what this error means? [Erlang, mochiweb, MySQL] - mysql

Question

I made a comet chat server with Erlang and Mochiweb. And I run the "./start-dev.sh" to start the server. But after about 1 month I got the following error:
=ERROR REPORT==== 26-Sep-2009::09:21:06 ===
{mochiweb_socket_server,235,
{child_error,
{badmatch,
{error,
[70,97,105,108,101,100,32,115,101,110,100,105,110,103,32,100,
97,116,97,32,111,110,32,115,111,99,107,101,116,32,58,32,
"closed"]}}}}
mysql: fetch "SELECT appKey FROM applications WHERE appID = 1" (id p1)
=CRASH REPORT==== 26-Sep-2009::09:21:10 ===
crasher:
initial call: mochiweb_socket_server:acceptor_loop/1
pid: <0.4271.23>
registered_name: []
exception error: no match of right hand side value
{error,[70,97,105,108,101,100,32,115,101,110,100,105,110,
103,32,100,97,116,97,32,111,110,32,115,111,99,
107,101,116,32,58,32,"closed"]}
in function moonwalker_web:loop/2
in call from mochiweb_http:headers/5
ancestors: [moonwalker_web,moonwalker_sup,<0.52.0>]
messages: []
links: [<0.54.0>,#Port<0.792854>]
dictionary: [{mochiweb_request_body,
<<"appID=1&appKey=keyy&userID=8048943&nickName=bill&buddies=N%3B&timestamp=1253928070154">>},
{mochiweb_request_recv,true},
{mochiweb_request_post,
[{"appID","1"},
{"appKey","key"},
{"userID","8048943"},
{"nickName",[143,229,167,144]},
{"buddies","N;"},
{"timestamp","1253928070154"}]},
{mochiweb_request_path,"/online"}]
trap_exit: false
status: running
heap_size: 2584
stack_size: 24
reductions: 1368
neighbours:
=ERROR REPORT==== 26-Sep-2009::09:21:10 ===
{mochiweb_socket_server,235,
{child_error,
{badmatch,
{error,
[70,97,105,108,101,100,32,115,101,110,100,105,110,103,32,100,
97,116,97,32,111,110,32,115,111,99,107,101,116,32,58,32,
"closed"]}}}}
And if turn the following numbers into characters
[70,97,105,108,101,100,32,115,101,110,100,105,110,103,32,100,
97,116,97,32,111,110,32,115,111,99,107,101,116,32,58,32,
"closed"]}}}}
they are
Failed sending data on socket :"closed"
Does that mean I have problems with MySQL connection or socket?
I don't know if this error has something to do with my "./start-dev.sh" or I just had some wrong settings?
And what else information do I have to provide for diagnosing?
Thanks and looking forward to your reply?

Answer 1

It looks like somewhere in the loop/2 function you don't handle an {error,Error} return from a function call. This causes the error which crashes the process. Without the code it is difficult to say what caused the error return.