Manpage of cblmd
Section: User Commands (1)
Updated: Oct 2006
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cblmd - Cheap Bastard Latency Monitor Daemon
cblmd [OPTION] <-H HOST[:PORT]>
is a high performance latency (one-way and round-trip), packet loss and jitter monitoring probe. When run on two or more servers, a full mesh of connections is automatically setup between the probes. The full mesh of connections are used to transmit UDP packets between the probes. Statistics are collected and stored within a MySQL database.
Probes may be added or removed from the full mesh in real time. To add a probe to the mesh, start a new probe configured to connect to the same MySQL database as the other probes. To remove a probe, shutdown the probe with a TERM signal. Settings for the full mesh of probes may be changed on any probe using the write option. These changes will be automatically propogated to all other probes.
NOTE: To generate accurate latency (one-way) statistics, all servers clocks must be syncronized via an NTP server. Round-trip statistics do not rely on a syncronized clock.
The newest version of CBLM is available at:
Options can be given in any order. Options without an argument can be combined after a single dash.
- -s, --source=IP
Source traffic from specified IP address. (Default: any)
- -p, --port=PORT
Listen for incoming traffic on specified PORT. (Default: 7447)
- -I, --interface=INTERFACE
Listen for incoming traffic on specified INTERFACE. (Default: any)
- -e, --name=STRING
Descriptive name for probe. Will be used to display results via web interface. (Default: reverse DNS)
- -r, --rate=NUM
The rate at which to transmit packets per minute from this probe. The rate is used per CoS marking. (Default: 120)
- -Q, --tos=TOS[:PRIORITY]
Transmit packets marked with specified ToS markings and priority. ToS is an 8 bit field within the IP header. Bits 2-7 are used for DSCP or bits 5-7 for Precedence. Values of 0 to 224 are valid for ToS values. A ToS value of 0 will provide Best Effort (DSCP: 0, Prec: 0). A ToS value of 64 will provide Assured Forwarding (DSCP: 16, Prec: 2). A ToS value of 128 will provide Network Control (DSCP: 32, Prec: 4). A ToS value of 192 will provide Network Control (DSCP: 48, Prec: 6). ToS values of 160 or more require root access. Priority allows vconfig(8) to map the specified priority (skb-priority) to the egress VLAN priority. Values of 1 to 7 are valid for priority. (Default: 0:0)
- -M, --dscp=DSCP[:PRIORITY]
Transmit packets marked with specified DSCP markings and priority. Values of 0 to 64 are valid for DSCP values. Priority allows vconfig(8) to map the specified priority (skb-priority) to the egress VLAN priority. Values of 1 to 7 are valid for priority. (Default: 0:0)
- -N, --precedence=PRECEDENCE[:PRIORITY]
Transmit packets marked with specified DSCP markings and priority. VAlues of 1 to 7 are valid for precedence. Priority allows vconfig(8) to map the specified priority (skb-priority) to the egress VLAN priority. Values of 1 to 7 are valid for priority. (Default: 0:0)
- -m, --maxttl=NUM
Maximum allowed one way TTL (time to live) in milliseconds between probes. (Default: 1000)
- -a, --maxage=NUM
Maximum age in second a probe may be out of contact with the database before being considered dead. (Default: 90)
- -k, --k=STRING
Key used to verify authorization of incoming packets. (Default: o-soraizu)
- -z, --size=BYTES
Size of transmited packet payload. (Default: 128)
- -x, --pattern=STRING
Pattern to load into packets payload. (Default: kusabana)
- -f, --fragment
Allow fragmentation of outgoing packets by disabling the DF (don't fragment) bit within the packet. (Default: off)
- -l, --ttl=NUM
Set outgoing packets time to live (TTL) to the specified value. Values between 1 and 255 are valid. (Default: 64)
- -X, --disable=<ott|jtr|tos|ooo|dup>
Disable the internal tracking of a feature such as OTT (one-way trip time), JTR (jitter), TOS, (type of service), OOO (out of order packets) or DUP (duplicate packets). This argument may be specified multiple times to disable more than one feature. (Default: none)
- -H, --dbhost=HOST[:PORT]
Use specified MySQL host and port for communication with the database. (Default: none)
- -S, --dbsock=SOCKET
Use specified MySQL socket for communication with the database. (Default: none)
- -D, --dbname=DATABASE
MySQL database to store data within. (Default: cblm)
- -U, --dbuser=USER
Use specified username for connecting to the database. (Default: cblm)
- -P, --dbpass=PASSWORD
Use specified password for connecting to the database. (Default: none)
- -C, --dbcomp
Use compression protocol to communicate with the database. (Default: off)
- -W, --write
Write locally specified preferences into the database and exit.
- -E, --print
Print probe preferences stored within the database and exit.
- -u, --user=USER
Run as user USER. (Default: current)
- -g, --group=GROUP
Run as group GROUP. (Default: current)
- -t, --chroot=DIR
Change root to DIRectory. (Default: none)
- -o, --stats[=FILE]
Write statistics information to FILE. (Default: /var/run/cblmd.stat)
- -n, --nice=[+/-]NUM
Run with a nice value of NUM. Values of -20 to 19 are valid. (Default: +5)
- -d, --debug[=INT]
Set the debug level to INT. Values of 1 to 9 are valid. (Default: off)
- -h, --help
Display the help/usage information.
- -v, --version
Display the version information.
Copyright (C) 2005-2006 Digital Genesis Software. All rights reserved.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License <http://www.gnu.org/copyleft/gpl.html>
for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
James M. Sella <email@example.com>
10/26/06 - Released version 2.9.4
06/20/06 - Released version 2.9.3
05/21/06 - Released version 2.9.2
05/02/06 - Released version 2.9.1
05/01/06 - Released version 2.9.0
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Time: 04:16:47 GMT, October 27, 2006