Configuring centralized logging from text log files in Unix with remote_syslog2

Use remote_syslog2 to aggregate logs from any text file, like app log files, in Unix and BSD.

Why remote_syslog2

To send log files to Papertrail from applications and daemons that don’t support syslog, run Papertrail’s tiny standalone remote_syslog2 daemon. It tracks one or more log files and sends new entries to Papertrail in realtime.

remote_syslog2 works for any text log files, has no impact to or reliance on the system syslog daemon or its logging configuration, is easy to set up, and forwards logs directly to Papertrail. No adjustments to syslog.conf, rsyslog.conf, or syslog-ng.conf are required.

Some applications that typically log to text files, such as MySQL, Apache, and Tomcat (log4j), have internal support for logging directly to syslog. For apps like these, either their internal syslog or remote_syslog2 can be used to send logs to Papertrail.

Setup

Automated (Configuration Management)

remote_syslog2 can be deployed and configured with configuration management tools. Papertrail provides official support for Chef, Puppet, and Salt:

These configuration management modules only configure and deploy remote_syslog2. To configure and manage the system’s syslog daemon configuration, see Configuring remote syslog from Unix/Linux and BSD/macOS.

Manual

Install remote_syslog2

Download the current release. To extract it and copy the binary into a system path, run:

$ tar xzf ./remote_syslog*.tar.gz
$ cd remote_syslog
$ sudo cp ./remote_syslog /usr/local/bin

RPM and Debian packages are also available.

Configure

Paths to log file(s) can be specified on the command-line, or save log_files.yml.example as /etc/log_files.yml. Edit it to define:

  • the path to this app’s log file, and any other log file(s) to watch.
  • the destination host and port provided under log destinations. If no destination port was provided, set host to logs.papertrailapp.com and remove the port config line to use the default port (514).

Start

Start the daemon:

$ sudo remote_syslog

Logs should appear in Papertrail within a few seconds of being written to the on-disk log file. Problem? See Troubleshooting.

remote_syslog requires read permission on the log files it is monitoring.

Auto-start

remote_syslog2 can be automated to start at boot using init scripts (examples) or your preferred daemon invocation method, such as monit or god. See remote_syslog --help or the full README on GitHub.


Troubleshooting

The system rebooted and remote_syslog didn’t start

Install an init file.

Logs not appearing?

Please feel free to drop a mail into support@papertrailapp.com, either instead of following these instructions or while trying them. We enjoy helping, and these steps are only here if they let you save time by troubleshooting independently.

There are a few reasons remote_syslog might not be sending logs.

Is remote_syslog running?

Check with ps auxww | grep [r]emote_syslog. Exactly 1 process should be shown, like this:

root     24501    0.0 0.4    13952 8864 ? S   Mar01 2:45 remote_syslog

Does it have the correct access permissions?

In the example above, the process is running as user root. If a user other than root is shown, does that user running remote_syslog have permission to write to /var/run/? /var/run/ is the default location for PID files (background).

If remote_syslog isn’t already running as root, try running it as root to test (such as with sudo), or specify an alternate location for the PID file (such as with remote_syslog --pid-file=/tmp/some.pid).

Did it stop running?

If you can start remote_syslog but it subsequently stops running, try leaving it attached to the terminal (rather than daemonizing) using remote_syslog -D.

Is it running, but suddenly stopped sending data?

…perhaps across many systems at the same time? This could be a firewall policy change or log rotation. However, remote_syslog plays well with all common log rotation systems (with no changes to the configuration of either), so we’d like to hear about this problem.

Is remote_syslog monitoring log files that are stored on an NFS share?

If so, enable polling via the --poll switch.

Detailed troubleshooting

The next step is to see what remote_syslog is actually doing. Typically that’s with strace, such as:

$ strace -tt -s 500 -fp 12345

…where 12345 is the process ID of remote_syslog, obtained from the second column of ps auxww. This will output every call that it makes. We suggest sending the strace output to a file:

$ strace -tt -s 500 -fp 12345 -o strace.log

Feel free to send the strace.log file to us via support@papertrailapp.com. We’ll look for a few things. Did the OS notify remote_syslog of writes to the log files? Did remote_syslog call sendto() (UDP) or connect() and send() (TCP) to try sending the message? What happened?

Extra

See other options with:

$ remote_syslog --help

See also Troubleshooting reachability.

Question?

Can we help? Just ask.