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irc:1461708000 [2017/05/27 13:44] (current)
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 +[08:51:00] <​mweb84>​ hi there, do I need a system property like "​vertx.clusterManagerFactory"​ in vert.x 3x clustering?
 +
 +[22:55:42] <​skullcrasher>​ is there a number on max verticles in a vert.x instance and also on max nodes in a vertx cluster?
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 +[22:56:13] <​AlexLehm>​ no, i don't think there is
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 +[23:01:39] <​temporalfox>​ skullcrasher sky is the limit
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 +[23:01:51] <​skullcrasher>​ hehe ok :D
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 +[23:01:55] <​skullcrasher>​ thx guys
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 +[23:02:57] <​skullcrasher>​ thought more about how many are feasable until the clusters get unusable (akka e.g. can have about 2500 cluster nodes until it crashes)
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 +[23:03:22] <​skullcrasher>​ but I have no problem if there is no know limitation :)
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 +[23:03:46] <​skullcrasher>​ also pretty unlikely I will reach that limit in near future :D
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 +[23:04:09] <​temporalfox>​ skullcrasher in vert.x it depends likely on the cluster manager implementation
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 +[23:04:14] <​temporalfox>​ ah there are limitations
 +
 +[23:04:29] <​temporalfox>​ it's just that we haven'​t tested ourselves the hard limits
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 +[23:04:54] <​AlexLehm>​ temporalfox:​ I have a strange issue with the dns resolver, I have removed the async resolver in mail-client and now i get a failure when resolving LOCALHOST
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 +[23:05:06] <​skullcrasher>​ temporalfox,​ all right, thx
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 +[23:05:11] <​temporalfox>​ do you have an /etc/hosts file ?
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 +[23:05:18] <​temporalfox>​ normally it gets it from there
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 +[23:05:18] <​AlexLehm>​ might be a netty issue though
 +
 +[23:05:28] <​AlexLehm>​ it works with localhost in lower case
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 +[23:05:33] <​temporalfox>​ what is the failure you are having ?
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 +[23:05:35] <​temporalfox>​ ah
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 +[23:05:37] <​temporalfox>​ never tried that
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 +[23:05:44] <​AlexLehm>​ i am on windows, i think there is localhost in hosts
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 +[23:05:55] <​temporalfox>​ Netty resolver parses the hosts file
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 +[23:05:57] <​temporalfox>​ even on windows
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 +[23:06:31] <​AlexLehm>​ ok, localhost is present in the windows host file
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 +[23:06:50] <​AlexLehm>​ could be a windows issue, i can try my test on a linux
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 +[23:07:48] <​skullcrasher>​ should I post feature wishes/​proposals in the github issues project or the google group?
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 +[23:08:19] <​temporalfox>​ if you have a precise idea I would suggest github
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 +[23:08:30] <​temporalfox>​ if you want to discuss, better use the google group
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 +[23:09:09] <​skullcrasher>​ ok. better google group then. It's about support for easy inter cluster communication.
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 +[23:09:55] <​AlexLehm>​ ok, that looks like an issue in netty, when I add LOCALHOST to the hosts file it works
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 +[23:11:19] <​temporalfox>​ skullcrasher looks interesting,​ eager to read what you suggest
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 +[23:11:45] <​temporalfox>​ AlexLehm what is the expected behavior for DNS resolving ?
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 +[23:11:47] <​skullcrasher>​ temporalfox,​ well not only suggest but also ask :D
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 +[23:13:01] <​AlexLehm>​ localhost will not always resolve in dns, but it should be present in /etc/hosts
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 +[23:13:20] <​AlexLehm>​ when I use the java classes for the same test, it resolves localhost, LOCALHOST and Localhost all to 127.0.0.1
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 +[23:14:36] <​AlexLehm>​ so localhost is not resolved with a real dns query i assume
 +
 +[23:15:17] <​AlexLehm>​ which is actually defined by /​etc/​nsswitch.conf in Linux
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 +[23:15:53] <​temporalfox>​ it would be interesting to know when the LOCALHOST/​localhost is done
 +
 +[23:16:09] <​temporalfox>​ is it done by the JVM when it look at hosts file or not
 +
 +[23:16:21] <​temporalfox>​ should it be handled by Netty when it resolves against hosts file ?
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 +[23:16:34] <​AlexLehm>​ yes i think so
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 +[23:16:35] <​temporalfox>​ where is defined this precise behavior ?
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 +[23:16:52] <​temporalfox>​ I think we can contribute this to Netty if we can prove it's the correct behavior :-)
 +
 +[23:17:02] <​temporalfox>​ worse case I think we can patch it in vertx core
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 +[23:17:10] <​temporalfox>​ the resolver is quite flexible
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 +[23:18:08] <​AlexLehm>​ usually a program will use a dnsclient in glibc, which takes a look at the nsswitch file and then /etc/hosts and dns client (and maybe nscd if it is installed)
 +
 +[23:19:05] <​AlexLehm>​ not sure what java uses, probably they have the same behaviour implement in java directly, i know there are additional cache settings for dns in java, so its probably not using the glibc functions
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 +[23:20:22] <​AlexLehm>​ i think the chances of someone using uppercase LOCALHOST are pretty slim, I used that because I was testing my hostname cert matcher code before, this is not necessary anymore since it now uses the jdk code
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 +[23:40:30] <​AlexLehm>​ ok, that is wrong in the netty code, they use a hostname with case as key
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 +[23:40:31] <​AlexLehm>​ https://​github.com/​netty/​netty/​blob/​4.1/​resolver/​src/​main/​java/​io/​netty/​resolver/​HostsFileParser.java#​L151
 +
 +[23:40:46] <​AlexLehm>​ i can create an issue for that