The `get_git_common_dir()` function retrieves the path to the common
directory for `the_repository`. Make it accept a `struct repository`
such that it can work on arbitrary repositories and make it part of the
repository subsystem. This reduces our reliance on `the_repository` and
clarifies scope.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A tests for "git maintenance" that were broken on Windows have been
corrected.
* ps/maintenance-detach-fix-more:
builtin/maintenance: fix loose objects task emitting pack hash
t7900: exercise detaching via trace2 regions
t7900: fix flaky test due to leaking background job
Maintenance tasks other than "gc" now properly go background when
"git maintenance" runs them.
* ps/maintenance-detach-fix:
run-command: fix detaching when running auto maintenance
builtin/maintenance: add a `--detach` flag
builtin/gc: add a `--detach` flag
builtin/gc: stop processing log file on signal
builtin/gc: fix leaking config values
builtin/gc: refactor to read config into structure
config: fix constness of out parameter for `git_config_get_expiry()`
Use of API functions that implicitly depend on the_repository
object in the config subsystem has been rewritten to pass a
repository object through the callchain.
* ps/config-wo-the-repository:
config: hide functions using `the_repository` by default
global: prepare for hiding away repo-less config functions
config: don't depend on `the_repository` with branch conditions
config: don't have setters depend on `the_repository`
config: pass repo to functions that rename or copy sections
config: pass repo to `git_die_config()`
config: pass repo to `git_config_get_expiry_in_days()`
config: pass repo to `git_config_get_expiry()`
config: pass repo to `git_config_get_max_percent_split_change()`
config: pass repo to `git_config_get_split_index()`
config: pass repo to `git_config_get_index_threads()`
config: expose `repo_config_clear()`
config: introduce missing setters that take repo as parameter
path: hide functions using `the_repository` by default
path: stop relying on `the_repository` in `worktree_git_path()`
path: stop relying on `the_repository` when reporting garbage
hooks: remove implicit dependency on `the_repository`
editor: do not rely on `the_repository` for interactive edits
path: expose `do_git_common_path()` as `repo_common_pathv()`
path: expose `do_git_path()` as `repo_git_pathv()`
The "loose-objects" maintenance tasks executes git-pack-objects(1) to
pack all loose objects into a new packfile. This command ends up
printing the hash of the packfile to stdout though, which clutters the
output of `git maintenance run`.
Fix this issue by disabling stdout of the child process.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In t7900, we exercise the `--detach` logic by checking whether the
command ended up writing anything to its output or not. This supposedly
works because we close stdin, stdout and stderr when daemonizing. But
one, it breaks on platforms where daemonize is a no-op, like Windows.
And second, that git-maintenance(1) outputs anything at all in these
tests is a bug in the first place that we'll fix in a subsequent commit.
Introduce a new trace2 region around the detach which allows us to more
explicitly check whether the detaching logic was executed. This is a
much more direct way to exercise the logic, provides a potentially
useful signal to tracing logs and also works alright on platforms which
do not have the ability to daemonize.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
[jc: dropped a stale in-code comment from a test]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the past, we used to execute `git gc --auto` as part of our automatic
housekeeping routines. As git-gc(1) may require quite some time to
perform the housekeeping, it knows to detach itself and run in the
background so that the user can continue their work.
Eventually, we refactored our automatic housekeeping to instead use the
more flexible git-maintenance(1) command. The upside of this new infra
is that the user can configure which maintenance tasks are performed, at
least to a certain degree. So while it continues to run git-gc(1) by
default, it can also be adapted to e.g. use git-multi-pack-index(1) for
maintenance of the object database.
The auto-detach of the new infra is somewhat broken though once the user
configures non-standard tasks. The problem is essentially that we detach
at the wrong level in the process hierarchy: git-maintenance(1) never
detaches itself, but instead it continues to be git-gc(1) which does.
When configured to only run the git-gc(1) maintenance task, then the
result is basically the same as before. But when configured to run other
tasks, then git-maintenance(1) will wait for these to run to completion.
Even worse, it may be that git-gc(1) runs concurrently with other
housekeeping tasks, stomping on each others feet.
