git/t/t7900-maintenance.sh

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maintenance: create basic maintenance runner The 'gc' builtin is our current entrypoint for automatically maintaining a repository. This one tool does many operations, such as repacking the repository, packing refs, and rewriting the commit-graph file. The name implies it performs "garbage collection" which means several different things, and some users may not want to use this operation that rewrites the entire object database. Create a new 'maintenance' builtin that will become a more general- purpose command. To start, it will only support the 'run' subcommand, but will later expand to add subcommands for scheduling maintenance in the background. For now, the 'maintenance' builtin is a thin shim over the 'gc' builtin. In fact, the only option is the '--auto' toggle, which is handed directly to the 'gc' builtin. The current change is isolated to this simple operation to prevent more interesting logic from being lost in all of the boilerplate of adding a new builtin. Use existing builtin/gc.c file because we want to share code between the two builtins. It is possible that we will have 'maintenance' replace the 'gc' builtin entirely at some point, leaving 'git gc' as an alias for some specific arguments to 'git maintenance run'. Create a new test_subcommand helper that allows us to test if a certain subcommand was run. It requires storing the GIT_TRACE2_EVENT logs in a file. A negation mode is available that will be used in later tests. Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:11:42 +03:00
#!/bin/sh
test_description='git maintenance builtin'
. ./test-lib.sh
GIT_TEST_COMMIT_GRAPH=0
maintenance: add incremental-repack task The previous change cleaned up loose objects using the 'loose-objects' that can be run safely in the background. Add a similar job that performs similar cleanups for pack-files. One issue with running 'git repack' is that it is designed to repack all pack-files into a single pack-file. While this is the most space-efficient way to store object data, it is not time or memory efficient. This becomes extremely important if the repo is so large that a user struggles to store two copies of the pack on their disk. Instead, perform an "incremental" repack by collecting a few small pack-files into a new pack-file. The multi-pack-index facilitates this process ever since 'git multi-pack-index expire' was added in 19575c7 (multi-pack-index: implement 'expire' subcommand, 2019-06-10) and 'git multi-pack-index repack' was added in ce1e4a1 (midx: implement midx_repack(), 2019-06-10). The 'incremental-repack' task runs the following steps: 1. 'git multi-pack-index write' creates a multi-pack-index file if one did not exist, and otherwise will update the multi-pack-index with any new pack-files that appeared since the last write. This is particularly relevant with the background fetch job. When the multi-pack-index sees two copies of the same object, it stores the offset data into the newer pack-file. This means that some old pack-files could become "unreferenced" which I will use to mean "a pack-file that is in the pack-file list of the multi-pack-index but none of the objects in the multi-pack-index reference a location inside that pack-file." 2. 'git multi-pack-index expire' deletes any unreferenced pack-files and updaes the multi-pack-index to drop those pack-files from the list. This is safe to do as concurrent Git processes will see the multi-pack-index and not open those packs when looking for object contents. (Similar to the 'loose-objects' job, there are some Git commands that open pack-files regardless of the multi-pack-index, but they are rarely used. Further, a user that self-selects to use background operations would likely refrain from using those commands.) 3. 'git multi-pack-index repack --bacth-size=<size>' collects a set of pack-files that are listed in the multi-pack-index and creates a new pack-file containing the objects whose offsets are listed by the multi-pack-index to be in those objects. The set of pack- files is selected greedily by sorting the pack-files by modified time and adding a pack-file to the set if its "expected size" is smaller than the batch size until the total expected size of the selected pack-files is at least the batch size. The "expected size" is calculated by taking the size of the pack-file divided by the number of objects in the pack-file and multiplied by the number of objects from the multi-pack-index with offset in that pack-file. The expected size approximates how much data from that pack-file will contribute to the resulting pack-file size. The intention is that the resulting pack-file will be close in size to the provided batch size. The next run of the incremental-repack task will delete these repacked pack-files during the 'expire' step. In this version, the batch size is set to "0" which ignores the size restrictions when selecting the pack-files. It instead selects all pack-files and repacks all packed objects into a single pack-file. This will be updated in the next change, but it requires doing some calculations that are better isolated to a separate change. These steps are based on a similar background maintenance step in Scalar (and VFS for Git) [1]. This was incredibly effective for users of the Windows OS repository. After using the same VFS for Git repository for over a year, some users had _thousands_ of pack-files that combined to up to 250 GB of data. We noticed a few users were running into the open file descriptor limits (due in part to a bug in the multi-pack-index fixed by af96fe3 (midx: add packs to packed_git linked list, 2019-04-29). These pack-files were mostly small since they contained the commits and trees that were pushed to the origin in a given hour. The GVFS protocol includes a "prefetch" step that asks for pre-computed pack- files containing commits and trees by timestamp. These pack-files were grouped into "daily" pack-files once a day for up to 30 days. If a user did not request prefetch packs for over 30 days, then they would get the entire history of commits and trees in a new, large pack-file. This led to a large number of pack-files that had poor delta compression. By running this pack-file maintenance step once per day, these repos with thousands of packs spanning 200+ GB dropped to dozens of pack- files spanning 30-50 GB. This was done all without removing objects from the system and using a constant batch size of two gigabytes. Once the work was done to reduce the pack-files to small sizes, the batch size of two gigabytes means that not every run triggers a repack operation, so the following run will not expire a pack-file. This has kept these repos in a "clean" state. [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/PackfileMaintenanceStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:36 +03:00
GIT_TEST_MULTI_PACK_INDEX=0
