The sphinxcontrib-versioning seems unmaintainted and I can't
get the fork that we used before this PR working on Python 3.10.
The situation wrt maintenance doesn't seem much better for
sphinx-multiversion, but, at least I could get it to work
with current sphinx versions.
The main problem with sphinx-multiversion is that it doesn't render
anything at `/`. I.e., `https://zrepl.github.io/configuration.html` will
be 404.
That's different from `sphinxcontrib-versioning`, and thus switching
to sphinx-multiversion would break URLs.
We host on GitHub pages and don't control the webserver,
so, we can't use webserver-level redirects to keep the URLs working.
We could create JS-level redirects, or `http-equiv`, but that's ugly as
well.
The simplest solution was to fork sphinx-multiversion and hard-code
zrepl's specific needs into that fork.
The fork is based off v0.2.4 and pinned via requirements.txt.
Here are its unique commits:
https://github.com/Holzhaus/sphinx-multiversion/compare/master...zrepl:sphinx-multiversion:zrepl
We should revisit `sphinx-polyversion` in the future once its docs
improve.
See
https://github.com/Holzhaus/sphinx-multiversion/issues/88#issuecomment-1606221194
This PR updates the various Python packages, as I couldn't get
sphinx-multiversion to work with the (very old) versions that were
pinned in `requirements.txt` prior to this PR.
This PR's `requirements.txt` is from a clean Python 3.10 venv on Ubuntu
22.10 after running
```
pip install sphinx sphinx-rtd-theme
pip install 'git+https://github.com/zrepl/sphinx-multiversion/@52c915d7ad898d9641ec48c8bbccb7d4f079db93#egg=sphinx_multiversion'
```
Before this PR, we would panic in the `check` phase of `endpoint.Send()`'s `TryBatchDestroy` call in the following cases: the current protection strategy does NOT produce a tentative replication cursor AND
* `FromVersion` is a tentative cursor bookmark
* `FromVersion` is a snapshot, and there exists a tentative cursor bookmark for that snapshot
* `FromVersion` is a bookmark != tentative cursor bookmark, but there exists a tentative cursor bookmark for the same snapshot as the `FromVersion` bookmark
In those cases, the `check` concluded that we would delete `FromVersion`.
It came to that conclusion because the tentative cursor isn't part of `obsoleteAbs` if the protection strategy doesn't produce a tentative replication cursor.
The scenarios above can happen if the user changes the protection strategy from "with tentative cursor" to one "without tentative replication cursor", while there is a tentative replication cursor on disk.
The workaround was to rename the tentative cursor.
In all cases above, `TryBatchDestroy` would have destroyed the tentative cursor.
In case 1, that would fail the `Send` step and potentially break replication if the cursor is the last common bookmark. The `check` conclusion was correct.
In cases 2 and 3, deleting the tentative cursor would have been fine because `FromVersion` was a different entity than the tentative cursor. So, destroying the tentative cursor would be the right call.
The solution in this PR is as follows:
* add the `FromVersion` to the `liveAbs` set of live abstractions
* rewrite the `check` closure to use the full dataset path (`fullpath`) to identify the concrete ZFS object instead of the `zfs.FilesystemVersionEqualIdentity`, which is only identified by matching GUID.
* Holds have no dataset path and are not the `FromVersion` in any case, so disregard them.
fixes#666
This PR adds a Prometheus counter called
`zrepl_zfs_list_unmatched_user_specified_dataset_count`.
Monitor for increases of the counter to detect filesystem filter rules that
have no effect because they don't match any local filesystem.
An example use case for this is the following story:
1. Someone sets up zrepl with `filesystems` filter for `zroot/pg14<`.
2. During the upgrade to Postgres 15, they rename the dataset to `zroot/pg15`,
but forget to update the zrepl `filesystems` filter.
3. zrepl will not snapshot / replicate the `zroot/pg15<` datasets.
Since `filesystems` rules are always evaluated on the side that has the datasets,
we can smuggle this functionality into the `zfs` module's `ZFSList` function that
is used by all jobs with a `filesystems` filter.
Dashboard changes:
- histogram with increase in $__interval, one row per job
- table with increase in $__range
- explainer text box, so, people know what the previous two are about
We had to re-arrange some panels, hence the Git diff isn't great.
closes https://github.com/zrepl/zrepl/pull/653
Co-authored-by: Christian Schwarz <me@cschwarz.com>
Co-authored-by: Goran Mekić <meka@tilda.center>
CircleCI artifacts are available publicly.
And regarding expiration of artifacts, it doesn't really
matter because I delete minio artifacts after 30d as well.
For this kind of debugging, we switched to env vars a while ago.
For example, ZREPL_RPC_DEBUG.
I don't think we have a substitute for the RPCLog stuff.
However, NetConnLogger is still in the codebase.
obsoletes https://github.com/zrepl/zrepl/pull/661
Originally, I had a patch that would replace all usages of
time.Duration in package config with the new config.Duration
types, but:
1. these are all timeouts/retry intervals that have default values.
Most users don't touch them, and if they do, they don't need
day or week units.
2. go-yaml's error reporting for yaml.Unmarshaler is inferior to
built-in types (line numbers are missing, so the error would not have
sufficient context)
fixes https://github.com/zrepl/zrepl/issues/486
The previous commits were done in response to updating to
the version that we now pin in this commit.
We do the update after the fixes so that each commit builds.
Before upgrading to Go 1.19, these platform tests would sproadically
fail due to the reason outlined in the comment
github.com/zrepl/zrepl/platformtest/tests.SendStreamMultipleCloseAfterEOF
github.com/zrepl/zrepl/platformtest/tests.SendStreamCloseAfterEOFRead
They are useful, not least to debug issues with debugging
SIGSYS caused by overly restrictive settings in the unit file.
