tomeduarte

# /srv/salt/shared/nginx/files/sites-available/default.lb
upstream app_nodes {
    # Build list of backend servers
    # using peer communication as the mine is cached and slow to pick up new hosts
    {% for server,ips in
        salt['publish.publish'](
            'G@roles:appnode',
            'network.ip_addrs', expr_form='compound').items() -%}
    #   host: {{ server }}
    {% for ip in ips -%}

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD