logForwarder man page

logForwarder — Log item to manage ssh tunnels between log components and tools


logForwarder - Tools for creating and maintaining ssh tunnels between log components in complex topologies


logForwarder [options] ...


logForwarder helps simplifying the maintenance of ssh tunnels between log components and tools, thus improving log scalability and configuration in complex network topologies. The components may be defined in a program to be monitored, they publish messages in the LogCentral. The tools get the messages subscribing to the LogCentral.

Before starting a log forwarder, you must:

  • launch omniNames on the local and remotes hosts.
  • launch the remote peer only defining its name and network configuration.
  • launch local peer and give him remote peer's name, ssh connection credentials, remote port to use and pass -C option to create the ssh tunnel.

[Remark: forwarders must be launched before the log tools/components]


--name [name]

String identifying the forwarder

--peer-name [name]

String identifying its peer on the other network

--ssh-host [host]

Host hosting the ssh tunnel

--ssh-login [login]

Login used to establish the ssh connection (default: current user login).

--ssh-key [/path/to/ssh/key]

Path to the ssh key (the private one !) used to establish the ssh connection (default: $HOME/.ssh/id_rsa).

--remote-port [port]

Port listening on the ssh host.

--remote-host [host]

Host to which the connection is made by the tunnel (corresponds to ssh options -L and -R).

--nb-retry [nb]

Number of times that the local forwarder will try to bind itself to the remote forwarder (default: 3).

--peer-ior [IOR]

Pass remote forwarder's IOR. By default, the local forwarder will retrive its peer IOR.


Here's a simple configuration:

  • We have two domains: net1 and net2, forwarders will be launched on hosts fwd.net1 and fwd.net2.
  • There's no link between hosts fwd.net1 and fwd.net2 but user may access fwd.net2 from fwd.net1 using a ssh connection.
  • We'll name fwd.net1 forwarder Fwd1 and fwd.net2 fowarder Fwd2.
  • One tool lives in fwd.net2 while a component lives on the net1 domain.

Command line for launchind Fwd1

fwd.net1$ logForwarder --name Fwd1 --peer-name Fwd2 \
  --ssh-host fwd.net2 --ssh-login dietUser \
  --ssh-key id rsa net2 --remote-port 50000

Command line to launch Fwd2

fwd.net2$ logForwarder --name Fwd2


The log service uses CORBA as its communication layer. While it's a flexible and robust middleware, it remains hard deploying the log on heterogeneous networks that are not reachable except through ssh tunnels. Log forwarders help administrator configuring their grid without manually set-up ssh tunnels which arguably is neither simple nor scalable. Log forwarders make it very easy configuring such topologies.


GRAAL INRIA Rhone-Alpes 46 allee d'Italie 69364 Lyon cedex 07, FRANCE Email: <diet-dev@ens-lyon.fr> WWW: http://graal.ens-lyon.fr/DIET

See Also

omniNames(1), dietForwarder(1), LogCentral(1)


On some systems, forwarder rules won't work unless you use IP addresses instead of hostnames


haikel.guemar@sysfera.com, kevin.coulomb@sysfera.com

License: GPLv3

Referenced By

DIETtestTool(1), LogCentral(1), testComponent(1).

2011-05-11 0.1