Class: RedisFailover::NodeSnapshot

Inherits:
Object
  • Object
show all
Defined in:
lib/redis_failover/node_snapshot.rb

Overview

Represents a snapshot of a particular redis node as seen by all currently running redis node managers.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(node) ⇒ NodeSnapshot

Creates a new instance.

Parameters:

  • the (String) —

    redis node

See Also:



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# File 'lib/redis_failover/node_snapshot.rb', line 12

def initialize(node)
  @node = node
  @available = {}
  @unavailable = []
end

Instance Attribute Details

#node ⇒ String (readonly)

Returns the redis node.

Returns:

  • (String) —

    the redis node



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# File 'lib/redis_failover/node_snapshot.rb', line 6

def node
  @node
end

Instance Method Details

#all_available? ⇒ Boolean

node was viewable

Returns:

  • (Boolean) —

    true if all node managers indicated that this



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# File 'lib/redis_failover/node_snapshot.rb', line 65

def all_available?
  available_count > 0 && unavailable_count == 0
end

#all_unavailable? ⇒ Boolean

node was unviewable

Returns:

  • (Boolean) —

    true if all node managers indicated that this



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# File 'lib/redis_failover/node_snapshot.rb', line 71

def all_unavailable?
  unavailable_count > 0 && available_count == 0
end

#available_count ⇒ Integer

this node is available

Returns:

  • (Integer) —

    the number of node managers saying



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# File 'lib/redis_failover/node_snapshot.rb', line 42

def available_count
  @available.size
end

#avg_latency ⇒ Integer

Returns the average available latency.

Returns:

  • (Integer) —

    the average available latency



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# File 'lib/redis_failover/node_snapshot.rb', line 53

def avg_latency
  return if @available.empty?
  @available.values.inject(0) { |sum, n| sum + n } / @available.size
end

#node_managers ⇒ Array<String>

Returns all node managers involved in this snapshot.

Returns:

  • (Array<String>) —

    all node managers involved in this snapshot



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# File 'lib/redis_failover/node_snapshot.rb', line 59

def node_managers
  (@available.keys + @unavailable).uniq
end

#to_s ⇒ String

Returns a friendly representation of this node snapshot.

Returns:

  • (String) —

    a friendly representation of this node snapshot



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# File 'lib/redis_failover/node_snapshot.rb', line 76

def to_s
  'Node %s available by %p, unavailable by %p (%d up, %d down)' %
    [node, @available, @unavailable, available_count, unavailable_count]
end

#unavailable_count ⇒ Integer

this node is unavailable

Returns:

  • (Integer) —

    the number of node managers saying



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# File 'lib/redis_failover/node_snapshot.rb', line 48

def unavailable_count
  @unavailable.size
end

#unviewable_by(node_manager) ⇒ Object

Declares this node unavailable by the specified node manager.

Parameters:

  • node_manager (String) —

    the node manager id



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# File 'lib/redis_failover/node_snapshot.rb', line 36

def unviewable_by(node_manager)
  @unavailable << node_manager
end

#viewable_by(node_manager, latency) ⇒ Object

Declares this node available by the specified node manager.

Parameters:

  • node_manager (String) —

    the node manager id

  • latency (Integer) —

    the latency



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# File 'lib/redis_failover/node_snapshot.rb', line 22

def viewable_by(node_manager, latency)
  @available[node_manager] = latency
end

#viewable_by?(node_manager) ⇒ Boolean

Determines if this node is viewable by a node manager.

Parameters:

  • node_manager (String) —

    the node manager id

Returns:

  • (Boolean) 


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# File 'lib/redis_failover/node_snapshot.rb', line 29

def viewable_by?(node_manager)
  @available.key?(node_manager)
end