curl client gets "Connection refused" error when rkv uses the default mem database backend

[h-w-chen]

get the latest version of rkv source code (commit de9428e), build and start rkv server; seemingly fine; however trying to curl curl http://127.0.0.1:8090/kv?key=a gets back unexpected response curl: (7) Failed to connect to 127.0.0.1 port 8090: Connection refused

The expected response is rev not found, since there is no such key yet

This seems a regression. Reverting back to prior commit, the curl gets response mvcc: Revision not found

[jshaofuturewei]

The default database store type has been changed to mem while memory databases are used for unit tests.

Please use redis databases when you start rkv locally.

[kxu1985]

I am also seeing this issue for consistency validation (sequential). Redis was deployed as backend. It affects the returned value (logged as 'nil' for some operations). Not sure if we have a workaround for this.

Btw, for consistency validation (linearizability) I did not see this issue (although used an older code version). But I am not sure if this is caused by sync/async configuration or recent code update.

[jshaofuturewei]

The error in the log are the jaeger exceptions. It looks like there is no jaeger instance in the localhost

Can you provide the revision number along with the value(213)? Did it read from async node?

For the line 69 and 70, why the read values are different?

[kxu1985]

Thanks for the comments. I did forget attaching the jaeger parameter when relaunching the process after build. Now these errors are gone!!

For concurrent read with multiple async nodes, I am seeing some interesting behaviors. I will share more details in tomorrow's scrum.