[tlug] Servers freeze

[Batara Kesuma <bkesuma@example.com>]

Hi,

I have 3 web servers, running Apache 2.0.49. The diagram looks like
this:

         +-------+ mod_proxy, mod_rewrite
         | Proxy | http://domain/
         +---+---+ 
             |
         +---+---+
         |       |
 +-------+-+   +-+-------+ mod_perl
 | Backend |   | Backend | http://1.domain:8080/ and
 +---------+   +---------+ http://2.domain:8080/

The Proxy will forward the request by reverse proxy to Backends for file
with .pl extensions. Other files are served from Proxy. The problem is,
sometimes I find the servers just freeze. I tried traceroute and ping to
all of them, and it was ok, so maybe it was not network problem. I also
tried to access directly to both Backends, but they didn't give any
response too. The load averages were very low, and the access_log just
stopped. It happens once in 2 or 3 hours and lasts for about 2-3
minutes. I also found no clue in the log file. Anyone has suggestions,
idea about this? 

Thanks,
Batara