Background
Yahoo JIRA issue Apache JIRA issue (TS-306)Currently, there is no log
rotation implemented for traffic.out, diags.log, and manager.log. Each of those
files is logged into using a different and unique way. This is in contrast to
the logging subsystem used to record the proxy accesses and errors, which
implements rotation. For example, the following files can be written into in
these ways. Note: these are not the only ways the files are written into.
traffic.out:Logs that are sent to stdout and stderr are forwarded to traffic.out
diags.log:Everything logged by using the Diags macros (Note(..), Error(..), …)
are put into diags.log
manager.log:traffic_manager logs its messages with fprintf’s and
mgmt_{log,elog,fatal,..} functions (which are deprecated) from
mgmt/utils/MgmtUtils.h. Some of those messages find their way into manager.log
Problem
Since those files aren’t being rotated, they can get too large for various
reasons (core, naughty plugins, proxy, etc). Furthermore, the lack of a unified
logging system makes changes to the logging infrastructure more work than one
would expect.
Solutions
To solve these problems, we have a couple options:
- Pipe logs from traffic.out, diags.log, and manager.log into a 3rd party
logging utility [1]
- Pros
- Virtually no changes to existing code base
- Easy
- Apache httpd & daemon tools already do this
- Cons
- Not an elegant solution
- Use the trafficserver script to spawn a daemon that periodically “stops
the world” (ie the logs wouldn’t flush) for all logging calls, and rotates the
files [1]
- Pros
- No difficult changes need to be made the current infrastructure, we would
only need to figure out how to 1) “stop the world” and 2) reload file
descriptors
- Cons
- It’s hard to say how big the interim buffer (for holding all the logs
while the world stops) should be
- Not the most elegant solution
- Reuse the proxy logging infrastructure, and make a LogObject managed by
the proxy’s global LogObjectManager for each of the log files we want to
implement rotation for.
- Pros
- No repeated code
- We would have a unified logging infrastructure
- Cons
- Significant changes to code base
- Would be difficult to log events before the proxy logging infrastructure
starts up [2]
Comments
James Peach has previously mentioned that log rotation for diags.log should be
implemented the same as all other rotated log files here
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[1] Kang Li; earlier proposal
https://docs.google.com/document/d/1c9E0i8N3krL3msiHOLpgR99UzNUAt5N6FP1L3W3ghGs
[2] http://articles.qos.ch/internalLogging.html
On Wednesday, June 17, 2015 5:20 PM, Daniel Xu
<[email protected]> wrote:
Apologies, here is the link.Logsubsystemunificationproposal.pdf
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On Wednesday, June 17, 2015 5:00 PM, Daniel Xu
<[email protected]> wrote:
Attached is a proposal to fix issue TS-306 (and more).
Please respond with any comments/concerns/criticisms you may have.
-Dan
