UML test server - Versionsgeschichte

Datacop: Änderungen von Valera (Diskussion) rückgängig gemacht und letzte Version von Datacop wiederhergestellt

2012-03-04T00:55:14Z

Änderungen von Valera (Diskussion) rückgängig gemacht und letzte Version von Datacop wiederhergestellt

Valera: /* User HOWTO */

2010-11-03T15:45:05Z

‎User HOWTO

Datacop: spam removed

2010-07-19T21:28:02Z

spam removed

Anstett454 am 19. Juli 2010 um 12:16 Uhr

2010-07-19T12:16:18Z

Ann999 am 19. Juli 2010 um 07:59 Uhr

2010-07-19T07:59:27Z

Aaron: /* List of cross dev instances / IP assignment */

2007-11-30T19:01:02Z

‎List of cross dev instances / IP assignment

Aaron: /* List of cross dev instances / IP assignment */

2007-11-30T19:00:45Z

‎List of cross dev instances / IP assignment

Aaron: table of running images

2007-11-28T10:34:15Z

table of running images

Aaron: add ip list

2007-11-28T10:19:25Z

add ip list

Hannes: give UML server pages a new home

2007-11-24T13:04:07Z

give UML server pages a new home

Neue Seite

= [http://www.user-mode-linux.org UML] test server =

current load and statistics: http://texas.funkfeuer.at

[[Bild:Texas.funkfeuer.at.png|right|300px|our UML server]]

[[Bild:Topology-1-small.png|center|600px|topo map 1500 UML instances running in parallel. Note the packetloss!]]
(check out the [[TopologyPics archive]] also)

topo map 1500 UML instances running in parallel. Note the packetloss!

We have already been running 2000 instances and there was still plenty of RAM left. So 1000 is a very safe bet. However according to the UML docu we can probably safely assume that we can scale up miuch higher because UML will only take the RAM that each instance actually needs.
UML actually has other shortcomings: high CPU overhead, lots of context swiches. Trying to increase the performance at the moment...

== current open todos UML server ==
Next important (*) things to do:
* DONE(aka) update texas's BIOS - FIXED
* add the packet loss tc rules (zethix already prepared it)
* create random netowkrs (easy)
* create network topologies based on a power law distribution ( a bit harder, but realistic for the internet)
* DONE(zethix) create scripts to find out which olsrd instances crashed
* create scripts to find out if a UML instance is not responsive anymore
* find better measurement tools . Look into sar
* DONE(aka) recompile host kernel and get rid of the "BUG: soft lockup detected on CPU#0!" messages
* DONE(aka) recompile host kernel and enable the preemtion patch
* DONE(zethix,aka) make hostfs so that developers can easily upload a new olsrd version to all uml instances. They should see the difference easily. Look into hostfs
* DONE(ake) increase performance of the UML simulator itself (decrease HZ, look into SKAS3 patch again, 32 bit recompile, talk with jeff etc)
* find more meaningful topology visualization tools (http://www.caida.org)
* add b.a.t.m.a.n to the root filesystem. (?)
* compare the scheduling / scalability of the test with [http://openvz.org/ OpenVZ] and [http://www.olsr.org/docs/README-Olsr-Switch.html olsr_switch]

== User HOWTO ==

NOTE! You are root on the system. Effectively we need lots of sudo privs. So... use it wisely.

# log in
# make clean
# edit common.sh and adapt the parameters to your needs
#!/bin/sh
#
# VARS
#
MAX_INSTANCES=1500
ROOT_FS=root_fs
NICELVL="-n 5"
u=$USER
#SINGLE=1
We supply you with a good working root filesystem (root_fs) so no need to change that. The SINGLE parameter just says that you want to start a single instance and be logged in (needed for debugging purposes)
# the UML instance can read files and programs from
$HOME/public_uml/share
This is where you can put your programs or your version of olsrd (and its libs) or the B.A.T.M.A.N. binaries.

N.B. This directory is shared between all UML instances that you will
start in your simulation, so, they all have read-only access to it.
It will appear inside each UML as /mnt/share/. There is also another,
per-instance, read-write directory that you can use to save data for
later analysis (e.g. redirect olsrd stdout to a file and print some
debugging info there). This second directory will be under
$HOME/public_uml/exp/<UML IP> (where UML IP is the ip address of each
UML instance). It will also appear as /mnt/exp inside UML's environment.

# put your special rcS file into $HOME/public_uml/share/etc/init.d/ . This rcS file will be called from the UML instances /etc/init.d/rcS startup script. Starting olsrd etc must be done from this user supplied rcS. In case there is no user supplied rcS, then the standard olsrd with the standard settings of the root_fs (/etc/olsrd.conf) us started.

# make

This will start the simulation.