maintenance: create basic maintenance runner The 'gc' builtin is our current entrypoint for automatically maintaining a repository. This one tool does many operations, such as repacking the repository, packing refs, and rewriting the commit-graph file. The name implies it performs "garbage collection" which means several different things, and some users may not want to use this operation that rewrites the entire object database. Create a new 'maintenance' builtin that will become a more general- purpose command. To start, it will only support the 'run' subcommand, but will later expand to add subcommands for scheduling maintenance in the background. For now, the 'maintenance' builtin is a thin shim over the 'gc' builtin. In fact, the only option is the '--auto' toggle, which is handed directly to the 'gc' builtin. The current change is isolated to this simple operation to prevent more interesting logic from being lost in all of the boilerplate of adding a new builtin. Use existing builtin/gc.c file because we want to share code between the two builtins. It is possible that we will have 'maintenance' replace the 'gc' builtin entirely at some point, leaving 'git gc' as an alias for some specific arguments to 'git maintenance run'. Create a new test_subcommand helper that allows us to test if a certain subcommand was run. It requires storing the GIT_TRACE2_EVENT logs in a file. A negation mode is available that will be used in later tests. Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:11:42 +03:00
test_expect_success 'help text' '
test_expect_code 129 git maintenance -h 2>err &&
test_i18ngrep "usage: git maintenance <subcommand>" err &&
maintenance: create basic maintenance runner The 'gc' builtin is our current entrypoint for automatically maintaining a repository. This one tool does many operations, such as repacking the repository, packing refs, and rewriting the commit-graph file. The name implies it performs "garbage collection" which means several different things, and some users may not want to use this operation that rewrites the entire object database. Create a new 'maintenance' builtin that will become a more general- purpose command. To start, it will only support the 'run' subcommand, but will later expand to add subcommands for scheduling maintenance in the background. For now, the 'maintenance' builtin is a thin shim over the 'gc' builtin. In fact, the only option is the '--auto' toggle, which is handed directly to the 'gc' builtin. The current change is isolated to this simple operation to prevent more interesting logic from being lost in all of the boilerplate of adding a new builtin. Use existing builtin/gc.c file because we want to share code between the two builtins. It is possible that we will have 'maintenance' replace the 'gc' builtin entirely at some point, leaving 'git gc' as an alias for some specific arguments to 'git maintenance run'. Create a new test_subcommand helper that allows us to test if a certain subcommand was run. It requires storing the GIT_TRACE2_EVENT logs in a file. A negation mode is available that will be used in later tests. Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:11:42 +03:00
test_expect_code 128 git maintenance barf 2>err &&
test_i18ngrep "invalid subcommand: barf" err &&
test_expect_code 129 git maintenance 2>err &&
test_i18ngrep "usage: git maintenance" err
'
test_expect_success 'run [--auto|--quiet]' '
GIT_TRACE2_EVENT="$(pwd)/run-no-auto.txt" \
git maintenance run 2>/dev/null &&
GIT_TRACE2_EVENT="$(pwd)/run-auto.txt" \
git maintenance run --auto 2>/dev/null &&
GIT_TRACE2_EVENT="$(pwd)/run-no-quiet.txt" \
git maintenance run --no-quiet 2>/dev/null &&
test_subcommand git gc --quiet <run-no-auto.txt &&
test_subcommand ! git gc --auto --quiet <run-auto.txt &&
test_subcommand git gc --no-quiet <run-no-quiet.txt
maintenance: create basic maintenance runner The 'gc' builtin is our current entrypoint for automatically maintaining a repository. This one tool does many operations, such as repacking the repository, packing refs, and rewriting the commit-graph file. The name implies it performs "garbage collection" which means several different things, and some users may not want to use this operation that rewrites the entire object database. Create a new 'maintenance' builtin that will become a more general- purpose command. To start, it will only support the 'run' subcommand, but will later expand to add subcommands for scheduling maintenance in the background. For now, the 'maintenance' builtin is a thin shim over the 'gc' builtin. In fact, the only option is the '--auto' toggle, which is handed directly to the 'gc' builtin. The current change is isolated to this simple operation to prevent more interesting logic from being lost in all of the boilerplate of adding a new builtin. Use existing builtin/gc.c file because we want to share code between the two builtins. It is possible that we will have 'maintenance' replace the 'gc' builtin entirely at some point, leaving 'git gc' as an alias for some specific arguments to 'git maintenance run'. Create a new test_subcommand helper that allows us to test if a certain subcommand was run. It requires storing the GIT_TRACE2_EVENT logs in a file. A negation mode is available that will be used in later tests. Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:11:42 +03:00
'
test_expect_success 'maintenance.auto config option' '
GIT_TRACE2_EVENT="$(pwd)/default" git commit --quiet --allow-empty -m 1 &&
test_subcommand git maintenance run --auto --quiet <default &&
GIT_TRACE2_EVENT="$(pwd)/true" \
git -c maintenance.auto=true \
commit --quiet --allow-empty -m 2 &&
test_subcommand git maintenance run --auto --quiet <true &&
GIT_TRACE2_EVENT="$(pwd)/false" \
git -c maintenance.auto=false \
commit --quiet --allow-empty -m 3 &&
test_subcommand ! git maintenance run --auto --quiet <false
'
test_expect_success 'maintenance.<task>.enabled' '
git config maintenance.gc.enabled false &&
git config maintenance.commit-graph.enabled true &&
GIT_TRACE2_EVENT="$(pwd)/run-config.txt" git maintenance run 2>err &&
test_subcommand ! git gc --quiet <run-config.txt &&
test_subcommand git commit-graph write --split --reachable --no-progress <run-config.txt
'
test_expect_success 'run --task=<task>' '
GIT_TRACE2_EVENT="$(pwd)/run-commit-graph.txt" \
git maintenance run --task=commit-graph 2>/dev/null &&
GIT_TRACE2_EVENT="$(pwd)/run-gc.txt" \
git maintenance run --task=gc 2>/dev/null &&
GIT_TRACE2_EVENT="$(pwd)/run-commit-graph.txt" \
git maintenance run --task=commit-graph 2>/dev/null &&
GIT_TRACE2_EVENT="$(pwd)/run-both.txt" \
git maintenance run --task=commit-graph --task=gc 2>/dev/null &&
test_subcommand ! git gc --quiet <run-commit-graph.txt &&
test_subcommand git gc --quiet <run-gc.txt &&
test_subcommand git gc --quiet <run-both.txt &&
test_subcommand git commit-graph write --split --reachable --no-progress <run-commit-graph.txt &&
test_subcommand ! git commit-graph write --split --reachable --no-progress <run-gc.txt &&
test_subcommand git commit-graph write --split --reachable --no-progress <run-both.txt
'
test_expect_success 'core.commitGraph=false prevents write process' '
GIT_TRACE2_EVENT="$(pwd)/no-commit-graph.txt" \
git -c core.commitGraph=false maintenance run \
--task=commit-graph 2>/dev/null &&
test_subcommand ! git commit-graph write --split --reachable --no-progress \
<no-commit-graph.txt
'
maintenance: test commit-graph auto condition The auto condition for the commit-graph maintenance task walks refs looking for commits that are not in the commit-graph file. This was added in 4ddc79b2 (maintenance: add auto condition for commit-graph task, 2020-09-17) but was left untested. The initial goal of this change was to demonstrate the feature works properly by adding tests. However, there was an off-by-one error that caused the basic tests around maintenance.commit-graph.auto=1 to fail when it should work. The subtlety is that if a ref tip is not in the commit-graph, then we were not adding that to the total count. In the test, we see that we have only added one commit since our last commit-graph write, so the auto condition would say there is nothing to do. The fix is simple: add the check for the commit-graph position to see that the tip is not in the commit-graph file before starting our walk. Since this happens before adding to the DFS stack, we do not need to clear our (currently empty) commit list. This does add some extra complexity for the test, because we also want to verify that the walk along the parents actually does some work. This means we need to add at least two commits in a row without writing the commit-graph. However, we also need to make sure no additional refs are pointing to the middle of this list or else the for_each_ref() in should_write_commit_graph() might visit these commits as tips instead of doing a DFS walk. Hence, the last two commits are added with "git commit" instead of "test_commit". Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-08 03:50:39 +03:00
