[chef] chef-client error

[zhang wei qiang < >]

Hello.I use the open source chef-server, began to run the chef-client no
problem, today in the server running tipsINFO: HTTP Request Returned
401Unauthorized : Failed to authenticate . Ensure that your client key is
valid.[Tue,22May 201209: 11:32 -0700] FATAL: Stacktrace dumped to / var / Chef
/ cache / chef-stacktrace.out[Tue,22May 201209: 11:32 -0700] FATAL: Net::
HTTPServerException: 401" Unauthorized"The client running tips[Tue,22May
201209: 22:12 -0700] INFO: Run List is [ ][Tue,22May 201209: 22:12 -0700] 
INFO:
Run List expands to [ ][Tue,22May 201209: 22:12 -0700] INFO: Starting Chef Run
for centos.com[Tue,22May 201209: 22:12 -0700] INFO: Running start
handlers[Tue,22May 201209: 22:12 -0700] INFO: Start handlers
complete.[Tue,22May 201209: 22:12 -0700] INFO: Loading cookbooks [ ][Tue,22May
201209: 22:12 -0700] WARN: Node centos.com has an empty run list.[Tue,22May
201209: 22:16 -0700] INFO: HTTP Request Returned 500Internal Server Error:
Connection failed user: Chef[Tue,22May 201209: 22:16 -0700] ERROR: Server
returned error for http: / /172.23.164.34: 4000/ nodes / centos.com, retrying
1/ 5 in3S[Tue,22May 201209: 22:23 -0700] INFO: HTTP Request Returned
500Internal Server Error: Connection failed user: Chef[Tue,22May 201209: 22:23
-0700] ERROR: Server returned error for http: / /172.23.164.34: 4000/ nodes /
centos.com, retrying 2/ 5 in7S[Tue,22May 201209: 22:37 -0700] INFO: HTTP
Request Returned 500Internal Server Error: Connection failed user:
Chef[Tue,22May 201209: 22:37 -0700] ERROR: Server returned error for http: /
/172.23.164.34: 4000/ nodes / centos.com, retrying 3/ 5 in15s[Tue,22May 
201209:
22:56 -0700] INFO: HTTP Request Returned 500Internal Server Error: Connection
failed user: Chef[Tue,22May 201209: 22:56 -0700] ERROR: Server returned error
for http: / /172.23.164.34: 4000/ nodes / centos.com, retrying 4/ 5
in19S[Tue,22May 201209: 23:19 -0700] INFO: HTTP Request Returned 500Internal
Server Error: Connection failed user: Chef[Tue,22May 201209: 23:19 -0700]
ERROR: Server returned error for http: / /172.23.164.34: 4000/ nodes /
centos.com, retrying 5/ 5 in42s[Tue,22May 201209: 24:05 -0700] INFO: HTTP
Request Returned 500Internal Server Error: Connection failed user:
Chef[Tue,22May 201209: 24:05 -0700] ERROR: Running exception 
handlers[Tue,22May
201209: 24:05 -0700] FATAL: Saving node information to / var / Chef / cache /
failed-run-data.json[Tue,22May 201209: 24:05 -0700] ERROR: Exception handlers
complete[Tue,22May 201209: 24:05 -0700] FATAL: Stacktrace dumped to / var /
Chef / cache / chef-stacktrace.out[Tue,22May 201209: 24:05 -0700] FATAL: Net::
HTTPFatalError:" Internal Server Error500"