It's annoying that many of the tests required a special build with the
"testing" feature. I think it's better to have a runtime check. It adds
a few CPU instructions to where failpoints are defined, even if they are
disabled, but that's a small price to pay for the convenience.
Fixes issue 2531, although differently from what was discussed on that
issue.
Changes:
* Remove `RemoteObjectId` concept from remote_storage.
Operate directly on /-separated names instead.
These names are now represented by struct `RemotePath` which was renamed from struct `RelativePath`
* Require remote storage to operate on relative paths for its contents, thus simplifying the way to derive them in pageserver and safekeeper
* Make `IndexPart` to use `String` instead of `RelativePath` for its entries, since those are just the layer names
This patch centralize the logic of creating & reading pid files into the
new pid_file module and improves upon / makes explicit a few race conditions
that existed with the previous code.
Starting Processes / Creating Pidfiles
======================================
Before this patch, we had three places that had very similar-looking
match lock_file::create_lock_file { ... }
blocks.
After this change, they can use a straight-forward call provided
by the pid_file:
pid_file::claim_pid_file_for_pid()
Stopping Processes / Reading Pidfiles
=====================================
The new pid_file module provides a function to read a pidfile,
called read_pidfile(), that returns a
pub enum PidFileRead {
NotExist,
NotHeldByAnyProcess(PidFileGuard),
LockedByOtherProcess(Pid),
}
If we get back NotExist, there is nothing to kill.
If we get back NotHeldByAnyProcess, the pid file is stale and we must
ignore its contents.
If it's LockedByOtherProcess, it's either another pidfile reader
or, more likely, the daemon that is still running.
In this case, we can read the pid in the pidfile and kill it.
There's still a small window where this is racy, but it's not a
regression compared to what we have before.
The NotHeldByAnyProcess is an improvement over what we had before
this patch. Before, we would blindly read the pidfile contents
and kill, even if no other process held the flock.
If the pidfile was stale (NotHeldByAnyProcess), then that kill
would either result in ESRCH or hit some other unrelated process
on the system. This patch avoids the latter cacse by grabbing
an exclusive flock before reading the pidfile, and returning the
flock to the caller in the form of a guard object, to avoid
concurrent reads / kills.
It's hopefully irrelevant in practice, but it's a little robustness
that we get for free here.
Maintain flock on Pidfile of ETCD / any InitialPidFile::Create()
================================================================
Pageserver and safekeeper create their pidfiles themselves.
But for etcd, neon_local creates the pidfile (InitialPidFile::Create()).
Before this change, we would unlock the etcd pidfile as soon as
`neon_local start` exits, simply because no-one else kept the FD open.
During `neon_local stop`, that results in a stale pid file,
aka, NotHeldByAnyProcess, and it would henceforth not trust that
the PID stored in the file is still valid.
With this patch, we make the etcd process inherit the pidfile FD,
thereby keeping the flock held until it exits.
* We were missing one cluster in production:
`prod-ap-southeast-1-epsilon` configs.
* We had `metrics` enabled. This means creating `ServiceScrape` objects,
but since those clusters don't have `kube-prometheus-stack` like older
ones, we are missing the CRDs, so the helm deploy fails.
The new "trace_read_requests" option was missing from the
parse_toml_tenant_conf function that reads the config file. Because of
that, the option was ignored, which caused the test_read_trace.py test
to fail. It used to work before commit 9a6c0be823, because the
TenantConfigOpt struct was constructed directly in tenant_create_handler,
but now it is saved and read back from disk even for a newly created
tenant.
The abovementioned bug was fixed in commit 09393279c6 already, which
added the missing code to parse_toml_tenant_conf() to parse the
new "trace_read_requests" option. This commit fixes one more function
that was missed earlier, and adds more detail to the error message if
parsing the config file fails.
helm values for the new `storage-broker`. gRPC, over secure connection
with a proper certificate, but no authentication.
Uses alb ingress in the old cluster and nginx ingress for the new one.
The chart is deployed and the addresses are functional, while the
pipeline doesn't exist yet.