test_expect_success 'commit-graph auto condition' '
COMMAND="maintenance run --task=commit-graph --auto --quiet" &&
GIT_TRACE2_EVENT="$(pwd)/cg-no.txt" \
git -c maintenance.commit-graph.auto=1 $COMMAND &&
GIT_TRACE2_EVENT="$(pwd)/cg-negative-means-yes.txt" \
git -c maintenance.commit-graph.auto="-1" $COMMAND &&
test_commit first &&
GIT_TRACE2_EVENT="$(pwd)/cg-zero-means-no.txt" \
git -c maintenance.commit-graph.auto=0 $COMMAND &&
GIT_TRACE2_EVENT="$(pwd)/cg-one-satisfied.txt" \
git -c maintenance.commit-graph.auto=1 $COMMAND &&
git commit --allow-empty -m "second" &&
git commit --allow-empty -m "third" &&
GIT_TRACE2_EVENT="$(pwd)/cg-two-satisfied.txt" \
git -c maintenance.commit-graph.auto=2 $COMMAND &&
COMMIT_GRAPH_WRITE="git commit-graph write --split --reachable --no-progress" &&
test_subcommand ! $COMMIT_GRAPH_WRITE <cg-no.txt &&
test_subcommand $COMMIT_GRAPH_WRITE <cg-negative-means-yes.txt &&
test_subcommand ! $COMMIT_GRAPH_WRITE <cg-zero-means-no.txt &&
test_subcommand $COMMIT_GRAPH_WRITE <cg-one-satisfied.txt &&
test_subcommand $COMMIT_GRAPH_WRITE <cg-two-satisfied.txt
'
test_expect_success 'run --task=bogus' '
test_must_fail git maintenance run --task=bogus 2>err &&
test_i18ngrep "is not a valid task" err
'
test_expect_success 'run --task duplicate' '
test_must_fail git maintenance run --task=gc --task=gc 2>err &&
test_i18ngrep "cannot be selected multiple times" err
'
maintenance: add prefetch task When working with very large repositories, an incremental 'git fetch' command can download a large amount of data. If there are many other users pushing to a common repo, then this data can rival the initial pack-file size of a 'git clone' of a medium-size repo. Users may want to keep the data on their local repos as close as possible to the data on the remote repos by fetching periodically in the background. This can break up a large daily fetch into several smaller hourly fetches. The task is called "prefetch" because it is work done in advance of a foreground fetch to make that 'git fetch' command much faster. However, if we simply ran 'git fetch <remote>' in the background, then the user running a foreground 'git fetch <remote>' would lose some important feedback when a new branch appears or an existing branch updates. This is especially true if a remote branch is force-updated and this isn't noticed by the user because it occurred in the background. Further, the functionality of 'git push --force-with-lease' becomes suspect. When running 'git fetch <remote> <options>' in the background, use the following options for careful updating: 1. --no-tags prevents getting a new tag when a user wants to see the new tags appear in their foreground fetches. 2. --refmap= removes the configured refspec which usually updates refs/remotes/<remote>/* with the refs advertised by the remote. While this looks confusing, this was documented and tested by b40a50264ac (fetch: document and test --refmap="", 2020-01-21), including this sentence in the documentation: Providing an empty `<refspec>` to the `--refmap` option causes Git to ignore the configured refspecs and rely entirely on the refspecs supplied as command-line arguments. 3. By adding a new refspec "+refs/heads/*:refs/prefetch/<remote>/*" we can ensure that we actually load the new values somewhere in our refspace while not updating refs/heads or refs/remotes. By storing these refs here, the commit-graph job will update the commit-graph with the commits from these hidden refs. 4. --prune will delete the refs/prefetch/<remote> refs that no longer appear on the remote. 5. --no-write-fetch-head prevents updating FETCH_HEAD. We've been using this step as a critical background job in Scalar [1] (and VFS for Git). This solved a pain point that was showing up in user reports: fetching was a pain! Users do not like waiting to download the data that was created while they were away from their machines. After implementing background fetch, the foreground fetch commands sped up significantly because they mostly just update refs and download a small amount of new data. The effect is especially dramatic when paried with --no-show-forced-udpates (through fetch.showForcedUpdates=false). [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/FetchStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:31 +03:00
test_expect_success 'run --task=prefetch with no remotes' '
git maintenance run --task=prefetch 2>err &&
test_must_be_empty err
'
test_expect_success 'prefetch multiple remotes' '
git clone . clone1 &&
git clone . clone2 &&
git remote add remote1 "file://$(pwd)/clone1" &&
git remote add remote2 "file://$(pwd)/clone2" &&
git -C clone1 switch -c one &&
git -C clone2 switch -c two &&
test_commit -C clone1 one &&
test_commit -C clone2 two &&
GIT_TRACE2_EVENT="$(pwd)/run-prefetch.txt" git maintenance run --task=prefetch 2>/dev/null &&
fetchargs="--prune --no-tags --no-write-fetch-head --recurse-submodules=no --refmap= --quiet" &&
test_subcommand git fetch remote1 $fetchargs +refs/heads/\\*:refs/prefetch/remote1/\\* <run-prefetch.txt &&
test_subcommand git fetch remote2 $fetchargs +refs/heads/\\*:refs/prefetch/remote2/\\* <run-prefetch.txt &&
test_path_is_missing .git/refs/remotes &&
git log prefetch/remote1/one &&
git log prefetch/remote2/two &&
git fetch --all &&
test_cmp_rev refs/remotes/remote1/one refs/prefetch/remote1/one &&
test_cmp_rev refs/remotes/remote2/two refs/prefetch/remote2/two
'
maintenance: add loose-objects task One goal of background maintenance jobs is to allow a user to disable auto-gc (gc.auto=0) but keep their repository in a clean state. Without any cleanup, loose objects will clutter the object database and slow operations. In addition, the loose objects will take up extra space because they are not stored with deltas against similar objects. Create a 'loose-objects' task for the 'git maintenance run' command. This helps clean up loose objects without disrupting concurrent Git commands using the following sequence of events: 1. Run 'git prune-packed' to delete any loose objects that exist in a pack-file. Concurrent commands will prefer the packed version of the object to the loose version. (Of course, there are exceptions for commands that specifically care about the location of an object. These are rare for a user to run on purpose, and we hope a user that has selected background maintenance will not be trying to do foreground maintenance.) 2. Run 'git pack-objects' on a batch of loose objects. These objects are grouped by scanning the loose object directories in lexicographic order until listing all loose objects -or- reaching 50,000 objects. This is more than enough if the loose objects are created only by a user doing normal development. We noticed users with _millions_ of loose objects because VFS for Git downloads blobs on-demand when a file read operation requires populating a virtual file. This step is based on a similar step in Scalar [1] and VFS for Git. [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/LooseObjectsStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:32 +03:00
