<div dir="ltr">Sorry everyone about the multiple posts with the same content...<div>My own posts weren't coming to me at all through email...</div><div>I just checked <a href="http://mailman.nginx.org/pipermail/nginx/2015-July/thread.html">http://mailman.nginx.org/pipermail/nginx/2015-July/thread.html</a></div><div>and found out all my posts were posted.</div><div><br></div><div>Again I apologize for the inconvenience.</div><div><br></div><div>:(</div><div><br></div><div>It was sincerely a mistake.</div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jul 27, 2015 at 12:29 AM, highclass99 <span dir="ltr"><<a href="mailto:highclass99@gmail.com" target="_blank">highclass99@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span style="font-size:12.8000001907349px">I have server A with a large HDD at IDC 1 (TB hdd)</span><div style="font-size:12.8000001907349px">I have server B with cheap bandwidth at IDC 2 (very small virtual server 20 GB hdd)</div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px">I send all image requests to server B, and it caches from A.</div><div style="font-size:12.8000001907349px">My problem is that on server IO is really high</div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px">Server B iostat</div><div style="font-size:12.8000001907349px"><div>Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util</div><div>sda 34.01 517.21 1263.36 76.72 19922.27 4751.42 18.41 2.95 2.20 0.36 47.67</div><div>sda1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00</div><div>sda2 34.01 517.21 1263.36 76.72 19922.27 4751.42 18.41 2.95 2.20 0.36 47.67</div><div>dm-0 0.00 0.00 1297.37 593.93 19922.27 4751.42 13.05 8.78 4.64 0.25 47.71</div><div>dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00</div></div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px">Here is my related nginx config</div><div style="font-size:12.8000001907349px"><div>--------------- cut --------------------------------------</div><div> proxy_cache_path /cache levels=1:2</div><div> keys_zone=MEDIA:200m</div><div> inactive=2d max_size=6g;</div></div><div style="font-size:12.8000001907349px">--------------- cut --------------------------------------<br></div><div style="font-size:12.8000001907349px"><div> location / {</div><div> proxy_pass <a href="http://server_a/" target="_blank">http://SERVER_A</a><br></div><div> proxy_cache MEDIA;</div><div> proxy_cache_key "$scheme$request_uri";</div><div><br></div><div> proxy_cache_valid 200 302 304 7d;</div><div> proxy_cache_valid 301 1h;</div><div> proxy_cache_valid any 1m;</div><div> proxy_cache_use_stale error timeout invalid_header http_500 http_502 http_503 http_504 http_404 updating;</div><div> proxy_ignore_headers Cache-Control Expires Set-Cookie;</div><div> proxy_cache_min_uses 3;</div><div> proxy_cache_revalidate on;</div><div> proxy_cache_lock on;</div><div> proxy_cache_lock_timeout 15s;</div><div><br></div><div> expires 7d;</div><div> }</div></div><div style="font-size:12.8000001907349px"><div>--------------- cut --------------------------------------<br></div><div><br></div><div>Server B has nothing else running.</div><div>Server B is sending about 200~400 MBs traffic outside</div><div>Is such a high IO load normal?</div><div>Is there a way I can decrease the IO load while keeping the caching of server B efficient?</div><div><br></div><div>Thank you.</div></div></div>
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