Hi folks,
I thought I’d ask this on the development group instead of the user one as this is a bit more technical in its nature; please accept my apologies if the question is rather a complete waste of time.
I have been reviewing the way we cluster our GeoServers and bouncing around trying to get my head around the ins and outs of the GWC or MapProxy etc. The documentation seems to hint that I should use a standalone GWC if I’m clustering but Andrea has pointed out that most people use the embedded GWC (I’m not sure if that is or is not within a cluster). I would also say we are not really a high end deployment but we are stuck with Windows and so we have been having issues that have led us to setup a cluster. I can’t comment on whether or not that is sensible but just for background if you are wondering why I’m even looking at this.
My current conclusion has been that I should use the embedded GWC but only run it on one instance of GeoServer (I have four in the cluster) and requests for totally uncached layers are then sent to a different URL.
The solution does appear to be improving things and seems almost perfect accept for one potentially minor issue. The method for splitting up requests by URL is not perfect and so there are a lot more requests going through a single server and a chance that the GWC instance may still need to do a fair amount of rendering. This is also the case for things like printing requests for example which will always miss our cache.
Each layer on a standalone GWC needs to have the setting but I’ve tried that on a GeoServer configuration and as expected the field is not used.
Would I be correct in thinking that there would not be an easy way to develop that setting in so that you can choose whether or not the embedded GWC uses the current instance or a URL to render missing (or other miss tile) requests?
I only ask as the ability to provide a wmsUrl at some level might provide an option to use a cluster of GeoServers for rendering as the URL could be an internal reference to a load balancer. I’ve no idea whether or not that is a good or bad idea as the internal route is probably faster in most contexts anyway so please accept my apologies if the idea is too silly to even contemplate.
Best Regards,
Paul Wittle
Hi folks,
I thought I’d ask this on the development group instead of the user one as this is a bit more technical in its nature; please accept my apologies if the question is rather a complete waste of time.
I have been reviewing the way we cluster our GeoServers and bouncing around trying to get my head around the ins and outs of the GWC or MapProxy etc. The documentation seems to hint that I should use a standalone GWC if I’m clustering but Andrea has pointed out that most people use the embedded GWC (I’m not sure if that is or is not within a cluster).
Yes, often in a cluster. That works reasonably well on Linux, but not so on Windows due to damn file locking.
Variants I’ve seen:
- Fully seeded layers prepared offline (on a out-of-cluster server) for long lived cached, that are getting shared via network (no writing happens)
- Each server having its small, local, isolated, non network shared, for caches that are short lived
- S3 storage of tiles (that solves the main issue of tile cache sharing on Linux NFS, which is poor performance on a network share). With the latest releases (yes, 2.14) there has been work to support Minio too (a open source S3 lookalike) but not sure what would happen with writes, if they are supported or not, still haven’t tried it.
I would also say we are not really a high end deployment but we are stuck with Windows and so we have been having issues that have led us to setup a cluster. I can’t comment on whether or not that is sensible but just for background if you are wondering why I’m even looking at this.
That’s not the best place to be, most of the Windows deployment I’ve seen eventually switched to Linux to get better performance and increased stability.
The Minio alternative looks interesting, I’d give it a look, if it works it may just solve the core of the problem (if not, it might be that it can be fixed with relatively little effort)
Cheers
Andrea
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GeoServer Professional Services from the experts! Visit http://goo.gl/it488V for more information. == Ing. Andrea Aime @geowolf Technical Lead GeoSolutions S.A.S. Via di Montramito 3/A 55054 Massarosa (LU) phone: +39 0584 962313 fax: +39 0584 1660272 mob: +39 339 8844549 http://www.geo-solutions.it http://twitter.com/geosolutions_it ------------------------------------------------------- Con riferimento alla normativa sul trattamento dei dati personali (Reg. UE 2016/679 - Regolamento generale sulla protezione dei dati “GDPR”), si precisa che ogni circostanza inerente alla presente email (il suo contenuto, gli eventuali allegati, etc.) è un dato la cui conoscenza è riservata al/i solo/i destinatario/i indicati dallo scrivente. Se il messaggio Le è giunto per errore, è tenuta/o a cancellarlo, ogni altra operazione è illecita. Le sarei comunque grato se potesse darmene notizia. This email is intended only for the person or entity to which it is addressed and may contain information that is privileged, confidential or otherwise protected from disclosure. We remind that - as provided by European Regulation 2016/679 “GDPR” - copying, dissemination or use of this e-mail or the information herein by anyone other than the intended recipient is prohibited. If you have received this email by mistake, please notify us immediately by telephone or e-mail.