test_expect_success 'loose-objects task' '
# Repack everything so we know the state of the object dir
git repack -adk &&
# Hack to stop maintenance from running during "git commit"
echo in use >.git/objects/maintenance.lock &&
# Assuming that "git commit" creates at least one loose object
test_commit create-loose-object &&
rm .git/objects/maintenance.lock &&
ls .git/objects >obj-dir-before &&
test_file_not_empty obj-dir-before &&
ls .git/objects/pack/*.pack >packs-before &&
test_line_count = 1 packs-before &&
# The first run creates a pack-file
# but does not delete loose objects.
git maintenance run --task=loose-objects &&
ls .git/objects >obj-dir-between &&
test_cmp obj-dir-before obj-dir-between &&
ls .git/objects/pack/*.pack >packs-between &&
test_line_count = 2 packs-between &&
ls .git/objects/pack/loose-*.pack >loose-packs &&
test_line_count = 1 loose-packs &&
# The second run deletes loose objects
# but does not create a pack-file.
git maintenance run --task=loose-objects &&
ls .git/objects >obj-dir-after &&
cat >expect <<-\EOF &&
info
pack
EOF
test_cmp expect obj-dir-after &&
ls .git/objects/pack/*.pack >packs-after &&
test_cmp packs-between packs-after
'
test_expect_success 'maintenance.loose-objects.auto' '
git repack -adk &&
GIT_TRACE2_EVENT="$(pwd)/trace-lo1.txt" \
git -c maintenance.loose-objects.auto=1 maintenance \
run --auto --task=loose-objects 2>/dev/null &&
test_subcommand ! git prune-packed --quiet <trace-lo1.txt &&
printf data-A | git hash-object -t blob --stdin -w &&
GIT_TRACE2_EVENT="$(pwd)/trace-loA" \
git -c maintenance.loose-objects.auto=2 \
maintenance run --auto --task=loose-objects 2>/dev/null &&
test_subcommand ! git prune-packed --quiet <trace-loA &&
printf data-B | git hash-object -t blob --stdin -w &&
GIT_TRACE2_EVENT="$(pwd)/trace-loB" \
git -c maintenance.loose-objects.auto=2 \
maintenance run --auto --task=loose-objects 2>/dev/null &&
test_subcommand git prune-packed --quiet <trace-loB &&
GIT_TRACE2_EVENT="$(pwd)/trace-loC" \
git -c maintenance.loose-objects.auto=2 \
maintenance run --auto --task=loose-objects 2>/dev/null &&
test_subcommand git prune-packed --quiet <trace-loC
'
maintenance: add incremental-repack task The previous change cleaned up loose objects using the 'loose-objects' that can be run safely in the background. Add a similar job that performs similar cleanups for pack-files. One issue with running 'git repack' is that it is designed to repack all pack-files into a single pack-file. While this is the most space-efficient way to store object data, it is not time or memory efficient. This becomes extremely important if the repo is so large that a user struggles to store two copies of the pack on their disk. Instead, perform an "incremental" repack by collecting a few small pack-files into a new pack-file. The multi-pack-index facilitates this process ever since 'git multi-pack-index expire' was added in 19575c7 (multi-pack-index: implement 'expire' subcommand, 2019-06-10) and 'git multi-pack-index repack' was added in ce1e4a1 (midx: implement midx_repack(), 2019-06-10). The 'incremental-repack' task runs the following steps: 1. 'git multi-pack-index write' creates a multi-pack-index file if one did not exist, and otherwise will update the multi-pack-index with any new pack-files that appeared since the last write. This is particularly relevant with the background fetch job. When the multi-pack-index sees two copies of the same object, it stores the offset data into the newer pack-file. This means that some old pack-files could become "unreferenced" which I will use to mean "a pack-file that is in the pack-file list of the multi-pack-index but none of the objects in the multi-pack-index reference a location inside that pack-file." 2. 'git multi-pack-index expire' deletes any unreferenced pack-files and updaes the multi-pack-index to drop those pack-files from the list. This is safe to do as concurrent Git processes will see the multi-pack-index and not open those packs when looking for object contents. (Similar to the 'loose-objects' job, there are some Git commands that open pack-files regardless of the multi-pack-index, but they are rarely used. Further, a user that self-selects to use background operations would likely refrain from using those commands.) 3. 'git multi-pack-index repack --bacth-size=<size>' collects a set of pack-files that are listed in the multi-pack-index and creates a new pack-file containing the objects whose offsets are listed by the multi-pack-index to be in those objects. The set of pack- files is selected greedily by sorting the pack-files by modified time and adding a pack-file to the set if its "expected size" is smaller than the batch size until the total expected size of the selected pack-files is at least the batch size. The "expected size" is calculated by taking the size of the pack-file divided by the number of objects in the pack-file and multiplied by the number of objects from the multi-pack-index with offset in that pack-file. The expected size approximates how much data from that pack-file will contribute to the resulting pack-file size. The intention is that the resulting pack-file will be close in size to the provided batch size. The next run of the incremental-repack task will delete these repacked pack-files during the 'expire' step. In this version, the batch size is set to "0" which ignores the size restrictions when selecting the pack-files. It instead selects all pack-files and repacks all packed objects into a single pack-file. This will be updated in the next change, but it requires doing some calculations that are better isolated to a separate change. These steps are based on a similar background maintenance step in Scalar (and VFS for Git) [1]. This was incredibly effective for users of the Windows OS repository. After using the same VFS for Git repository for over a year, some users had _thousands_ of pack-files that combined to up to 250 GB of data. We noticed a few users were running into the open file descriptor limits (due in part to a bug in the multi-pack-index fixed by af96fe3 (midx: add packs to packed_git linked list, 2019-04-29). These pack-files were mostly small since they contained the commits and trees that were pushed to the origin in a given hour. The GVFS protocol includes a "prefetch" step that asks for pre-computed pack- files containing commits and trees by timestamp. These pack-files were grouped into "daily" pack-files once a day for up to 30 days. If a user did not request prefetch packs for over 30 days, then they would get the entire history of commits and trees in a new, large pack-file. This led to a large number of pack-files that had poor delta compression. By running this pack-file maintenance step once per day, these repos with thousands of packs spanning 200+ GB dropped to dozens of pack- files spanning 30-50 GB. This was done all without removing objects from the system and using a constant batch size of two gigabytes. Once the work was done to reduce the pack-files to small sizes, the batch size of two gigabytes means that not every run triggers a repack operation, so the following run will not expire a pack-file. This has kept these repos in a "clean" state. [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/PackfileMaintenanceStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:36 +03:00
test_expect_success 'incremental-repack task' '
packDir=.git/objects/pack &&
for i in $(test_seq 1 5)
