FAQ
Latest fluentd works on Ruby 2.4 or later.
If you want to run fluentd on ruby 2.3 or earlier, use fluentd 1.8 or earlier versions.
Use td-agent 3. It includes v1.
No difference. v1 is built on top of v0.14. Use v1 for a newer installation. We use v1 or v1.x on our document.
The timestamps of Fluentd and its logger libraries depend on your system's clock. It is highly recommended that you set up NTP on your nodes so that your clocks remain synced with the correct clocks.
Use
"#{ENV['YOUR_ENV_VARIABLE']}"
. For example:some_field "#{ENV['FOO_HOME']}"
Note that it must be double quotes, not single quotes.
There are several reasons:
- If you get
Address already in use
error, another process has alreadyusedhost:port
. Check port conflict between processes/plugins. - If you get
Permission denied
error, you likely tried to use a well-knownport without permission. Searchwell-known ports
for how to use well-known ports.Usecapabilities
or something.
If you get other errors, Google it.
Fluentd supports tzinfo v1.1 or later and recent td-agent / official images install tzinfo v2 by default. The problem is several plugins depend on ActiveSupport and ActiveSupport doesn't support tzinfo v2. To resolve this problem, there are 2 approaches.
- Uninstall tzinfo v2 and install tzinfo v1.1 manually
- Update plugin to remove ActiveSupport dependency. ActiveSupport is mainly for Ruby on Rails,so using ActiveSupport for several convenient methods is overengineering.
Former is easier approach.
This means that the event is emitted but there is no
<match>
directive for it. For example, if you emit the event with foo.bar
tag, you need to define <match>
for foo.bar
tag like <match foo.**>
.You may hit
"\xC3" from ASCII-8BIT to UTF-8
like UndefinedConversionError
in the plugin. This error happens when string encoding is set to ASCII-8BIT
but the actual content is UTF-8
. Fluentd and all its plugins treat the logs as ASCII-8BIT
by default but some libraries assume that the log encoding is UTF-8
. This is why this error occurs.There are several approaches to avoid this problem:
- Set encoding correctly:
- The
tail
input plugin has encoding related parameters to change thelog encoding. - Use
record_modifier
filter plugin to change the encoding. See
- Use
yajl
(Yajl.load
/Yajl.dump
) instead ofjson
when error happensinsideJSON.parse
/JSON.dump
/to_json
.
If you are using Alpine Linux, you need to install
ruby-bigdecimal
to use Oj
as the JSON parser. Please Execute the following command to see if the warning persists:# apk add --update ruby-bigdecimal
If you are willing to write Regexp, fluentd-ui's
in_tail
editor or Fluentular is a great tool to verify your Regexps.If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is an open-source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache License 2.0.
Last modified 9mo ago