Re: DNS performance

From: Thomas Lee (tfl_at_psp.co.uk)
Date: 12/01/04 

Date: Wed, 1 Dec 2004 17:51:17 +0000

In message <eXxH3731EHA.3816@TK2MSFTNGP09.phx.gbl>, Dave Munday
<thehappymundays@hotmail.com> writes
>Hi
>
>I have a piece of 3Com network monitoring software that is reporting a high
>response time from my DNS servers typically 5000 ms against a threshold of
>1000 ms.
>
>I know the built in performance momnitor has many counters relating to DNS
>is there anything in particular I should look at.
>
>My servers are dual processors with a gigabit of RAM and normail file and
>print serivces run slowly.

Your starting point is to look at the fab-4: CPU utilisation, Disk
utilisation, Memory usage (particularly paging) and network I/O. From
the fact that DNS is slow, and your file/print is running slow, suggests
you have a bottle neck somewhere.

On a well tuned system, you'll see:

1. CPU utilisation for the system fairly low (if you see sustained > 70%
with lots of peaks higher, you may have a CPU bottle neck. Also, the CPU
queue should, in your case, be 2 or less.

2. Memory - pages/second - this should be less than 5-10/sec on a
sustained basis.

3. Disk I/O - %IO should be less than 30% on s sustained basis.

4. Network - your link should be less than around 40% used.

Above these numbers you may have an issue, which you can then drill down
into.

HTH

Thomas 

-- 
Thomas Lee
doctordns@gmail.com

Relevant Pages

  • Re: Windows cannot find the network path error message in GPMC
    ... Preferred DNS server. ... bar of the Network Connections window, ... sure you have Forwarders to your ISP DNS servers Enabled. ... preventing access to this computer from the Internet" is Not checked on this ...
    (microsoft.public.windows.group_policy)
  • Re: User GPO doesnt replicate on one of my workstations
    ... client computers* ... all computers on the network must use the DNS servers for the ... sure that the IP addresses for the preferred and alternate DNS servers are ...
    (microsoft.public.windows.group_policy)
  • Re: DNS poisoning or ??
    ... Knowing that the suspected IP address is on the Internap network, if you issue an nslookup against one of the Internap DNS servers for information regarding your domain, you will notice that the Internap DNS server is handing out false/misleading information for mail.greenborder.com when #1) they don't own the domain in question, and #2) such DNS record does not exist for the domain in question. ... Interestingly enough, if you lookup the same record against the primary DNS servers listed when you issue a $ whois 216.52.7.214, the DNS ... So the issue at hand is being propagated by the other DNS servers listed above NS-A through NS-D.PNAP.NET (on the 64.95.x.x network). ...
    (Security-Basics)
  • Re: FQDN
    ... These servers would be on the network and not accessible until the network is up and running. ... It may also be useful for naming systems on a small local network (I have 3 systems on my local lan, too few to warrant the overhead and knowledge requirement to set up a local DNS server), and to provide basic name services for times with the DNS servers are not available, due to network issues or system crashes. ... You tell your system how you want it to use the various name service providers (hosts file, DNS, others) using the /etc/nsswitch.conf file. ...
    (Debian-User)
  • Re: Windows Hangs
    ... Well, the first thing you have to look at is the event logs, the CPU and ... You should also consider looking at DNS, as slow responses pulling ... information from AD would indicate that one or more of your DNS servers are ...
    (microsoft.public.windows.server.active_directory)