do
test_commit $i || return 1
done &&
# Create three disjoint pack-files with size BIG, small, small.
echo HEAD~2 | git pack-objects --revs $packDir/test-1 &&
test_tick &&
git pack-objects --revs $packDir/test-2 <<-\EOF &&
HEAD~1
^HEAD~2
EOF
test_tick &&
git pack-objects --revs $packDir/test-3 <<-\EOF &&
HEAD
^HEAD~1
EOF
rm -f $packDir/pack-* &&
rm -f $packDir/loose-* &&
ls $packDir/*.pack >packs-before &&
test_line_count = 3 packs-before &&
# the job repacks the two into a new pack, but does not
# delete the old ones.
git maintenance run --task=incremental-repack &&
ls $packDir/*.pack >packs-between &&
test_line_count = 4 packs-between &&
# the job deletes the two old packs, and does not write
maintenance: auto-size incremental-repack batch When repacking during the 'incremental-repack' task, we use the --batch-size option in 'git multi-pack-index repack'. The initial setting used --batch-size=0 to repack everything into a single pack-file. This is not sustainable for a large repository. The amount of work required is also likely to use too many system resources for a background job. Update the 'incremental-repack' task by dynamically computing a --batch-size option based on the current pack-file structure. The dynamic default size is computed with this idea in mind for a client repository that was cloned from a very large remote: there is likely one "big" pack-file that was created at clone time. Thus, do not try repacking it as it is likely packed efficiently by the server. Instead, we select the second-largest pack-file, and create a batch size that is one larger than that pack-file. If there are three or more pack-files, then this guarantees that at least two will be combined into a new pack-file. Of course, this means that the second-largest pack-file size is likely to grow over time and may eventually surpass the initially-cloned pack-file. Recall that the pack-file batch is selected in a greedy manner: the packs are considered from oldest to newest and are selected if they have size smaller than the batch size until the total selected size is larger than the batch size. Thus, that oldest "clone" pack will be first to repack after the new data creates a pack larger than that. We also want to place some limits on how large these pack-files become, in order to bound the amount of time spent repacking. A maximum batch-size of two gigabytes means that large repositories will never be packed into a single pack-file using this job, but also that repack is rather expensive. This is a trade-off that is valuable to have if the maintenance is being run automatically or in the background. Users who truly want to optimize for space and performance (and are willing to pay the upfront cost of a full repack) can use the 'gc' task to do so. Create a test for this two gigabyte limit by creating an EXPENSIVE test that generates two pack-files of roughly 2.5 gigabytes in size, then performs an incremental repack. Check that the --batch-size argument in the subcommand uses the hard-coded maximum. Helped-by: Chris Torek <chris.torek@gmail.com> Reported-by: Son Luong Ngoc <sluongng@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:37 +03:00
