Re: CLOSE_WAIT pileup and Application Timeout - Mailing list pgsql-general

From Francesco Benetton
Subject Re: CLOSE_WAIT pileup and Application Timeout
Date
Msg-id CACJJLizTMX=yYfScuoPZ0=tfh5wdd3P09pSYnBu+Bsh6C6=CLw@mail.gmail.com
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In response to CLOSE_WAIT pileup and Application Timeout  (KK CHN <kkchn.in@gmail.com>)
List pgsql-general

If I understand clearly, postgresql is used as a Data server for the backend, and so the Android app does not connect directly to postgresql.
The first idea is a problem on closing or recycling the connection by the backend after executing the request. Maybe wrong client connection pooling settings?

Il ven 4 ott 2024, 06:29 KK CHN <kkchn.in@gmail.com> ha scritto:
List,

I am facing a  network (TCP IP connection closing issue) .

Running a  mobile tablet application, Android application to update the status of vehicles fleet say around 1000 numbers installed with the app on each vehicle along  with a  vehicle tracking  application server solution based on Java and Wildfly with  PosrgreSQL16 backend.

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).


  The mobile tablet communicates to the backend application over mobile data (4G/5G SIMS). 

The  running vehicles may disconnect  or be unable to send the location data in between if the mobile data coverage is less or absent in a particular area where data coverage is nil or signal strength less. 

The server on which the backend application runs most often ( a week's time  or so) shows connection timeout and is unable to serve tracking  of  the vehicles further.

When we restart the  Wildfly server  the application returns to normal.  again the issue repeats  after a week or two. 

In the Server machine when this bottleneck occurs  I am seeing  a lot of  TCP/IP CLOSE_WAIT   ( 3000 to 5000 ) when the server backend becomes unresponsive. 

What is the root cause of this issue ?   Is it due to the android application unable to send the CLOSE_WAIT ACK due to poor mobile data connectivity ? 


 If so, how do people  address this issue ?  and what may be a fix ?  

 Any  directions / or reference material most welcome. 

Thank you,
Krishane





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