Re: Performance issue -- serving from cache

Brad House <[email protected]> Sat, 14 Feb 2026 17:55:44 -0500
Newsgroups gmane.comp.web.squid.general
Message-ID <[email protected]>
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AUFS cache is currently being used.  I'm pretty sure I tried rock after 
and noticed worse performance but I don't recall trying to tune it.

On 2/14/26 5:40 PM, Jonathan Lee wrote:
> Is it rock cache and how many workers are you using ?
> Sent from my iPhone
>
>> On Feb 14, 2026, at 11:45, Brad House <[email protected]> wrote:
>>
>> 
>>
>> I've got a squid deployment where serving from cache can be slower 
>> than an uncached download.  I'm seeing speeds of around 50MB/s when 
>> serving from cache, which is much slower than anticipated.  Infact, 
>> when hitting fast upstream servers, serving of a non-cached asset is 
>> faster (even though its still hitting squid to fetch it).
>>
>> I'm thinking there's got to be something wrong with my squid 
>> configuration, I'm currently running on Rocky Linux 10 with Squid 6.10-6.
>>
>> The VM I'm using currently has 4 cores, 16G RAM and 100G of usable 
>> space.  I used fio to measure disk performance and I got
>>
>>   * Random Write: 3629MiB/s (1MB block), 33.2k (4k block) IOPS
>>   * Random Read: 8391MiB/s (1MB block), 43.5k (4k block) IOPS
>>
>> Adding more cpu cores or ram doesn't appear to impact performance.
>>
>> The underlying infrastructure is made up of hypervisors with dual 
>> 100G uplinks, both the client and squid run on the same hypervisor 
>> cloud.  Network performance is not the issue.
>>
>> As a test, I spun up Apache Traffic Server and get over 800MB/s when 
>> serving from cache.
>>
>> We have a large on site build system that spins up runners for GitHub 
>> actions, and they're constantly fetching large assets from the 
>> internet for each build, hence our desire for a caching proxy.  We'd 
>> rather not switch to Apache Traffic Server as that doesn't have SSL 
>> bump capability (we haven't yet enabled that capability in squid, 
>> however). Hopefully there's a simple configuration I'm missing.
>>
>> Just for testing I was pulling large image via http that is below my 
>> max object size: 
>> http://mirrors.edge.kernel.org/ubuntu-releases/20.04.6/ubuntu-20.04.6-live-server-amd64.iso
>>
>> Configuration below:
>>
>> acl public src 0.0.0.0/0
>> acl SSL_ports port 443
>> acl Safe_ports port 80
>> acl Safe_ports port 443
>> http_access deny !Safe_ports
>> http_access deny CONNECT !SSL_ports
>> http_access allow localhost manager
>> http_access deny manager
>> http_access allow public
>> http_access deny to_localhost
>> http_access deny to_linklocal
>> http_access deny all
>> http_port 8080
>> maximum_object_size 2 GB
>> cache_dir aufs /var/spool/squid 325632 16 256
>> cache_mem 1000 MB
>> maximum_object_size_in_memory 102400 KB
>> coredump_dir /var/spool/squid
>> refresh_pattern -i (/cgi-bin/|\?) 0    0%    0
>> refresh_pattern deb$   129600 100% 129600
>> refresh_pattern udeb$   129600 100% 129600
>> refresh_pattern tar.gz$  129600 100% 129600
>> refresh_pattern tar.xz$  129600 100% 129600
>> refresh_pattern tar.bz2$  129600 100% 129600
>> refresh_pattern \/(Packages|Sources)(|\.bz2|\.gz|\.xz)$ 0 0% 0 
>> refresh-ims
>> refresh_pattern \/Release(|\.gpg)$ 0 0% 0 refresh-ims
>> refresh_pattern \/InRelease$ 0 0% 0 refresh-ims
>> refresh_pattern \/(Translation-.*)(|\.bz2|\.gz|\.xz)$ 0 0% 0 refresh-ims
>> refresh_pattern changelogs.ubuntu.com\/.*  0  1% 1
>>
>>
>> Thanks!
