Need to document minimum server requirements for running Checkbook.

[kfogel]

In general, we need to describe the hardware requirements for running Checkbook on a dataset of a given size.

Here's an example of where specifically this would help:

In /opt/apache-tomcat-6.0.35/bin/catalina.sh, we saw that CATALINA_OPTS had "-Xms7130M" and "-Xmx7130M". Is that too much memory for most people just playing in a sandbox? We reduced to 512M and it seemed to be fine at first; when it was 7130, we got errors in /opt/apache-tomcat-6.0.35/logs/catalina.out:

Error occurred during initialization of VM
Could not reserve enough space for object heap

On the other hand, we later re-launched in a massive AWS instance because initial Solr indexing was taking forever. So maybe the default settings truly are necessary -- in which case, we should document the size of server needed to satisfy them.

[zamicol]

@kfogel ,

I ran this on an old pentium 4 with 2 GB of ram and plenty of swap space. It worked fine with a lower setting of "-Xms2130M" and "-Xmx2130M".

In my latest pull request I made a note of these settings.