Hi Seba, the metatiling lock is taken to prevent multiple requests from building the same meta-tile, so one is actually building the output, while all others are waiting for the tiles to be produced.
Given your explanation, maybe you have a very large meta-tiling factor in your layer, and the production of the full meta-tile (single large image containing all tiles) really takes that much time? For that time, all other requests hitting the same meta-tile will be blocked, waiting. If that's the case, then a quick way to get the server to respond faster, is to reduce the meta-tiling factor Cheers Andrea On Fri, Mar 17, 2023 at 6:34 PM Seba Oszlak <sosz...@gmail.com> wrote: > Hello Everyone! > > A couple of days ago we started experiencing severe downtime on our > Geoserver instance that was working fine for a long time before this. > For context we have Geo 2.22.0 running on Tomcat 9 on a Windows Server > 2019. > > All our requests go to GWC gmaps service with an URL in this format: > > > /geoserver/gwc/service/gmaps?FORMAT=image/png8&LAYERS=skycop:Referencias+Vectorial+2&ZOOM=17&X=44602&Y=75080&VIEWPARAMS=Perfil:USERNAME;ShowLabels:1&_swc=1678964828059 > > In the latest version of our application, we have added a new parameter in > the VIEWPARAMS for the requests (ShowLabels) and that of course in turn > provoked a complete reseed of the Cache. Since then, when the server is > under normal load, threads take a very long time to resolve (500/600 sec), > or never resolve at all. So after a little while all Tomcat threads become > busy and unresponsive. > > We have no errors recorded on the logs, no matter what log level we set. > > Our DB (SQL Server) is configured with a 64 connections pool. Is working > normally and responding plenty fast to Geoserver, so we have mostly > discarded that as the bottleneck. > > Investigating further, we see many of the threads are mostly idle waiting > for something, so after some thread dumps, we found that most of the treads > are stuck on this line of code where it seems to be waiting on a lock to be > released for the metadata.properties.gz file: > > > https://github.com/geoserver/geoserver/blob/main/src/gwc/src/main/java/org/geoserver/gwc/layer/GeoServerTileLayer.java#L594 > > I should add that during the night, with light load, the server is > responding fine to requests in no more than 2/3 seconds. (And much faster > obviously if the cache is hit). > > If anyone can give us a clue on where to look further or any other > information or possible solution... we will be very very grateful! > > Thank you very much! > > Sebastian Oszlak > > _______________________________________________ > Geoserver-users mailing list > > Please make sure you read the following two resources before posting to > this list: > - Earning your support instead of buying it, but Ian Turton: > http://www.ianturton.com/talks/foss4g.html#/ > - The GeoServer user list posting guidelines: > http://geoserver.org/comm/userlist-guidelines.html > > If you want to request a feature or an improvement, also see this: > https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer > > > Geoserver-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geoserver-users > -- Regards, Andrea Aime == GeoServer Professional Services from the experts! Visit http://bit.ly/gs-services-us for more information. == Ing. Andrea Aime @geowolf Technical Lead GeoSolutions Group phone: +39 0584 962313 fax: +39 0584 1660272 mob: +39 339 8844549 https://www.geosolutionsgroup.com/ 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
_______________________________________________ Geoserver-users mailing list Please make sure you read the following two resources before posting to this list: - Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/ - The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer Geoserver-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geoserver-users