# a new one because the batch size is not high enough to
# pack the largest pack-file.
maintenance: add incremental-repack task The previous change cleaned up loose objects using the 'loose-objects' that can be run safely in the background. Add a similar job that performs similar cleanups for pack-files. One issue with running 'git repack' is that it is designed to repack all pack-files into a single pack-file. While this is the most space-efficient way to store object data, it is not time or memory efficient. This becomes extremely important if the repo is so large that a user struggles to store two copies of the pack on their disk. Instead, perform an "incremental" repack by collecting a few small pack-files into a new pack-file. The multi-pack-index facilitates this process ever since 'git multi-pack-index expire' was added in 19575c7 (multi-pack-index: implement 'expire' subcommand, 2019-06-10) and 'git multi-pack-index repack' was added in ce1e4a1 (midx: implement midx_repack(), 2019-06-10). The 'incremental-repack' task runs the following steps: 1. 'git multi-pack-index write' creates a multi-pack-index file if one did not exist, and otherwise will update the multi-pack-index with any new pack-files that appeared since the last write. This is particularly relevant with the background fetch job. When the multi-pack-index sees two copies of the same object, it stores the offset data into the newer pack-file. This means that some old pack-files could become "unreferenced" which I will use to mean "a pack-file that is in the pack-file list of the multi-pack-index but none of the objects in the multi-pack-index reference a location inside that pack-file." 2. 'git multi-pack-index expire' deletes any unreferenced pack-files and updaes the multi-pack-index to drop those pack-files from the list. This is safe to do as concurrent Git processes will see the multi-pack-index and not open those packs when looking for object contents. (Similar to the 'loose-objects' job, there are some Git commands that open pack-files regardless of the multi-pack-index, but they are rarely used. Further, a user that self-selects to use background operations would likely refrain from using those commands.) 3. 'git multi-pack-index repack --bacth-size=<size>' collects a set of pack-files that are listed in the multi-pack-index and creates a new pack-file containing the objects whose offsets are listed by the multi-pack-index to be in those objects. The set of pack- files is selected greedily by sorting the pack-files by modified time and adding a pack-file to the set if its "expected size" is smaller than the batch size until the total expected size of the selected pack-files is at least the batch size. The "expected size" is calculated by taking the size of the pack-file divided by the number of objects in the pack-file and multiplied by the number of objects from the multi-pack-index with offset in that pack-file. The expected size approximates how much data from that pack-file will contribute to the resulting pack-file size. The intention is that the resulting pack-file will be close in size to the provided batch size. The next run of the incremental-repack task will delete these repacked pack-files during the 'expire' step. In this version, the batch size is set to "0" which ignores the size restrictions when selecting the pack-files. It instead selects all pack-files and repacks all packed objects into a single pack-file. This will be updated in the next change, but it requires doing some calculations that are better isolated to a separate change. These steps are based on a similar background maintenance step in Scalar (and VFS for Git) [1]. This was incredibly effective for users of the Windows OS repository. After using the same VFS for Git repository for over a year, some users had _thousands_ of pack-files that combined to up to 250 GB of data. We noticed a few users were running into the open file descriptor limits (due in part to a bug in the multi-pack-index fixed by af96fe3 (midx: add packs to packed_git linked list, 2019-04-29). These pack-files were mostly small since they contained the commits and trees that were pushed to the origin in a given hour. The GVFS protocol includes a "prefetch" step that asks for pre-computed pack- files containing commits and trees by timestamp. These pack-files were grouped into "daily" pack-files once a day for up to 30 days. If a user did not request prefetch packs for over 30 days, then they would get the entire history of commits and trees in a new, large pack-file. This led to a large number of pack-files that had poor delta compression. By running this pack-file maintenance step once per day, these repos with thousands of packs spanning 200+ GB dropped to dozens of pack- files spanning 30-50 GB. This was done all without removing objects from the system and using a constant batch size of two gigabytes. Once the work was done to reduce the pack-files to small sizes, the batch size of two gigabytes means that not every run triggers a repack operation, so the following run will not expire a pack-file. This has kept these repos in a "clean" state. [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/PackfileMaintenanceStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:36 +03:00
git maintenance run --task=incremental-repack &&
ls .git/objects/pack/*.pack >packs-after &&
maintenance: auto-size incremental-repack batch When repacking during the 'incremental-repack' task, we use the --batch-size option in 'git multi-pack-index repack'. The initial setting used --batch-size=0 to repack everything into a single pack-file. This is not sustainable for a large repository. The amount of work required is also likely to use too many system resources for a background job. Update the 'incremental-repack' task by dynamically computing a --batch-size option based on the current pack-file structure. The dynamic default size is computed with this idea in mind for a client repository that was cloned from a very large remote: there is likely one "big" pack-file that was created at clone time. Thus, do not try repacking it as it is likely packed efficiently by the server. Instead, we select the second-largest pack-file, and create a batch size that is one larger than that pack-file. If there are three or more pack-files, then this guarantees that at least two will be combined into a new pack-file. Of course, this means that the second-largest pack-file size is likely to grow over time and may eventually surpass the initially-cloned pack-file. Recall that the pack-file batch is selected in a greedy manner: the packs are considered from oldest to newest and are selected if they have size smaller than the batch size until the total selected size is larger than the batch size. Thus, that oldest "clone" pack will be first to repack after the new data creates a pack larger than that. We also want to place some limits on how large these pack-files become, in order to bound the amount of time spent repacking. A maximum batch-size of two gigabytes means that large repositories will never be packed into a single pack-file using this job, but also that repack is rather expensive. This is a trade-off that is valuable to have if the maintenance is being run automatically or in the background. Users who truly want to optimize for space and performance (and are willing to pay the upfront cost of a full repack) can use the 'gc' task to do so. Create a test for this two gigabyte limit by creating an EXPENSIVE test that generates two pack-files of roughly 2.5 gigabytes in size, then performs an incremental repack. Check that the --batch-size argument in the subcommand uses the hard-coded maximum. Helped-by: Chris Torek <chris.torek@gmail.com> Reported-by: Son Luong Ngoc <sluongng@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:37 +03:00
test_line_count = 2 packs-after
'
test_expect_success EXPENSIVE 'incremental-repack 2g limit' '
for i in $(test_seq 1 5)
do
test-tool genrandom foo$i $((512 * 1024 * 1024 + 1)) >>big ||
