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Can a web server determine if its active node is a HA fail-safe system without hard coding anything on the server itself?

I can think of several hacks using ping, the field name and the common name HA, but I think they lead to data leakage.

If the box even knows its part of the HA cluster, or what is the cluster name? Is this more of a DNS feature? Is there any API open for mailboxes to join the HA cluster and request the id of the current active node?

I want to distinguish between inactive node and active node in the notification mechanisms for the running program. If the active node warns that I want to get into the pager and in the inactive node, I want to send an email. Clicking a definition on the warning level moves the same problem elsewhere.

EASY DECISION: Polling the server from an external agent that connects through the network makes any shell game who is an active node a controversial point. To clarify this, the only thing the page will be on is the remote agent controlling the real one. Each inbox can send emails all day for everything I need.

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It really depends on the HA system used.

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Therefore, you can make a simple ifconfig output request to determine if the server supports an active node or not, for example, if eth0 was a configured interface:

ACTIVE_NODE=`ifconfig | grep -c 'eth0:0'`

This will set the $ ACTIVE_NODE variable to 1 (for active) and 0 (if in standby). Hope this helps.

http://www.of-networks.co.uk

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Source: https://habr.com/ru/post/1705544/

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