It used to be a separate piece of state, but after 9a6c0be823 it's just
an alias for the Tenant being in Attaching state. It was only used in
one assertion in a test, but that check doesn't make sense anymore, so
just remove it.
Fixes https://github.com/neondatabase/neon/issues/2930
Added basic instrumentation to integrate sentry with the proxy, pageserver, and safekeeper processes.
Currently in sentry there are three projects, one for each process. Sentry url is sent to all three processes separately via cli args.
Closes https://github.com/neondatabase/neon/issues/2537
Follow-up of https://github.com/neondatabase/neon/pull/2950
With the new model that prevents attaching without the remote storage,
it has started to be even more odd to add attach-with-files
functionality (in addition to the issues raised previously).
Adds two separate commands:
* `POST {tenant_id}/ignore` that places a mark file to skip such tenant
on every start and removes it from memory
* `POST {tenant_id}/schedule_load` that tries to load a tenant from
local FS similar to what pageserver does now on startup, but without
directory removals
Move missing_layers property to Option<HashSet<RelativePath>>
This will allow the safe removal of it once the upgrade of all page servers is done with this new code
- Replace `seqscan_prefetch_buffers` with `effective_io_concurrency` and
`maintenance_io_concurrency` for `clickbench-compare` job (see
https://github.com/neondatabase/neon/pull/2876)
- Get the database name in a runtime (it can be `main` or `neondb` or
something else)
```
warning: named argument `file` is not used by name
--> pageserver/src/tenant/timeline.rs:1078:54
|
1078 | trace!("downloading image file: {}", file = path.display());
| -- ^^^^ this named argument is referred to by position in formatting string
| |
| this formatting argument uses named argument `file` by position
|
= note: `#[warn(named_arguments_used_positionally)]` on by default
help: use the named argument by name to avoid ambiguity
|
1078 | trace!("downloading image file: {file}", file = path.display());
| ++++
```
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
- **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.
- Change "WAL service" to "safekeepers" in the architecture section. The
safekeepers together form the WAL service, but we don't use that term
much in the code.
- Replace the short list of pageserver components with a link /docs. We
have more details there.
- Add "Other resources" to Documention section, with links to some blog
posts and a video presentation.
- Remove notice at the top about the Zenith -> Neon rename. There are
still a few references to Zenith in the codebase, but not so many that
we would need to call it out at the top anymore.
Our shutdown procedure for "pageserver init" was buggy. Firstly, it
merely sent the process a SIGKILL, but did not wait for it to actually
exit. Normally, it should exit quickly as SIGKILL cannot be caught or
ignored by the target process, but it's still asynchronous and the
process can still be alive when the kill(2) call returns. Secondly,
"neon_local" removed the PID file after sending SIGKILL, even though the
process was still running. That hid the first problem: if we didn't
remove the PID file, and you start a new pageserver process while the
old one is still running, you would get an error when the new process
tries to lock the PID file.
We've been seeing a lot of "Cannot assign requested address" failures in
the CI lately. Our theory is that when we run "pageserver init"
immediately followed by "pageserver start", the first process is still
running and listening on the port when the second invocation starts up.
This commit hopefully fixes the problem.
It is generally a bad idea for the "neon_local" to remove the PID file
on the child process's behalf. The correct way would be for the server
process to remove the PID file, after it has fully shutdown everything
else. We don't currently have a robust way to ensure that everything has
truly shut down and closed, however.
A simpler way is to simply never remove the PID file. It's not necessary
to remove the PID file for correctness: we cannot rely on the cleanup to
happen anyway, if the server process crashes for example. Because of
that, we already have all the logic in place to deal with a stale PID
file that belonged to a process that already exited. Let's rely on that
on normal shutdown too.
We used to have a bug where the pageserver just got stuck if the
client sent a CopyDone message before reaching end of tar stream. That
showed up with an empty tar file, as one example. That was
inadvertently fixed by code refactorings, but let's add a regression
test for it, so that we don't accidentally re-introduce the bug later.
