Differentiate and propagate missing digest errors #15761
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…ocess_execution` and `nodes`. [ci skip-build-wheels]
[ci skip-build-wheels]
tdyas
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…ore resilient (#15850) As described in #11331, in order to avoid having to deal with missing remote content later in the pipeline, `--remote-cache-eager-fetch` currently defaults to true. This means that before calling a cache hit a hit, we fully download the output of the cache entry. In warm-cache situations, this can mean downloading a lot more than is strictly necessary. In theory, you could imagine `eager_fetch=False` downloading only stdio and no file content at all for a 100% cache hit rate run of tests. In practice, high hitrate runs [see about 80% fewer bytes downloaded, and 50% fewer RPCs](#11331 (comment)) than with `eager_fetch=True`. To begin moving toward disabling `eager_fetch` by default (and eventually, ideally, removing the flag entirely), this change begins "backtracking" when missing digests are encountered. Backtracking is implemented by "catching" `MissingDigest` errors (introduced in #15761), and invalidating their source `Node` in the graph. When a `Node` that produced a missing digest re-runs, it does so using progressively fewer caches (as introduced in #15854), in order to cache bust both local and remote partial cache entries. `eager_fetch=False` was already experimental, in that any `MissingDigest` error encountered later in the run would kill the entire run. Backtracking makes `eager_fetch=False` less experimental, in that we are now very likely to recover from a `MissingDigest` error. But it is still the case with `eager_fetch=False` that persistent remote infrastructure errors (those that last longer than our retry budget or timeout) could kill a run. Given that, we will likely want to gain more experience and further tune timeouts and retries before changing the default. Fixes #11331. [ci skip-build-wheels]
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…15979) As reported in #15954, backtracking doesn't currently work when a synchronous method like `Workspace.write_digests` is the source of a `MissingDigest` error. This was due to a TODO left behind in #15761, where we did not propagate the `Failure` type "through" `@rule` bodies. To fix this, we add a conversion from `Failure` to `PrErr` which wraps in a well known exception type, and then look for that type when converting back from `PyErr` to `Failure`. Fixes #15954.
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…antsbuild#15979) As reported in pantsbuild#15954, backtracking doesn't currently work when a synchronous method like `Workspace.write_digests` is the source of a `MissingDigest` error. This was due to a TODO left behind in pantsbuild#15761, where we did not propagate the `Failure` type "through" `@rule` bodies. To fix this, we add a conversion from `Failure` to `PrErr` which wraps in a well known exception type, and then look for that type when converting back from `PyErr` to `Failure`. Fixes pantsbuild#15954. # Building wheels and fs_util will be skipped. Delete if not intended. [ci skip-build-wheels]
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…antsbuild#15979) As reported in pantsbuild#15954, backtracking doesn't currently work when a synchronous method like `Workspace.write_digests` is the source of a `MissingDigest` error. This was due to a TODO left behind in pantsbuild#15761, where we did not propagate the `Failure` type "through" `@rule` bodies. To fix this, we add a conversion from `Failure` to `PrErr` which wraps in a well known exception type, and then look for that type when converting back from `PyErr` to `Failure`. Fixes pantsbuild#15954. # Building wheels and fs_util will be skipped. Delete if not intended. [ci skip-build-wheels]
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…Cherry-pick of #15979) (#16001) As reported in #15954, backtracking doesn't currently work when a synchronous method like `Workspace.write_digests` is the source of a `MissingDigest` error. This was due to a TODO left behind in #15761, where we did not propagate the `Failure` type "through" `@rule` bodies. To fix this, we add a conversion from `Failure` to `PrErr` which wraps in a well known exception type, and then look for that type when converting back from `PyErr` to `Failure`. Fixes #15954. [ci skip-build-wheels] Co-authored-by: Stu Hood <stuhood@gmail.com>
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In order to begin lazily fetching digests for #11331, we need to be able to differentiate errors caused by missing digests.
This change introduces
{StoreError,ProcessError,Failure}::MissingDigest, which are bubbled up to the level of graphNodes, and which will allow us to introduce retry in a followup change.MissingDigestis produced byload_bytes_withand a few other low-levelStoremethods (which now return anErr(MissingDigest)rather thanOption).There should not be any behavior changes.