Fix this bug by asking git-gc(1) to not detach when it is being invoked
via git-maintenance(1). Instead, git-maintenance(1) now respects a new
config "maintenance.autoDetach", the equivalent of "gc.autoDetach", and
detaches itself into the background when running as part of our auto
maintenance. This should continue to behave the same for all users which
use the git-gc(1) task, only. For others though, it means that we now
properly perform all tasks in the background. The default behaviour of
git-maintenance(1) when executed by the user does not change, it will
remain in the foreground unless they pass the `--detach` option.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Same as the preceding commit, add a `--[no-]detach` flag to the
git-maintenance(1) command. This will be used in a subsequent commit to
fix backgrounding of that command when configured with a non-standard
set of tasks.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running `git gc --auto`, the command will by default detach and
continue running in the background. This behaviour can be tweaked via
the `gc.autoDetach` config, but not via a command line switch. We need
that in a subsequent commit though, where git-maintenance(1) will want
to ask its git-gc(1) child process to not detach anymore.
Add a `--[no-]detach` flag that does this for us.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When detaching, git-gc(1) will redirect its stderr to a "gc.log" log
file, which is then used to surface errors of a backgrounded process to
the user. To ensure that the file is properly managed on abnormal exit
paths, we install both signal and exit handlers that try to either
commit the underlying lock file or roll it back in case there wasn't any
error.
This logic is severly broken when handling signals though, as we end up
calling all kinds of functions that are not signal safe. This includes
malloc(3P) via `git_path()`, fprintf(3P), fflush(3P) and many more
functions. The consequence can be anything, from deadlocks to crashes.
Unfortunately, we cannot really do much about this without a larger
refactoring.
The least-worst thing we can do is to not set up the signal handler in
the first place. This will still cause us to remove the lockfile, as the
underlying tempfile subsystem already knows to unlink locks when
receiving a signal. But it may cause us to remove the lock even in the
case where it would have contained actual errors, which is a change in
behaviour.
The consequence is that "gc.log" will not be committed, and thus
subsequent calls to `git gc --auto` won't bail out because of this.
Arguably though, it is better to retry garbage collection rather than
having the process run into a potentially-corrupted state.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're leaking config values in git-gc(1) when those values are tracked
as strings. Introduce a new `gc_config_release()` function that releases
this memory to plug those leaks and release old values before populating
the config fields via `git_config_string()` et al.
Note that there is one small gotcha here with the "--prune" option. Next
to passing a string, this option also accepts the "--no-prune" option
that overrides the default or configured value. We thus need to discern
between the option not having been passed by the user and the negative
variant of it. This is done by using a simple sentinel value that lets
us discern these cases.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-gc(1) command knows to read a bunch of config keys to tweak its
own behaviour. The values are parsed into global variables, which makes
it hard to correctly manage the lifecycle of values that may require a
memory allocation.
Refactor the code to use a `struct gc_config` that gets populated and
passed around. For one, this makes previously-implicit dependencies on
these config values clear. Second, it will allow us to properly manage
the lifecycle in the next commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The type of the out parameter of `git_config_get_expiry()` is a pointer
to a constant string, which creates the impression that ownership of the
returned data wasn't transferred to the caller. This isn't true though
and thus quite misleading.
Adapt the parameter to be of type `char **` and adjust callers
accordingly. While at it, refactor `get_shared_index_expire_date()` to
drop the static `shared_index_expire` variable. It is only used in that
function, and furthermore we would only hit the code where we parse the
expiry date a single time because we already use a static `prepared`
variable to track whether we did parse it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor `git_config_get_expiry()` to accept a `struct repository` such
that we can get rid of the implicit dependency on `the_repository`.
Rename the function accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We implicitly depend on `the_repository` in our hook subsystem because
we use `strbuf_git_path()` to compute hook paths. Remove this dependency
by accepting a `struct repository` as parameter instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a parameter to each_ref_fn so that callers to the ref APIs
that use this function as a callback can have acess to the
unresolved value of a symbolic ref.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both `peel_object()` and `peel_iterated_oid()` implicitly rely on
`the_repository` to look up objects. Despite the fact that we want to
get rid of `the_repository`, it also leads to some restrictions in our
ref iterators when trying to retrieve the peeled value for a repository
other than `the_repository`.
