$iow = MogileFS::IOStatWatcher->new()

Returns a new IOStatWatcher object.

$iow->set_hosts( host1 [, host2 [, ...] ] )

Sets the list of hosts to connect to for collecting IOStat information. This call can block if you pass it hostnames instead of ip addresses.

Upon successful connection, the on_stats callback will be called each time the statistics are collected. Error states (failed connections, etc.) will trigger retries on 60 second intervals, and disconnects will trigger an immediate reconnect.

$iow->on_stats( coderef )

Sets the coderef called for the "on_stats" callback.

on_stats->( host, stats )

Called each time device use statistics are collected. The "host" argument is the value passed in to the "set_hosts" method. The "stats" object is a hashref of mogile device numbers (without leading "dev") to their corresponding utilization percentages.