Before this PR, the log is
```
2015/09/1 13:18:31 etcdmain: client: etcd cluster is unavailable or
misconfigured
```
It is quite hard for people to understand what happens.
Now we print out the exact reason for the failure, and explains the way
to handle it.
We always want to use GOMAXPROCS() as the way go parses it. When in go1.4, we
want to expose GOMAXPROCS value, so we set GOMAXPROCS explicitly as the
way go 1.4 does and print it out.
But it becomes a problem when go 1.5 changes the way to set GOMAXPROCS.
Fix the problem by stop setting GOMAXPROCS and get its value directly.
Due to this change, it sets default GOMAXPROCS to the
number of CPUs available when compiling in go 1.5, which matches how go 1.5 works:
https://docs.google.com/document/d/1At2Ls5_fhJQ59kDK2DFVhFu3g5mATSXqqV5QrxinasI/edit
This is a behavior change in etcd 2.2.
It uses heartbeat interval and election timeout to estimate the
expected request timeout.
This PR helps etcd survive under high roundtrip-time environment,
e.g., globally-deployed cluster.
This solves the problem that etcd may fatal because its critical path
cannot get file descriptor resource when the number of clients is too
big. The PR lets the client listener close client connections
immediately after they are accepted when
the file descriptor usage in the process reaches some pre-set limit, so
it ensures that the internal critical path could always get file
descriptor when it needs.
When there are tons to clients connecting to the server, the original
behavior is like this:
```
2015/08/4 16:42:08 etcdserver: cannot monitor file descriptor usage
(open /proc/self/fd: too many open files)
2015/08/4 16:42:33 etcdserver: failed to purge snap file open
default2.etcd/member/snap: too many open files
[halted]
```
Current behavior is like this:
```
2015/08/6 19:05:25 transport: accept error: closing connection,
exceed file descriptor usage limitation (fd limit=874)
2015/08/6 19:05:25 transport: accept error: closing connection,
exceed file descriptor usage limitation (fd limit=874)
2015/08/6 19:05:26 transport: accept error: closing connection,
exceed file descriptor usage limitation (fd limit=874)
2015/08/6 19:05:27 transport: accept error: closing connection,
exceed file descriptor usage limitation (fd limit=874)
2015/08/6 19:05:28 transport: accept error: closing connection,
exceed file descriptor usage limitation (fd limit=874)
2015/08/6 19:05:28 etcdserver: 80% of the file descriptor limit is
used [used = 873, limit = 1024]
```
It is available at linux system today because pkg/runtime only has linux
support.
At present it prints the whole usage and flags, which cause the exact
error message is hidden two screens above.
Fixes#3141
Signed-off-by: Guohua Ouyang <gouyang@redhat.com>
If the user sets TLS info, this implies that he wants to listen on TLS.
If etcd finds that urls to listen is still HTTP schema, it prints out
warning to notify user about possible wrong setting.
etcd shows an odd message on configuration error like this (partially):
```
... discovery or bootstrap flags are setChoose one of ...
^^^^^^^^^
```
This commit fixes the message format problem.
This PR set maxIdleConnsPerHost to 128 to let proxy handle 128 concurrent
requests in long term smoothly.
If the number of concurrent requests is bigger than this value,
proxy needs to create one new connection when handling each request in
the delta, which is bad because the creation consumes resource and may
eat up your ephemeral port.
