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Subject: Re: mod_sflow
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From: Neil McKee <neil.mckee@inmon.com>
In-Reply-To: <20110110235249.3c2d2269@baldur>
Date: Tue, 11 Jan 2011 16:21:48 -0800
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 <20110110235249.3c2d2269@baldur>
To: modules-dev@httpd.apache.org

I removed all the ap_assert() calls.

The "master" process that is forked at the beginning will simply bow-out =
gracefully if it loses self-confidence,  which will result in the pipe =
being closed.  When a child processes detects this (or any other IPC or =
mutex problem) it will log an error and go into a "logging disabled" =
state where it will ignore all subsequent transactions and generally do =
as little as possible.

http://code.google.com/p/mod-sflow/source/browse/trunk/mod_sflow.c?r=3D22

Does anyone have any comments about the choice of performance counters =
for HTTP?=20

typedef struct _SFLHTTP_counters {
  uint32_t method_option_count;
  uint32_t method_get_count;
  uint32_t method_head_count;
  uint32_t method_post_count;
  uint32_t method_put_count;
  uint32_t method_delete_count;
  uint32_t method_trace_count;
  uint32_t method_connect_count;
  uint32_t method_other_count;
  uint32_t status_1XX_count;
  uint32_t status_2XX_count;
  uint32_t status_3XX_count;
  uint32_t status_4XX_count;
  uint32_t status_5XX_count;
  uint32_t status_other_count;
} SFLHTTP_counters;

For example,  Ganglia already supports sFlow for monitoring cluster =
performance and could easily be extended to monitor web-farms using =
these counters.

http://blog.sflow.com/2010/10/ganglia.html

Neil


On Jan 10, 2011, at 3:52 PM, Nick Kew wrote:

> On Fri, 7 Jan 2011 15:06:19 -0800
> Neil McKee <neil.mckee@inmon.com> wrote:
>=20
>> Hello all,
>>=20
>> A new module that exports log data using the sFlow protocol is =
available for review:
>>=20
>> http://mod-sflow.googlecode.com
>=20
> I started to look at it, then got distracted.
>=20
> Five-minute review:
> (1) It looks well-formed as a module.  If the question was
>     meant to be "have I got the basics", then the answer is yes.
> (2) I don't like modules that die on error.  Use of ap_assert
>     makes me uneasy.
>=20
> --=20
> Nick Kew
>=20
> Available for work, contract or permanent.
> http://www.webthing.com/~nick/cv.html