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Log4j2 Syslog appender is not writing the 1st message to syslog after the syslog service is restarted

We have configured our application to write some specific log messages to System's Syslog file using the Syslog appender of Log4j2. No issue in writing the Syslog to the file. But when the syslog service is restarted, the first log message is not written to the syslog. The subsequent messages are written.
Enabled debug logs of Log4j, no exception is seen while writing 1st message to syslog after the restart. But for the subsequent request, the following messages were captured in the Log4j2 log.
2022-01-27 18:07:40,120 ajp-nio-0.0.0.0-8009-exec-3 DEBUG Reconnecting localhost/127.0.0.1:514
2022-01-27 18:07:40,121 ajp-nio-0.0.0.0-8009-exec-3 DEBUG Creating socket localhost/127.0.0.1:514
2022-01-27 18:07:40,122 ajp-nio-0.0.0.0-8009-exec-3 DEBUG Closing SocketOutputStream java.net.SocketOutputStream#1a769d7
2022-01-27 18:07:40,122 ajp-nio-0.0.0.0-8009-exec-3 DEBUG Connection to localhost:514 reestablished: Socket[addr=localhost/127.0.0.1,port=514,localport=57852]
I took threaddump and checked whether the Reconnector thread is running but no such exists in the threaddump. I am clueless here, any help on finding the reason for missing the message would be helpful.
Environment details:
CentOS 7.9 + RSyslog Service,
Application deployed in Tomcat and running on Java 11,
Log4j2 version is 2.17.1

This is due to the way plain text TCP syslog works. Check out this post for further information.
This "bug" exists, since version 8.1901 and newer.
The only way you can fix this - as far as i know - is to send the messages over the RELP protocol. See omrelp module.

Logback will only log a message to syslog once

I've tried several examples of using logback to write to syslog, but the only that I've found that works is this JavaCodeGeeks example. It writes a message to syslog, but it only writes a message once no matter how many times I run the code. If I change the message it will write it to syslog, but only once.
I'm on Ubuntu 19.10. I've uncommented the following four lines from my /etc/rsyslog.conf and restarted :
# provides UDP syslog reception
module(load="imudp")
input(type="imudp" port="514")
# provides TCP syslog reception
module(load="imtcp")
input(type="imtcp" port="514")
The only change I made to the javacodegeeks code is to comment out the remote appender in logback.xml. It only logs to the localhost syslog.
What causes this weird behavior?

To log all messages you have to set
$RepeatedMsgReduction off
in /etc/rsyslog.conf and restart rsyslog.
https://www.rsyslog.com/doc/v8-stable/configuration/action/rsconf1_repeatedmsgreduction.html
The default was on in Ubuntu 19.10.

Pivotal server log messages not show in Spring tools suite

I am working on Spring web MVC. I am using Spring tools suite and pivotal server. I did not found any server log messages in STS. Console only show the server startup message. I want to view all the server message, error and exceptions. Currently I am unable to view any server error messages and errors.
The console is showing the message like this-
Nov 19, 2016 1:08:21 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 1312 ms
Nov 19, 2016 1:08:26 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 5332 ms

i see the question is old but I came across the same issue just now and didn't want to let this one go unanswered ;)
I found an solution from pivotal themselves. But it has a little typo in it: The first line in the logging.properties is
handlers= java.util.logging.ConsoleHandler.level= INFO
but should rather be just
handlers= java.util.logging.ConsoleHandler
This should do the trick.
And if you would still want to keep the default catalina, localhost, etc. files of the tcServer additional to the console output you can modify or copy the logging.properties file found inside of your tcServer - base instance ({pivotal-tc-server-folder}/base-instance/conf/).
Here are many configurations but the one concerning the console output, which is otherwise only in the catalina-{date}.log is in the line
.handlers = 1catalina.org.apache.juli.AsyncFileHandler
just change it to
.handlers = 1catalina.org.apache.juli.AsyncFileHandler, java.util.logging.ConsoleHandler
and you'll have both: logs and console output.
Best regards,
Uwe

