[mapserver-users] Mapserver installation in cloud environments (kubernetes)

Tue Apr 27 08:39:45 PDT 2021

Hi all,

Thanks for your reactions and replies to my request if there is experience
in running UMN MapServer in the cloud. Sorry about the delay in responding.

I had a look at the MapServerless AWS Lambda Layer project and
corresponding video. Thanks for sharing this work!

Pre-rendered tiles are of course good for background maps, but for other
layers, esp. frequently updated layers and layers where we want to allow
custom styling, feature info, etc. map tiles are not good alternatives.

Interesting to me was the feedback from Wouter about the Dutch NGDI (PDOK),
which seems to be more similar to our GDIs (province level and national
level OGC services in Switzerland). Interesting to hear that you are
copying data as close as possible to the pods (Geopackage or by bringing
Postgis really close to the Pods).

In the case of QGIS Server it is also interesting to see that the different
vector data seem to matter substantially. We have a QGIS Server performance
suite published at http://test.qgis.org/perf_test/graffiti/ --> scroll to
the latest date. In the performance test suite there is a section comparing
different vector data sources. See f.e.
http://test.qgis.org/perf_test/graffiti/2021_04_27_01_00/report.html#c395b4ae16b447f1b3e6fc127a4531da
where Postgis and SpatiaLite data sources are substantially faster than
Shapefile and Geopackage is clearly the looser. Not sure if the same
applies for UMN MapServer? Maybe that is a pattern that applies to QGIS
Server only ...

Wouter: I would be interested in learning more about the
"ogc-webservice-proxy" you mention for determining the
size/duration/location. Do you have more to share regarding this proxy
service? What is the purpose of it and how does it work? Do you also
separate short-running requests (e.g. GetFeatureInfo or GetLegendGraphics)
vs long-running requests (GetMap, printing services, report generation)?

Is your "traefik" load balancer using "round robin" load balancing or
something more advanced based on system load or even by using an
estimate/prediction how long a request might take based on the parameters
submitted?

Thanks all for the interesting discussion!

Andreas

On Fri, 23 Apr 2021 at 22:07, Wouter Visscher <wouter.visscher at gmail.com>
wrote:

> Hi Andreas,
>
> To answer your question: "Do you know of any work ...."
>
> For the Dutch National Geodata Infrastructure (PDOK) we are running now
> (over a year) hundreds of OGC WMS/WMTS/WFS servers (primarily Mapserver and
> Mapproxy) on aks (Azure kubernetes).
>
> The challenges you are describing sound very similar to ours :)
>
> To give some small inside on some of our solutions regarding:
> deployment: kustomize and operators
> cloud optimization: (regarding data) geohashes over GPKG and PostGIS
> tables and getting the data as close to the pods as possible.
> load balancing: (infrastructure wise) 'standaard'
> loadbalancing with traefik, (OGC wise) we are working on a
> 'ogc-webservice-proxy' for determining the size/duration/location,
> basically what is going to be the impact of a request.
> resource sharing: (infrastructure) ScaleSets for nodes, and ReplicaSets
> based on load, (data) because we have most of the data in GPKG we 'copy'
> the data around. So for a service that scales up to 4 pods we have 4 of the
> same GPKG copied to that node.
>
> I will share your knowledge with my colleagues, but it seems you reached a
> lot of the same conclusions (so far I have read) we have.
>
> On Fri, Apr 23, 2021 at 5:20 PM Andreas Neumann <andreas at qgis.org> wrote:
>
>> Hi,
>>
>> For a small project as part of the Swiss National Geodata Infrastructure
>> (grant project) several people worked on a study document called
>> "Cloud-optimized OGC WMS Server" where we analyzed problems that can arise
>> when you install an OGC web server in the cloud (e.g. docker image deployed
>> via Kubernetes, OpenShift or the likes). This work had a focus on QGIS
>> Server with it's own set of problems - but some of the issues studied in
>> this document also matter for other OGC WMS servers, such as UMN Mapserver
>> or Geoserver, such as the load balancing problem, how to share resources,
>> etc.
>>
>> Here is the link to the document (not in final form yet, but close to
>> being final):
>> https://docs.google.com/document/d/1cOUWgzalRx7CHWTFgHz6-uyScsCcoaEmYC0VBHdZShQ/edit#heading=h.c7gq4lie7ys2
>>
>> I wonder if any similar work has been done specifically around problems,
>> challenges and solutions when you deploy UMN Mapserver in cloud
>> environments? Do you know of any work?
>>
>> One major problem that probably all installations of an OGC WMS server
>> have is how to deploy a more intelligent load balancing system? Often, the
>> default load balancer is some kind of round robin load balancer system, but
>> often this leads to inferior results where "cheap and short" requests (such
>> as a simple GetFeatureInfo or GetLegendGraphics request) can be queued
>> behind a long-running GetMap request (potentially with many layers, many
>> features and a high-dpi, such as 600dpi, where the request can take several
>> seconds to process.
>>
>> In our production system we are currently separating the requests to
>> dedicated instances for short requests and potentially long requests, to
>> avoid the above mentioned scenario, but we are not so satisfied with the
>> solution, as it is  a bit inflexible and also a bit harder to maintain.
>> Ideally, we would like to have a more intelligent load balancer with
>> incoming queue that holds back requests as long as all WMS server instances
>> are busy. This would avoid the situation where a "less intelligent" load
>> balancer would simply forward the requests to instances based on
>> Round-Robin principle.
>>
>> Do you know of any work in the UMN Mapserver community regarding cloud
>> deployment, cloud optimization, load balancing and resource sharing?
>>
>> In our study document I'd like to also include the perspective of other
>> WMS servers besides QGIS server, so any input would be welcome.
>>
>> Thanks,
>> Andreas
>>
>> --
>> Andreas Neumann
>> QGIS.ORG board member (treasurer)
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-- 

--
Andreas Neumann
QGIS.ORG board member (treasurer)
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