This is one of those things you come across once every year or two and you can never remember exactly how to do it. The issue is when your Java WAR File that is compiled and packaged during your build process keeps growing in size over time as you are adding extra features and functionality to your Java web application. It’s a good problem to come across as it means that you are building things your customers love. We’ll not go into the discussion of large applications VS micro services, we’ll leave that for another blog post at some point.
We’re looking at Apache Tomcat 7 here since this is the default out of the box version of Tomcat that comes packaged with Amazon Linux 2 which many people will be using. We’re going to assume that you’ve got that all set up the way you need it, so again, we’ll not be covering that off today.
The issue you’ve likely faced when you have come to upload your WAR file is that it simply doesn’t upload and you may have noticed that uploading your WAR file gets to a certain percentage complete then just seems to stop uploading. Thankfully this is quite an easy fix to do, once you know what you’re looking for and how to find the file you need to edit.
By default on Amazon Linux 2, Apache Tomcat 7 creates a shared location where the configuration files for the Tomcat Manager live, this is within;
/usr/share/tomcat/webapps/manager/
So all you need to go and do is edit the web.xml file in the following location by running the command;
sudo nano /usr/share/tomcat/webapps/manager/WEB-INF/web.xml
And you’ll see a section of code in there that allows you to change the MaxFileSize configuration settings. If you’re more familiar with PHP, this is similar to the upload_max_filesize and post_max_size PHP directives in your php.ini configuration file.
<multipart-config>
<!-- 50MB max -->
<!--<max-file-size>52428800</max-file-size>-->
<!--<max-request-size>52428800</max-request-size>-->
<!-- 100MB max -->
<max-file-size>104857600</max-file-size>
<max-request-size>104857600</max-request-size>
<file-size-threshold>0</file-size-threshold>
</multipart-config>
Simply change those details to whatever file size you need. The default for Apache Tomcat is a 50MB file size. So just configure that to whatever you need. As touched upon earlier, always consider when you’re doing this is you need to start thinking about breaking up the application into smaller components that work together in a micro services approach. But this comes with more challenges that you need to be considering at that point too.
Once you’ve got this configured, simply restart Apache Tomcat 7 and you’re good to go.
sudo service tomcat restart
You should now be able to upload your larger WAR file via the Tomcat Manager interface.
Michael Cropper