Added pattern match to handle timeouts for github Issue 86

[mk1s]

riaknostic Issue #86 -- Timeout message cached in local stats and causes crash

A recent customer issue revealed a condition where their repeated calls to riak_kv_status:statistics/0 were timing out and storing the {badrpc, timeout} message as the stats, causing riaknostic to crash.

Reproducer

application:set_env(riaknostic, local_stats, {badrpc, timeout}).
application:get_env(riaknostic, local_stats).
riaknostic:main([]).

Fix

The riaknostic_node module is responsible for fetching and caching the stats, so a pattern match was added to the has_stats/0 function to handle the {badrpc, Reason} message and return as if no stats were currently cached so it will refetch in this state.

Test

application:set_env(riaknostic, local_stats, {badrpc, timeout}).
application:get_env(riaknostic, local_stats).
riaknostic:main([]).
{ok, {badrpc, timeout}} =:= application:get_env(riaknostic, local_stats).

[bsparrow435]

Looks like indentation was messed up a bit here.

[bsparrow435]

@mk1s had one indentation comment, other than that, +1 and ready to merge. Bors is not set up for riaknostic so we'll need to do it manually.

[zeeshanlakhani]

@bsparrow435 we just need the indentation and it's ready to merge right?

[bsparrow435]

yep, and the indentation isnt essential, erlang and all

[zeeshanlakhani]

@bsparrow435. Cool. @mk1s, if you want to update w/ the indentation, that'd be rad. Otherwise, no matter what, we'll try and review and get this in for 2.1.2 (as we're in the midst of figuring out the necessary release needs going forward)