Hi Patrick,

You may be running out of ports which erlang uses for TCP sockets - try
increasing ERL_MAX_PORTS in etc/vm.args

Cheers, Jon
Basho Technologies.

On Mon, Sep 26, 2011 at 12:17 PM, Patrick Van Stee
<vans...@highgroove.com>wrote:

> We're running a small, 2 node riak cluster (on 2 m1.large boxes) using the
> LevelDB backend and have been trying to write ~250 keys a second at it. With
> a small dataset everything was running smoothly. However, after storing
> several hundred thousand keys some performance issues started to show up.
>
> * We're running out of file descriptors which is causing nodes to crash
> with the following error:
>
> 2011-09-24 00:23:52.097 [error] <0.110.0> CRASH REPORT Process [] with 0
> neighbours crashed with reason: {error,accept_failed}
> 2011-09-24 00:23:52.098 [error] <0.121.0> application: mochiweb, "Accept
> failed error", "{error,emfile}
>
> Setting the max_open_files limit in the app.config doesn't seem to help.
>
> * Writes have slowed down by an order of magnitude. I even set the n_val,
> w, and dw bucket properties to 1 without any noticeable difference. Also we
> switched to using protocol buffers to make sure there wasn't any extra
> overhead when using HTTP.
>
> * Running map reduce jobs that use a range query on a secondary index
> started returning an error, {"error":"map_reduce_error"}, once our dataset
> increased in size. Feeding a list of keys works fine, but querying the index
> for keys seems to be timing out:
>
> 2011-09-26 16:37:57.192 [error] <0.136.0> Supervisor riak_pipe_fitting_sup
> had child undefined started with {riak_pipe_fitting,start_link,undefined} at
> <0.3497.0> exit with reason
> {timeout,{gen_server,call,[{riak_pipe_vnode_master,'riak@10.206.105.52
> '},{return_vnode,{'riak_vnode_req_v1',502391187832497878132516661246222288006726811648,{raw,#Ref<0.0.1.88700>,<0.3500.0>},{cmd_enqueue,{fitting,<0.3499.0>,#Ref<0.0.1.88700>,#Fun<riak_kv_mrc_pipe.0.133305895>,#Fun<riak_kv_mrc_pipe.1.125635227>},{<<"ip_queries">>,<<"uaukXZn5rZQ0LrSED3pi-fE-JjU">>},infinity,[{502391187832497878132516661246222288006726811648,'
> riak@10.206.105.52'}]}}}]}} in context child_terminated
>
> Is anyone familiar with these problems or is there anything else I can try
> to increase the performance when using LevelDB?
> _______________________________________________
> riak-users mailing list
> riak-users@lists.basho.com
> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
>
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