title: Graphite. Some metrics lost, but seen in tcpdump
body: <p>I'm using graphite for pretty long time, and first time facing issue with some metrics getting… lost?
  Through <code>tcpdump -nA dst port 2003</code> I can see that metrics are delivered to Graphite node. 
  Also, some of them are getting created in whisper database, and seen in <code>/var/log/carbon/updates.log</code>
  But most of them are not appearing anywhere.</p>
  
  <p><strong>So my question is:</strong> how do I debug it? How do I prove that Graphite really receives these metrics from eth0?</p>
  
  <p>I couldn't find any debug logs except for <code>updates.log</code> in carbon.</p>
  
  <p><strong>Log:</strong></p>
  
  <pre><code>sudo tcpdump -An dst port 2003 | grep 172_31_00_01 | grep requests
  </code></pre>
  
  <blockquote>
    <p>backend.dev.172_31_00_01.requests.max 60554.34 1453734067
    backend.dev.172_31_00_01.requests.mean 16714.87 1453734067
    backend.dev.172_31_00_01.requests.min 2.93 1453734067
    backend.dev.172_31_00_01.requests.stddev 12185.74 1453734067
    backend.dev.172_31_00_01.requests.p50 16415.87 1453734067
    backend.dev.172_31_00_01.requests.p75 20314.51 1453734067
    backend.dev.172_31_00_01.requests.p95 41526.36 1453734067
    backend.dev.172_31_00_01.requests.p98 54370.59 1453734067
    backend.dev.172_31_00_01.requests.p99 60368.68 1453734067
    backend.dev.172_31_00_01.requests.p999 60553.31 1453734067
    backend.dev.172_31_00_01.requests.count 3141 1453734067
    backend.dev.172_31_00_01.requests.m1_rate 2.02 1453734067
    backend.dev.172_31_00_01.requests.m5_rate 1.95 1453734067
    backend.dev.172_31_00_01.requests.m15_rate 1.20 1453734067
    backend.dev.172_31_00_01.requests.mean_rate 0.66 1453734067
    backend.dev.172_31_00_01.requests.mark_sessionid_active.max 152.59 1453734067
    backend.dev.172_31_00_01.requests.mark_sessionid_active.mean 41.86 1453734067
    backend.dev.172_31_00_01.requests.mark_sessionid_active.min 0.82 1453734067
    backend.dev.172_31_00_01.requests.mark_sessionid_active.stddev 24.84 1453734067
    backend.dev.172_31_00_01.requests.mark_sessionid_active.p75 57.51 1453734067
    backend.dev.172_31_00_01.requests.mark_sessionid_active.p95 85.78 1453734067</p>
  </blockquote>
  
  <pre><code>$ pwd
  /var/lib/graphite/whisper/backend/dev/172_31_00_01/requests
  $ ls -Rl
  .:
  total 1796
  drwxr-xr-x 2 _graphite _graphite    4096 Jan 25 14:25 mark_sessionid_active
  -rw-r--r-- 1 _graphite _graphite 1831744 Jan 25 15:05 mean.wsp
  
  ./mark_sessionid_active:
  total 3584
  -rw-r--r-- 1 _graphite _graphite 1831744 Jan 25 15:05 min.wsp
  -rw-r--r-- 1 _graphite _graphite 1831744 Jan 25 15:05 stddev.wsp
  </code></pre>
  
  <p><strong>PS:</strong> It's not new installation, it works for several months now, and no metrics was lost until today.</p>