Hi all,
I am looking into running a 4-node couchdb 2.3 with this config in
default.ini and I made sure no other config file override them:
[cluster]
q = 8
n = 4
r = 1
w = 1
But when i create a test DB and check the settings I get:
curl -s couch01:5984/mytest1234 |jq . .... .... "cluster": { "q": 8, "n": 4,
"w": 3, "r": 3 },
r and w settings are not respected and seem stuck to be the defaults.
When I kill 3 of the machine and test reads and writes, they still work
fine so it doesn't seem like the r and w are actually 3 either. I checked
if the debug logs printed out the r and w anywhere to confirm what is being
configured or executed but there is nothing.
It is unclear if r and w are active in this version of couch. I can see the
they have been partially removed from the documentation
https://docs.couchdb.org/en/master/cluster/theory.html as opposed to
couchdb 2.0.0 original doc
https://web.archive.org/web/20160109122310/https://docs.couchdb.org/en/stable/cluster/theory.html
Additionally curl -s couch01:5984/mytest1234/doc?r=3
still works even if 3 out of the 4 nodes are dead which is unexpected per
the quorum documentation here
https://docs.couchdb.org/en/master/cluster/sharding.html#quorum
My specific concern with r and w is that if r is 3 this means 3 times more
network and disk IO since it will have to read 3 times from remote
machines. My use case really doesn't need this and performance will suffer.
This is a little hard to test so I was hopinh someone can shed some light
on the current situation with r and w in couch 2.3.
Thanks
