+1
I think that the configurations of all locators should be identical, or
at least in terms of a few "critical" properties. One would also need to
be able to amend some property changes at runtime, to allow for the
changing of configuration without taking all the locators offline.
"remote-locators" would be a good candidate.
--Udo
On 1/3/17 09:50, Jacob Barrett wrote:
If we consider the locators as the directory service for the cluster then
it makes no sense for them to be configured differently. I think locators
should be force to adopt the configuration of the other locator in the
cluster or refuse to join the cluster until their config is updated to
match.
On Tue, Jan 3, 2017 at 8:52 AM Jinmei Liao <jil...@pivotal.io> wrote:
Calling all the pros with knowledge on cluster configurations:
This is regarding this current behavior of Cluster Config: Assuming a
cluster has 2 locators, locator-A-with-CC (with cluster config enabled),
and locator-B-without-CC (without cluster config enabled), currently any
commands a user executes through Gfsh that affects cluster config (create
region, deploy/undeploy etc) will change cluster config no matter which
locator he connects to.
The implementation of this behavior is quite complicated: the command needs
to:
1. find out from DM if there is any locator that has CC enabled (the DM
needs to maintain a flag simply for this purpose).
2. find out from DM the list of locators that has CC enabled.
3. loop through this list, execute a remote function on that locator to
change the CC. (depending on the nature of the command, the function is
different).
4. break out of the loop if one execution is successful. (it only needs to
update only one locator, since the cc region is replicated across
locators).
Quite often, the locator that ends up executing the function call will the
be locator that executes the command, but we still need to do the remote
call. So I am wondering:
A: What are the use cases where a cluster might have a mix of locators with
and without CC? Is it quite common?
B: Is there a chance that when a user connects to a locator without CC
enabled, he actually WANTS all the commands he execute WON'T affect CC?
C: Can we change the behavior to B? That is: the commands will only change
CC only if the user is connected to a locator that has CC enabled? (of
course, we will provide enough warning if the commands are on a locator
without CC telling him that won't affect cluster config. We will also
provides commands that will show the current state of Cluster Config)
This behavior change would greatly simply our implementation of cluster
config and get rid of lots of spaghetti code.
--
Cheers
Jinmei