Refactor these functions such that both take a repository as argument
and remove the now-unnecessary restrictions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Apply the rules that rewrite callers of "refs" interfaces to explicitly
pass `struct ref_store`. The resulting patch has been applied with the
`--whitespace=fix` option.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A scheduled "git maintenance" job is expected to work on all
repositories it knows about, but it stopped at the first one that
errored out. Now it keeps going.
* js/for-each-repo-keep-going:
maintenance: running maintenance should not stop on errors
for-each-repo: optionally keep going on an error
In https://github.com/microsoft/git/issues/623, it was reported that
maintenance stops on a missing repository, omitting the remaining
repositories that were scheduled for maintenance.
This is undesirable, as it should be a best effort type of operation.
It should still fail due to the missing repository, of course, but not
leave the non-missing repositories in unmaintained shapes.
Let's use `for-each-repo`'s shiny new `--keep-going` option that we just
introduced for that very purpose.
This change will be picked up when running `git maintenance start`,
which is run implicitly by `scalar reconfigure`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git pack-refs" learned the "--auto" option, which is a useful
addition to be triggered from "git gc --auto".
Acked-by: Karthik Nayak <karthik.188@gmail.com>
cf. <CAOLa=ZRAEA7rSUoYL0h-2qfEELdbPHbeGpgBJRqesyhHi9Q6WQ@mail.gmail.com>
* ps/pack-refs-auto:
builtin/gc: pack refs when using `git maintenance run --auto`
builtin/gc: forward git-gc(1)'s `--auto` flag when packing refs
t6500: extract objects with "17" prefix
builtin/gc: move `struct maintenance_run_opts`
builtin/pack-refs: introduce new "--auto" flag
builtin/pack-refs: release allocated memory
refs/reftable: expose auto compaction via new flag
refs: remove `PACK_REFS_ALL` flag
refs: move `struct pack_refs_opts` to where it's used
t/helper: drop pack-refs wrapper
refs/reftable: print errors on compaction failure
reftable/stack: gracefully handle failed auto-compaction due to locks
reftable/stack: use error codes when locking fails during compaction
reftable/error: discern locked/outdated errors
reftable/stack: fix error handling in `reftable_stack_init_addition()`
When running `git maintenance run --auto`, then the various subtasks
will only run as needed. Thus, we for example end up only packing loose
objects if we hit a certain threshold.
Interestingly enough, the "pack-refs" task is actually _never_ executed
when the auto-flag is set because it does not have a condition at all.
As 41abfe15d9 (maintenance: add pack-refs task, 2021-02-09) mentions:
The 'auto_condition' function pointer is left NULL for now. We could
extend this in the future to have a condition check if pack-refs
should be run during 'git maintenance run --auto'.
It is not quite clear from that quote whether it is actually intended
that the task doesn't run at all in this mode. Also, no test was added
to verify this behaviour. Ultimately though, it feels quite surprising
that `git maintenance run --auto --task=pack-refs` would quietly never
do anything at all.
In any case, now that we do have the logic in place to let ref backends
decide whether or not to repack refs, it does make sense to wire it up
accordingly. With the "reftable" backend we will thus now perform
auto-compaction, which optimizes the refdb as needed.
But for the "files" backend we now unconditionally pack refs as it does
not yet know to handle the "auto" flag. Arguably, this can be seen as a
bug fix given that previously the task never did anything at all.
Eventually though we should amend the "files" backend to use some
heuristics for auto compaction, as well.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Forward the `--auto` flag to git-pack-refs(1) when it has been invoked
with this flag itself. This does not change anything for the "files"
backend, which will continue to eagerly pack refs. But it does ensure
that the "reftable" backend only compacts refs as required.
