system_monitor has to be found in application (or included_applications)
otherwise dialyzer fails with Unknown function
Adding to 'applications' would cause a deadlock because one
cannot call application:ensure_all_started in the application/2
callback.
Fixes https://emqx.atlassian.net/browse/EMQX-10944
Also updates ekka -> 0.15.15, mria -> 0.6.4
How to test
===========
1. Start 2 or more EMQX nodes and merge them in a cluster.
2. Stop them in order.
3. Start only the first node that was stopped in the previous step.
4. Wait until the log is printed.
Or, more easily:
1. Start 2 or more EMQX nodes and merge them in a cluster.
2. Stop all but one.
3. Run `mria_mnesia:diagnosis([]).` on that node.
Example output
==============
```
Check check_open_ports should get ok but got #{msg =>
"some ports are unreachable",
results =>
#{'emqx@172.100.239.4' =>
#{open_ports =>
#{4370 => false,
5370 =>
false},
ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
4}],
status =>
bad_ports},
'emqx@172.100.239.5' =>
#{open_ports =>
#{4370 => false,
5370 =>
false},
ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
5}],
status =>
bad_ports}}}
```
After one node is back:
```
Check check_open_ports should get ok but got #{msg =>
"some ports are unreachable",
results =>
#{'emqx@172.100.239.4' =>
#{ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
4}],
status => ok},
'emqx@172.100.239.5' =>
#{open_ports =>
#{4370 => false,
5370 =>
false},
ports_to_check =>
[4370,5370],
resolved_ips =>
[{172,100,239,
5}],
status =>
bad_ports}}}
```
Prior to this change, when EMQX daemon mode failed to start
it's not quite easy for users to understand what went wrong.
All the know is the node did not start in time
and then instructed to boot the node in 'console' mode wishing
for some logs.
However, the node might actuay be running, causing 'console' mode
to fail with a different reason.
With this change, after a filure of daemon mode boot,
we issue a diagnosis.
1. if node can not be found from ps -ef, instruct the user
to find information in erlang.log.N
2. if the node is found running, but not responding to pings
instruct the user to check if the node name is
resolvable and reachable
3. if the node is responding to pings but emqx app is not
running, then it's likely a bug. so the user is advised
to report a github issue.
* feat(emqx_conf): move conf manager for emqx_machine to emqx_conf
* chore(emqx_conf): change emqx:get_config/2 to emqx_conf:get/2
* fix: common test failed
* fix: badmatch by typo wrong key
* fix(emqx_conf): get the wrong core nodes
* fix(emqx_conf): get core node's tnx_id not latest tnx_id
* fix: add ro_transation when copy conf file
* fix: delete debug info
* fix: change ekka_rlog to mria_rlog
* fix: remove cluster_rpc from emqx_machine.
* fix: don't call ekka:start/0 explicitly
* fix: ekka should be start in emqx_machine
prior to this cahnge emqx node shutdown is done by init:stop
which might have undesired stop order of the applications
in this change, emqx_machine_terminator is added to stop apps
in defined order and then terminate the node in infinite loop
ieQu1