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Complete XML Reference



Your platform description should follow the specification presented in the simgrid.dtd DTD file. The same DTD is used for both platform and deployment files.

<config>

Adding configuration flags directly into the platform file becomes particularly useful when the realism of the described platform depends on some specific flags. For example, this could help you to finely tune SMPI. Almost all :ref:`command-line configuration items <options_list>` can be configured this way.

Each configuration flag is described as a :ref:`pf_tag_prop` whose id is the name of the flag and value is what it has to be set to.

Parent tags: :ref:`pf_tag_platform` (must appear before any other tags)
Children tags: :ref:`pf_tag_prop`
Attributes: none

<?xml version = '1.0'?>
<!DOCTYPE platform SYSTEM "https://simgrid.org/simgrid.dtd">
<platform version = "4.1">
  <config>
    <prop id = "maxmin/precision" value = "0.000010" />
    <prop id = "cpu/optim" value = "TI" />
    <prop id = "network/model" value = "SMPI" />
    <prop id = "smpi/bw-factor" value = "65472:0.940694;15424:0.697866;9376:0.58729" />
  </config>

  <!-- The rest of your platform -->
</platform>

<host>

A host is the computing resource on which an actor can run. See :cpp:class:`simgrid::s4u::Host`.

Parent tags: :ref:`pf_tag_zone` (only leaf zones, i.e., zones containing neither inner zones nor clusters)
Children tags: :ref:`pf_tag_mount`, :ref:`pf_tag_prop`, :ref:`pf_tag_storage`
Attributes:

id:

Host name. Must be unique over the whole platform.
speed:

Computational power (per core, in flop/s). If you use DVFS, provide a comma-separated list of values for each pstate (see :ref:`howto_dvfs`).
core:

Amount of cores (default: 1). See :ref:`howto_multicore`.
availability_file:

File containing the availability profile. Almost every lines of such files describe timed events as date ratio. Example:

1 0.5
2 0.2
5 1
LOOPAFTER 5
  • At time t = 1, half of the host computational power (0.5 means 50%) is used to process some background load, hence only 50% of this initial power remains available to your own simulation.
  • At time t = 2, the available power drops at 20% of the initial value.
  • At time t = 5, the host can compute at full speed again.
  • At time t = 10, the profile is reset (as we are 5 seconds after the last event). Then the available speed will drop again to 50% at time t = 11.

If your profile does not contain any LOOPAFTER line, then it will be executed only once and not repeated.

Warning

Don't get fooled: Bandwidth and Latency profiles of a :ref:`pf_tag_link` contain absolute values, while Availability profiles of a :ref:`pf_tag_host` contain ratios.
state_file:

File containing the state profile. Almost every lines of such files describe timed events as date boolean. Example:

1 0
2 1
LOOPAFTER 8
  • At time t = 1, the host is turned off (a zero value means OFF)
  • At time t = 2, the host is turned back on (any other value than zero means ON)
  • At time t = 10, the profile is reset (as we are 8 seconds after the last event). Then the host will be turned off again at time t = 11.

If your profile does not contain any LOOPAFTER line, then it will be executed only once and not repeated.
coordinates:

Vivaldi coordinates (meaningful for Vivaldi zones only). See :ref:`pf_tag_peer`.
pstate:

Initial pstate (default: 0, the first one). See :ref:`howto_dvfs`.

<link>

SimGrid links usually represent one-hop network connections (see :cpp:class:`simgrid::s4u::Link`), i.e., a single wire. They can also be used to abstract a larger network interconnect, e.g., the entire transcontinental network, into a single element.

Parent tags: :ref:`pf_tag_zone` (both leaf zones and inner zones)
Children tags: :ref:`pf_tag_prop`
Attributes:

id:

Link name. Must be unique over the whole platform.
bandwidth:

Maximum bandwidth for this link. You must specify a unit as follows.

Units in bytes and powers of 2 (1 KiBps = 1,024 Bps):

Bps, KiBps, MiBps, GiBps, TiBps, PiBps, or EiBps.

