Add HTTP endpoint to initialize safekeeper timeline from peer
safekeepers. This is useful for initializing new safekeeper to replace
failed safekeeper. Not fully "correct" in all cases, but should work in
most.
This code is not suitable for production workloads but can be tested on
staging to get started. New endpoint is separated from usual cases and
should not affect anything if no one explicitly uses a new endpoint. We
can rollback this commit in case of issues.
Refactors walsenders out of timeline.rs to makes it less convoluted into
separate WalSenders with its own lock, but otherwise having the same structure.
Tracking of in-memory remote_consistent_lsn is also moved there as it is mainly
received from pageserver.
State of walsender (feedback) is also restructured to be cleaner; now it is
either PageserverFeedback or StandbyFeedback(StandbyReply, HotStandbyFeedback),
but not both.
Otherwise it can lag a lot, preventing WAL segments cleanup. Also max
wal_backup_lsn on update, pulling it down is pointless.
Should help with https://github.com/neondatabase/neon/issues/3957, but
will not fix it completely.
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.
Add a condition to switch walreceiver connection to safekeeper that is
located in the same availability zone. Switch happens when commit_lsn of
a candidate is not less than commit_lsn from the active connection. This
condition is expected not to trigger instantly, because commit_lsn of a
current connection is usually greater than commit_lsn of updates from
the broker. That means that if WAL is written continuously, switch can
take a lot of time, but it should happen eventually.
Now protoc 3.15+ is required for building neon.
Fixes https://github.com/neondatabase/neon/issues/3200
- Add support for splitting async postgres_backend into read and write halfes.
Safekeeper needs this for bidirectional streams. To this end, encapsulate
reading-writing postgres messages to framed.rs with split support without any
additional changes (relying on BufRead for reading and BytesMut out buffer for
writing).
- Use async postgres_backend throughout safekeeper (and in proxy auth link
part).
- In both safekeeper COPY streams, do read-write from the same thread/task with
select! for easier error handling.
- Tidy up finishing CopyBoth streams in safekeeper sending and receiving WAL
-- join split parts back catching errors from them before returning.
Initially I hoped to do that read-write without split at all, through polling
IO:
https://github.com/neondatabase/neon/pull/3522
However that turned out to be more complicated than I initially expected
due to 1) borrow checking and 2) anon Future types. 1) required Rc<Refcell<...>>
which is Send construct just to satisfy the checker; 2) can be workaround with
transmute. But this is so messy that I decided to leave split.
This API is rather pointless, as sane choice anyway requires knowledge of peers
status and leaders lifetime in any case can intersect, which is fine for us --
so manual elections are straightforward. Here, we deterministically choose among
the reasonably caught up safekeepers, shifting by timeline id to spread the
load.
A step towards custom broker https://github.com/neondatabase/neon/issues/2394
With the ability to pass commit_lsn. This allows to perform project WAL recovery
through different (from the original) set of safekeepers (or under different
ttid) by
1) moving WAL files to s3 under proper ttid;
2) explicitly creating timeline on safekeepers, setting commit_lsn to the
latest point;
3) putting the lastest .parital file to the timeline directory on safekeepers, if
desired.
Extend test_s3_wal_replay to exersise this behaviour.
Also extends timeline_status endpoint to return postgres information.
Another preparatory commit for pg15 support:
* generate bindings for both pg14 and pg15;
* update Makefile and CI scripts: now neon build depends on both PostgreSQL versions;
* some code refactoring to decrease version-specific dependencies.
Re-export only things that are used by other modules.
In the future, I'm imagining that we run bindgen twice, for Postgres
v14 and v15. The two sets of bindings would go into separate
'bindings_v14' and 'bindings_v15' modules.
Rearrange postgres_ffi modules.
Move function, to avoid Postgres version dependency in timelines.rs
Move function to generate a logical-message WAL record to postgres_ffi.
To flush inmemory layer eventually when no new data arrives, which helps
safekeepers to suspend activity (stop pushing to the broker). Default 10m should
be ok.
Mitigates latency fee, making push throughput 1-1.5 order of magnitude bigger.
Also make leases per timeline, not per whole safekeeper, avoiding storing
garbage in etcd for deleted timelines while safekeeper is alive.
I made the check at launcher level with the perspective of generally moving
election (decision who offloads) there.
Also log timeline 'active' changes.
Separate task is launched for each timeline and stopped when timeline doesn't
need offloading. Decision who offloads is done through etcd leader election;
currently there is no pre condition for participating, that's a TODO.
neon_local and tests infrastructure for remote storage in safekeepers added,
along with the test itself.
ref #1009
Co-authored-by: Anton Shyrabokau <ahtoxa@Antons-MacBook-Pro.local>
* There is no auth in Safekeeper HTTP at all currently,
so simply calling `check_permission` is not enough.
* There are no checks of Safekeeper still working with the data,
as "still working" is burry now: a timeline may be "active"
while there are no compute nodes and all data is propagated.
* Still, callmemaybe is deactivated, and timeline is removed from the
internal map. It can easily sneak back in case of race conditions
and implicit creations, though.
Make it remember when timeline starts in general and on this safekeeper in
particular (the point might be later on new safekeeper replacing failed one).
Bumps control file and walproposer protocol versions.
While protocol is bumped, also add safekeeper node id to
AcceptorProposerGreeting.
ref #1561
Remove when it is consumed by all of 1) pageserver (remote_consistent_lsn) 2)
safekeeper peers 3) s3 WAL offloading.
In test s3 offloading for now is mocked by directly bumping s3_wal_lsn.
ref #1403
