scripts.mit.edu

Is Java supported?

Short answer: No.

There are two aspects to this question: general Java programs (short answer: we try) and Java Servlets (short answer: we’d like to).

General Java programs

We try to allow running Java programs on Scripts (such as cron jobs or CGI programs). However, keeping Java programs working requires ongoing work from the maintainers and the maintainers don’t use Java and therefore often won’t notice when it breaks. Consequently, we recommend picking a better-supported language (such as Python) if you have a choice.

The issue with Java programs is that by default Java will attempt to allocate a large fraction of the system’s memory when it starts up. On most systems this is fine, because the operating system will not reserve the memory until Java writes to it, rather than merely allocates it. However, to ensure that Scripts remains responsive for our many users, we limit how much memory a single process can allocate (unfortunately, Linux does not allow limiting how much memory a process can use, except by limiting the amount a process can allocate). We attempt to configure Java and these memory limits such that Java can run within them, but sometimes part of this configuration breaks without our noticing.

Java Servlets

We do not currently support running Java Servlets. We would like to, and would welcome SIPB prospectives interested in adding support, but expect that it would take significant work.