95th Percentile Bandwidth Monitoring
kenneth at mail1.ttak.org
Tue May 26 21:17:31 MDT 2009
Many data centers bill on the 95th percentile. Might anyone have a
suggestion for a good 95th percentile bandwidth monitoring tool? I
would prefer one that will take 5 minute snapshots and dump the bit
rates to a database (the 5 minute interval would also closely match the
interval to which data centers sample bit rates). This would enable me
to programmatically trigger other events. My firewalls are all Linux
based iptables systems (fronted with Shorewall).
I would like to be able monitor our data usage, to make sure we keep our
95th percentile at an acceptable level so we don't break the bank. I
would like to eventually have an automated script that will trigger, if
our usage is high for the month, and throttle our bandwidth down.
I thought about screen scraping the reports the data centers generate,
but I ran into a few snags. One data center has a reporting tool, but
it is too full of ajax to make screen scraping a viable option. The
other data center does not have an online reporting tool, but will
generate reports on demand.
I then found a list of many Linux based bandwidth monitoring tools, but
they all work like "top" and are not any good at giving me sampled data
at any interval. Then I thought about screen scraping TX/RX bytes from
"ifconfig", but I found out that the counters rolls over and the output
is not very consistent, which made screen scraping very ugly. I next
found vnstat has a timed traffic monitor, which I ran ever 5 minutes for
5 seconds, screen scraped the kB/s, which gave gave me more what I was
looking for, but I still think it is a pretty ugly hack. I am really
hoping to find a tool that will output what I am looking for in such a
way that I don't have to screen scrape it.
I also would like to generate reports, so I looked at Cacti, but this
appears to need to be pointed to an SNMP source. I saw a few mentions
of running an SNMP service on the Linux server. Would that get me the
bit rates I am looking for?
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