curl-loader-devel

curl-loader needs a big WARNING message

[Edward L. <ed...@je...>]

I recently tried to use curl-loader to test a production server.  I
didn't realize (until looking at the source) that curl-loader made
kernel calls to modify the network configuration of the server it runs
on (i.e. adding static IP addresses to server and changing the routing
table).

 

I assumed that the INTERFACE, IP_ADDR_MIN and IP_ADDR_MAX worked with
definitions that already existed, vs actually making them.  Creating
these definitions is potentially VERY DANGEROUS, especially if the
program is run on a production system.  Most folks will want to run
tools like cur-loader on systems that are on the same segment as the
server they're testing.  For me, this meant running it on another
production server since we work with a hosting provider.  The resulting
curl-loader changes to the IP configuration of the machine it ran on
caused 1 week of general mayhem.

 

Suggestions:

 

1)      Add a BIG warning about IP network configuration by curl-loader

2)      Create a -changeNetworkIfNeeded option.  Without this option,
curl-loader will attempt to satisfy INTERFACE, IP_ADDR_MIN and
IP_ADDR_MAX without reconfiguring the network of the host it runs on.
If the host can't satisfy what's requested, curl-loader errors out,
telling the user to use the changeNetworkIfNeeded option to make the
test work.

Re: curl-loader needs a big WARNING message

[Robert I. <cor...@gm...>]

Hi Edward,

On Wed, Nov 26, 2008 at 8:24 PM, Edward Lott <ed...@je...> wrote:

>  I recently tried to use curl-loader to test a production server.  I
> didn't realize (until looking at the source) that curl-loader made kernel
> calls to modify the network configuration of the server it runs on (i.e.
> adding static IP addresses to server and changing the routing table).
>

It is a testing tool, isn't it? The place for testing tools are
at testing machines in the lab.

>
>
> I assumed that the INTERFACE, IP_ADDR_MIN and IP_ADDR_MAX worked with
> definitions that already existed, vs actually making them.  Creating these
> definitions is potentially VERY DANGEROUS, especially if the program is run
> on a production system.  Most folks will want to run tools like cur-loader
> on systems that are on the same segment as the server they're testing.  For
> me, this meant running it on another production server since we work with a
> hosting provider.  The resulting curl-loader changes to the IP configuration
> of the machine it ran on caused 1 week of general mayhem.
>
>
>
> Suggestions:
>
>
>
> 1)      Add a BIG warning about IP network configuration by curl-loader
>
I am in disagreement with you.

> 2)      Create a –changeNetworkIfNeeded option.  Without this option,
> curl-loader will attempt to satisfy INTERFACE, IP_ADDR_MIN and IP_ADDR_MAX
> without reconfiguring the network of the host it runs on.  If the host can't
> satisfy what's requested, curl-loader errors out, telling the user to use
> the changeNetworkIfNeeded option to make the test work.
>

There are options for doing that, please read the FAQs.

Truly,
Robert Iakobashvili, Ph.D.
......................................................................
www.ghotit.com
Assistive technology that understands you
......................................................................

Re: curl-loader needs a big WARNING message

[Robert I. <cor...@gm...>]

Hi,

On Wed, Nov 26, 2008 at 8:24 PM, Edward Lott <ed...@je...> wrote:
>
> I recently tried to use curl-loader to test a production server.  I didn't realize (until looking at the source) that curl-loader made kernel calls to modify the network configuration of the server it runs on (i.e. adding static IP addresses to server and changing the routing table).

The extract from the README file in curl-loader-<version> directory:

================================================================
 IP-addresses from IP_ADDR_MIN up to IP_ADDR_MAX are the interval to
be used for
 loading clients. The interval of the addresses should be large enough
to supply
 a dedicated IP for each client. Another mode that can be used is "single IP
 address" for all clients. When IP_ADDR_MIN and IP_ADDR_MAX have the same valid
 IP-address, it will be used for all clients. If the IP-addresses specified by
 the tags do not exist, curl-loader adds them as the secondary IPs to
the loading
network interface.
Remember, that you should ensure smooth routing from the addresses used to
server and from server back to the client addresses. Another route to ensure,
 when is appropriate, is to/from DNS server for resolving. Firewalling
(netfilter/iptables) settings are also among those to check.

=============================================================

Still, you might wish to improve the documentation, and send your patches for
README file, FAQs. man-pages, web-site, etc as the unified diff to the list.

Note, that we do not have any doc writers, therefore, such assistance would
be very much appreciated.

--
Truly,
Robert Iakobashvili, Ph.D.
......................................................................
www.ghotit.com
Assistive technology that understands you
......................................................................