namerd: should POST set ETag?

[olix0r]

> POST /api/1/dtabs/default HTTP/1.1
> Host: 104.197.46.186
> User-Agent: curl/7.43.0
> Accept: */*
> Content-type: application/dtab
> Content-Length: 192
> 
* upload completely sent off: 192 out of 192 bytes
< HTTP/1.1 204 No Content
< Content-Length: 0
< 

I'd expect creation to set an ETag on the repsonse?

[adleong]

in the case of zookeeper storage, the version number doesn't come back in the response from create. that means that it would require a second call to zk to get the version number. we can definitely do this, I just wanted to point out that it's not free.

[olix0r]

@adleong zookeeper itself gives us this for free, but we currently have some poor abstractions that hide it from us: The [setData api](https://zookeeper.apache.org/doc/r3.4.6/api/org/apache/zookeeper/ZooKeeper.html#setData%28java.lang.String, byte[], int%29) returns a Stat that contains the node's version.

We'll likely have to move away from the finagle-serverset abstractions...

[adleong]

I agree in general that we need to move away from the finagle-serverset abstractions to have the flexibility we want. In this case, setData returns a Stat but create does not.

[adleong]

My last comment wasn't clear. Zookeeper's create method does not return a Stat so I don't think moving off of finagle-serversets helps in this particular case.