handle server side DESCRIBE

[fruch]

It was implemented on Scylla in:

scylladb/scylladb#11106

scylla-cqlsh has the code to support it, but for now it's disabled for scylla, we need to find a way to identify the server side is supported

few options:

• based on scylla version
• trying it on server side and fallback to client side
• scylla to introduce a feature flags on a virtual table ?

[raphaelsc]

Bumped into this today.

[fruch]

Bumped into this today.

What do you mean bumped, it was causing an issue ? or the describe didn't work as you expected ?

[fruch]

@roydahan this is not exactly specific to our group, but I think whom could take it, would learn lots in the process.

[fruch]

@avelanarius FYI this task is something I'm not getting to, and it sound like a something the driver team might suited to handle.

[raphaelsc]

Bumped into this today.

What do you mean bumped, it was causing an issue ? or the describe didn't work as you expected ?

By bumped, I meant that cqlsh doesn't use server-side describe by default, meaning that I had to user other means to access it. There are new attributes being introduced to Scylla that cannot be seen today with cqlsh.

[avelanarius]

few options:

• based on scylla version
• trying it on server side and fallback to client side
• scylla to introduce a feature flags on a virtual table ?

I think "trying it on server side and fallback to client side" makes the most sense. I'm currently working on this issue (now only fixing tests which have hardcoded expected responses) and those are the reasons I listed:

The other possible solutions were rejected:

• Based on Scylla version: would require ugly hard-coding of versions
• Modifying Scylla to provide some indication that this feature is
  enabled: Scylla 5.2 is already released without it, by implementing
  it in another way, we'll get it out sooner
• Do a trial "DESCRIBE" at the start of connection to detect if the
  server supports it: if cqlsh ever supported connecting to multiple
  nodes (right now it uses WhiteListRoundRobinPolicy) we would have
  to do the check on all of the nodes in case a rolling upgrade is
  currently occurring and some of the nodes don't support server-side
  DESCRIBE.

[avelanarius]

Refs scylladb/scylladb#14895 - maybe I'll adjust the cqlsh tests to be more lenient towards missing whitespace, but it should be fixed in Scylla nevertheless.

[mykaul]

We should prioritize this (for scylladb/scylladb#16482 , if we choose this path)

[roydahan]

@avelanarius I moved it back to you since I saw you wrote you were working on this issue.
I'm not sure if you meant that you finished and bump into tests failures or started from the tests and stopped there.
In any case, scylladb/scylladb#14895 is fixed now.

Let's get done with this one as well.

[mykaul]

@roydahan - this went in without tests. In general, I'm not sure where's the CI for cqlsh and where are its own tests.

[fruch]

@roydahan - this went in without tests. In general, I'm not sure where's the CI for cqlsh and where are its own tests.

As part of the work in:
#88

@sylwiaszunejko tested it with dtest, there is a whole integration suite there for cqlsh, also covering describe.

Also the unit tests and use integration tests in cqlsh repo are covering, and were refactored during the work ion that PR.

[mykaul]

@roydahan - this went in without tests. In general, I'm not sure where's the CI for cqlsh and where are its own tests.

As part of the work in: #88

@sylwiaszunejko tested it with dtest, there is a whole integration suite there for cqlsh, also covering describe.

Also the unit tests and use integration tests in cqlsh repo are covering, and were refactored during the work ion that PR.

Great - thanks. I could not find the cqlsh tests.

[Lorak-mmk]

@roydahan - this went in without tests. In general, I'm not sure where's the CI for cqlsh and where are its own tests.

As part of the work in: #88

@sylwiaszunejko tested it with dtest, there is a whole integration suite there for cqlsh, also covering describe.

Also the unit tests and use integration tests in cqlsh repo are covering, and were refactored during the work ion that PR.

If dtests are the only tests for clqsh, then perhaps cqlsh CI should run them automatically?