Units in bits and powers of 2 (1 Bps = 8 bps):

bps, Kibps, Mibps, Gibps, Tibps, Pibps, or Eibps.

Units in bytes and powers of 10 (1 KBps = 1,000 Bps):

Bps, KBps, MBps, GBps, TBps, PBps, or EBps.

Units in bits and powers of 10:

bps, Kbps, Mbps, Gbps, Tbps, Pbps, or Ebps.
latency:

Latency for this link (default: 0.0). You must specify a unit as follows.

Unit

Meaning

Duration in seconds

ps

picosecond

10⁻¹² = 0.000000000001

ns

nanosecond

10⁻⁹ = 0.000000001

us

microsecond

10⁻⁶ = 0.000001

ms

millisecond

10⁻³ = 0.001

s

second

1

m

minute

60

h

hour

60 * 60

d

day

60 * 60 * 24

w

week

60 * 60 * 24 * 7
sharing_policy:

Sharing policy for the link. Possible values are SHARED, FATPIPE or SPLITDUPLEX (default: SPLITDUPLEX).

If set to SPLITDUPLEX, the link models the full-duplex behavior, as meant in TCP or UDP. To that extend, the link is actually split in two links whose names are suffixed with "_UP" and "_DOWN". You should then specify the direction to use when referring to that link in a :ref:`pf_tag_link_ctn`.

If set to FATPIPE, flows have no impact on each other, hence each flow can exploit the full bandwidth. This models Internet backbones that cannot get saturated by your application. From your application point of view, there is no congestion on these backbones.

If set to SHARED, the available bandwidth is fairly shared among ALL flows traversing this link. The resulting link is not full-duplex (as UDP or TCP would be): communications in both directions share the same link. Prefer SPLITDUPLEX for TCP flows.
bandwidth_file:

File containing the bandwidth profile. Almost every lines of such files describe timed events as date bandwidth (in bytes per second). Example:

4.0 40000000
8.0 60000000
LOOPAFTER 12.0
  • At time t = 4, the bandwidth is of 40 MBps.
  • At time t = 8, it raises to 60MBps.
  • At time t = 24, it drops at 40 MBps again.

If your profile does not contain any LOOPAFTER line, then it will be executed only once and not repeated.

Warning

Don't get fooled: Bandwidth and Latency profiles of a :ref:`pf_tag_link` contain absolute values, while Availability profiles of a :ref:`pf_tag_host` contain ratios.
latency_file:
File containing the latency profile.

Almost every lines of such files describe timed events as date latency (in seconds). Example:

1.0 0.001
3.0 0.1
LOOPAFTER 5.0
  • At time t = 1, the latency is of 1ms (0.001 second)
  • At time t = 3, the latency is of 100ms (0.1 second)
  • At time t = 8 (5 seconds after the last event), the profile loops.
  • At time t = 9 (1 second after the loop reset), the latency is back at 1ms.

If your profile does not contain any LOOPAFTER line, then it will be executed only once and not repeated.

Warning

Don't get fooled: Bandwidth and Latency profiles of a :ref:`pf_tag_link` contain absolute values, while Availability profiles of a :ref:`pf_tag_host` contain ratios.
state_file:

File containing the state profile. See :ref:`pf_tag_host`.

<link_ctn>

An element in a route, representing a previously defined link.

Parent tags: :ref:`pf_tag_route`
Children tags: none
Attributes:

id:Link that is to be included in this route.
direction:either UP (by default) or DOWN, specifying whether to use the uplink or downlink component of the link (that must follow the SPLITDUPLEX sharing policy).
Please refer to the sharing_policy attribute in :ref:`pf_tag_link`.

<peer>

This tag represents a peer, as in Peer-to-Peer (P2P) networks. It is handy to model situations where hosts have an asymmetric connectivity. Computers connected through set-top-boxes usually have a much better download rate than their upload rate. To model this, <peer> creates and connects several elements: an host, an upload link and a download link.

Parent tags: :ref:`pf_tag_zone` (only with Vivaldi routing)
Children tags: none
Attributes:

id:

Name of the host. Must be unique on the whole platform.
speed:

Computational power (in flop/s).