return 1
done &&
git add big &&
git commit -m "Add big file (1)" &&
# ensure any possible loose objects are in a pack-file
git maintenance run --task=loose-objects &&
rm big &&
for i in $(test_seq 6 10)
do
test-tool genrandom foo$i $((512 * 1024 * 1024 + 1)) >>big ||
return 1
done &&
git add big &&
git commit -m "Add big file (2)" &&
# ensure any possible loose objects are in a pack-file
git maintenance run --task=loose-objects &&
# Now run the incremental-repack task and check the batch-size
GIT_TRACE2_EVENT="$(pwd)/run-2g.txt" git maintenance run \
--task=incremental-repack 2>/dev/null &&
test_subcommand git multi-pack-index repack \
--no-progress --batch-size=2147483647 <run-2g.txt
maintenance: add incremental-repack task The previous change cleaned up loose objects using the 'loose-objects' that can be run safely in the background. Add a similar job that performs similar cleanups for pack-files. One issue with running 'git repack' is that it is designed to repack all pack-files into a single pack-file. While this is the most space-efficient way to store object data, it is not time or memory efficient. This becomes extremely important if the repo is so large that a user struggles to store two copies of the pack on their disk. Instead, perform an "incremental" repack by collecting a few small pack-files into a new pack-file. The multi-pack-index facilitates this process ever since 'git multi-pack-index expire' was added in 19575c7 (multi-pack-index: implement 'expire' subcommand, 2019-06-10) and 'git multi-pack-index repack' was added in ce1e4a1 (midx: implement midx_repack(), 2019-06-10). The 'incremental-repack' task runs the following steps: 1. 'git multi-pack-index write' creates a multi-pack-index file if one did not exist, and otherwise will update the multi-pack-index with any new pack-files that appeared since the last write. This is particularly relevant with the background fetch job. When the multi-pack-index sees two copies of the same object, it stores the offset data into the newer pack-file. This means that some old pack-files could become "unreferenced" which I will use to mean "a pack-file that is in the pack-file list of the multi-pack-index but none of the objects in the multi-pack-index reference a location inside that pack-file." 2. 'git multi-pack-index expire' deletes any unreferenced pack-files and updaes the multi-pack-index to drop those pack-files from the list. This is safe to do as concurrent Git processes will see the multi-pack-index and not open those packs when looking for object contents. (Similar to the 'loose-objects' job, there are some Git commands that open pack-files regardless of the multi-pack-index, but they are rarely used. Further, a user that self-selects to use background operations would likely refrain from using those commands.) 3. 'git multi-pack-index repack --bacth-size=<size>' collects a set of pack-files that are listed in the multi-pack-index and creates a new pack-file containing the objects whose offsets are listed by the multi-pack-index to be in those objects. The set of pack- files is selected greedily by sorting the pack-files by modified time and adding a pack-file to the set if its "expected size" is smaller than the batch size until the total expected size of the selected pack-files is at least the batch size. The "expected size" is calculated by taking the size of the pack-file divided by the number of objects in the pack-file and multiplied by the number of objects from the multi-pack-index with offset in that pack-file. The expected size approximates how much data from that pack-file will contribute to the resulting pack-file size. The intention is that the resulting pack-file will be close in size to the provided batch size. The next run of the incremental-repack task will delete these repacked pack-files during the 'expire' step. In this version, the batch size is set to "0" which ignores the size restrictions when selecting the pack-files. It instead selects all pack-files and repacks all packed objects into a single pack-file. This will be updated in the next change, but it requires doing some calculations that are better isolated to a separate change. These steps are based on a similar background maintenance step in Scalar (and VFS for Git) [1]. This was incredibly effective for users of the Windows OS repository. After using the same VFS for Git repository for over a year, some users had _thousands_ of pack-files that combined to up to 250 GB of data. We noticed a few users were running into the open file descriptor limits (due in part to a bug in the multi-pack-index fixed by af96fe3 (midx: add packs to packed_git linked list, 2019-04-29). These pack-files were mostly small since they contained the commits and trees that were pushed to the origin in a given hour. The GVFS protocol includes a "prefetch" step that asks for pre-computed pack- files containing commits and trees by timestamp. These pack-files were grouped into "daily" pack-files once a day for up to 30 days. If a user did not request prefetch packs for over 30 days, then they would get the entire history of commits and trees in a new, large pack-file. This led to a large number of pack-files that had poor delta compression. By running this pack-file maintenance step once per day, these repos with thousands of packs spanning 200+ GB dropped to dozens of pack- files spanning 30-50 GB. This was done all without removing objects from the system and using a constant batch size of two gigabytes. Once the work was done to reduce the pack-files to small sizes, the batch size of two gigabytes means that not every run triggers a repack operation, so the following run will not expire a pack-file. This has kept these repos in a "clean" state. [1] https://github.com/microsoft/scalar/blob/master/Scalar.Common/Maintenance/PackfileMaintenanceStep.cs Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-25 15:33:36 +03:00
'
test_expect_success 'maintenance.incremental-repack.auto' '
git repack -adk &&
git config core.multiPackIndex true &&
git multi-pack-index write &&
GIT_TRACE2_EVENT="$(pwd)/midx-init.txt" git \
-c maintenance.incremental-repack.auto=1 \
maintenance run --auto --task=incremental-repack 2>/dev/null &&
test_subcommand ! git multi-pack-index write --no-progress <midx-init.txt &&
test_commit A &&
git pack-objects --revs .git/objects/pack/pack <<-\EOF &&
HEAD
^HEAD~1
EOF
GIT_TRACE2_EVENT=$(pwd)/trace-A git \
-c maintenance.incremental-repack.auto=2 \
maintenance run --auto --task=incremental-repack 2>/dev/null &&
test_subcommand ! git multi-pack-index write --no-progress <trace-A &&
test_commit B &&
git pack-objects --revs .git/objects/pack/pack <<-\EOF &&
HEAD
^HEAD~1
EOF
GIT_TRACE2_EVENT=$(pwd)/trace-B git \
-c maintenance.incremental-repack.auto=2 \
maintenance run --auto --task=incremental-repack 2>/dev/null &&
test_subcommand git multi-pack-index write --no-progress <trace-B
'
maintenance: add --schedule option and config 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>
2020-09-11 20:49:15 +03:00
test_expect_success '--auto and --schedule incompatible' '
test_must_fail git maintenance run --auto --schedule=daily 2>err &&
test_i18ngrep "at most one" err
'
test_expect_success 'invalid --schedule value' '
test_must_fail git maintenance run --schedule=annually 2>err &&
test_i18ngrep "unrecognized --schedule" err
'
test_expect_success '--schedule inheritance weekly -> daily -> hourly' '
git config maintenance.loose-objects.enabled true &&
git config maintenance.loose-objects.schedule hourly &&
git config maintenance.commit-graph.enabled true &&
git config maintenance.commit-graph.schedule daily &&
git config maintenance.incremental-repack.enabled true &&
git config maintenance.incremental-repack.schedule weekly &&
GIT_TRACE2_EVENT="$(pwd)/hourly.txt" \
git maintenance run --schedule=hourly 2>/dev/null &&
test_subcommand git prune-packed --quiet <hourly.txt &&
test_subcommand ! git commit-graph write --split --reachable \
--no-progress <hourly.txt &&
