Improve sync performance for pull-mirrors #19125
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I think tests for |
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#19235 might make this unnecessary. In particular the call to |
I haven't studied the referenced PR in detail. The main merit of this PR is that it, for pull-mirrors, reduces the number of |
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I did take #19235 for a spin and the mirror cloning/sync does indeed look better with that PR (nice work!), but it still does a number of I tried a few of the repos benchmarked in the description of this PR and noted that although the situation is better after #19235, this PR still gives an additional 6 time improvement (roughly speaking). So for the case of pull-mirrors it feels like there is still quite a lot to be gained, both in time and in system resources. |
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For large repositories with many tags, SyncReleasesWithTags can be a costly
operation (taking several minutes to complete). The reason is two-fold
1. on sync, every upstream repo tag is compared (for changes) against existing
local entries in the release table to ensure that they are up-to-date.
2. the procedure for getting each tag involves several git operations
git show-ref --tags -- v8.2.4477
git cat-file -t 29ab6ce9f36660cffaad3c8789e71162e5db5d2f
git cat-file -p 29ab6ce9f36660cffaad3c8789e71162e5db5d2f
git rev-list --count 29ab6ce9f36660cffaad3c8789e71162e5db5d2f
of which the 'git rev-list --count' can be particularly heavy.
This commit optimizes performance for pull-mirrors. We utilize the fact that a
pull-mirror is always identical to its upstream and rebuild the entire release
table on every sync and use a batch 'git for-each-ref .. refs/tags' call to
retrieve all tags in one go.
For large mirror repos, with hundreds of annotated tags, this brings down the
duration of the sync operation from several minutes to a few seconds.
Signed-off-by: Peter Gardfjäll <peter.gardfjall.work@gmail.com>
For large repositories with many tags, SyncReleasesWithTags can be a costly
operation (taking several minutes to complete). The reason is two-fold
1. on sync, every upstream repo tag is compared (for changes) against existing
local entries in the release table to ensure that they are up-to-date.
2. the procedure for getting each tag involves several git operations
git show-ref --tags -- v8.2.4477
git cat-file -t 29ab6ce9f36660cffaad3c8789e71162e5db5d2f
git cat-file -p 29ab6ce9f36660cffaad3c8789e71162e5db5d2f
git rev-list --count 29ab6ce9f36660cffaad3c8789e71162e5db5d2f
of which the 'git rev-list --count' can be particularly heavy.
This commit optimizes performance for pull-mirrors. We utilize the fact that a
pull-mirror is always identical to its upstream and rebuild the entire release
table on every sync and use a batch 'git for-each-ref .. refs/tags' call to
retrieve all tags in one go.
For large mirror repos, with hundreds of annotated tags, this brings down the
duration of the sync operation from several minutes to a few seconds.
Signed-off-by: Peter Gardfjäll <peter.gardfjall.work@gmail.com>
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Generally looks good to me.
The only nit is that the return len(data), bytes.TrimSpace(data), nil is really strange .....
If it is a must and the test case is correct (which means git has strange behaviors), here we need a clear comment to describe why the TrimSpace is needed.
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Codecov Report
@@ Coverage Diff @@
## main #19125 +/- ##
==========================================
+ Coverage 47.50% 47.56% +0.05%
==========================================
Files 931 934 +3
Lines 130513 130681 +168
==========================================
+ Hits 61998 62152 +154
- Misses 61043 61056 +13
- Partials 7472 7473 +1
Continue to review full report at Codecov.
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* giteaoffical/main: Fix broken of team create (go-gitea#19288) Remove `git.Command.Run` and `git.Command.RunInDir*` (go-gitea#19280) Performance improvement for add team user when org has more than 1000 repositories (go-gitea#19227) [skip ci] Updated translations via Crowdin Update JS dependencies (go-gitea#19281) Fix container download counter (go-gitea#19287) go.mod: update kevinburke/ssh_config to v1.2.0 (go-gitea#19286) Fix global packages enabled avaiable (go-gitea#19276) Add Goroutine stack inspector to admin/monitor (go-gitea#19207) Move checks for pulls before merge into own function (go-gitea#19271) Restore user autoregistration with email addresses (go-gitea#19261) Improve sync performance for pull-mirrors (go-gitea#19125) Refactor `git.Command.Run*`, introduce `RunWithContextString` and `RunWithContextBytes` (go-gitea#19266) Move reaction to models/issues/ (go-gitea#19264)
This PR addresses #18352
It aims to improve performance (and resource use) of the
SyncReleasesWithTagsoperation for pull-mirrors.For large repositories with many tags,
SyncReleasesWithTagscan be a costly operation (taking several minutes to complete). The reason is two-fold:on sync, every upstream repo tag is compared (for changes) against existing local entries in the release table to ensure that they are up-to-date.
the procedure for getting each tag involves a series of git operations
of which the
git rev-list --countcan be particularly heavy.This PR optimizes performance for pull-mirrors. We utilize the fact that a pull-mirror is always identical to its upstream and rebuild the entire release table on every sync and use a batch
git for-each-ref .. refs/tagscall to retrieve all tags in one go.For large mirror repos, with hundreds of annotated tags, this brings down the duration of the sync operation from several minutes to a few seconds. A few unscientific examples run on my local machine:
0m28,673s0m2,244s8m00s0m8,520s14m20,383s0m35,467sI added a
foreachrefpackage which contains a flexible way of specifying which reference fields are of interest (git-for-each-ref(1)) and to produce a parser for the expected output. These could be reused in other places wherefor-each-refis used. I'll add unit tests for those if the overall PR looks promising.