Class: UState::Server::Index

Inherits:
Object
  • Object
show all
Defined in:
lib/ustate/server/index.rb

Defined Under Namespace

Classes: ParseFailed

Constant Summary collapse

THREADS = 
1000
BUFFER_SIZE = 
10
EXPIRY =

Forget about states after

1000
INSERT_RATE_INTERVAL =

Update metrics every

5
INSERT_TIMES_INTERVAL = 
5

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ Index

Returns a new instance of Index.



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# File 'lib/ustate/server/index.rb', line 25

def initialize(opts = {})
  @db = Sequel.sqlite

  @server = opts[:server]
  @threads = opts[:threads] || THREADS
  @pool = []

  @on_state_change = []
  @on_state_once = []
  @on_state = []

  @expiry = opts[:expiry] || EXPIRY

  @insert_rate_interval = opts[:insert_rate_interval] || INSERT_RATE_INTERVAL
  @insert_times_interval = opts[:insert_times_interval] || INSERT_TIMES_INTERVAL
  setup_db
end

Instance Attribute Details

#db ⇒ Object (readonly)

Returns the value of attribute db.



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# File 'lib/ustate/server/index.rb', line 20

def db
  @db
end

#expiry ⇒ Object

Returns the value of attribute expiry.



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# File 'lib/ustate/server/index.rb', line 21

def expiry
  @expiry
end

#insert_rate_interval ⇒ Object

Returns the value of attribute insert_rate_interval.



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# File 'lib/ustate/server/index.rb', line 22

def insert_rate_interval
  @insert_rate_interval
end

#insert_times_interval ⇒ Object

Returns the value of attribute insert_times_interval.



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# File 'lib/ustate/server/index.rb', line 23

def insert_times_interval
  @insert_times_interval
end

#queue ⇒ Object (readonly)

Returns the value of attribute queue.



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# File 'lib/ustate/server/index.rb', line 20

def queue
  @queue
end

Instance Method Details

#<<(s) ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 47

def <<(s)
  t0 = Time.now
  process s
  dt = Time.now - t0
  @insert_times << dt
  @insert_rate << 1
end

#clear ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 43

def clear
  setup_db
end

#on_state(state = nil, &block) ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 84

def on_state(state = nil, &block)
  if block_given?
    @on_state |= [block]
  else
    @on_state.each do |callback|
      callback.call state
    end
  end
end

#on_state_change(old = nil, new = nil, &block) ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 64

def on_state_change(old = nil, new = nil, &block)
  if block_given?
    @on_state_change |= [block]
  else
    @on_state_change.each do |callback|
      callback.call old, new
    end
  end
end

#on_state_once(state = nil, &block) ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 74

def on_state_once(state = nil, &block)
  if block_given?
    @on_state_once |= [block]
  else
    @on_state_once.each do |callback|
      callback.call state
    end
  end
end

#process(s) ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 94

def process(s)
  if s.once
    on_state_once s
    return on_state s
  end

  if current = @db[:states][host: s.host, service: s.service]
    # Update
    if current[:time] <= s.time
      if current[:state] != s.state
        on_state_change row_to_state(current), s
      end           

      # Update
      @db[:states].filter(host: s.host, service: s.service).update(
        state: s.state,
        time: s.time,
        description: s.description,
        metric_f: s.metric_f
      )
    end
  else
    # Insert
    @db[:states].insert(
      host: s.host,
      service: s.service,
      state: s.state,
      time: s.time,
      description: s.description,
      metric_f: s.metric_f
    )
  end

  on_state s
end

#query(q) ⇒ Object

Returns an array of States matching Query.



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# File 'lib/ustate/server/index.rb', line 131

def query(q)
  parser = QueryStringParser.new
  if q.string
    unless expression = parser.parse(q.string)
      raise ParseFailed, "error parsing #{q.string.inspect} at line #{parser.failure_line}:#{parser.failure_column}: #{parser.failure_reason}"
    end
    filter = expression.sql
  else
    # No string? All states.
    filter = true
  end
  
  ds = @db[:states].filter filter
  ds.all.map do |row|
    row_to_state row
  end
end

#reap ⇒ Object

Remove states older than @expiry



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# File 'lib/ustate/server/index.rb', line 150

def reap
  @db[:states].filter { |s| 
    s.time < (Time.now - @expiry).to_i 
  }.each do |row|
    on_state_change(
      row_to_state(row),
      row_to_state(
        row.merge(
          state: 'unknown',
          description: "ustate has not heard from this service since #{Time.at(row[:time])}",
          metric_f: nil, 
          time: Time.now.to_i
        )
      )
    )
    @db[:states].filter(host: row[:host], state: row[:state]).delete
  end
end

#reaper ⇒ Object

Periodically expire old states.



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# File 'lib/ustate/server/index.rb', line 170

def reaper
  Thread.new do
    loop do
      sleep 1
      reap
    end
  end
end

#row_to_state(row) ⇒ Object

Converts a row to a State



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# File 'lib/ustate/server/index.rb', line 180

def row_to_state(row)
  State.new(row)
end

#setup_db ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 184

def setup_db
  @db.drop_table :states rescue nil
  @db.create_table :states do
    String :host
    String :service
    String :state
    String :description, :text => true
    Integer :time
    Float :metric_f
    primary_key [:host, :service]
  end
end

#start ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 197

def start
  stop!
  @pool = []
  @reaper = reaper

  @insert_rate = MetricThread.new(Mtrc::Rate) do |r|
    self << State.new(
      service: "ustate insert rate",
      state: "ok",
      host: Socket.gethostname,
      time: Time.now.to_i,
      metric_f: r.rate.to_f,
    )
  end
  @insert_rate.interval = @insert_rate_interval
  
  @insert_times = MetricThread.new(Mtrc::SortedSamples) do |r|
    self << State.new(
      service: "ustate insert 50",
      state: "ok",
      host: Socket.gethostname,
      time: Time.now.to_i,
      metric_f: r % 50,
    )
    self << State.new(
      service: "ustate insert 95",
      state: "ok",
      host: Socket.gethostname,
      time: Time.now.to_i,
      metric_f: r % 95,
    )
    self << State.new(
      service: "ustate insert 99",
      state: "ok",
      host: Socket.gethostname,
      time: Time.now.to_i,
      metric_f: r % 99,
    )
  end
  @insert_times.interval = @insert_times_interval
end

#stop ⇒ Object

Finish up



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# File 'lib/ustate/server/index.rb', line 240

def stop
  @insert_rate.stop rescue nil
  @insert_times.stop rescue nil
end

#stop! ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 245

def stop!
  @pool.each do |thread|
    thread.kill
  end
end

#thread(s) ⇒ Object 



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# File 'lib/ustate/server/index.rb', line 55

def thread(s)
  Thread.new do
    process s
    @pooltex.synchronize do
      @pool.delete Thread.current
    end
  end
end