When the 'maintenance.strategy' config option is set to 'incremental',
a default maintenance schedule is enabled. Add the 'pack-refs' task to
that strategy at the weekly cadence.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To provide an on-ramp for users to use background maintenance without
several 'git config' commands, create a 'maintenance.strategy' config
option. Currently, the only important value is 'incremental' which
assigns the following schedule:
* gc: never
* prefetch: hourly
* commit-graph: hourly
* loose-objects: daily
* incremental-repack: daily
These tasks are chosen to minimize disruptions to foreground Git
commands and use few compute resources.
The 'maintenance.strategy' is intended as a baseline that can be
customzied further by manually assigning 'maintenance.<task>.enabled'
and 'maintenance.<task>.schedule' config options, which will override
any recommendation from 'maintenance.strategy'. This operates similarly
to config options like 'feature.experimental' which operate as "meta"
config options that change default config values.
This presents a way forward for updating the 'incremental' strategy in
the future or adding new strategies. For example, a potential strategy
could be to include a 'full' strategy that runs the 'gc' task weekly
and no other tasks by default.
Helped-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Maintenance currently triggers when certain data-size thresholds are
met, such as number of pack-files or loose objects. Users may want to
run certain maintenance tasks based on frequency instead. For example,
a user may want to perform a 'prefetch' task every hour, or 'gc' task
every day. To help these users, update the 'git maintenance run' command
to include a '--schedule=<frequency>' option. The allowed frequencies
are 'hourly', 'daily', and 'weekly'. These values are also allowed in a
new config value 'maintenance.<task>.schedule'.
The 'git maintenance run --schedule=<frequency>' checks the '*.schedule'
config value for each enabled task to see if the configured frequency is
at least as frequent as the frequency from the '--schedule' argument. We
use the following order, for full clarity:
'hourly' > 'daily' > 'weekly'
Use new 'enum schedule_priority' to track these values numerically.
The following cron table would run the scheduled tasks with the correct
frequencies:
0 1-23 * * * git -C <repo> maintenance run --schedule=hourly
0 0 * * 1-6 git -C <repo> maintenance run --schedule=daily
0 0 * * 0 git -C <repo> maintenance run --schedule=weekly
This cron schedule will run --schedule=hourly every hour except at
midnight. This avoids a concurrent run with the --schedule=daily that
runs at midnight every day except the first day of the week. This avoids
a concurrent run with the --schedule=weekly that runs at midnight on
the first day of the week. Since --schedule=daily also runs the
'hourly' tasks and --schedule=weekly runs the 'hourly' and 'daily'
tasks, we will still see all tasks run with the proper frequencies.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some commands run 'git maintenance run --auto --[no-]quiet' after doing
their normal work, as a way to keep repositories clean as they are used.
Currently, users who do not want this maintenance to occur would set the
'gc.auto' config option to 0 to avoid the 'gc' task from running.
However, this does not stop the extra process invocation. On Windows,
this extra process invocation can be more expensive than necessary.
Allow users to drop this extra process by setting 'maintenance.auto' to
'false'.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The incremental-repack task updates the multi-pack-index by deleting pack-
files that have been replaced with new packs, then repacking a batch of
small pack-files into a larger pack-file. This incremental repack is faster
than rewriting all object data, but is slower than some other
maintenance activities.
The 'maintenance.incremental-repack.auto' config option specifies how many
pack-files should exist outside of the multi-pack-index before running
the step. These pack-files could be created by 'git fetch' commands or
by the loose-objects task. The default value is 10.
Setting the option to zero disables the task with the '--auto' option,
and a negative value makes the task run every time.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The loose-objects task deletes loose objects that already exist in a
pack-file, then place the remaining loose objects into a new pack-file.
If this step runs all the time, then we risk creating pack-files with
very few objects with every 'git commit' process. To prevent
overwhelming the packs directory with small pack-files, place a minimum
number of objects to justify the task.
The 'maintenance.loose-objects.auto' config option specifies a minimum
number of loose objects to justify the task to run under the '--auto'
option. This defaults to 100 loose objects. Setting the value to zero
will prevent the step from running under '--auto' while a negative value
will force it to run every time.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of writing a new commit-graph in every 'git maintenance run
--auto' process (when maintenance.commit-graph.enalbed is configured to
be true), only write when there are "enough" commits not in a
commit-graph file.
This count is controlled by the maintenance.commit-graph.auto config
option.
To compute the count, use a depth-first search starting at each ref, and
leaving markers using the SEEN flag. If this count reaches the limit,
then terminate early and start the task. Otherwise, this operation will
peel every ref and parse the commit it points to. If these are all in
the commit-graph, then this is typically a very fast operation. Users
with many refs might feel a slow-down, and hence could consider updating
their limit to be very small. A negative value will force the step to
run every time.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, a normal run of "git maintenance run" will only run the 'gc'
task, as it is the only one enabled. This is mostly for backwards-
compatible reasons since "git maintenance run --auto" commands replaced
previous "git gc --auto" commands after some Git processes. Users could
manually run specific maintenance tasks by calling "git maintenance run
--task=<task>" directly.
Allow users to customize which steps are run automatically using config.
The 'maintenance.<task>.enabled' option then can turn on these other
tasks (or turn off the 'gc' task).
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
