Earth Notes: On Website Technicals (2020-09)Updated 2021-03-18 21:12 GMT.
By Damon Hart-Davis.
2020-09-23: Domain Property in GSC
I have added the whole of
earth.org.uk as a new-style 'domain property' in Google Search Console (GSC).
I note that:
- crawl stats are not available for the new domain property
- the domain performance graph looks somewhat different to the canonical property performance (possibly in part because of the move of some traffic to https)
The domain property performance graph shows ~500k impressions for the last year, with the http canonical showing about double that. Interesting the ratio for clocks is somewhat less... The graph shapes are sufficiently different that I think a chunk of data has gone missing from the domain stats.
2020-09-22: Cache-Control Simplification
I have simplified the config for the m. and amp. files. They now have a uniform Cache-Control for all files, set at ~1 day for amp. (to avoid larding on top of the AMP cache too much) and ~11 days for m. to minimise traffic even at the cost of being a bit more stale. Having the same value for all objects per site shoudl maximise H2 (and H3) compression.
Expires header is not used to reduce header size. (
Etag are also omitted.)
The actual Cache-Control max-ages used are 92222 and 922222 seconds for amp. and m. respectively for an efficient representation for H1, H2, and H3. (For H2 and H3 the static Huffman code sizes for the digits themselves are relevant.)
public' value is unlikely to help overall, so is omitted.
2020-09-21: Canonical WWW Now HTTPS
2020-09-20: Forever Expiry Time 31536000s
Noting the special support for an expiry time of 31536000 seconds (365 days) to mean 'forever' in QPACK: Header Compression for HTTP/3 (H3), I am making that the 'forever' time for EOU (www/static) too.
I've also removed the Firefox-only 'immutable' from the Cache-Control header. (In fact Safari also supports 'immutable', I see.) Most browsers probably won't use it, it takes some space, and prevents use of the built-in H3 static header compression entry.
The magic config line (to exactly match H3 the static table entry) is now:
Header set Cache-Control "public, max-age=31536000"
2020-09-18: Anchor AutoAds off
A 90-day AdSense test finished today, which indicated that having a heavier-than-average ad load did not generate more revenue than a below-average ad load. So I'm back on the less-pushy below-average setting.
I also took the opportunity to turn off the 'anchor' ads that stick to the top of (desktop) pages when viewed on mobile. I find them distracting and a significant waste of screen real-estate.
It's difficult to tell for sure, but I think that traffic from Google is coming off its peak of the last year or so, at least looking at the GSC performance graph. Impressions are good, but actual clickthroughs less convincing...
2020-09-17: H2 Strangeness
I tried out HTTP/2 Test:
Verify HTTP/2 support. For
https://www.earth.org.uk I get
HTTP/2 protocol is supported and
ALPN extension is supported. (Both are also supported over plain http, but no browser will make use of that in practice! For some reason although http AMP shows the same, http m says that both are unsupported, on https also: odd.)
It turns out there was some stray Let's Encrypt 'auto' config hanging around:
# ls -al /etc/apache2/sites-enabled/ m.earth.org.uk.conf -> ../sites-available/m.earth.org.uk.conf m.earth.org.uk-le-ssl.conf -> /etc/apache2/sites-available/m.earth.org.uk-le-ssl.conf
Removing the link, and restarting Apache makes all well with the world, or at least well with the HTTP/2 test:
# rm /etc/apache2/sites-enabled/m.earth.org.uk-le-ssl.conf # /etc/init.d/apache2 restart
2020-09-04: AMP HTTPS Now Preferred
As of today the preferred scheme for the AMP pages is https, though http will still be served and should be fully functional.
This means in practice:
- Making the
amphtmllink in the header and AMP navigation link point to the https version.
- Giving all the header inter-version and canonical and navigation links explicit http / https schemes.
- Making redirects between versions appropriate in terms of schemes, retaining https as appropriate to avoid security snafus (
principle of least surprise).
- Using the correct scheme in
It will take a little while to get all the wrinkles out!
In future, the m/lite preferred version is likely to remain http for speed, and the www/desktop preferred version become https for a small SEO boost.
2020-10-28: HTTPS Doubles Page Crawl Time
GSC's average page download time (now at ~10kB per page) has risen from ~250ms to ~500ms with the switch from http to https preferred.
Note that Google's crawlers are generally coming from across the Altantic, multiplying the effects of the extra TLS setup handshake. If the crawlers ever get to use H3 (HTTP/3) including header compression, some of that may come back.
As of today mean page fetch size is a little under 10kB and ~180 pages are crawled per day, as given in GSC's crawl stats for the AMP site version.
2020-09-01: Brotli Sides
I have enabled Brotli static pre-compression for supporting top-level pages, such as the home and sitemap pages. If that doesn't cause any problems then I shall extend such
br content-encoding to main pages also, either side of making the https set canonical for (say) AMP and desktop. (Brotli compression only works over https.)