title: High # of N expired objects. Why? - (inside is my varnishstat and default.vcl)
body: <p>I have apache2 with Varnich 2 running. My prob is that even though my cache-control is set to 1 year, varnish still have a load of N expired objects <strong>1971</strong>. Here's my default.vcl it shows my setting any tips?:</p>
  
  <pre><code>backend apache {
  .host = "127.0.0.1";
  .port = "8080";
  }
  
  sub vcl_recv {
  
  if (req.http.Accept-Encoding) {
      if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg)$") {
          # No point in compressing these
          remove req.http.Accept-Encoding;
      } elsif (req.http.Accept-Encoding ~ "gzip") {
          set req.http.Accept-Encoding = "gzip";
      } elsif (req.http.Accept-Encoding ~ "deflate") {
          set req.http.Accept-Encoding = "deflate";
      } else {
          # unkown algorithm
          remove req.http.Accept-Encoding;
      }
  }
  
   if (req.url ~ "\.(ico|png|gif|jpg|swf|css|js)$") {
      return(lookup);
   }
  }
  
  ## Fetch
  sub vcl_fetch {
  
  # strip the cookie before the image is inserted into cache.
   if (req.url ~ "\.(ico|png|gif|jpg|swf|css|js)$") {
     unset beresp.http.set-cookie;
  }
  
  ## Remove X-Forwarded-For header if exists.
          remove req.http.X-Forwarded-For;
  
  ## insert client IP address as X-Forwarded-For.
          set    req.http.X-Forwarded-For = req.http.rlnclientipaddr;
  
  ## Deliver the content
          return(deliver);
  }
  
  ## Deliver
  sub vcl_deliver {
  
  ## Clean header
          remove resp.http.X-Varnish;
          remove resp.http.Via;
      remove resp.http.Age;
          remove resp.http.X-Powered-By;
  
      if (obj.hits &gt; 0) {
          set resp.http.X-Cache = "HIT";
      } else {
          set resp.http.X-Cache = "MISS";
      }
  
  }
  </code></pre>
  
  <p>Varnishstat, this is my output:</p>
  
  <pre><code>client_conn              4165         0.26 Client connections accepted
  client_drop                 1         0.00 Connection dropped, no sess/wrk
  client_req               5036         0.31 Client requests received
  cache_hit                1235         0.08 Cache hits
  cache_hitpass               0         0.00 Cache hits for pass
  cache_miss               2329         0.14 Cache misses
  backend_conn             1359         0.08 Backend conn. success
  backend_unhealthy            0         0.00 Backend conn. not attempted
  backend_busy                0         0.00 Backend conn. too many
  backend_fail                0         0.00 Backend conn. failures
  backend_reuse            2442         0.15 Backend conn. reuses
  backend_toolate          1223         0.08 Backend conn. was closed
  backend_recycle          3666         0.23 Backend conn. recycles
  backend_unused              0         0.00 Backend conn. unused
  fetch_head                  0         0.00 Fetch head
  fetch_length             3665         0.23 Fetch with Length
  fetch_chunked              51         0.00 Fetch chunked
  fetch_eof                   0         0.00 Fetch EOF
  fetch_bad                   0         0.00 Fetch had bad headers
  fetch_close                67         0.00 Fetch wanted close
  fetch_oldhttp               0         0.00 Fetch pre HTTP/1.1 closed
  fetch_zero                 15         0.00 Fetch zero len
  fetch_failed                0         0.00 Fetch failed
  n_sess_mem                 30          .   N struct sess_mem
  n_sess                      0          .   N struct sess
  n_object                  314          .   N struct object
  n_vampireobject             0          .   N unresurrected objects
  n_objectcore              318          .   N struct objectcore
  n_objecthead              361          .   N struct objecthead
  n_smf                       0          .   N struct smf
  n_smf_frag                  0          .   N small free smf
  n_smf_large                 0          .   N large free smf
  n_vbe_conn                  1          .   N struct vbe_conn
  n_wrk                      10          .   N worker threads
  n_wrk_create               10         0.00 N worker threads created
  n_wrk_failed                0         0.00 N worker threads not created
  n_wrk_max              567851        35.17 N worker threads limited
  n_wrk_queue                 0         0.00 N queued work requests
  n_wrk_overflow             37         0.00 N overflowed work requests
  n_wrk_drop                  4         0.00 N dropped work requests
  n_backend                   1          .   N backends
  n_expired                1971          .   N expired objects
  n_lru_nuked                 0          .   N LRU nuked objects
  n_lru_saved                 0          .   N LRU saved objects
  n_lru_moved              1211          .   N LRU moved objects
  n_deathrow                  0          .   N objects on deathrow
  losthdr                     0         0.00 HTTP header overflows
  n_objsendfile               0         0.00 Objects sent with sendfile
  n_objwrite               4810         0.30 Objects sent with write
  n_objoverflow               0         0.00 Objects overflowing workspace
  s_sess                   4164         0.26 Total Sessions
  s_req                    5036         0.31 Total Requests
  s_pipe                      0         0.00 Total pipe
  s_pass                   1472         0.09 Total pass
  s_fetch                  3798         0.24 Total fetch
  s_hdrbytes            1925358       119.25 Total header bytes
  s_bodybytes         111698308      6918.45 Total body bytes
  sess_closed              2172         0.13 Session Closed
  sess_pipeline               0         0.00 Session Pipeline
  sess_readahead              0         0.00 Session Read Ahead
  sess_linger              3290         0.20 Session Linger
  sess_herd                3093         0.19 Session herd
  shm_records            343107        21.25 SHM records
  shm_writes              40917         2.53 SHM writes
  shm_flushes                 0         0.00 SHM flushes due to overflow
  shm_cont                    3         0.00 SHM MTX contention
  shm_cycles                  0         0.00 SHM cycles through buffer
  sm_nreq                     0         0.00 allocator requests
  sm_nobj                     0          .   outstanding allocations
  sm_balloc                   0          .   bytes allocated
  sm_bfree                    0          .   bytes free
  sma_nreq                 6015         0.37 SMA allocator requests
  sma_nobj                  627          .   SMA outstanding allocations
  sma_nbytes            4035862          .   SMA outstanding bytes
  sma_balloc           34755299          .   SMA bytes allocated
  sma_bfree            30719437          .   SMA bytes free
  sms_nreq                    3         0.00 SMS allocator requests
  sms_nobj                    0          .   SMS outstanding allocations
  sms_nbytes                  0          .   SMS outstanding bytes
  sms_balloc               1464          .   SMS bytes allocated
  sms_bfree                1464          .   SMS bytes freed
  backend_req              3801         0.24 Backend requests made
  n_vcl                       1         0.00 N vcl total
  n_vcl_avail                 1         0.00 N vcl available
  n_vcl_discard               0         0.00 N vcl discarded
  n_purge                     1          .   N total active purges
  n_purge_add                 1         0.00 N new purges added
  n_purge_retire              0         0.00 N old purges deleted
  n_purge_obj_test            0         0.00 N objects tested
  n_purge_re_test             0         0.00 N regexps tested against
  n_purge_dups                0         0.00 N duplicate purges removed
  hcb_nolock               1245         0.08 HCB Lookups without lock
  hcb_lock                    0         0.00 HCB Lookups with lock
  hcb_insert               2319         0.14 HCB Inserts
  esi_parse                   0         0.00 Objects ESI parsed (unlock)
  esi_errors                  0         0.00 ESI parse errors (unlock)
  accept_fail                 0         0.00 Accept failures
  client_drop_late            3         0.00 Connection dropped late
  uptime                  16145         1.00 Client uptime
  </code></pre>
  
  <p>If this helps, this is how I set cache-control in my apache2 conf:</p>
  
  <pre><code>&lt;FilesMatch "\.(ico|pdf|gif|jpg|jpeg|png|swf|js|css)$"&gt;
  ExpiresActive On
  ExpiresDefault A31556926
  Header unset ETag
  FileETag None
  &lt;/FilesMatch&gt;
  </code></pre>
  
  <p>Can't figure out why my N expired objects is soo high?</p>