Too many files opened by a node

[aletomsic]

I've found an issue in the clock-SI + partitioned log branch (as I have merged them into clock-SI to support the "one log per preflist" feature).
In this branch, there are currently 4 files opened "per vnode" (as there is a logging_vnode that opens N; a log per partition, and a clock-SI vnode that opens one).

THE PROBLEM

When starting a single node cluster, all of these files are opened by a single unix process. I was getting the error:

[error] Supervisor riak_core_vnode_sup had child undefined started with {riak_core_vnode,start_link,undefined} at <0.1453.0> exit with reason bad return value: {stop,{file_error,"./data/1301649895747835411525156804137939564381064921088_log3",emfile}} in context child_terminated

Unix allows, by default, a maximum of 256 file descriptors opened per process, and this limit was exceeded when running a single node cluster. you can check that in your machine with "ulimit -n".

Solution

change (only for the current session) the maximum number of file descriptors allowed per process with:

ulimit -n new_limit

LEARNED:

• All erlang processes run in a single unix process (at least I didn't know that).

[cmeiklejohn]

Closing.