User’s Guide – version 3.5
NetFlow Tracker
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AS Names
This page lets you assign names to AS numbers appearing in reports. AS numbers
below 34816 are assigned by several agencies; NetFlow Tracker comes with many of
these ASes already named. Numbers between 34816 and 64511 are held by the
IANA and should not be used. Numbers above 64511 are for private use and can be
named using this page. You can assign or edit the name for a public or reserved AS by
clicking “(more…)” in the title of the AS column.
Subnet Names
This page lets you assign names to the IP subnets that appear in reports. The network
mask length appearing in a network report is the one used by the router to route the
traffic described, so you may need to configure names for subnets that overlap.
Database Settings
This page lets you improve the performance of reports and charts, and change the
number of days for which data is retained.
•
Expect large result sets controls the method by which the database server
manipulates raw data. If you have a fast disk subsystem you should set this to
“Always” to ensure reports over large amounts of data perform well. If you have a
slower disk subsystem, lots of RAM and a relatively small amount of data, you
might consider setting this to “Never”, but bear in mind that reports over large
amounts of data may take considerably longer to run.
•
Maximum in-memory temporary table size is the maximum amount of memory the
database server will use during a query when it has been told not to expect a large
result set. Increasing this will increase the amount of data that can be reported on
with “Expect large result sets” set to “Never” before there is a significant drop in
performance.
•
Sort buffer size is the size of the buffer used to reduce the amount of disk seeks
when sorting rows for grouping or final display. Increasing this will improve
reporting speed, but you are unlikely to see much improvement for sizes above
128MB.
•
Hold back real-time data for determines the number of seconds after its end each
one-minute sample of real-time data is held in RAM before being committed to
disk. You may need to increase this to avoid
ignored flows
.
•
MySQL can not access temporary files should be unchecked to improve the
performance of inserts database. However, it is possible that on Unix the user the
NetFlow Tracker user runs as has a umask that creates temporary files that
MySQL cannot read; in this case you must check this setting.
•
Number of threads to use to generate a report controls the number of threads
used to generate real-time charts over time and pie charts. You should not set
this to more than the number of CPU cores in your system and are unlikely to see
any benefit beyond 4.
