CICO-55340 Store slave connections in instance variable to avoid repe…

…ated new connections

lib/lhm/throttler/slave_lag.rb

@@ -15,7 +15,6 @@ def initialize(options = {})
  @timeout_seconds = INITIAL_TIMEOUT
  @stride = options[:stride] || DEFAULT_STRIDE
  @allowed_lag = options[:allowed_lag] || DEFAULT_MAX_ALLOWED_LAG
- @slave_connections = {}
  end
 
  def execute
@@ -43,6 +42,10 @@ def throttle_seconds
  end
  end
 
+ def slave_connections
+ @slave_connections ||= slave_hosts.map { |slave_host| slave_connection(slave_host) }
+ end
+
  def slave_hosts
  slaves = get_slaves.map { |slave_host| slave_host.partition(':')[0] }
  .delete_if { |slave| slave == 'localhost' || slave == '127.0.0.1' }
@@ -55,13 +58,12 @@ def get_slaves
  end
 
  def max_current_slave_lag
- max = slave_hosts.map { |slave| slave_lag(slave) }.flatten.push(0).max
+ max = slave_connections.map { |slave_connection| slave_lag(slave_connection) }.flatten.push(0).max
  Lhm.logger.info "Max current slave lag: #{max}"
  max
  end
 
- def slave_lag(slave)
- conn = slave_connection(slave)
+ def slave_lag(conn)
  if conn.respond_to?(:exec_query)
  result = conn.exec_query(SQL_SELECT_MAX_SLAVE_LAG)
  result.map { |row| row['Seconds_Behind_Master'].to_i }