This change does not impact git-maintenance(1) because this command will
in fact never run the pack-refs task when run with `--auto`. This issue
will be addressed in a subsequent commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're about to start using `struct maintenance_run_opts` in
`maintenance_task_pack_refs()`. Move its definition up to prepare for
this.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce the ability to append comments to modifications
made using git-config. Example usage:
git config --comment "changed via script" \
--add safe.directory /home/alice/repo.git
based on the proposed patch, the output produced is:
[safe]
directory = /home/alice/repo.git #changed via script
Users need to be able to distinguish between config entries made
using automation and entries made by a human. Automation can add
comments containing a URL pointing to explanations for the change
made, avoiding questions from users as to why their config file
was changed by a third party.
The implementation ensures that a # character is unconditionally
prepended to the provided comment string, and that the comment
text is appended as a suffix to the changed key-value-pair in the
same line of text. Multi-line comments (i.e. comments containing
linefeed) are rejected as errors, causing Git to exit without
making changes.
Comments are aimed at humans who inspect or change their Git
config using a pager or editor. Comments are not meant to be
read or displayed by git-config at a later time.
Signed-off-by: Ralph Seichter <github@seichter.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git maintenance register` registers the repository in the user's global
config. `$XDG_CONFIG_HOME/git/config` is supposed to be used if
`~/.gitconfig` does not exist. However, this command creates a
`~/.gitconfig` file and writes to that one even though the XDG variant
exists.
This used to work correctly until 50a044f1e4 (gc: replace config
subprocesses with API calls, 2022-09-27), when the command started calling
the config API instead of git-config(1).
Also change `unregister` accordingly.
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename this function to a more descriptive name since we want to use the
existing name for a new function.
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git repack" learned "--max-cruft-size" to prevent cruft packs from
growing without bounds.
* tb/repack-max-cruft-size:
repack: free existing_cruft array after use
builtin/repack.c: avoid making cruft packs preferred
builtin/repack.c: implement support for `--max-cruft-size`
builtin/repack.c: parse `--max-pack-size` with OPT_MAGNITUDE
t7700: split cruft-related tests to t7704
Cruft packs are an alternative mechanism for storing a collection of
unreachable objects whose mtimes are recent enough to avoid being
pruned out of the repository.
When cruft packs were first introduced back in b757353676
(builtin/pack-objects.c: --cruft without expiration, 2022-05-20) and
a7d493833f (builtin/pack-objects.c: --cruft with expiration,
2022-05-20), the recommended workflow consisted of:
- Repacking periodically, either by packing anything loose in the
repository (via `git repack -d`) or producing a geometric sequence
of packs (via `git repack --geometric=<d> -d`).
- Every so often, splitting the repository into two packs, one cruft
to store the unreachable objects, and another non-cruft pack to
store the reachable objects.
Repositories may (out of band with the above) choose periodically to
prune out some unreachable objects which have aged out of the grace
period by generating a pack with `--cruft-expiration=<approxidate>`.
This allowed repositories to maintain relatively few packs on average,
and quarantine unreachable objects together in a cruft pack, avoiding
the pitfalls of holding unreachable objects as loose while they age out
(for more, see some of the details in 3d89a8c118
(Documentation/technical: add cruft-packs.txt, 2022-05-20)).
This all works, but can be costly from an I/O-perspective when
frequently repacking a repository that has many unreachable objects.
This problem is exacerbated when those unreachable objects are rarely
(if every) pruned.
Since there is at most one cruft pack in the above scheme, each time we
update the cruft pack it must be rewritten from scratch. Because much of
the pack is reused, this is a relatively inexpensive operation from a
CPU-perspective, but is very costly in terms of I/O since we end up
rewriting basically the same pack (plus any new unreachable objects that
have entered the repository since the last time a cruft pack was
generated).
At the time, we decided against implementing more robust support for
multiple cruft packs. This patch implements that support which we were
lacking.
Introduce a new option `--max-cruft-size` which allows repositories to
accumulate cruft packs up to a given size, after which point a new
generation of cruft packs can accumulate until it reaches the maximum
size, and so on. To generate a new cruft pack, the process works like
so:
- Sort a list of any existing cruft packs in ascending order of pack
size.
