mod_proxyでhot-standby

active/standbyって言ったりもするかも。日本語のドキュメントにはまだ翻訳されてないんですね。

status=+Hでhot-standbyになる。

ProxyPass / balancer://hotcluster/
<Proxy balancer://hotcluster>
  BalancerMember http://1.2.3.4:8009 loadfactor=1
  BalancerMember http://1.2.3.5:8009 loadfactor=2
  # The below is the hot standby
  BalancerMember http://1.2.3.6:8009 status=+H
  ProxySet lbmethod=bytraffic
</Proxy>
  • statusパラメータの説明

Single letter value defining the initial status of this worker: 'D' is disabled, 'S' is stopped, 'I' is ignore-errors, 'H' is hot-standby and 'E' is in an error state. Status can be set (which is the default) by prepending with '+' or cleared by prepending with '-'. Thus, a setting of 'S-E' sets this worker to Stopped and clears the in-error flag.