Wildfly JSF resources: err_invalid_chunked_encoding

My customer web application is currently on an AWS-EC2 Linux instance, running WildFly 8.2.0.Final "Tweek".
I'm not using Apache or other web servers, just accessing the application server on port 8080 (the system is forwarding to 8080 all traffic on port 80).
Application works fine everywhere, but yesterday I found a very weird issue on one of my customer's browsers. However, it's not related to the browser, because I already tried installing Firefox and Chrome, in addition to IE, and the problem is still there. The client OS is Win8.1.
The CSS and JS files are not loaded by the browser: Chrome prints this message in the console:
ERR_INVALID_CHUNKED_ENCODING
However, if I click on the file and 'Open link in new tab', I can actually see the file's content!
My static files are JSF resources, for example:
/javax.faces.resource/primefaces.css.htm?ln=primefaces&v=5.1
Response headers are, for example:
Content-Type:application/javascript
Date:Fri, 27 Mar 2015 16:32:51 GMT
ETag:W/"312861-1427473269000"
Expires:Fri, 03 Apr 2015 16:32:51 GMT
Last-Modified:Fri, 27 Mar 2015 16:21:09 GMT
I saw the content-length is also zero, which I suppose is the cause for the problem.
How to find out more info on that? What's the solution for that type of error? Thanks

How to design log structure for a Java application

Am new to java, I know Java has Log4J, logback etc for logging purposes. My question is more around how many log files should we have in a application. Should it be per thread, per group of threads, process, exception etc. In our application there is a possibility of having a large number of threads and am thinking about cons of having log file per thread. Are there best practices for logging in applications having huge number of threads .
Thanks in advance!

1 log for messages - Call it SystemOut.log
1 log for stack traces - Call it SystemErr.log
1 log for traces - Call it Trace.log
1 log for native stdout - Call it nativeStdOut.log
1 log for native stderr - Call it nativeStdErr.log
Have a config panel that sets:
maxSize
maxCount
When a log hits max size, starting rolling them upto maxCount and append a timestamp to the rolled filename.

I think that good solution would be to name your threads and write logs together with the name of thread in which log occurred. Thanks to that you will be able to both analysis logs separately for each thread or analysis all logs together.

Typically there is one log file per application (process) -- rarely for Thread and never be Exception. Sometimes this log file is split into various different log levels: debug messages in one bucket, information in another, warnings/errors in a third. This makes it easy to watch for errors by only looking at the warning-and-more-critical file.
log4j has a configuration file in which you can route certain messages to certain files using different criteria. Here's a sample of the log4j properties file:
# default is WARN and above going to the appender "logfile" and STDOUT
log4j.rootLogger=WARN, logfile, stdout
# write to ui.log for a day and then move to .yyyy-MM-dd suffix
log4j.appender.logfile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.logfile.File=ui.log
log4j.appender.logfile.Append=true
log4j.appender.logfile.DatePattern='.'yyyy-MM-dd
# but we log information message from classes in the package com.mprew.be
log4j.logger.com.mprew.be=INFO
log4j, and custom loggers, decorate each time with a Class name, priority level, date/time, etc.. For example:
# date time priority Class-name Log message
2012-03-26 00:55:39,545 [INFO] CmsClientTask Content is up-to-date
Typically exceptions are written out as multiple lines so you can get the entire stack-trace.
2012-03-26 01:55:35,777 [INFO] ExceptionInterceptor Reporting problem to customer
org.springframework.NoSuchRequestException: No request handling method
at com.ui.base.BaseController.invokeNamedHandler(BaseController.java:240)
at com.ui.base.BaseController.handleRequestInternal(BaseController.java:100)
at com.ui.base.CoreServices.handleRequest(CoreServicesController.java:147)
...
In our distributed system, we route all logs from all of the system to 2 servers which write a debug, info, and warning logs. Along with the date/time, class name, priority, and message, the log messages also have the hostname and a specific log token so we can easily identify classes of problems. The following is on one line:
2012-03-26 00:00:00.045 UTC INFO FE8 TrayController TRAY_CLIENT_LOOKUP
message=created unknown client with partner STW9
Then we can easily grep for specific issues.
Hope this helps.