Currently it is possible for elasticsearch users to have -XX:+HeapDumpOnOutOfMemoryError enabled (it is enabled by default), but in many installations (rpm/deb) the default location ($ES_HOME which is usually /var/share/elasticsearch) is not writable.
Alternatively the location can be explicitly defined with -XX:HeapDumpPath= but this location may not be writable... so if an OOM happens, no heapdump can be written, which in turn greatly complicates debugging the root cause.
It would be great to as a first step have this as part of bootstrap checks, initially creating a warning and in a later version actually blocking elasticsearch starting.
This could be difficult considering the Java security manager...