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Tree [70bda7] master ndoutils-2-0-0 / History
Hendrik Baecker
Read Me
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NDO README
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***************
!! IMPORTANT !!
***************
This code is still an alpha/beta quality, so expect problems if you intend to use
it. Make sure that you aren't using it with your only production installation of
Nagios, or it could take down the Nagios process if the NDOMOD module segfaults.
Nagios could segfault silently and you might never know that Nagios crashed...
****************
ABOUT THIS ADDON
****************
The NDOUTILS (Nagios Data Output Utils) addon allows you to move status and event
information from Nagios to a database for later retrieval and processing.
This addon consists of several parts. Here are the most interesting ones...
1. The NDOMOD event broker module. This module is intended to be loaded
by the Nagios process at runtime. Its only role is to dump all events and
data from Nagios to a TCP socket or a regular file or Unix domain socket on
the local filesystem somewhere. If you want realtime transfer of data to MySQL,
dump the data to a TCP or Unix domain socket. If you want delayed transfer of
data into MySQL (i.e. you need to transfer the data to another host first),
dump the data to a regular file.
2. The NDO2DB daemon. This standalone daemon reads input (that was produced
by the NDOMOD broker module) from a TCP or Unix domain socket, parses that
data, and then dumps it into one or more MySQL databases. The daemon is
capable of handling multiple client connections simultaneously, so you can
have multiple instances of the NDOMOD module writing to the same TCP or Unix
domain socket at the same time.
3. The FILE2SOCK utility. This simple utility reads data from a standard file
and dumps it to either a TCP or a Unix domain socket. This is useful if you
are having the NDOMOD module write to a standard file that you later want to
send to the NDO2DB daemon. If the module and the daemon are running on
different machines, you can periodically use SSH to transfer the file from the
monitoring machine to the machine running the NDO2DB daemon, and then use the
FILE2SOCK utility to send the contents of that file to the TCP socket or Unix
domain socket that the NDO2DB daemon is reading.
4. The LOG2NDO utility. This utility is used for importing historical log
archives from NetSaint and Nagios and sending them to the NDO2DB daemon.
It takes a single log file as its input and can output data to either a
TCP socket, a Unix domain socket or standard output.
**********************
COMPILING INSTRUCTIONS
**********************
Use the following commands to compile the NDO broker module, NDO2DB daemon, and
additional utilities:
./configure
make
If the configure script is unable to locate your MySQL or PostgreSQL development
libraries, you may need to help it out by using the --with-mysql-lib or
--with-pgsql-lib options. Here's an example:
./configure --with-mysql-lib=/usr/lib/mysql
*****************************
INITIALIZING THE SQL DATABASE
*****************************
Before you start using the NDO utilities, you should create the database where
you will be storing all Nagios-related information.
NOTE: As of 02/12/2006, only MySQL databases are supported. PostgreSQL support
will likely be added in the future.
1. Create a database for storing the data (e.g. 'nagios')
2. Create a username/password that has at least the following privileges for
the database:
SELECT, INSERT, UPDATE, DELETE
3. Run the DB installation script in the db/ subdirectory of the NDO distribution
to create the necessary tables in the database.
cd db
./installdb
4. Make sure the database name, prefix, and username/password you just created
and setup match the variable specified in the NDO2DB config file (see below).
***********************************
INSTALLING THE NDOMOD BROKER MODULE
***********************************
NOTE:
There are two different versions of the NDOMOD module that
get compiled, so make sure you use the module that matches the
version of Nagios you are running, and adjust the directions given
below to fit the name of the module version you're using.
ndomod-2x.o = NDOMOD module for Nagios 2.x
ndomod-3x.o = NDOMOD module for Nagios 3.x
ndomod-4x.o = NDOMOD module for Nagios 4.x (unstable)
1. Copy the compiled NDOMOD module to your Nagios installation:
cp src/ndomod-2x.o /usr/local/nagios/bin/ndomod.o
The command above assumes that you are using Nagios 2.x, and thus
are installing the 2.x version of the NDOMOD module.
2. Copy the sample NDOMOD config file to your Nagios installation
after modifying it to suit your needs:
cp config/ndomod.cfg /usr/local/nagios/etc
3. Add a line similiar to the following to the *main* Nagios config
file (usually /usr/local/nagios/etc/nagios.cfg):
broker_module=/usr/local/nagios/bin/ndomod.o config_file=/usr/local/nagios/etc/ndomod.cfg
The config directive above will cause Nagios to load the NDOMOD
event broker the next time it starts. Of course, this requres that
you compiled Nagios with support for the event broker in the first
place. :-)
4. Make sure you have a line similar to the following in the *main* Nagios
config file (usually /usr/local/nagios/etc/nagios.cfg):
event_broker_options=-1
That directive will cause the Nagios daemon to send data to the NDOMOD
module. Without that option, NDOMOD won't get any information.
