Topic: mod_jk setup with Tomcat 7 freezes and 502

[b0s]

Hi
A rather complicated tomcat java webapp freezes ~3 times a week. The application itself installed and configured tomcat, but apache and mod_jk I installed myself.
Freeze = main page does not load and nothing is written into catalina.out about it (loglevel warn). And going directly though aadress:8080/appmain is also "frozen". Not sure if this is caused by mod_jk somehow, so I would need to know if my setup is correct in that part. Can this tomcat freeze be caused by apache or mod_jk at all?
If this cannot be caused by my apache, mod_jk setup I need to contact the software-s support.

Soft:
Centos 6.4
Oracle JDK 1.7.051
tomcat 7.0.33 preconfigured by the application
mod_jk version 1.2.39
Apache 2.2.15
The application is meant to be accessed though apache-s SSL for certificate information ( SSLOptions +ExportCertData). https://aadress/appmain

httpd.conf changes:
Timeout 60
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 10
<IfModule worker.c>
StartServers 4
MaxClients 300
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 5000
</IfModule>
And aliases like Alias /app_html/ "/opt/app/appname/app_html/"

SSL.conf contains Certificate handling and some RewriteCond-s for ending session.

workers.properties
workers.tomcat_home=/opt/user/app/Tomcat
workers.java_home=/usr/java/latest/
ps=/
#ajp13 worker
worker.list=ajp13
worker.ajp13.port=8009
worker.ajp13.host=localhost
worker.ajp13.type=ajp13
worker.ajp13.socket_keepalive=1
worker.ajp13.socket_timeout=15
worker.ajp13.retries=3
worker.ajp13.retry_interval=100
worker.ajp13.max_packet_size=16384
worker.inprocess.jvm_lib=$(workers.java_home)$(ps)jre$(ps)lib$(ps)amd64$(ps)server$(ps)libjvm.so

mod_jk.conf
<IfModule !mod_jk.c>
LoadModule jk_module /etc/httpd/modules/mod_jk.so
</IfModule>
JkWorkersFile "/etc/httpd/conf.d/workers.properties"
JkLogFile "/etc/httpd/logs/mod_jk.log"
JkShmFile "/etc/httpd/logs/mod_jk.shm"
JkRequestLogFormat "%w %V %T"
JkLogLevel info
JkLogStampFormat "[%a %b %d %H:%M:%S %Y]"
JkOptions +DisableReuse
JkMount /appmain ajp13
JkMount /appmain/* ajp13

Adding to mod_jk advanced options like keepalives, retries, JkShmFile, +DisableReuse and enabling apache-s keepalive caused 502 bad gateway errors showing up.
Is there something wrong is this setup, that could cause a tomcat freeze or 502 bad gateway errors?

Thank you in advance!