N.B. When the simulation is started, an olsrd instance is started on
the host as well. You can use it if you need to interact with the
olsrd network - for instance, topology maps are generated through this
instance (see below).

# Issuing commands inside UML manually - the 'make' command creates a screen session for every UML process it creates, and redirects its input and output there. You can use screen to attach to a particular session. Use
screen -ls (as root)
to list all available sessions, and
screen -S blabla.10.0.x.y -d -RR
to attach to a session. This will give you shell access to the system.

N.B. All modifications to the root filesystem will be preserved only
for the duration of the simulation! Once it is stopped, changes will
be lost!

# observe the success on http://texas.funkfeuer.at or create a new topo map via ( cd /var/www/topo; ./doit.sh ). If you see a [http://en.wikipedia.org/wiki/Complete_graph complete graph], then your version has little packetloss!

# stop it via
make clean
or
make stop

Please make sure (by looking at http://texas.funkfeuer.at) if you are the only person running a simulation at the moment!

'''Some things to note'''

* the topology visualisation scripts run with nice level +5
the UML instances with nicelevel +10 (see run.sh)
-> Never ever go higher than nicelevel 0 because then you will disturb the system monitoring (munin) tools and we will not be able to see what the seimulation is doing.
*

== Open questions/bug reports? ==

@@ Zeile 1: / Zeile 1: @@
 = [http://www.user-mode-linux.org UML] test server =
-current load and statistics: [http://www.bestessays.com.au/ dissertation]
+current load and statistics: http://texas.funkfeuer.at
 == List of cross dev instances / IP assignment ==

@@ Zeile 1: / Zeile 1: @@
 = [http://www.user-mode-linux.org UML] test server =
-current load and statistics: [http://www.bestessays.com.au/dissertation-services.php dissertation]
+current load and statistics: [http://www.bestessays.com.au/ dissertation]
 == List of cross dev instances / IP assignment ==

@@ Zeile 1: / Zeile 1: @@
 = [http://www.user-mode-linux.org UML] test server =
-current load and statistics: http://texas.funkfeuer.at
+current load and statistics: [http://www.bestessays.com.au/dissertation-services.php dissertation]
 == List of cross dev instances / IP assignment ==

@@ Zeile 17: / Zeile 17: @@
 | linux
 |<font color=green>OK</font>
-|-|-
+|-
 |10.254.0.1
 | openbsd

@@ Zeile 12: / Zeile 12: @@
 !align="left" | status
 |-
 |10.254.0.1
 | openbsd
@@ Zeile 53: / Zeile 59: @@
 We have already been running 2000 instances and there was still  plenty of RAM left. So 1000 is a very safe bet. However according to the UML docu we can probably safely assume that we can scale up miuch higher because UML will only take the RAM that each instance actually needs.
 UML actually has other shortcomings: high CPU overhead, lots of context swiches. Trying to increase the performance at the moment...
 == current open todos UML server ==

@@ Zeile 143: / Zeile 143: @@
 -> Never ever go higher than nicelevel 0 because then you will disturb the system monitoring (munin) tools and we will not be able to see what the seimulation is doing.
+*
 == Open questions/bug reports? ==

@@ Zeile 5: / Zeile 5: @@
 == List of cross dev instances / IP assignment ==
-.254.0.1 ............ openbsd (qemu, i386). <font color=red>NOT OK</font>
+{| width="100%" border=0 class="events vcalendar"
-.254.0.2 ............ freebsd (qemu, i386). <font color=red>NOT OK</font>
+!align="left" width="150" | IP
-.254.0.3 ............ netbsd (qemu, i386). <font color=red>NOT OK</font>
+!align="left" | OS
-.254.0.3 ............ netbsd (qemu, i386). <font color=red>NOT OK</font>
+!align="left" | plattform
+!align="left" | screen session

← Nächstältere Version		Version vom 28. November 2007, 10:19 Uhr
Zeile 2:		Zeile 2:

	current load and statistics: http://texas.funkfeuer.at		current load and statistics: http://texas.funkfeuer.at
		+
		+	== List of cross dev instances / IP assignment ==
		+
		+	10.254.0.1 ............ openbsd (qemu, i386). <font color=red>NOT OK</font>
		+	10.254.0.2 ............ freebsd (qemu, i386). <font color=red>NOT OK</font>
		+	10.254.0.3 ............ netbsd (qemu, i386). <font color=red>NOT OK</font>
		+	10.254.0.3 ............ netbsd (qemu, i386). <font color=red>NOT OK</font>
		+
		+

	[[Bild:Texas.funkfeuer.at.png\|right\|300px\|our UML server]]		[[Bild:Texas.funkfeuer.at.png\|right\|300px\|our UML server]]