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debian linux sysadmin

Using hitch with varnish on Debian Jessie

I ended up needing to install hitch on a server recently, so the https:// traffic could be routed through Varnish (along with the existing ‘http’ stuff) for performance reasons. The server only runs WordPress sites, so there are WordPress specific things in the Varnish configuration (vcl) file below. Versions: Varnish 5.2, Hitch 1.4.4, Apache 2.4 and […]

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debian

varnish throttling

I came across the varnish throttle module the other day – which seems quite useful – and certainly gives better control over abusive requests than using fail2ban (in that, only specific URLs/request types can be targeted and blocked with the throttle module, while fail2ban tends to trigger the blocking of any traffic from a client […]

Categories
linux performance

Checking varnish configuration syntax

If you’ve updated your varnish server’s configuration, there doesn’t seem to be an equivalent of ‘apachectl configtest’ for it, but you can do : varnishd -C -f /etc/varnish/default.vcl If everything is correct, varnish will then dump out the generated configuration. Otherwise you’ll get an error message pointing you to a specific line number.

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Uncategorized

Varnish + Zope – Multiple zope instances behind a single varnish cache

I run multiple Zope instances on one server. Each Zope instance listens on a different port (localhost:100xx). Historically I’ve just used Apache as a front end which forwards requests to the Zope instance. Unfortunately there are periods of the year when one site gets a deluge of requests (for example; when hosting a school site, […]