If you use DVFS, provide a comma-separated list of values for each pstate (see :ref:`howto_dvfs`).
bw_in:

Bandwidth of the private downstream link, along with its unit. See :ref:`pf_tag_link`.
bw_out:

Bandwidth of the private upstream link, along with its unit. See :ref:`pf_tag_link`.
lat:

Latency of both private links. See :ref:`pf_tag_link`.
coordinates:

Coordinates of the gateway for this peer.

The communication latency between a host A = (xA,yA,zA) and a host B = (xB,yB,zB) is computed as follows:

latency = sqrt( (xA-xB)² + (yA-yB)² ) + zA + zB

See the documentation of :cpp:class:`simgrid::kernel::routing::VivaldiZone` for details on how the latency is computed from the coordinates, and on how the up and down bandwidth are used.
availability_file:

File containing the availability profile. See the full description in :ref:`pf_tag_host`
state_file:

File containing the state profile. See the full description in :ref:`pf_tag_host`

<platform>

Parent tags: none (this is the root tag of every file)
Children tags: :ref:`pf_tag_config` (must come first), :ref:`pf_tag_cluster`, :ref:`pf_tag_cabinet`, :ref:`pf_tag_peer`, :ref:`pf_tag_zone`, :ref:`pf_tag_trace`, :ref:`pf_tag_trace_connect`, or :ref:`pf_tag_actor` in :ref:`deployment <deploy>` files.|br| Attributes:

version:Version of the DTD, describing the whole XML format. This versionning allow future evolutions, even if we avoid backward-incompatible changes. The current version is 4.1. The simgrid_update_xml program can upgrade most of the past platform files to the most recent formalism.

<prop>

This tag can be used to attach user-defined properties to some platform elements. Both the name and the value can be any string of your wish. You can use this to pass extra parameters to your code and the plugins.

From your code, you can interact with these properties using the following functions:

Parent tags: :ref:`pf_tag_actor`, :ref:`pf_tag_config`, :ref:`pf_tag_cluster`, :ref:`pf_tag_host`, :ref:`pf_tag_link`, :ref:`pf_tag_storage`, :ref:`pf_tag_zone`
Children tags: none
Attributes:

id:Name of the defined property.
value:Value of the defined property.

<route>

A path between two network locations, composed of several occurences of :ref:`pf_tag_link` .

Parent tags: :ref:`pf_tag_zone`
Children tags: :ref:`pf_tag_link_ctn`
Attributes:

src:Host from which this route starts. Must be an existing host.
dst:Host to which this route leads. Must be an existing host.
symmetrical:Whether this route is symmetrical, ie, whether we are defining the route dst -> src at the same time. Valid values: yes, no,``YES``, NO.

<router>

A router is similar to a :ref:`pf_tag_host`, but it cannot contain any actor. It is only useful to some routing algorithms. In particular, they are useful when you want to use the NS3 bindings to break the routes that are longer than 1 hop.

Parent tags: :ref:`pf_tag_zone` (only leaf zones, i.e., zones containing neither inner zones nor clusters)
Children tags: :ref:`pf_tag_prop`, :ref:`pf_tag_storage`
Attributes:

id:Router name. No other host or router may have the same name over the whole platform.
coordinates:Vivaldi coordinates. See :ref:`pf_tag_peer`.

<zone>

A networking zone is an area in which elements are located. See :cpp:class:`simgrid::s4u::Zone`.

Parent tags: :ref:`pf_tag_platform`, :ref:`pf_tag_zone` (only internal nodes, i.e., zones containing only inner zones or clusters but no basic elements such as host or peer)
Children tags (if internal zone): :ref:`pf_tag_cluster`, :ref:`pf_tag_link`, :ref:`pf_tag_zone`
Children tags (if leaf zone): :ref:`pf_tag_host`, :ref:`pf_tag_link`, :ref:`pf_tag_peer`
Attributes:

id:Zone name. No other zone may have the same name over the whole platform.
routing:Routing algorithm to use.