The cluster represents a cluster of MongoDB server nodes, either a single node, a replica set, or a mongos server.
@attribute [r] options The cluster options. @attribute [r] seeds The seeds the cluster was initialized with.
@attribute [r] options The cluster options. @attribute [r] seeds The seeds the cluster was initialized with.
Initialize the new cluster.
@example Initialize the cluster.
Cluster.new([ "localhost:27017" ], down_interval: 20)
@param [ Hash ] options The cluster options.
@option options :down_interval number of seconds to wait before attempting
to reconnect to a down node. (30)
@option options :refresh_interval number of seconds to cache information
about a node. (300)
@option options [ Integer ] :timeout The time in seconds to wait for an
operation to timeout. (5)
@since 1.0.0
# File lib/moped/cluster.rb, line 100 def initialize(hosts, options) @seeds = hosts @nodes = hosts.map { |host| Node.new(host, options) } @peers = [] @options = { down_interval: 30, max_retries: 20, refresh_interval: 300, retry_interval: 0.25 }.merge(options) end
Get the credentials for the cluster.
@example Get the authentication details.
cluster.auth
@return [ Hash ] the cached authentication credentials for this cluster.
@since 1.0.0
# File lib/moped/cluster.rb, line 19 def auth @auth ||= {} end
Disconnects all nodes in the cluster. This should only be used in cases where you know you're not going to use the cluster on the thread anymore and need to force the connections to close.
@return [ true ] True if the disconnect succeeded.
@since 1.2.0
# File lib/moped/cluster.rb, line 30 def disconnect nodes(include_arbiters: true).each { |node| node.disconnect } and true end
Get the interval at which a node should be flagged as down before retrying.
@example Get the down interval, in seconds.
cluster.down_interval
@return [ Integer ] The down interval.
@since 1.2.7
# File lib/moped/cluster.rb, line 43 def down_interval options[:down_interval] end
# File lib/moped/cluster.rb, line 277 def inspect "<#{self.class.name} nodes=#{@nodes.inspect}>" end
Get the number of times an operation should be retried before raising an error.
@example Get the maximum retries.
cluster.max_retries
@return [ Integer ] The max retries.
@since 1.2.7
# File lib/moped/cluster.rb, line 56 def max_retries options[:max_retries] end
Returns the list of available nodes, refreshing 1) any nodes which were down and ready to be checked again and 2) any nodes whose information is out of date. Arbiter nodes are not returned.
@example Get the available nodes.
cluster.nodes
@return [ Array<Node> ] the list of available nodes.
@since 1.0.0
# File lib/moped/cluster.rb, line 123 def nodes(opts = {}) current_time = Time.new down_boundary = current_time - down_interval refresh_boundary = current_time - refresh_interval # Find the nodes that were down but are ready to be refreshed, or those # with stale connection information. needs_refresh, available = @nodes.partition do |node| node.down? ? (node.down_at < down_boundary) : node.needs_refresh?(refresh_boundary) end # Refresh those nodes. available.concat refresh(needs_refresh) # Now return all the nodes that are available and participating in the # replica set. available.reject do |node| node.down? || !member?(node) || (!opts[:include_arbiters] && node.arbiter?) end end
Refreshes information for each of the nodes provided. The node list defaults to the list of all known nodes.
If a node is successfully refreshed, any newly discovered peers will also be refreshed.
@example Refresh the nodes.
cluster.refresh
@param [ Array<Node> ] nodes_to_refresh The nodes to refresh.
@return [ Array<Node> ] the available nodes
@since 1.0.0
# File lib/moped/cluster.rb, line 158 def refresh(nodes_to_refresh = @nodes) refreshed_nodes = [] seen = {} # Set up a recursive lambda function for refreshing a node and it's peers. refresh_node = ->(node) do unless seen[node] seen[node] = true # Add the node to the global list of known nodes. @nodes << node unless @nodes.include?(node) begin node.refresh # This node is good, so add it to the list of nodes to return. refreshed_nodes << node unless refreshed_nodes.include?(node) # Now refresh any newly discovered peer nodes - this will also # remove nodes that are not included in the peer list. refresh_peers(node, &refresh_node) rescue Errors::ConnectionFailure # We couldn't connect to the node. end end end nodes_to_refresh.each(&refresh_node) refreshed_nodes.to_a end
Get the interval in which the node list should be refreshed.
@example Get the refresh interval, in seconds.
cluster.refresh_interval
@return [ Integer ] The refresh interval.
@since 1.2.7
# File lib/moped/cluster.rb, line 68 def refresh_interval options[:refresh_interval] end
Get the operation retry interval - the time to wait before retrying a single operation.
@example Get the retry interval, in seconds.
cluster.retry_interval
@return [ Integer ] The retry interval.
@since 1.2.7
# File lib/moped/cluster.rb, line 81 def retry_interval options[:retry_interval] end
Yields the replica set's primary node to the provided block. This method will retry the block in case of connection errors or replica set reconfiguration.
@example Yield the primary to the block.
cluster.with_primary do |node| # ... end
@param [ Integer ] retries The number of times to retry.
@raises [ ConnectionFailure ] When no primary node can be found
@return [ Object ] The result of the yield.
@since 1.0.0
# File lib/moped/cluster.rb, line 205 def with_primary(retries = max_retries, &block) if node = nodes.find(&:primary?) begin node.ensure_primary do return yield node.apply_auth(auth) end rescue Errors::ConnectionFailure, Errors::ReplicaSetReconfigured # Fall through to the code below if our connection was dropped or the # node is no longer the primary. end end if retries > 0 # We couldn't find a primary node, so refresh the list and try again. warning(" MOPED: Retrying connection to primary for replica set #{inspect}") sleep(retry_interval) refresh with_primary(retries - 1, &block) else raise( Errors::ConnectionFailure, "Could not connect to a primary node for replica set #{inspect}" ) end end
Yields a secondary node if available, otherwise the primary node. This method will retry the block in case of connection errors.
@example Yield the secondary to the block.
cluster.with_secondary do |node| # ... end
@param [ Integer ] retries The number of times to retry.
@raises [ ConnectionFailure ] When no primary node can be found
@return [ Object ] The result of the yield.
@since 1.0.0
# File lib/moped/cluster.rb, line 246 def with_secondary(retries = max_retries, &block) available_nodes = nodes.shuffle!.partition(&:secondary?).flatten while node = available_nodes.shift begin return yield node.apply_auth(auth) rescue Errors::ConnectionFailure warning(" MOPED: Connection failed to secondary node #{node.inspect}, trying next node.") # That node's no good, so let's try the next one. next rescue Errors::ReplicaSetReconfigured # That node's no good, so let's try the next one. next end end if retries > 0 # We couldn't find a secondary or primary node, so refresh the list and # try again. warning(" MOPED: Could not connect to any node in replica set #{inspect}, refreshing list.") sleep(retry_interval) refresh with_secondary(retries - 1, &block) else raise( Errors::ConnectionFailure, "Could not connect to any secondary or primary nodes for replica set #{inspect}" ) end end
# File lib/moped/cluster.rb, line 283 def initialize_copy(_) @nodes = @nodes.map(&:dup) end
# File lib/moped/cluster.rb, line 287 def member?(node) @peers.empty? || @peers.include?(node) end
# File lib/moped/cluster.rb, line 291 def refresh_peers(node, &block) peers = node.peers return if !peers || peers.empty? peers.each do |node| block.call(node) unless @nodes.include?(node) @peers.push(node) unless peers.include?(node) end end
# File lib/moped/cluster.rb, line 300 def warning(message) if logger = Moped.logger logger.warn(message) end end