Support write/query via OpenTSDB API

[jiacai2050]

Describe This Problem

Currently there are three query language supported in CeresDB: SQL/InfluxQL/PromQL. It would be great to also support OpenTSBD query API.

Proposal

There are many API in OpenTSDB, the following two API are most important, so we can first implement those.

• [ ] http://opentsdb.net/docs/build/html/api_http/query/index.html
• [x] http://opentsdb.net/docs/build/html/api_http/put.html

Additional Context

No response

[parkma99]

I would like to work query api, I am newer fo this project, Could you give me some suggestion to start?😊

[jiacai2050]

Thanks for you interests, let us know when you have any problems.

Generally speaking, you need to convert opentsdb query syntax to datafusion plan, you can refer how InfluxQL is implemented here:

• https://github.com/CeresDB/ceresdb/blob/b6a0563226035bfa704a69fed685d030dea6f2ef/proxy/src/influxdb/mod.rs#L39

[parkma99]

I find it's very hard to me current 😢😢，I give up to others this issue.

[jiacai2050]

@parkma99 😅 Thanks anyway, you can try other issue first.

• https://github.com/CeresDB/ceresdb/labels/contributor%20friendly

[jiacai2050]

This docs explain how opentsdb query is executed:

Filtering

Grouping

Downsampling

Interpolation

Aggregation

Rate Conversion

Functions

Expressions

Understanding the order of operations is important. When returning query results the following is the order in which processing takes place.