- Starting from the beginning of the list, group cruft packs together
while the accumulated size is smaller than the maximum specified
pack size.
- Combine the objects in these cruft packs together into a new cruft
pack, along with any other unreachable objects which have since
entered the repository.
Once a cruft pack grows beyond the size specified via `--max-cruft-size`
the pack is effectively frozen. This limits the I/O churn up to a
quadratic function of the value specified by the `--max-cruft-size`
option, instead of behaving quadratically in the number of total
unreachable objects.
When pruning unreachable objects, we bypass the new code paths which
combine small cruft packs together, and instead start from scratch,
passing in the appropriate `--max-pack-size` down to `pack-objects`,
putting it in charge of keeping the resulting set of cruft packs sized
correctly.
This may seem like further I/O churn, but in practice it isn't so bad.
We could prune old cruft packs for whom all or most objects are removed,
and then generate a new cruft pack with just the remaining set of
objects. But this additional complexity buys us relatively little,
because most objects end up being pruned anyway, so the I/O churn is
well contained.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A previous commit implemented the `gc.repackFilter` config option
to specify a filter that should be used by `git gc` when
performing repacks.
Another previous commit has implemented
`git repack --filter-to=<dir>` to specify the location of the
packfile containing filtered out objects when using a filter.
Let's implement the `gc.repackFilterTo` config option to specify
that location in the config when `gc.repackFilter` is used.
Now when `git gc` will perform a repack with a <dir> configured
through this option and not empty, the repack process will be
passed a corresponding `--filter-to=<dir>` argument.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A previous commit has implemented `git repack --filter=<filter-spec>` to
allow users to filter out some objects from the main pack and move them
into a new different pack.
Users might want to perform such a cleanup regularly at the same time as
they perform other repacks and cleanups, so as part of `git gc`.
Let's allow them to configure a <filter-spec> for that purpose using a
new gc.repackFilter config option.
Now when `git gc` will perform a repack with a <filter-spec> configured
through this option and not empty, the repack process will be passed a
corresponding `--filter=<filter-spec>` argument.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update "git maintainance" timers' implementation based on systemd
timers to work with WSL.
* js/systemd-timers-wsl-fix:
maintenance(systemd): support the Windows Subsystem for Linux
Unused parameters to functions are marked as such, and/or removed,
in order to bring us closer to -Wunused-parameter clean.
* jk/unused-post-2.42-part2:
parse-options: mark unused parameters in noop callback
interpret-trailers: mark unused "unset" parameters in option callbacks
parse-options: add more BUG_ON() annotations
merge: do not pass unused opt->value parameter
parse-options: mark unused "opt" parameter in callbacks
parse-options: prefer opt->value to globals in callbacks
checkout-index: delay automatic setting of to_tempfile
format-patch: use OPT_STRING_LIST for to/cc options
merge: simplify parsing of "-n" option
merge: make xopts a strvec
When running in the Windows Subsystem for Linux (WSL), it is usually
necessary to use the Git Credential Manager for authentication when
performing the background fetches.
This requires interoperability between the Windows Subsystem for Linux
and the Windows host to work, which uses so-called vsocks, i.e. sockets
intended for communcations between virtual machines and the host they
are running on.
However, when Git is configured to run background maintenance via
`systemd`, the address families available to those maintenance processes
are restricted, and did not include `AF_VSOCK`. This leads to problems
e.g. when a background fetch tries to access github.com:
systemd[437]: Starting Optimize Git repositories data...
git[747387]: WSL (747387) ERROR: UtilBindVsockAnyPort:285: socket failed 97
git[747381]: fatal: could not read Username for 'https://github.com': No such device or address
git[747381]: error: failed to prefetch remotes
git[747381]: error: task 'prefetch' failed
systemd[437]: git-maintenance@hourly.service: Main process exited, code=exited, status=1/FAILURE
systemd[437]: git-maintenance@hourly.service: Failed with result 'exit-code'.
systemd[437]: Failed to start Optimize Git repositories data.
