Support configure participants/observers role for zookeeper instance

[qixiaogang]

Description

Here is the case, a zookeeper cluster that some zookeeper instances plays as participants, some play as observers. For example, a zookeeper cluster with 7 zookeeper nodes, 3 of them plays as participants, 4 of them plays as observers.

Suggestions for an improvement

Can we introduce a role concept in the readiness script, and if the role is observers, reconfigure the zookeeper node as observer, if the role is participant, reconfigure the zookeeper node as participant.

Thanks

[Ranganaths8]

@qixiaogang can you explain why we need zk instances to have a role of observers ?

[qixiaogang]

@Ranganaths8 As you know, that observers scale the clusters without Hurting Write Performance, see See https://zookeeper.apache.org/doc/r3.4.13/zookeeperObservers.html#ch_Introduction. So it will be great if operator support configuring observers

[Ranganaths8]

@qixiaogang got it - thanks

[aparajita89]

bump @Ranganaths8 was this picked up?

[anishakj]

@aparajita89 we have not picked up this as it is not critical for our usecase

[aparajita89]

oh ok, thanks for the update @anishakj