5. ndomod processing options. As of ndoutils2.x, users can define which
types of data are processed and stored by ndoutils. Each of these options
can be defined in the ndomod.cfg file, and are considered a replacement for
previous ndomod_processing_options config option, which used a bitmask. The
following processing options are available.
acknowledgement_data=1
adaptive_contact_data=1
adaptive_host_data=1
adaptive_program_data=1
adaptive_service_data=1
aggregated_status_data=1
comment_data=1
contact_status_data=1
downtime_data=1
event_handler_data=1
external_command_data=1
flapping_data=1
host_check_data=1
host_status_data=1
log_data=1
main_config_data=1
notification_data=1
object_config_data=1
process_data=1
program_status_data=1
retention_data=1
service_check_data=1
service_status_data=1
statechange_data=1
system_command_data=1
timed_event_data=1
****************************
INSTALLING THE NDO2DB DAEMON
****************************
NOTE:
There are two different versions of the NDO2DB daemon that
get compiled, so make sure you use the daemon that matches the
version of Nagios you are running, and adjust the directions given
below to fit the name of the daemon you're using.
ndo2db-2x.o = NDO2DB daemon for Nagios 2.x
ndo2db-3x.o = NDO2DB daemon for Nagios 3.x
ndo2db-4x.o = NDO2DB daemon for Nagios 4.x
1. Copy the compiled NDO2DB daemon to your Nagios installation:
cp src/ndo2db-2x /usr/local/nagios/bin/ndo2db
The command above assumes that you are using Nagios 2.x, and thus
are installing the 2.x version of the NDO2DB daemon.
2. Copy the sample NDO2DB config file to your Nagios installation
after modifying it to suit your needs (pay attention to the DB
config settings).
cp config/ndo2db.cfg /usr/local/nagios/etc
3. Start the daemon running! An init script will be developed soon...
/usr/local/nagios/bin/ndo2db -c /usr/local/nagios/etc/ndo2db.cfg
************************
TUNING KERNEL PARAMETERS
************************
NDOUTILS uses a single message queue to communicate between the broker
module and the NDO2DB daemon. Depending on the operating system, there
may be parameters that need to be tuned in order for this communication
to work correctly. The discussion below applies specifically to Linux,
but may apply generally to other Unices as well.
There are three Linux kernel parameters that determine the resources
provided to the messaging subsystem:
* kernel.msgmax is the maximum size of a single message in a
message queue
* kernel.msgmni is the maximum number of messages allowed in any
one message queue
* kernel.msgmnb is the total number of bytes allow in all messages
in any one message queue
To see the current values for any of these parameters, cat
/proc/sys/kernel/msg{max|mni|mnb}.
In order for NDOUTILS to work at all, kernel.msgmax must be greater than
the size of the queue_msg struct (currently 1026 bytes). Most Linux
distributions set kernel.msgmax to a default of 65536.
If there are insufficient resources for sending messages between the
broker and the daemon, you will see an entry similar to the following
in your logs. (This is logged via the syslog facility, using the level
LOG_ERR and the default facility.)
ndo2db: Warning: Retrying message send. This can occur because
you have too few messages allowed or too few total bytes
allowed in message queues. You are currently using 16 of 16
mesages and 65536 of 65536 bytes in the queue. See README for
kernel tuning options.
If you see this entry, the message will likely eventually be sent,
but retrying uses system resources, and there is the possibility that
more messages will queued than can be handled, causing the broker
module to stall.
If you are close to or have exceeded the number of messages, you may
need to increase kernel.msgmni. If you are close to or have exceeded
the number of bytes in the queue, you may need to increase
kernel.msgmnb. In some cases you may need to increase both.
A conservative approach would be to double the necessary value, stop
and restart both the NDO2DB daemon and Nagios Core, and watch for any
further messages. Note that if NDO2DB is started after Nagios Core,
you may see the warning above as the broker module first attempts to
flush its backlog of messages.
To increase a value, echo the value to /proc/sys/kernel/msgmni or
/proc/sys/kernel/msgmnb as appropriate.
For example, to increase the number of messages allowed in the queue
to 32, use the command 'echo 32 > /proc/sys/kernel/msgmni' (without
the quotes).
Once you have determine the correct parameters, you can make them
permanent by editing /etc/sysctl.conf. Add or update the line of
the form 'kernel.msg{mni|mnb} = <value>' with the value(s) determined
above. The next time the system is booted, the values of the
parameters in /etc/sysctl.conf will be loaded.