NAME

       nameserv::auto - Name service facility, Client Extension

SYNOPSIS

       package require Tcl  8.4

       package require nameserv::auto  ?0.3?

       package require nameserv

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DESCRIPTION

       Please read the document Name service facility, introduction first.

       This package provides the exact same API as is provided by package nameserv, i.e the regular name service
       client. It differs from the former by taking measures to ensure that longer-lived data, i.e. bound names,
       continuous  and unfulfilled async searches, survive the loss of the connection to the name server as much
       as is possible.

       This means that the bound names and continuous and unfulfilled async searches are remembered  client-side
       and  automatically  re-entered  into  the server when the connection comes back after its loss. For bound
       names there is one important limitation to such restoration: It is possible that a name  of  this  client
       was  bound  by  a different client while the connection was gone. Such names are fully lost, and the best
       the package can and will do is to inform the user of this.

API

       The user-visible API is mainly identical the API of nameserv and is therefore not described here.  Please
       read the documentation of nameserv.

       The differences are explained in the sections OPTIONS and EVENTS.

OPTIONS

       This  package supports all the option of package nameserv, and one more. The additional option allows the
       user to specifies the time interval between attempts to restore a lost connection.

       -delay milliseconds
              The value of this option is an integer value > 0 which specifies  the  interval  to  wait  between
              attempts  to  restore  a  lost  connection,  in  milliseconds. The default value is 1000, i.e. one
              second.

EVENTS

       This package generates all of the events of package nameserv, and two more. Both events are generated for
       the tag nameserv.

       lost-name
              This event is generated when a bound name is truly lost, i.e. could  not  be  restored  after  the
              temporary  loss  of  the  connection to the name server. It indicates that a different client took
              ownership of the name while this client was out of contact.

              The detail information of the event will be a Tcl dictionary containing two keys, name, and  data.
              Their values hold all the information about the lost name.

       re-connection
              This  event  is  generated  when the connection to the server is restored. The remembered data has
              been restored when the event is posted.

              The event has no detail information.

DESIGN

       The package is implemented on top of the regular nameservice client, i.e.  package nameserv.  It  detects
       the loss of the connection by listening for lost-connection events, on the tag nameserv.

       It  reacts to such events by starting a periodic timer and trying to reconnect to the server whenver this
       timer triggers. On success the timer is canceled,  a  re-connection  event  generated,  and  the  package
       proceeds to re-enter the remembered bound names and continous searches.

       Another  loss  of  the  connection,  be  it during or after re-entering the remembered information simply
       restarts the timer and subsequent reconnection attempts.

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes, will undoubtedly contain bugs and  other  problems.   Please
       report      such      in      the     category     nameserv     of     the     Tcllib     SF     Trackers
       [http://sourceforge.net/tracker/?group_id=12883].  Please also report any ideas for enhancements you  may
       have for either package and/or documentation.

SEE ALSO

       nameserv(3tcl)

KEYWORDS

       automatic, client, name service, reconnect, restore

CATEGORY

       Networking

COPYRIGHT

       Copyright (c) 2007-2008 Andreas Kupries <andreas_kupries@users.sourceforge.net>

nns                                                    0.3                                  nameserv::auto(3tcl)