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POWhen a Tomcat (embedded) Server slows down and eventually becomes unresponsive what is the most common cause
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  1. POWhen a Tomcat (embedded) Server slows down and eventually becomes unresponsive what is the most common cause
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    copied!<p>I'm inspecting a rather large server cluster. There are 15 odd servers running instances of an ERP. The various instances tend to have specific uses &amp; then there are also 2 high traffic web sites hosted with apache &amp; mod_jk for static content. All dozen server use a single database. Which I'm looking into the appropriate High Availability, Load Balancing,Replication solution for. I've been keeping an eye on the Sys Admin guy for a couple of days and all he seems to do is restart the server when an end user complains of slowness or unresponsiveness.</p> <p>In fact some end users send emails saying, pls restart the server.</p> <p>I'm a software engineer but my clients have asked me to leave the application layer for now at least the application itself &amp; try to boost performance via the layers beneath, container/appserver, io, network, hardware I suppose.</p> <p>Anyway can anyone give me an indication of why slow down occures at high usage &amp; why a restart would help, there must be a way to achieve the result of a restart before a restart is needed or an end user had reason to complain.</p> <p>I realize this may be a dumb question, I feel as if I should know. It might have to do with IO and sockets along with the threads working with them. But I need more insight. As I've gained development experience I've got closer to ground zero, I suppose the lowest level of the application, after which I suppose comes the network stack then hardware. I've never had a mental image of what happens beneath where the web app context is created and added to tomcat embeddable.</p> <p>A bit of background, Tomcat 5 embedded, along with Apache Geronimo. I know for a fact the this version of the app is old, hasn't upgraded when the project that birthed it was still around. It has cache issues &amp; thread handling issues, which were both improved in later additions but upgrading right now isn't an option.</p>
 

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