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Files

Eliza Weisman fc52d45a0f appender: impl MakeWriter for RollingFileAppender (#1760 )

## Motivation

Currently, `tracing-appender`'s `RollingFileAppender` does not implement
the `MakeWriter` trait. This means it can only be used by either
wrapping it in `NonBlocking`, or by wrapping it in a `Mutex`. However,
this shouldn't be strictly necessary, as `&File` implements `io::Write`.
It should thus only be necessary to introduce locking when we are in the
process of _rotating_ the log file.

## Solution

This branch adds a `MakeWriter` implementation for
`RollingFileAppender`. This is done by moving the file itself inside of
an `RwLock`, so that a read lock is acquired to write to the file. This
allows multiple threads to write to the file without contention. When
the file needs to be rolled, the rolling thread acquires the write lock
to replace the file. Acquiring the write lock is guarded by an atomic
CAS on the timestamp, so that only a single thread will try to roll the
file. This prevents other threads from immediately rolling the file
_again_ when the write lock is released.

I...should probably write tests for that, though.

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

2021-12-19 16:23:54 -08:00

examples

appender: impl MakeWriter for RollingFileAppender (#1760 )

2021-12-19 16:23:54 -08:00

Cargo.toml

chore: fix cargo MSRV field typo (#1742 )

2021-11-23 13:50:24 -08:00

README.md

examples: backport fmt-multiple-writers.rs to v0.1.0 branch (#1187 )

2021-01-12 15:46:45 -08:00

README.md

Tracing Examples

This directory contains a collection of examples that demonstrate the use of the tracing ecosystem:

tracing:
- counters: Implements a very simple metrics system to demonstrate how subscribers can consume field values as typed data.
- sloggish: A demo Subscriber implementation that mimics the output of slog-term's Compact formatter.
tracing-attributes:
- attrs-basic: A simple example of the #[instrument] attribute.
- attrs-literal-field-names: Demonstrates using literal field names rather than rust tokens..
- attrs-args: An example implementing a simple recursive calculation of Fibonacci numbers, to demonstrate how the #[instrument] attribute can record function arguments.
tracing-subscriber:
- fmt: Demonstrates the use of the fmt module in tracing-subscriber, which provides a subscriber implementation that logs traces to the console.
- fmt-stderr: Demonstrates overriding the output stream used by the fmt subscriber.
- fmt-custom-field: Demonstrates overriding how the fmt subscriber formats fields on spans and events.
- fmt-custom-event: Demonstrates overriding how the fmt subscriber formats events.
- fmt-multiple-writers.rs: demonstrates how fmt::Layer can write to multiple destinations (in this instance, stdout and a file) simultaneously.
- subscriber-filter: Demonstrates the tracing-subscriber::filter module, which provides a layer which adds configurable filtering to a subscriber implementation.
- tower-load: Demonstrates how dynamically reloadable filters can be used to debug a server under load in production.
- journald: Demonstrates how to use fmt and journald layers to output to both the terminal and the system journal.
- toggle-layers : Demonstrates how Layers can be wrapped with an Option allowing them to be dynamically toggled.
tracing-futures:
- spawny-thing: Demonstrates the use of the #[instrument] attribute macro asynchronous functions.
- tokio-spawny-thing.rs: Similar to spawny-thingy, but with the additional demonstration instrumenting concurrent tasks created with tokio::spawn.
- futures-proxy-server: Demonstrates the use of tracing-futures by implementing a simple proxy server, based on this example from tokio.
- async_fn: Demonstrates how asynchronous functions can be instrumented.
- echo: Demonstrates a tracing-instrumented variant of Tokio's echo example.
tracing-flame:
- infero-flame: Demonstrates the use of tracing-flame to generate a flamegraph from spans.
tracing-tower:
- tower-client: Demonstrates the use of tracing-tower to instrument a simple tower HTTP/1.1 client.
- tower-server: Demonstrates the use of tracing-tower to instrument a simple tower HTTP/1.1 server.
tracing-serde:
- serde-yak-shave: Demonstrates the use of tracing-serde by implementing a subscriber that emits trace output as JSON.
tracing-log:
- hyper-echo: Demonstrates how tracing-log can be used to record unstructured logs from dependencies as tracing events, by instrumenting this example from hyper, and using tracing-log to record logs emitted by hyper.
tracing-opentelemetry:
- opentelemetry: Demonstrates how tracing-opentelemetry can be used to export and visualize tracing span data.
- opentelemetry-remote-context: Demonstrates how tracing-opentelemetry can be used to extract and inject remote context when traces span multiple systems.