fix: fsync: false when writing cache files #9695
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Some tests are failing since we have assertions about what the function is called with, updating the tests should be quick 👍 |
We're using writeFileAtomic here in order to get atomic rename, not to get full system power failure resilience. Most(tm) filesystems will guarantee either/or during a crash here, which is plenty enough for us. fsync is a nearly 3x slowdown for me, ts-jest'ing my whole codebase (~900 files in testcase).
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Codecov Report
@@ Coverage Diff @@
## master #9695 +/- ##
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Coverage 65.09% 65.09%
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Files 287 287
Lines 12144 12144
Branches 3007 3009 +2
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Hits 7905 7905
Misses 3604 3604
Partials 635 635
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Summary
writeFileAtomicdefaults to runningfsyncon the file after use.fsyncis a nearly 3x slowdown for me, ts-jest'ing my whole codebase (~900 files in testcase).ubuntudefaults to/tmpas regular filesystem (i.e. not tmpfs), and some filesystems/devices have a large overhead for these repeatedfsyncs. I happen to be on nvme (sm961), andbtrfs.We're using
writeFileAtomichere in order to get atomic rename, not to get full system power failure resilience. Most(tm) filesystems will guarantee either/or during a system power failure here, which is plenty enough for us.Test plan
There should be no functional changes here (even during a system power failure), only a performance increase in all cases, and a drastic performance increase in some cases.