Address this (pun intended) by adding the `AF_VSOCK` address family to
the allow list.
This fixes https://github.com/microsoft/git/issues/604.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous commit argued that parse-options callbacks should try to
use opt->value rather than touching globals directly. In some cases,
however, that's awkward to do. Some callbacks touch multiple variables,
or may even just call into an abstracted function that does so.
In some of these cases we _could_ convert them by stuffing the multiple
variables into a single struct and passing the struct pointer through
opt->value. But that may make other parts of the code less readable,
as the struct relationship has to be mentioned everywhere.
Let's just accept that these cases are special and leave them as-is. But
we do need to mark their "opt" parameters to satisfy -Wunused-parameter.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each of the scheduler update callbacks gets the descriptor of the lock
file, but only the crontab updater needs it. We have to retain the
unused descriptors because these are dispatched from a table of function
pointers, but we should mark them to silence -Wunused-parameter.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Hourly and other schedule of "git maintenance" jobs are randomly
distributed now.
* ds/maintenance-schedule-fuzz:
maintenance: update schedule before config
maintenance: fix systemd schedule overlaps
maintenance: use random minute in systemd scheduler
maintenance: swap method locations
maintenance: use random minute in cron scheduler
maintenance: use random minute in Windows scheduler
maintenance: use random minute in launchctl scheduler
maintenance: add get_random_minute()
Windows updates.
* ds/maintenance-on-windows-fix:
git maintenance: avoid console window in scheduled tasks on Windows
win32: add a helper to run `git.exe` without a foreground window
When running 'git maintenance start', the current pattern is to
configure global config settings to enable maintenance on the current
repository and set 'maintenance.auto' to false and _then_ to set up the
schedule with the system scheduler.
This has a problematic error condition: if the scheduler fails to
initialize, the repository still will not use automatic maintenance due
to the 'maintenance.auto' setting.
Fix this gap by swapping the order of operations. If Git fails to
initialize maintenance, then the config changes should never happen.
Reported-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'git maintenance run' command prevents concurrent runs in the same
repository using a 'maintenance.lock' file. However, when using systemd
the hourly maintenance runs the same time as the daily and weekly runs.
(Similarly, daily maintenance runs at the same time as weekly
maintenance.) These competing commands result in some maintenance not
actually being run.
This overlap was something we could not fix until we made the recent
change to not use the builting 'hourly', 'daily', and 'weekly' schedules
in systemd. We can adjust the schedules such that:
1. Hourly runs avoid the 0th hour.
2. Daily runs avoid Monday.
This will keep maintenance runs from colliding when using systemd.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_random_minute() method was created to allow maintenance
schedules to be fixed to a random minute of the hour. This randomness is
only intended to spread out the load from a number of clients, but each
client should have an hour between each maintenance cycle.
Add this random minute to the systemd integration.
This integration is more complicated than similar changes for other
schedulers because of a neat trick that systemd allows: templating.
The previous implementation generated two template files with names
of the form 'git-maintenance@.(timer|service)'. The '.timer' or
'.service' indicates that this is a template that is picked up when we
later specify '...@<schedule>.timer' or '...@<schedule>.service'. The
'<schedule>' string is then used to insert into the template both the
'OnCalendar' schedule setting and the '--schedule' parameter of the
'git maintenance run' command.
In order to set these schedules to a given minute, we can no longer use
the 'hourly', 'daily', or 'weekly' strings for '<schedule>' and instead
need to abandon the template model for the .timer files. We can still
use templates for the .service files. For this reason, we split these
writes into two methods.
Modify the template with a custom schedule in the 'OnCalendar' setting.
This schedule has some interesting differences from cron-like patterns,
but is relatively easy to figure out from context. The one that might be
confusing is that '*-*-*' is a date-based pattern, but this must be
omitted when using 'Mon' to signal that we care about the day of the
week. Monday is used since that matches the day used for the 'weekly'
schedule used previously.
Now that the timer files are not templates, we might want to abandon the
'@' symbol in the file names. However, this would cause users with
existing schedules to get two competing schedules due to different
names. The work to remove the old schedule name is one thing that we can
avoid by keeping the '@' symbol in our unit names. Since we are locked
into this name, it makes sense that we keep the template model for the
.service files.
