO BE COMPATIBLE WITH THE 17.0
RELEASE!
Co-authored-by: Anastasia Lubennikova <anastasia@neon.tech>
Co-authored-by: Alexander Bayandin <alexander@neon.tech>
Co-authored-by: Konstantin Knizhnik <knizhnik@neon.tech>
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
When walproposer observes now higher term it restarts instead of
crashing whole compute with PANIC; this avoids compute crash after
term_bump call. After successfull election we're still checking
last_log_term of the highest given vote to ensure basebackup is good,
and PANIC otherwise.
It will be used for migration per
035-safekeeper-dynamic-membership-change.md
and
https://github.com/neondatabase/docs/pull/21
ref https://github.com/neondatabase/neon/issues/8700
Protocol version 2 has been the default for a while now, and we no
longer have any computes running in production that used protocol
version 1. This completes the migration by removing support for v1 in
both the pageserver and the compute.
See issue #6211.
## Problem
Currently, we compare `neon.safekeepers` values as is, so we
unnecessarily restart walproposer even if safekeepers set didn't change.
This leads to errors like:
```log
FATAL: [WP] restarting walproposer to change safekeeper list
from safekeeper-8.us-east-2.aws.neon.tech:6401,safekeeper-11.us-east-2.aws.neon.tech:6401,safekeeper-10.us-east-2.aws.neon.tech:6401
to safekeeper-11.us-east-2.aws.neon.tech:6401,safekeeper-8.us-east-2.aws.neon.tech:6401,safekeeper-10.us-east-2.aws.neon.tech:6401
```
## Summary of changes
Split the GUC into the list of individual safekeepers and properly
compare. We could've done that somewhere on the upper level, e.g.,
control plane, but I think it's still better when the actual config
consumer is smarter and doesn't rely on upper levels.
## Problem
See https://neondb.slack.com/archives/C07J14D8GTX/p1724347552023709
Manipulations with LRU list in relation size cache are performed under
shared lock
## Summary of changes
Take exclusive lock
## 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
Multiple increase/decrease LFC limit may cause unlimited growth of LFC
file because punched holes while LFC shrinking are not reused when LFC
is extended.
## Summary of changes
Keep track of holes and reused them when LFC size is increased.
## 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
Logical replication BGW checking replication lag is not reloading config
## Summary of changes
Add handling of reload config request
## 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>
