com.stuartsierra / log.dev
I read the Logback manual so you don't have to.
This does not provide a logging API. It just provides the necessary dependencies and configuration to get all the log messages going to the same place.
This is intended as a quick way to get logging set up in a new project, or as an example to follow when configuring logging in your own project. It is probably not suitable for production use.
Releases and dependency information
Latest stable release is 0.2.0
Releases are on Clojars
Leiningen dependency information:
Maven dependency information:
<dependency> <groupId>com.stuartsierra</groupId> <artifactId>log.dev</artifactId> <version>0.2.0</version> </dependency>
Gradle dependency information:
Note on Logback totalSizeCap
log.dev currently depends on Logback 1.1.7, which includes support for
totalSizeCap property to limit the total size of log files.
See Automatic expiration, below.
However, as described in LOGBACK-1166, the total size limit is not applied to the two most recent "periods" of logs. As a result, the total space occupied by logs can still grow without bound within a single day.
Logback 1.1.8 drops the "untouchable periods" behavior, but also introduces LOGBACK-1236 which causes spurious warning messages to be printed to the console on startup. There is a fix for this issue scheduled to be included in Logback 1.1.9.
What this means for you
If you want a real limit on log file size, configure your project to depend on:
[ch.qos.logback/logback-classic "1.1.8"] [ch.qos.logback/logback-core "1.1.8"]
But if you do this, you will get spurious INFO and WARN messages printed to the console when your app starts up, such as "SizeAndTimeBasedFNATP is deprecated. Use SizeAndTimeBasedRollingPolicy instead".
Or you can wait until Logback 1.1.9 is released with fixes both issues. See Logback News for release announcements.
Add this library as a dependency to your project.
Add exclusions for all other logging implementations that might be in the transitive dependencies of your project.
:exclusions in log.dev's project.clj file for an
Local config file
Add a file named
log_dev_app.properties to your project's resources,
at the root of the classpath, containing the following property:
com.example.your.application with the top-level namespace of
Where are my logs?
Only log messages at levels WARN and ERROR will be printed to the console (STDOUT). These messages may or may not be visible in an interactive shell or REPL, depending on your development tooling and configuration.
Output file: log/app.log
If you set up the properties file as described above in Configuration,
all log messages from your application code will be written to the
log/app.log relative to the working directory in which your
program was started.
Output file: log/all.log
All log messages from all namespaces and packages (your
application code plus all libraries) will be written out to a file
log/all.log relative to the working directory in which your program
Any Java or Clojure code using any of the following logging APIs will have their log messages written via Logback:
Automatic log file rotation
Each log file will be rotated daily and every time it reaches 64 MB in size.
Rotated log files will be named like
YYYY-MM-DD is the date and
N is a sequence number.
The current log files are always
they may be replaced by new files due to rotation. So if you are
monitoring those files with another program, for example
tail -f, you
may need to restart the monitor every time a file is rotated.
The amount of disk space used by log files is limited to:
- 512 MB total for
- 512 MB total for
This adds up to an overall maximum of 1 GB for all log files.
When the total size of the current and rotated log files exceeds these limits, the oldest files will be deleted.
Any log files more than 15 days old will be deleted automatically.
All levels enabled
All logging levels are enabled in this configuration.
This log configuration is verbose and synchronous. This is good for visibility during development but bad for performance.
Do not use log.dev if you are optimizing or benchmarking code which does any logging.
If any code or library in your project uses the java.util.logging APIs, you will need to initialize the SLF4J bridge by doing the following when your application starts.
import org.slf4j.bridge.SLF4JBridgeHandler; //... SLF4JBridgeHandler.removeHandlersForRootLogger(); SLF4JBridgeHandler.install();
(import (org.slf4j.bridge SLF4JBridgeHandler)) (SLF4JBridgeHandler/removeHandlersForRootLogger) (SLF4JBridgeHandler/install)
See the SLF4JBridgeHandler documentation for details.
You will probably want to customize the logging configuration for production use. To do that, remove log.dev from your project's dependencies and replace it with your custom configuration.
Refer to project.clj for an example of how to configure your dependencies to forward all log APIs via SLF4J to Logback.
Refer to resources/logback.xml for an example of how to configure Logback.
Copyright and License
The MIT License (MIT)
Copyright © 2014 Stuart Sierra
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.