The mdbd daemon is a companion to the dominator daemon. It queries one or more Machine DataBases and provides the dominator with information about machines (subs) to manage.
The daemon writes processed and filtered MDB data to a local file
(/var/lib/Dominator/mdb by default) which the
dominator can consume. Thus, both mdbd and
dominator must run on the same machine.
Mdbd is started at boot time, usually by one of the provided init scripts. The mdbd process is baby-sat by the init script; if the process dies the init script will re-start it. It may be stopped with the command:
service mdbd stopwhich also kills the baby-sitting init script. It may be started with the command:
service mdbd startThere are many command-line flags which may change the behaviour of mdbd but many have defaults which should be adequate for most deployments. Built-in help is available with the command:
mdbd -hThe init script reads configuration parameters from the
/etc/default/mdbd file. The following is the minimum likely
set of parameters that will need to be configured.
The USERNAME variable specifies the username that
mdbd should run as. Since mdbd does not need root
privileges, the init script runs mdbd as this user.
Mdbd requires "upstream" data sources. A configuration file
(/var/lib/mdbd/mdb.sources.list by default) specifies the
data sources to be collected from.
To directly query AWS for all running instances in a region, you
would use the following configuration file. It will query all the
accounts for which you have API keys in your
~/.aws/credentials file:
aws-localAn example configuration file which specifies to collect MDB data
from CIS (Cloud Intelligence Service, being developed at Symantec) for
the us-east-1 cluster is:
cis http://cis.us-east-1.aws.net:9200/aws/aws_nodes/_search?size=10000Since CIS is built on top of Elastic Search, the configuration is primarily an Elastic Search query.