Last Modified
  2016-09-30 19:32:14 +0000
Requires

## Description

The base connection pool class, which all other connection pools are based on. This class is not instantiated directly, but subclasses should at the very least implement the following API:

initialize(Database, Hash) | Initialize using the passed Sequel::Database object and options hash.
hold(Symbol, &block) | Yield a connection object (obtained from calling the block passed to `initialize`) to the current block. For sharded connection pools, the Symbol passed is the shard/server to use.
disconnect(Symbol) | Disconnect the connection object. For sharded connection pools, the Symbol passed is the shard/server to use.
servers | An array of shard/server symbols for all shards/servers that this connection pool recognizes.
size | an integer representing the total number of connections in the pool, or for the given shard/server if sharding is supported.

For sharded connection pools, the sharded API adds the following methods:

add_servers(Array of Symbols) | start recognizing all shards/servers specified by the array of symbols.
remove_servers(Array of Symbols) | no longer recognize all shards/servers specified by the array of symbols.