Class: Redis::Connection::Ruby

Inherits:
Object
  • Object
show all
Defined in:
lib/redis/elasticache/failover.rb

Constant Summary collapse

RDS_READONLY_ERROR = 
"READONLY You can't write against a read only slave.".freeze
RDS_READONLY_MESSAGE = 
"A write operation was issued to an RDS slave node.".freeze

Instance Method Summary collapse

Instance Method Details

#format_error_reply(line) ⇒ Object

Amazon RDS supports failover, but because it uses DNS magic to point to the master node, TCP connections are not disconnected and we can issue write operations to a node that is no longer the master. Under normal conditions this should be interpreted as a ‘CommandError`, but with RDS replication groups, we should consider this a `BaseConnectionError` so we terminate the connection, reconnect and retry the operation with the correct node as the master accepting writes.



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# File 'lib/redis/elasticache/failover.rb', line 18

def format_error_reply(line)
  error_message = line.strip
  if error_message == RDS_READONLY_ERROR
    raise BaseConnectionError, RDS_READONLY_MESSAGE
  else
    CommandError.new(error_message)
  end
end