terminating connection because of crash of another server process

Solution 1:

Linux's out-of-memory killer is probably terminating processes. This means your server is misconfigured. It's strongly advised that you not let Linux overcommit memory, so it responds with a proper out-of-memory error to the application instead of killing processes almost at random. PostgreSQL is designed to handle out-of-memory conditions, but cannot do so if Linux kills processes instead of reporting out-of-memory.

To confirm that's what is happening here, check the kernel message log with the dmesg command.

See http://www.postgresql.org/docs/current/static/kernel-resources.html#LINUX-MEMORY-OVERCOMMIT