>>
>> -Brad
>>
>> _______________________________________________
>> squid-users mailing list
>> [email protected]
>> https://lists.squid-cache.org/listinfo/squid-users
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    <p>AUFS cache is currently being used.  I'm pretty sure I tried rock
      after and noticed worse performance but I don't recall trying to
      tune it.</p>
    <div class="moz-cite-prefix">On 2/14/26 5:40 PM, Jonathan Lee wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:[email protected]">
      <meta http-equiv="content-type" content="text/html; charset=UTF-8">
      Is it rock cache and how many workers are you using ?<br
        id="lineBreakAtBeginningOfSignature">
      <div dir="ltr">Sent from my iPhone</div>
      <div dir="ltr"><br>
        <blockquote type="cite">On Feb 14, 2026, at 11:45, Brad House
          <a class="moz-txt-link-rfc2396E" href="mailto:[email protected]">&lt;[email protected]&gt;</a> wrote:<br>
          <br>
        </blockquote>
      </div>
      <blockquote type="cite">
        <div dir="ltr">
          <meta http-equiv="content-type"
            content="text/html; charset=UTF-8">
          <p>I've got a squid deployment where serving from cache can be
            slower than an uncached download.  I'm seeing speeds of
            around 50MB/s when serving from cache, which is much slower
            than anticipated.  Infact, when hitting fast upstream
            servers, serving of a non-cached asset is faster (even
            though its still hitting squid to fetch it).  </p>
          <p>I'm thinking there's got to be something wrong with my
            squid configuration, I'm currently running on Rocky Linux 10
            with Squid 6.10-6.</p>
          <p>The VM I'm using currently has 4 cores, 16G RAM and 100G of
            usable space.  I used fio to measure disk performance and I
            got </p>
          <ul data-list-tree="true" data-indent="1" data-border="0"
style="margin: 4px 0 4px 24px; padding: 0; list-style-position: outside">
            <li style="margin: 2px 0; padding: 0; color: #1d1c1d">Random
              Write: 3629MiB/s (1MB block), 33.2k (4k block) IOPS</li>
            <li style="margin: 2px 0; padding: 0; color: #1d1c1d">Random
              Read: 8391MiB/s (1MB block), 43.5k (4k block) IOPS</li>
          </ul>
          <p>Adding more cpu cores or ram doesn't appear to impact
            performance.</p>
          <p>The underlying infrastructure is made up of hypervisors
            with dual 100G uplinks, both the client and squid run on the
            same hypervisor cloud.  Network performance is not the
            issue.</p>
          <p>As a test, I spun up Apache Traffic Server and get over
            800MB/s when serving from cache.</p>
          <p>We have a large on site build system that spins up runners
            for GitHub actions, and they're constantly fetching large
            assets from the internet for each build, hence our desire
            for a caching proxy.  We'd rather not switch to Apache
            Traffic Server as that doesn't have SSL bump capability (we
            haven't yet enabled that capability in squid, however). 
            Hopefully there's a simple configuration I'm missing.</p>
          <p>Just for testing I was pulling large image via http that is
            below my max object size:
            <a class="moz-txt-link-freetext"
href="http://mirrors.edge.kernel.org/ubuntu-releases/20.04.6/ubuntu-20.04.6-live-server-amd64.iso"
              moz-do-not-send="true">http://mirrors.edge.kernel.org/ubuntu-releases/20.04.6/ubuntu-20.04.6-live-server-amd64.iso</a></p>
          <p>Configuration below:</p>
          <p>acl public src 0.0.0.0/0<br>
            acl SSL_ports port 443<br>
            acl Safe_ports port 80<br>
            acl Safe_ports port 443<br>
            http_access deny !Safe_ports<br>
            http_access deny CONNECT !SSL_ports<br>
            http_access allow localhost manager<br>
            http_access deny manager<br>
            http_access allow public<br>
            http_access deny to_localhost<br>
            http_access deny to_linklocal<br>
            http_access deny all<br>
            http_port 8080<br>
            maximum_object_size 2 GB<br>
            cache_dir aufs /var/spool/squid 325632 16 256<br>
            cache_mem 1000 MB<br>
            maximum_object_size_in_memory 102400 KB<br>
            coredump_dir /var/spool/squid<br>
            refresh_pattern -i (/cgi-bin/|\?) 0    0%    0<br>
            refresh_pattern deb$   129600 100% 129600<br>
            refresh_pattern udeb$   129600 100% 129600<br>
            refresh_pattern tar.gz$  129600 100% 129600<br>
            refresh_pattern tar.xz$  129600 100% 129600<br>
            refresh_pattern tar.bz2$  129600 100% 129600<br>
            refresh_pattern \/(Packages|Sources)(|\.bz2|\.gz|\.xz)$ 0 0%
            0 refresh-ims<br>
            refresh_pattern \/Release(|\.gpg)$ 0 0% 0 refresh-ims<br>
            refresh_pattern \/InRelease$ 0 0% 0 refresh-ims<br>
            refresh_pattern \/(Translation-.*)(|\.bz2|\.gz|\.xz)$ 0 0% 0
            refresh-ims<br>
            refresh_pattern changelogs.ubuntu.com\/.*  0  1% 1</p>
          <p><br>
          </p>
          <p>Thanks!</p>
          <p>-Brad</p>
          <span>_______________________________________________</span><br>
          <span>squid-users mailing list</span><br>
          <span><a class="moz-txt-link-abbreviated" href="mailto:[email protected]">[email protected]</a></span><br>
          <span><a class="moz-txt-link-freetext" href="https://lists.squid-cache.org/listinfo/squid-users">https://lists.squid-cache.org/listinfo/squid-users</a></span><br>
        </div>
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