These legacy flags support are here only because we do not want
CoreOS updates to break people.
Now people will be aware of that they switch to etcd3. Do not need
to support 0.x flags any more.
Added a new command line option to etcd server to read in a YAML
based configuration file. I've also added an example configuration
file with comments and a set of test cases.
This commit adds a new option for activating profiling based on pprof
in etcd process.
- -enable-pprof: boolean type option which activates profiling
For example, if a client URL is http://localhost:12379, users and
developers access heap profiler with this URL:
http://localhost:12379/debug/pprof/heap
Current membership changing functionality of etcd seems to have a
problem which can cause deadlock.
How to produce:
1. construct N node cluster
2. add N new nodes with etcdctl member add, without starting the new members
What happens:
After finishing add N nodes, a total number of the cluster becomes 2 *
N and a quorum number of the cluster becomes N + 1. It means
membership change requires at least N + 1 nodes because Raft treats
membership information in its log like other ordinal log append
requests.
Assume the peer URLs of the added nodes are wrong because of miss
operation or bugs in wrapping program which launch etcd. In such a
case, both of adding and removing members are impossible because the
quorum isn't preserved. Of course ordinal requests cannot be
served. The cluster would seem to be deadlock.
Of course, the best practice of adding new nodes is adding one node
and let the node start one by one. However, the effect of this problem
is so serious. I think preventing the problem forcibly would be
valuable.
Solution:
This patch lets etcd forbid adding a new node if the operation changes
quorum and the number of changed quorum is larger than a number of
running nodes. If etcd is launched with a newly added option
-strict-reconfig-check, the checking logic is activated. If the option
isn't passed, default behavior of reconfig is kept.
Fixes https://github.com/coreos/etcd/issues/3477
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>
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.
Before this PR, people can set listen-client-urls without setting
advertise-client-urls, and leaves advertise-client-urls as default
localhost value. The client libraries which sync the cluster info
fetch wrong advertise-client-urls and cannot connect to the cluster.
This PR avoids this case and provides better UX.
On the other hand, this change is safe because people always want to set
advertise-client-urls if listen-client-urls is set. The default localhost
advertise url cannot be accessed from the outside, and should always be
set except that etcd is bootstrapped with no flag.
We start to resolve host into tcp addrs since we generate
tcp based initial-cluster during srv discovery. However it
creates problems around tls and cluster verification. The
srv discovery only needs to use resolved the tcp addr to
find the local node. It does not have to resolve everything
and use the resolved addrs.
This fixes#2488 and #2226
Currently this doesn't work if a user wants to try out a single machine
cluster but change the name for whatever reason. This is because the
name is always "default" and the
```
./bin/etcd -name 'baz'
```
This solves our problem on CoreOS where the default is `ETCD_NAME=%m`.
