Class | Sequel::ShardedSingleConnectionPool |
In: |
lib/sequel/connection_pool/sharded_single.rb
|
Parent: | Sequel::ConnectionPool |
A ShardedSingleConnectionPool is a single threaded connection pool that works with multiple shards/servers.
Initializes the instance with the supplied block as the connection_proc.
The single threaded pool takes the following options:
# File lib/sequel/connection_pool/sharded_single.rb, line 15 15: def initialize(opts={}, &block) 16: super 17: @conns = {} 18: @servers = opts.fetch(:servers_hash, Hash.new(:default)) 19: add_servers([:default]) 20: add_servers(opts[:servers].keys) if opts[:servers] 21: end
Adds new servers to the connection pool. Primarily used in conjunction with master/slave or shard configurations. Allows for dynamic expansion of the potential slaves/shards at runtime. servers argument should be an array of symbols.
# File lib/sequel/connection_pool/sharded_single.rb, line 26 26: def add_servers(servers) 27: servers.each{|s| @servers[s] = s} 28: end
Yield all of the currently established connections
# File lib/sequel/connection_pool/sharded_single.rb, line 31 31: def all_connections 32: @conns.values.each{|c| yield c} 33: end
The connection for the given server.
# File lib/sequel/connection_pool/sharded_single.rb, line 36 36: def conn(server=:default) 37: @conns[@servers[server]] 38: end
Disconnects from the database. Once a connection is requested using hold, the connection is reestablished. Options:
# File lib/sequel/connection_pool/sharded_single.rb, line 44 44: def disconnect(opts={}, &block) 45: block ||= @disconnection_proc 46: (opts[:server] ? Array(opts[:server]) : servers).each{|s| disconnect_server(s, &block)} 47: end
Yields the connection to the supplied block for the given server. This method simulates the ConnectionPool#hold API.
# File lib/sequel/connection_pool/sharded_single.rb, line 51 51: def hold(server=:default) 52: begin 53: server = pick_server(server) 54: yield(@conns[server] ||= make_new(server)) 55: rescue Sequel::DatabaseDisconnectError 56: disconnect_server(server, &@disconnection_proc) 57: raise 58: end 59: end
Remove servers from the connection pool. Primarily used in conjunction with master/slave or shard configurations. Similar to disconnecting from all given servers, except that after it is used, future requests for the server will use the :default server instead.
# File lib/sequel/connection_pool/sharded_single.rb, line 65 65: def remove_servers(servers) 66: raise(Sequel::Error, "cannot remove default server") if servers.include?(:default) 67: servers.each do |server| 68: disconnect_server(server, &@disconnection_proc) 69: @servers.delete(server) 70: end 71: end