Resolves: #15433
When I converted prometheus to use slog in #14906, I update both the
`QueryLogger` interface, as well as how the log calls to the
`QueryLogger` were built up in `promql.Engine.exec()`. The backing
logger for the `QueryLogger` in the engine is a
`util/logging.JSONFileLogger`, and it's implementation of the `With()`
method updates the logger the logger in place with the new keyvals added
onto the underlying slog.Logger, which means they get inherited onto
everything after. All subsequent calls to `With()`, even in later
queries, would continue to then append on more and more keyvals for the
various params and fields built up in the logger. In turn, this causes
unbounded growth of the logger, leading to increased memory usage, and
in at least one report was the likely cause of an OOM kill. More
information can be found in the issue and the linked slack thread.
This commit does a few things:
- It was referenced in feedback in #14906 that it would've been better
to not change the `QueryLogger` interface if possible, this PR
proposes changes that bring it closer to alignment with the pre-3.0
`QueryLogger` interface contract
- reverts `promql.Engine.exec()`'s usage of the query logger to the
pattern of building up an array of args to pass at once to the end log
call. Avoiding the repetitious calls to `.With()` are what resolve the
issue with the logger growth/memory usage.
- updates the scrape failure logger to use the update `QueryLogger`
methods in the contract.
- updates tests accordingly
- cleans up unused methods
Builds and passes tests successfully. Tested locally and confirmed I
could no longer reproduce the issue/it resolved the issue.
Signed-off-by: TJ Hoplock <t.hoplock@gmail.com>
For: #14355
This commit updates Prometheus to adopt stdlib's log/slog package in
favor of go-kit/log. As part of converting to use slog, several other
related changes are required to get prometheus working, including:
- removed unused logging util func `RateLimit()`
- forward ported the util/logging/Deduper logging by implementing a small custom slog.Handler that does the deduping before chaining log calls to the underlying real slog.Logger
- move some of the json file logging functionality to use prom/common package functionality
- refactored some of the new json file logging for scraping
- changes to promql.QueryLogger interface to swap out logging methods for relevant slog sugar wrappers
- updated lots of tests that used/replicated custom logging functionality, attempting to keep the logical goal of the tests consistent after the transition
- added a healthy amount of `if logger == nil { $makeLogger }` type conditional checks amongst various functions where none were provided -- old code that used the go-kit/log.Logger interface had several places where there were nil references when trying to use functions like `With()` to add keyvals on the new *slog.Logger type
Signed-off-by: TJ Hoplock <t.hoplock@gmail.com>
This creates a new `model` directory and moves all data-model related
packages over there:
exemplar labels relabel rulefmt textparse timestamp value
All the others are more or less utilities and have been moved to `util`:
gate logging modetimevfs pool runtime
Signed-off-by: beorn7 <beorn@grafana.com>
TJ Hoplock