Timeouts
^^^^^^^^

Timeouts in Lustre are handled by grouping connections into classes,
thus the timeout appropriate for a client connection to an OST is a
common property for all the OSTs on that client. That timeout may
differ from a timeout for other connections or replies. A full list of
the classes and how they are managed will wait for now.

Every request message indicates a timeout value and every reply answers
with the value the service will honor. Initial connection requests
propose a value for the timeout, and subsequent requests and replies
pass that value back and forth as part of the RPC descriptor
('pb_timeout').

Service Times
^^^^^^^^^^^^^

Closely related to the timeouts in Lustre are the service times that
are expect and observed for each connection class. A request will
always list the service time as 0 in the RPC descriptor
('pb_service_time'). The reply lists the time the server actual to
send the reply.