Fluentd custom parser plugin raises uninitialized constant Fluent error - ruby

Question

I am trying to implement a custom fluentd parser plugin. As suggested in the docs, I have created the following file called parser_unordered_multiline.rb and put it in the location /etc/td-agent/plugin/.
# #Package: Fluentd
# #Module: Unordered Multiline Parser Plugin
# #Author: Amyth Singh <mail#amythsingh.com>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
module Fluent
class TextParser
class UnorderedMultilineParser < Parser
Plugin.register_parser('unordered_multiline', self)
## Define configuration params
config_param :delimiter, :string, :default => " "
config_param :time_format, :string, :default => nil
## configures our parser plugin
def configure(conf)
super
if #delimiter.length != 1
raise ConfigError, "delimiter must be a single character. #{#delimiter} is not."
end
#time_parser = TimeParser.new(#time_format)
end
def parse(text)
time, key_values = text.split(" ", 2)
time = #time_parser.parse(time)
record = {}
key_values.split(#delimiter).each { |kv|
k, v = kv.split("=", 2)
record[k] = v
}
yield time, record
end
end
end
end
I am using the same code given in the example in the documentation (just with a different name) but the fluentd logs show the error:
unexpected error error="uninitialized constant Fluent::TextParser::Parser"
Following is the full stack trace
2015-12-23 14:38:23 +0530 [info]: starting fluentd-0.10.50
2015-12-23 14:38:23 +0530 [info]: reading config file path="/etc/td-agent/td-agent.conf"
2015-12-23 14:38:23 +0530 [error]: unexpected error error="uninitialized constant Fluent::TextParser::Parser"
2015-12-23 14:38:23 +0530 [error]: /etc/td-agent/plugin/parser_unordered_multiline.rb:21:in `<class:TextParser>'
2015-12-23 14:38:23 +0530 [error]: /etc/td-agent/plugin/parser_unordered_multiline.rb:20:in `<module:Fluent>'
2015-12-23 14:38:23 +0530 [error]: /etc/td-agent/plugin/parser_unordered_multiline.rb:19:in `<top (required)>'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/plugin.rb:59:in `block in load_plugin_dir'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/plugin.rb:57:in `each'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/plugin.rb:57:in `load_plugin_dir'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/engine.rb:129:in `load_plugin_dir'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:369:in `block in init_engine'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:366:in `each'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:366:in `init_engine'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:129:in `block in start'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:246:in `call'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:246:in `main_process'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:221:in `block in supervise'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:220:in `fork'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:220:in `supervise'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/supervisor.rb:126:in `start'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/lib/fluent/command/fluentd.rb:160:in `<top (required)>'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:73:in `require'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:73:in `require'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/lib/ruby/gems/2.1.0/gems/fluentd-0.10.50/bin/fluentd:6:in `<top (required)>'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/bin/fluentd:23:in `load'
2015-12-23 14:38:23 +0530 [error]: /opt/td-agent/embedded/bin/fluentd:23:in `<top (required)>'
2015-12-23 14:38:23 +0530 [error]: /usr/sbin/td-agent:7:in `load'
2015-12-23 14:38:23 +0530 [error]: /usr/sbin/td-agent:7:in `<main>'
2015-12-23 14:38:23 +0530 [info]: process finished code=256
2015-12-23 14:38:23 +0530 [warn]: process died within 1 second. exit.
And this is how my configuration file looks like.
<source>
type tail
path /var/log/mail/mail*
pos_file /var/log/td-agent/tmp/access.log
exclude_path ["/var/log/mail/*.gz", "/var/log/mail/*.zip"]
read_from_head true
time_format %M %d %H:%M:%S
port 5140
format unordered_multiline
tag mail
</source>
<match mail>
type copy
<store>
type elasticsearch
logstash_format true
flush_interval 30s
</store>
</match>
I am fairly new to ruby and fluentd, Can anybody tell me what this error is all about ?
update
According to the plugin management docs, even the path seems correct