mdbd

Documentation

Overview

Package mdbd implements a simple MDB watcher.

Package mdbd may be used to read MDB data from a file or remote server and watch for updates.

Index

• func StartMdbDaemon(mdbFileName string, logger log.Logger) <-chan *mdb.Mdb

Functions

func StartMdbDaemon

func StartMdbDaemon(mdbFileName string, logger log.Logger) <-chan *mdb.Mdb

StartMdbDaemon starts an in-process "daemon" goroutine which watches for MDB updates. At startup it will read the file named by mdbFileName for MDB data. The default format is JSON, but if the filename extension is ".gob" then GOB format is read. If the file is present and contains MDB data, the MDB data are sent over the returned channel, otherwise no MDB data are sent initially.

By default the file is monitored for updates and if the file is replaced by a different inode, MDB data are read from the new inode. If the MDB data are different than previously read, they are sent over the channel. This mode of operation is designed for consuming MDB data via the file-system from a local mdbd daemon.

Alternatively, if a remote MDB server is specified with the -mdbServerHostname and -mdbServerPortNum command-line flags then the remote MDB server is queried for MDB data. As MDB updates are received they are saved in the file and sent over the channel. In this mode of operation the file is read only once at startup. The file acts as a local cache of the MDB data received from the server, in case the MDB server is not available at a subsequent restart of the application.

The logger will be used to log problems.