Co-authored-by: Heikki Linnakangas <heikki@neon.tech>
I'm not a fan of "Paused", for two reasons:
- Paused implies that the tenant/timeline with no activity on it. That's
not true; the tenant/timeline can still have active tasks working on it.
- Paused implies that it can be resumed later. It can not. A tenant or
timeline in this state cannot be switched back to Active state anymore.
A completely new Tenant or Timeline struct can be constructed for the
same tenant or timeline later, e.g. if you detach and later re-attach
the same tenant, but that's a different thing.
Stopping describes the state better. I also considered "ShuttingDown",
but Stopping is simpler as it's a single word.
The code in this change was extracted from PR #2595, i.e., Heikki’s draft
PR for on-demand download.
High-Level Changes
- storage_sync module rewrite
- Changes to Tenant Loading
- Changes to Timeline States
- Crash-safe & Resumable Tenant Attach
There are several follow-up work items planned.
Refer to the Epic issue on GitHub:
https://github.com/neondatabase/neon/issues/2029
Metadata:
closes https://github.com/neondatabase/neon/pull/2785
unsquashed history of this patch: archive/pr-2785-storage-sync2/pre-squash
Co-authored-by: Dmitry Rodionov <dmitry@neon.tech>
Co-authored-by: Christian Schwarz <christian@neon.tech>
===============================================================================
storage_sync module rewrite
===========================
The storage_sync code is rewritten. New module name is storage_sync2, mostly to
make a more reasonable git diff.
The updated block comment in storage_sync2.rs describes the changes quite well,
so, we will not reproduce that comment here. TL;DR:
- Global sync queue and RemoteIndex are replaced with per-timeline
`RemoteTimelineClient` structure that contains a queue for UploadOperations
to ensure proper ordering and necessary metadata.
- Before deleting local layer files, wait for ongoing UploadOps to finish
(wait_completion()).
- Download operations are not queued and executed immediately.
Changes to Tenant Loading
=========================
Initial sync part was rewritten as well and represents the other major change
that serves as a foundation for on-demand downloads. Routines for attaching and
loading shifted directly to Tenant struct and now are asynchronous and spawned
into the background.
Since this patch doesn’t introduce on-demand download of layers we fully
synchronize with the remote during pageserver startup. See details in
`Timeline::reconcile_with_remote` and `Timeline::download_missing`.
Changes to Tenant States
========================
The “Active” state has lost its “background_jobs_running: bool” member. That
variable indicated whether the GC & Compaction background loops are spawned or
not. With this patch, they are now always spawned. Unit tests (#[test]) use the
TenantConf::{gc_period,compaction_period} to disable their effect (15db566).
This patch introduces a new tenant state, “Attaching”. A tenant that is being
attached starts in this state and transitions to “Active” once it finishes
download.
The `GET /tenant` endpoints returns `TenantInfo::has_in_progress_downloads`. We
derive the value for that field from the tenant state now, to remain
backwards-compatible with cloud.git. We will remove that field when we switch
to on-demand downloads.
Changes to Timeline States
==========================
The TimelineInfo::awaits_download field is now equivalent to the tenant being
in Attaching state. Previously, download progress was tracked per timeline.
With this change, it’s only tracked per tenant. When on-demand downloads
arrive, the field will be completely obsolete. Deprecation is tracked in
isuse #2930.
Crash-safe & Resumable Tenant Attach
====================================
Previously, the attach operation was not persistent. I.e., when tenant attach
was interrupted by a crash, the pageserver would not continue attaching after
pageserver restart. In fact, the half-finished tenant directory on disk would
simply be skipped by tenant_mgr because it lacked the metadata file (it’s
written last). This patch introduces an “attaching” marker file inside that is
present inside the tenant directory while the tenant is attaching. During
pageserver startup, tenant_mgr will resume attach if that file is present. If
not, it assumes that the local tenant state is consistent and tries to load the
tenant. If that fails, the tenant transitions into Broken state.
Change the default region for staging from `us-east-1` to `us-east-2`
for project creation.
Remove REGION_ID from `neon-branch-create` since we don't use it.