(See previous commit for an example.)
Go 1.19 uses it during startup.
From the Go changelog:
> On Unix operating systems, Go programs that import package os now
> automatically increase the open file limit (RLIMIT_NOFILE) to the
> maximum allowed value; that is, they change the soft limit to match the
> hard limit. This corrects artificially low limits set on some systems
> for compatibility with very old C programs using the select system call.
> Go programs are not helped by that limit, and instead even simple
> programs like gofmt often ran out of file descriptors on such systems
> when processing many files in parallel. One impact of this change is
> that Go programs that in turn execute very old C programs in child
> processes may run those programs with too high a limit. This can be
> corrected by setting the hard limit before invoking the Go program.
A newer version of staticheck found these:
> SA4029: sort.StringSlice is a type, not a function, and
> sort.StringSlice(variants) doesn't sort your values; consider using
> sort.Strings instead (staticcheck)
Go 1.18 deprecated net.Error.Temporary().
This commit cleans up places where we use it incorrectly.
Also, the rpc layer defines some errors that implement
interface { Temporary() bool }
I added comments to all of the implementations to indicate
whether they will be required if net.Error.Temporary is ever
ever removed in the future.
For HandshakeError, the Temporary() return value is actually
important. I moved & rewrote a (previously misplaced) comment
there.
The ReadStreamError changes were
1. necessary to pacify newer staticcheck and
2. technically, an error can implement Temporary()
without being net.Err. This applies to some syscall
errors in the standard library.
Reading list for those interested:
- https://github.com/golang/go/issues/45729
- https://groups.google.com/g/golang-nuts/c/-JcZzOkyqYI
- https://man7.org/linux/man-pages/man2/accept.2.html
Note: This change was prompted by staticheck:
> SA1019: neterr.Temporary has been deprecated since Go 1.18 because it
> shouldn't be used: Temporary errors are not well-defined. Most
> "temporary" errors are timeouts, and the few exceptions are surprising.
> Do not use this method. (staticcheck)
The previous commit c743c7b03f
broke the hooks unit tests.
GitHub was not configured to require passing tests for master merge.
Didn't notice it locally due to Go's test caching.
I amended this before pushing this change.
Before this change, resuming from an unencrypted dataset with
send.raw=true specified wouldn't work with zrepl due to overly
restrictive resume token checking.
An initial PR to fix this was made in https://github.com/zrepl/zrepl/pull/503
but it didn't address the core of the problem.
The core of the problem was that zrepl assumed that if a resume token
contained `rawok=true, compressok=true`, the resulting send would be
encrypted. But if the sender dataset was unencrypted, such a resume would
actually result in an unencrypted send.
Which could be totally legitimate but zrepl failed to recognize that.
BACKGROUND
==========
The following snippets of OpenZFS code are insightful regarding how the
various ${X}ok values in the resume token are handled:
- 6c3c5fcfbe/module/zfs/dmu_send.c (L1947-L2012)
- 6c3c5fcfbe/module/zfs/dmu_recv.c (L877-L891)
- https://github.com/openzfs/zfs/blob/6c3c5fc/lib/libzfs/libzfs_sendrecv.c#L1663-L1672
Basically, some zfs send flags make the DMU send code set some DMU send
stream featureflags, although it's not a pure mapping, i.e, which DMU
send stream flags are used depends somewhat on the dataset (e.g., is it
encrypted or not, or, does it use zstd or not).
Then, the receiver looks at some (but not all) feature flags and maps
them to ${X}ok dataset zap attributes.
These are funnelled back to the sender 1:1 through the resume_token.
And the sender turns them into lzc flags.
As an example, let's look at zfs send --raw.
if the sender requests a raw send on an unencrypted dataset, the send
stream (and hence the resume token) will not have the raw stream
featureflag set, and hence the resume token will not have the rawok
field set. Instead, it will have compressok, embedok, and depending
on whether large blocks are present in the dataset, largeblockok set.
WHAT'S ZREPL'S ROLE IN THIS?
============================
zrepl provides a virtual encrypted sendflag that is like `raw`,
but further ensures that we only send encrypted datasets.
For any other resume token stuff, it shoudn't do any checking,
because it's a futile effort to keep up with ZFS send/recv features
that are orthogonal to encryption.
CHANGES MADE IN THIS COMMIT
===========================
- Rip out a bunch of needless checking that zrepl would do during
planning. These checks were there to give better error messages,
but actually, the error messages created by the endpoint.Sender.Send
RPC upon send args validation failure are good enough.
- Add platformtests to validate all combinations of
(Unencrypted/Encrypted FS) x (send.encrypted = true | false) x (send.raw = true | false)
for cases both non-resuming and resuming send.
Additional manual testing done:
1. With zrepl 0.5, setup with unencrypted dataset, send.raw=true specified, no send.encrypted specified.
2. Observe that regular non-resuming send works, but resuming doesn't work.
3. Upgrade zrepl to this change.
4. Observe that both regular and resuming send works.
closes https://github.com/zrepl/zrepl/pull/613
Use it from a top-level test case to queue the
execution of sub-tests after this test case is complete.
Note that the testing harness executes the subtest
_after_ the current top-level test. Hence, the subtest
cannot use any ZFS state of the top-level test.
There were and still is too many words. It's a very white paper vibe.
Docs needs to be more brief, exact, and on-point.
closes https://github.com/zrepl/zrepl/pull/618
Previously with unordered list, and 'are considered'
left if unsure whether one or all files are 'considered'.
In reality, the first valid is used, so an ordered list and
perhaps better wording communicates this fact.
refs https://github.com/zrepl/zrepl/pull/618
