Hi Mark, Sorry I'm not familiar with what a Selector is? However on one system I've noticed 28000 such connections. Are these caused by client connections? I'm not saying the connection originates from a client, but does the type of socket get create because of client connections?
On Tue, Mar 31, 2020 at 1:20 PM Mark Thomas <ma...@apache.org> wrote: > On 31/03/2020 11:20, Aditya Kumar wrote: > > Tomcat 9.0.30 on Windows Server 2012 / Java 1.8 > > > > I've noticed on a freshly installed version of tomcat 9, upon startup > there > > are several connections to and from localhost on different ports > > > > For example on my tomcat server there are 4 connections to and from > > localhost (output from netstat) > > > > TCP 0.0.0.0:8080 0.0.0.0:0 LISTENING > 3972 > > TCP 127.0.0.1:55618 127.0.0.1:55619 ESTABLISHED > 3972 > > TCP 127.0.0.1:55619 127.0.0.1:55618 ESTABLISHED > 3972 > > TCP 127.0.0.1:55620 127.0.0.1:55621 ESTABLISHED > 3972 > > TCP 127.0.0.1:55621 127.0.0.1:55620 ESTABLISHED > 3972 > > TCP [::]:8080 [::]:0 LISTENING > 3972 > > > > These can grow to a large number (several thousand) on a busy system. > What > > are these connections used for? What caused them? What thread are they > > attributed to? > > The Java NIO implementation on Windows uses TCP for intra-process > signalling. It opens a pair of self-connected sockets for every Selector. > > Mark > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
