Is not just the MapCache instances but also MapServer instances included so in 
theory you have X MapServers accepting request depending on the number of 
instances.
Making tests today I discover that if we use just Vector and Raster layer I can 
reach 100 tiles/s in a VM with 8core and 8GB RAM even though the ram is under 
1GB of use.
A 4core reach the same speed, and I was using –p 5 and 10 respectively.

Yesterday I came across this article 
https://www.maptiler.com/blog/2018/04/maps-with-docker.html and I was wondering 
if was something possible also with MapServer/MapCache.

Again if we use just Vector and Raster I think I can seed in 15 days instead of 
more than 60 days but is still a lot because I have 4 cache to seed twice a 
year.

Sebastiano Laini
Web Developer
Buchanan Computing

From: Travis Kirstine [mailto:traviskirst...@gmail.com]
Sent: 19 November 2019 16:11
To: Sebastiano Laini <sebastiano.la...@buchanancomputing.co.uk>
Cc: mapserver-users@lists.osgeo.org
Subject: Re: [mapserver-users] MapCache clusters

I don't think multiple instances of MapCache will help for seeding, in general 
most of the seeding time depends on the zoom level, with each higher zoom level 
taking 4 x the time as the proceeding zoom level (e.g. zoom 20 take 4 x the 
time to seed as zoom 19)  .  This can vary depending on your source service as 
there may be certain map scales / zoom levels that take longer per tile to 
render due to expression, labels, # of features etc... If you were to seed two 
levels for each mapcache instance you still would be waiting for the higher 
zoom levels to complete.   Using multiple load balanced mapserver nodes across 
multiple VM may improve things a bit however if all the VMs are hosted on the 
same physical server this may be slower overall.  For seeding I have heard you 
can use 2x the number of cores so you could set up a single mapcache server 
using -n 16 pointing at the load balanced source.

Regards



On Mon, 18 Nov 2019 at 10:47, Sebastiano Laini 
<sebastiano.la...@buchanancomputing.co.uk<mailto:sebastiano.la...@buchanancomputing.co.uk>>
 wrote:
Hi All,

I was wondering if is possible to dockerise my server and then use multiple 
cluster to seed the cache? I know I can use multiple processes with the –n and 
–p flag though I’m wondering there is a limit on how much you can really 
increase those number.

E.g. I dockerise the server and I spawn a 8core VM with 16GB ram, I can use 
sure –p 8 or maybe 10 but still I think that will require like 60 days to seed 
the whole UK with our data, can I spawn another machine and speed up the 
process? For example another 8core VM.

We have 4 caches with different style that are updated twice a year so if it 
takes me 60 days for each by the time I finish it’s already time to start again.

I was wondering maybe I can run multiple VM and seed one or maybe 2 levels on 
each VM or if I spawn a new VM the original process will take advantage of the 
new VM?
In a VM I’m going to have MapServer and MapCache and I will use a subdomain 
under a load balancer just to seed while the domain will be use just for the 
seeded cache and in the same way will be under a load balancer.

Regards,

Sebastiano Laini
Web Developer
Buchanan Computing
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