test_subcommand ! git multi-pack-index write --no-progress <hourly.txt &&
GIT_TRACE2_EVENT="$(pwd)/daily.txt" \
git maintenance run --schedule=daily 2>/dev/null &&
test_subcommand git prune-packed --quiet <daily.txt &&
test_subcommand git commit-graph write --split --reachable \
--no-progress <daily.txt &&
test_subcommand ! git multi-pack-index write --no-progress <daily.txt &&
GIT_TRACE2_EVENT="$(pwd)/weekly.txt" \
git maintenance run --schedule=weekly 2>/dev/null &&
test_subcommand git prune-packed --quiet <weekly.txt &&
test_subcommand git commit-graph write --split --reachable \
--no-progress <weekly.txt &&
test_subcommand git multi-pack-index write --no-progress <weekly.txt
'
test_expect_success 'maintenance.strategy inheritance' '
for task in commit-graph loose-objects incremental-repack
do
git config --unset maintenance.$task.schedule || return 1
done &&
test_when_finished git config --unset maintenance.strategy &&
git config maintenance.strategy incremental &&
GIT_TRACE2_EVENT="$(pwd)/incremental-hourly.txt" \
git maintenance run --schedule=hourly --quiet &&
GIT_TRACE2_EVENT="$(pwd)/incremental-daily.txt" \
git maintenance run --schedule=daily --quiet &&
test_subcommand git commit-graph write --split --reachable \
--no-progress <incremental-hourly.txt &&
test_subcommand ! git prune-packed --quiet <incremental-hourly.txt &&
test_subcommand ! git multi-pack-index write --no-progress \
<incremental-hourly.txt &&
test_subcommand git commit-graph write --split --reachable \
--no-progress <incremental-daily.txt &&
test_subcommand git prune-packed --quiet <incremental-daily.txt &&
test_subcommand git multi-pack-index write --no-progress \
<incremental-daily.txt &&
# Modify defaults
git config maintenance.commit-graph.schedule daily &&
git config maintenance.loose-objects.schedule hourly &&
git config maintenance.incremental-repack.enabled false &&
GIT_TRACE2_EVENT="$(pwd)/modified-hourly.txt" \
git maintenance run --schedule=hourly --quiet &&
GIT_TRACE2_EVENT="$(pwd)/modified-daily.txt" \
git maintenance run --schedule=daily --quiet &&
test_subcommand ! git commit-graph write --split --reachable \
--no-progress <modified-hourly.txt &&
test_subcommand git prune-packed --quiet <modified-hourly.txt &&
test_subcommand ! git multi-pack-index write --no-progress \
<modified-hourly.txt &&
test_subcommand git commit-graph write --split --reachable \
--no-progress <modified-daily.txt &&
test_subcommand git prune-packed --quiet <modified-daily.txt &&
test_subcommand ! git multi-pack-index write --no-progress \
<modified-daily.txt
'
test_expect_success 'register and unregister' '
test_when_finished git config --global --unset-all maintenance.repo &&
git config --global --add maintenance.repo /existing1 &&
git config --global --add maintenance.repo /existing2 &&
git config --global --get-all maintenance.repo >before &&
git maintenance register &&
test_cmp_config false maintenance.auto &&
git config --global --get-all maintenance.repo >between &&
cp before expect &&
pwd >>expect &&
test_cmp expect between &&
git maintenance unregister &&
git config --global --get-all maintenance.repo >actual &&
test_cmp before actual
'
maintenance: add start/stop subcommands Add new subcommands to 'git maintenance' that start or stop background maintenance using 'cron', when available. This integration is as simple as I could make it, barring some implementation complications. The schedule is laid out as follows: 0 1-23 * * * $cmd maintenance run --schedule=hourly 0 0 * * 1-6 $cmd maintenance run --schedule=daily 0 0 * * 0 $cmd maintenance run --schedule=weekly where $cmd is a properly-qualified 'git for-each-repo' execution: $cmd=$path/git --exec-path=$path for-each-repo --config=maintenance.repo where $path points to the location of the Git executable running 'git maintenance start'. This is critical for systems with multiple versions of Git. Specifically, macOS has a system version at '/usr/bin/git' while the version that users can install resides at '/usr/local/bin/git' (symlinked to '/usr/local/libexec/git-core/git'). This will also use your locally-built version if you build and run this in your development environment without installing first. This conditional schedule avoids having cron launch multiple 'git for-each-repo' commands in parallel. Such parallel commands would likely lead to the 'hourly' and 'daily' tasks competing over the object database lock. This could lead to to some tasks never being run! Since the --schedule=<frequency> argument will run all tasks with _at least_ the given frequency, the daily runs will also run the hourly tasks. Similarly, the weekly runs will also run the daily and hourly tasks. The GIT_TEST_CRONTAB environment variable is not intended for users to edit, but instead as a way to mock the 'crontab [-l]' command. This variable is set in test-lib.sh to avoid a future test from accidentally running anything with the cron integration from modifying the user's schedule. We use GIT_TEST_CRONTAB='test-tool crontab <file>' in our tests to check how the schedule is modified in 'git maintenance (start|stop)' commands. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-11 20:49:18 +03:00
test_expect_success 'start from empty cron table' '
GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance start &&
# start registers the repo
git config --get --global maintenance.repo "$(pwd)" &&
grep "for-each-repo --config=maintenance.repo maintenance run --schedule=daily" cron.txt &&
grep "for-each-repo --config=maintenance.repo maintenance run --schedule=hourly" cron.txt &&
grep "for-each-repo --config=maintenance.repo maintenance run --schedule=weekly" cron.txt
'
test_expect_success 'stop from existing schedule' '
GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance stop &&
# stop does not unregister the repo
git config --get --global maintenance.repo "$(pwd)" &&
# Operation is idempotent
GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance stop &&
test_must_be_empty cron.txt
'
test_expect_success 'start preserves existing schedule' '
echo "Important information!" >cron.txt &&
GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance start &&
grep "Important information!" cron.txt
'
test_expect_success 'register preserves existing strategy' '
git config maintenance.strategy none &&
git maintenance register &&
test_config maintenance.strategy none &&
git config --unset maintenance.strategy &&
git maintenance register &&
test_config maintenance.strategy incremental
'
maintenance: create basic maintenance runner The 'gc' builtin is our current entrypoint for automatically maintaining a repository. This one tool does many operations, such as repacking the repository, packing refs, and rewriting the commit-graph file. The name implies it performs "garbage collection" which means several different things, and some users may not want to use this operation that rewrites the entire object database. Create a new 'maintenance' builtin that will become a more general- purpose command. To start, it will only support the 'run' subcommand, but will later expand to add subcommands for scheduling maintenance in the background. For now, the 'maintenance' builtin is a thin shim over the 'gc' builtin. In fact, the only option is the '--auto' toggle, which is handed directly to the 'gc' builtin. The current change is isolated to this simple operation to prevent more interesting logic from being lost in all of the boilerplate of adding a new builtin. Use existing builtin/gc.c file because we want to share code between the two builtins. It is possible that we will have 'maintenance' replace the 'gc' builtin entirely at some point, leaving 'git gc' as an alias for some specific arguments to 'git maintenance run'. Create a new test_subcommand helper that allows us to test if a certain subcommand was run. It requires storing the GIT_TRACE2_EVENT logs in a file. A negation mode is available that will be used in later tests. Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:11:42 +03:00
test_done