class Lpxc
Public Class Methods
After parsing opts and initializing defaults, the initializer will start 2 threads. One thread for sending HTTP requests and another thread for flusing log messages to the outlet thread periodically.
- :hash => {}
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A data structure for grouping log messages by token.
- :request_queue => SizedQueue.new
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Contains HTTP requests ready for outlet thread to deliver to logplex.
- :default_token => nil
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You can specify a token that will be used for any call to
Lpxc#puts
that doesn't include a token. - :structured_data => '-'
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Structured-data field for syslog headers. Ignored by logplex.
- :msgid => '-'
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Msg ID field for syslog headers. Ignored by logplex.
- :procid => 'lpxc'
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Proc ID field for syslog headers. This will show up in the Heroku logs tail command as: app [lpxc].
- :hostname => 'myhost'
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Hostname field for syslog headers. Ignored by logplex.
- :max_reqs_per_conn => 1_000
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Number of requests before we re-establish our keep-alive connection to logplex.
- :conn_timeout => 2
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Number of seconds before timing out a sindle request to logplex.
- :batch_size => 300
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Max number of log messages inside single HTTP request.
- :flush_interval => 0.5
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Fractional number of seconds before flushing all log messages in buffer to logplex.
- :logplex_url => 'https://east.logplex.io/logs'
-
HTTP server that will accept our log messages.
- :disable_delay_flush => nil
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Force flush only batch_size is reached.
# File lib/lpxc.rb, line 70 def initialize(opts={}) @hash_lock = Mutex.new @hash = opts[:hash] || Hash.new @request_queue = opts[:request_queue] || SizedQueue.new(1) @default_token = opts[:default_token] @structured_data = opts[:structured_data] || "-" @msgid = opts[:msgid] || "-" @procid = opts[:procid] || "lpxc" @hostname = opts[:hostname] || "myhost" @max_reqs_per_conn = opts[:max_reqs_per_conn] || 1_000 @conn_timeout = opts[:conn_timeout] || 2 @batch_size = opts[:batch_size] || 300 @flush_interval = opts[:flush_interval] || 0.5 @user_agent = opts[:user_agent] || ENV["LPXC_USER_AGENT"] || "Lpxc (Ruby #{RUBY_VERSION})" @logplex_url = URI((opts[:logplex_url] || ENV["LOGPLEX_URL"] || raise("Must set logplex url.")).to_s) #Keep track of the number of requests that the outlet #is processing. This value is used by the wait function. @req_in_flight = 0 #Initialize the last_flush to an arbitrary time. @last_flush = Time.now + @flush_interval #Start the processing threads. Thread.new {outlet} Thread.new {delay_flush} unless opts[:disable_delay_flush] at_exit {wait} unless opts[:disable_at_exit_flush] end
Automatically create an Lpxc
client object for a given URL if none exists, and use it to send msg using the token from the URL.
# File lib/lpxc.rb, line 102 def self.puts(msg, url, opts={}) @lock = Mutex.new url = url.is_a?(URI) ? url : URI(url) server = [url.host, url.port, url.scheme] @clients ||= {} opts[:logplex_url] = url c = @lock.synchronize { @clients[server] ||= Lpxc.new(opts) } c.puts(msg, url.password) end
Public Instance Methods
Empty all log messages into a request queue. Messages will be grouped by token such that each request contains messages with homogeneus tokens. A seperate thread will process the requests.
# File lib/lpxc.rb, line 144 def flush to_be_processed = nil @hash_lock.synchronize do to_be_processed = @hash @hash = {} end process_hash(to_be_processed) end
The interface to publish logs into the stream. This function will set the log message to the current time in UTC. If the buffer for this token's log messages is full, it will flush the buffer.
# File lib/lpxc.rb, line 115 def puts(msg, tok=@default_token) q = nil @hash_lock.synchronize do #Messages are grouped by their token since 1 http request #to logplex must only contain log messages belonging to a single token. q = @hash[tok] ||= LogMsgQueue.new(@batch_size) end q.enqueue({:t => Time.now.utc, :token => tok, :msg => msg}) # Flush all of the queues if any queue is full. flush if q.full? end
Wait until all of the data has been cleared from memory. This is useful if you don't want your program to exit before we are able to deliver log messages to logplex.
# File lib/lpxc.rb, line 130 def wait(max=10) Timeout.timeout(max) do sleep(0.1) until @hash.length.zero? && @request_queue.empty? && @req_in_flight.zero? end true rescue Timeout::Error => _ end
Private Instance Methods
This method must be called in order for the messages to be sent to Logplex. This method also spawns a thread that allows the messages to be batched. Messages are flushed from memory every 500ms or when we have 300 messages, whichever comes first.
# File lib/lpxc.rb, line 184 def delay_flush loop do begin flush if interval_ready? sleep(0.01) rescue => e $stderr.puts("at=start-error error=#{e.message}") if ENV['DEBUG'] end end end
Format the user message into RFC5425 format. This method also prepends the length to the message.
# File lib/lpxc.rb, line 201 def fmt(data) pkt = "<190>1 " pkt += "#{data[:t].strftime("%Y-%m-%dT%H:%M:%S+00:00")} " pkt += "#{@hostname} " pkt += "#{data[:token]} " pkt += "#{@procid} " pkt += "#{@msgid} " pkt += "#{@structured_data} " pkt += data[:msg] "#{pkt.size} #{pkt}" end
# File lib/lpxc.rb, line 195 def interval_ready? (Time.now.to_f - @last_flush.to_f).abs >= @flush_interval end
We use a keep-alive connection to send data to LOGPLEX_URL. Each request will contain one or more log messages.
# File lib/lpxc.rb, line 215 def outlet loop do http = Net::HTTP.new(@logplex_url.host, @logplex_url.port) http.set_debug_output($stdout) if ENV['DEBUG'] http.use_ssl = true if @logplex_url.scheme == 'https' begin http.start do |conn| num_reqs = 0 while num_reqs < @max_reqs_per_conn #Blocks waiting for a request. req = @request_queue.deq @req_in_flight += 1 resp = nil begin Timeout::timeout(@conn_timeout) {resp = conn.request(req)} rescue => e $stdout.puts("at=req-error msg=#{e.message}") if ENV['DEBUG'] next ensure @req_in_flight -= 1 end num_reqs += 1 $stdout.puts("at=req-sent status=#{resp.code}") if ENV['DEBUG'] end end rescue => e $stdout.puts("at=req-error msg=#{e.message}") if ENV['DEBUG'] ensure http.finish if http.started? end end end
# File lib/lpxc.rb, line 155 def process_hash(h) h.each do |tok, queue| #Copy the messages from the queue into the payload array. payloads = queue.flush next if payloads.nil? || payloads.empty? #Use the payloads array to build a string that will be #used as the http body for the logplex request. body = "" payloads.flatten.each do |payload| body += "#{fmt(payload)}" end #Build a new HTTP request and place it into the queue #to be processed by the HTTP connection. req = Net::HTTP::Post.new(@logplex_url.path) req.basic_auth("token", tok) req.add_field('Content-Type', 'application/logplex-1') req.add_field('User-Agent', @user_agent) if @user_agent req.body = body @request_queue.enq(req) @last_flush = Time.now end end