On Mon, Oct 7, 2024 at 12:07 AM Alvaro Herrera <alvhe...@alvh.no-ip.org> wrote:
> On 2024-Oct-04, KK CHN wrote: > > > The mobile tablets are installed with the android based vehicle > > tracking app which updated every 30 seconds its location fitted inside > the > > vehicle ( lat long coordinates) to the PostgreSQL DB through the java > > backend application to know the latest location of the vehicle and its > > movement which will be rendered in a map based front end. > > > > The vehicles on the field communicate via 443 to 8080 of the Wildfly > > (version 27 ) deployed with the vehicle tracking application developed > with > > Java(version 17). > > It sounds like setting TCP keepalives in the connections between the > Wildfly and the vehicles might help get the number of dead connections > down to a reasonable level. Then it's up to Wildfly to close the > connections to Postgres in a timely fashion. (It's not clear from your > description how do vehicle connections to Wildfly relate to Postgres > connections.) > > Where do I have to introduce the TCP keepalives ? in the OS level or application code level ? [root@dbch wildfly-27.0.0.Final]# cat /proc/sys/net/ipv4/tcp_keepalive_time 7200 [root@dbch wildfly-27.0.0.Final]# cat /proc/sys/net/ipv4/tcp_keepalive_intvl 75 [root@dbch wildfly-27.0.0.Final]# cat /proc/sys/net/ipv4/tcp_keepalive_probes 9 [root@dbch wildfly-27.0.0.Final]# These are the default values in the OS level. Do I need to reduce all the above three values to say 600, 20, 5 ? Or need to be handled in the application backend code ? Any hints much appreciated.. > > I wonder if the connections from Wildfly to Postgres use SSL? Because > there are reported cases where TCP connections are kept and accumulate, > causing problems -- but apparently SSL is a necessary piece for that to > happen. > No SSL in between Wildfly (8080 ) to PGSQL(5432). Both the machines internal lan VMs in the same network. Only the devices on the field (fitted on the vehicles) communicate to the application backend via a public URL :443 port then it connectes to the 8080 of wildfly then the java code connects the database server running on 5432 on the internal LAN network. > > -- > Álvaro Herrera 48°01'N 7°57'E — > https://www.EnterpriseDB.com/ > Thou shalt study thy libraries and strive not to reinvent them without > cause, that thy code may be short and readable and thy days pleasant > and productive. (7th Commandment for C Programmers) >