The rest of the change involves making sure we are writing these .timer
and .service files before initializing the schedule with 'systemctl' and
deleting the files when we are done. Some changes are also made to share
the random minute along with a single computation of the execution path
of the current Git executable.
In addition, older Git versions may have written a
'git-maintenance@.timer' template file. Be sure to remove this when
successfully enabling maintenance (or disabling maintenance).
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The systemd_timer_write_unit_templates() method writes a single template
that is then used to start the hourly, daily, and weekly schedules with
systemd.
However, in order to schedule systemd maintenance on a given minute,
these templates need to be replaced with specific schedules for each of
these jobs.
Before modifying the schedules, move the writing method above the
systemd_timer_enable_unit() method, so we can write a specific schedule
for each unit.
The diff is computed smaller by showing systemd_timer_enable_unit() and
systemd_timer_delete_units() move instead of
systemd_timer_write_unit_templates() and
systemd_timer_delete_unit_templates().
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_random_minute() method was created to allow maintenance
schedules to be fixed to a random minute of the hour. This randomness is
only intended to spread out the load from a number of clients, but each
client should have an hour between each maintenance cycle.
Add this random minute to the cron integration.
The cron schedule specification starts with a minute indicator, which
was previously inserted as the "0" string but now takes the given minute
as an integer parameter.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_random_minute() method was created to allow maintenance
schedules to be fixed to a random minute of the hour. This randomness is
only intended to spread out the load from a number of clients, but each
client should have an hour between each maintenance cycle.
Add this random minute to the Windows scheduler integration.
We need only to modify the minute value for the 'StartBoundary' tag
across the three schedules.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_random_minute() method was created to allow maintenance
schedules to be fixed to a random minute of the hour. This randomness is
only intended to spread out the load from a number of clients, but each
client should have an hour between each maintenance cycle.
Use get_random_minute() when constructing the schedules for launchctl.
The format already includes a 'Minute' key which is modified from 0 to
the random minute.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we initially created background maintenance -- with its hourly,
daily, and weekly schedules -- we considered the effects of all clients
launching fetches to the server every hour on the hour. The worry of
DDoSing server hosts was noted, but left as something we would consider
for a future update.
As background maintenance has gained more adoption over the past three
years, our worries about DDoSing the big Git hosts has been unfounded.
Those systems, especially those serving public repositories, are already
resilient to thundering herds of much smaller scale.
However, sometimes organizations spin up specific custom server
infrastructure either in addition to or on top of their Git host. Some
of these technologies are built for a different range of scale, and can
hit concurrency limits sooner. Organizations with such custom
infrastructures are more likely to recommend tools like `scalar` which
furthers their adoption of background maintenance.
To help solve for this, create get_random_minute() as a method to help
Git select a random minute when creating schedules in the future. The
integrations with this method do not yet exist, but will follow in
future changes.
To avoid multiple sources of randomness in the Git codebase, create a
new helper function, git_rand(), that returns a random uint32_t. This is
similar to how rand() returns a random nonnegative value, except it is
based on csprng_bytes() which is cryptographic and will return values
larger than RAND_MAX.
One thing that is important for testability is that we notice when we
are under a test scenario and return a predictable result. The schedules
themselves are not checked for this value, but at least one launchctl
test checks that we do not unnecessarily reboot the schedule if it has
not changed from a previous version.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We just introduced a helper to avoid showing a console window when the
scheduled task runs `git.exe`. Let's actually use it.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The vast majority of files including object-store.h did not need dir.h
nor khash.h. Split the header into two files, and let most just depend
upon object-store-ll.h, while letting the two callers that need it
depend on the full object-store.h.
After this patch:
$ git grep -h include..object-store | sort | uniq -c
2 #include "object-store.h"
129 #include "object-store-ll.h"
Diff best viewed with `--color-moved`.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This also made it clear that several .c files that depended upon path.h
were missing a #include for it; add the missing includes while at it.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt