On Wed, Oct 3, 2018 at 4:35 PM Mark Thomas <ma...@apache.org> wrote: > On 03/10/18 14:48, Rémy Maucherat wrote: > > Hi, > > > > As I talked about during the latest TomcatCon (and the previous one in > > London actually ...), there's a cloud aware cluster members provider that > > can be contributed to Tomcat. > > > > The current code is here: > https://github.com/rmaucher/tomcat-in-the-cloud > > It uses Kubernetes to retrieve the members of a cluster, rather than > > multicast (which isn't available) or static (which is well ... static) > > member providers. > > > > Credits: > > Maxime Beck and JGroups did the initial code > > Keiichi Fujino explained how to refactor it to fit in the Catalina > cluster > > API > > and I refactored it as he told me to > > > > Problems: > > Only does Kubernetes for now (which is likely ok since it's now widely > > available) > > No objections on this point. A quick look at the code indicates > additional CloudMembershipProvider implementations should be fairly > simple to add as required. >
Yes, it's very small, most of the work is knowing to use your cloud infrastructure (... :( ). > > > JSON parser dependency (org.json) that is likely not ok to have as is in > > the lib folder (solutions: package renaming using a script or include > json > > code in Tomcat) > > Because we get JSON from Kubernetes? Is there any other interface we > could use that doesn't return JSON? Well, it's very simple, you get the pods list that way, afaik they don't like xml at all, it's all either yml or json. I guess it's "simpler" (ahem). > Are other providers (Docker is the > one that comes immediately to mind) also going to require JSON? > Yes, that comes to mind, I don't know their orchestration yet (it's called Docker swarm) but it looks like json responses as well. > > Other random thoughts: > - Make it an optional library that we depend on at compile time but > don't ship? Fail start-up if it is not present when the > CloudMembershipProvider is configured? > - Package the cloud membership provider stuff extras and include the > JSON JAR in that? > > It is only 64Kb (if I am looking at the correct JAR). I am a little > concerned about conflicts with web applications shipping alternative > versions of the JAR. We should be OK on this point as none of the > clustering objects that touch JSON should be visible to web applications. > Yes, it's small, but it's probably a commonly used library. So a decision has to be made about it. > > > Needs more testing > > Tomcat 9.0.13 needed (with some fixmes related to that in the code) > > > > Comments ? > > It it is intended for inclusion in Tomcat then the sooner it is in the > Tomcat code base the better. It doesn't have to ship with a release > straight away if it isn't release ready. > Ok, no problem with that. Rémy
