<div class="post-text">
                <p>Hi,
I have a caching-only dns server which get ~3k queries per second. Here 
is specs:</p>

<pre class="prettyprint"><code><span class="typ">Xeon</span><span class="pln"> dual</span><span class="pun">-</span><span class="pln">core </span><span class="lit">2</span><span class="pun">,</span><span class="lit">8GHz</span><span class="pln"> </span><span class="lit">4GB</span><span class="pln"> of RAM<br>
</span><span class="typ">Centos</span><span class="pln"> </span><span class="lit">5x</span><span class="pln"> 32bit </span><span class="pun">(</span><span class="pln">kernel </span><span class="lit">2.6</span><span class="pun">.</span><span class="lit">18</span><span class="pun">-</span><span class="lit">164.15</span><span class="pun">.</span><span class="lit">1.el5PAE</span><span class="pun">)</span><span class="pln"> <br>
bind </span><span class="lit">9.4</span><span class="pun">.</span><span class="lit">2</span><span class="pln"><br></span></code></pre>

<p>rndc status:
recursive clients: 666/4900/5000</p>

<p></p>

<p>Bind always uses 100% on one core on single-thread config. After I 
recompiled it to multi-thread, it uses nearly 200% on two core :( No 
iowait, only sys and user. I searched around but didn't see any info 
about how bind use CPU. Why does it become bottleneck?</p>

<p>One more thing, here is RAM usage:</p>

<pre class="prettyprint"><code><span class="pln">cat </span><span class="pun">/</span><span class="pln">proc</span><span class="pun">/</span><span class="pln">meminfo <br></span><span class="typ">MemTotal</span><span class="pun">:</span><span class="pln">      </span><span class="lit">4147876</span><span class="pln"> kB<br>
</span><span class="typ">MemFree</span><span class="pun">:</span><span class="pln">       </span><span class="lit">1863972</span><span class="pln"> kB<br></span><span class="typ">Buffers</span><span class="pun">:</span><span class="pln">        </span><span class="lit">143632</span><span class="pln"> kB<br>
</span><span class="typ">Cached</span><span class="pun">:</span><span class="pln">         </span><span class="lit">372792</span><span class="pln"> kB<br></span><span class="typ">SwapCached</span><span class="pun">:</span><span class="pln">          </span><span class="lit">0</span><span class="pln"> kB<br>
</span><span class="typ">Active</span><span class="pun">:</span><span class="pln">        </span><span class="lit">1916804</span><span class="pln"> kB<br></span><span class="typ">Inactive</span><span class="pun">:</span><span class="pln">       </span><span class="lit">276056</span><span class="pln"> kB<br>
</span></code></pre>

<p></p>

<p>Do you have any idea?</p>

<p>TIA,</p>

<p>-giobuon<br></p>

            </div>